Last data update: May 13, 2024. (Total: 46773 publications since 2009)
Records 1-30 (of 56 Records) |
Query Trace: ter Kuile FO[original query] |
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Policy uptake and implementation of the RTS,S/AS01 malaria vaccine in sub-Saharan African countries: status 2 years following the WHO recommendation
Osoro CB , Ochodo E , Kwambai TK , Otieno JA , Were L , Sagam CK , Owino EJ , Kariuki S , Ter Kuile FO , Hill J . BMJ Glob Health 2024 9 (4) In October 2021, the WHO recommended the world's first malaria vaccine-RTS,S/AS01-to prevent malaria in children living in areas with moderate-to-high transmission in sub-Saharan Africa (SSA). A second malaria vaccine, R21/Matrix-M, was recommended for use in October 2023 and added to the WHO list of prequalified vaccines in December 2023. This study analysis assessed the country status of implementation and delivery strategies for RTS,S/AS01 by searching websites for national malaria policies, guidelines and related documents. Direct contact with individuals working in malaria programmes was made to obtain documents not publicly available. 10 countries had documents with information relating to malaria vaccine implementation, 7 referencing RTS,S/AS01 and 3 (Burkina Faso, Kenya and Nigeria) referencing RTS,S/AS01 and R21/Matrix-M. Five other countries reported plans for malaria vaccine roll-out without specifying which vaccine. Ghana, Kenya and Malawi, which piloted RTS,S/AS01, have now integrated the vaccine into routine immunisation services. Cameroon and Burkina Faso are the first countries outside the pilot countries to incorporate the vaccine into national immunisation services. Uganda plans a phased RTS,S/AS01 introduction, while Guinea plans to first pilot RTS,S/AS01 in five districts. The RTS,S/AS01 schedule varied by country, with the first dose administered at 5 or 6 months in all countries but the fourth dose at either 18, 22 or 24 months. SSA countries have shown widespread interest in rolling out the malaria vaccine, the Global Alliance for Vaccines and Immunization having approved financial support for 20 of 30 countries which applied as of March 2024. Limited availability of RTS,S/AS01 means that some approved countries will not receive the required doses. Vaccine availability and equity must be addressed even as R21/Matrix-M becomes available. |
Chemoprevention for malaria with monthly intermittent preventive treatment with dihydroartemisinin-piperaquine in pregnant women living with HIV on daily co-trimoxazole in Kenya and Malawi: a randomised, double-blind, placebo-controlled trial
Barsosio HC , Madanitsa M , Ondieki ED , Dodd J , Onyango ED , Otieno K , Wang D , Hill J , Mwapasa V , Phiri KS , Maleta K , Taegtmeyer M , Kariuki S , Schmiegelow C , Gutman JR , Ter Kuile FO . Lancet 2024 403 (10424) 365-378 BACKGROUND: The efficacy of daily co-trimoxazole, an antifolate used for malaria chemoprevention in pregnant women living with HIV, is threatened by cross-resistance of Plasmodium falciparum to the antifolate sulfadoxine-pyrimethamine. We assessed whether addition of monthly dihydroartemisinin-piperaquine to daily co-trimoxazole is more effective at preventing malaria infection than monthly placebo plus daily co-trimoxazole in pregnant women living with HIV. METHODS: We did an individually randomised, two-arm, placebo-controlled trial in areas with high-grade sulfadoxine-pyrimethamine resistance in Kenya and Malawi. Pregnant women living with HIV on dolutegravir-based combination antiretroviral therapy (cART) who had singleton pregnancies between 16 weeks' and 28 weeks' gestation were randomly assigned (1:1) by computer-generated block randomisation, stratified by site and HIV status (known positive vs newly diagnosed), to daily co-trimoxazole plus monthly dihydroartemisinin-piperaquine (three tablets of 40 mg dihydroartemisinin and 320 mg piperaquine given daily for 3 days) or daily co-trimoxazole plus monthly placebo. Daily co-trimoxazole consisted of one tablet of 160 mg sulfamethoxazole and 800 mg trimethoprim. The primary endpoint was the incidence of Plasmodium infection detected in the peripheral (maternal) or placental (maternal) blood or tissue by PCR, microscopy, rapid diagnostic test, or placental histology (active infection) from 2 weeks after the first dose of dihydroartemisinin-piperaquine or placebo to delivery. Log-binomial regression was used for binary outcomes, and Poisson regression for count outcomes. The primary analysis was by modified intention to treat, consisting of all randomised eligible participants with primary endpoint data. The safety analysis included all women who received at least one dose of study drug. All investigators, laboratory staff, data analysts, and participants were masked to treatment assignment. This trial is registered with ClinicalTrials.gov, NCT04158713. FINDINGS: From Nov 11, 2019, to Aug 3, 2021, 904 women were enrolled and randomly assigned to co-trimoxazole plus dihydroartemisinin-piperaquine (n=448) or co-trimoxazole plus placebo (n=456), of whom 895 (99%) contributed to the primary analysis (co-trimoxazole plus dihydroartemisinin-piperaquine, n=443; co-trimoxazole plus placebo, n=452). The cumulative risk of any malaria infection during pregnancy or delivery was lower in the co-trimoxazole plus dihydroartemisinin-piperaquine group than in the co-trimoxazole plus placebo group (31 [7%] of 443 women vs 70 [15%] of 452 women, risk ratio 0·45, 95% CI 0·30-0·67; p=0·0001). The incidence of any malaria infection during pregnancy or delivery was 25·4 per 100 person-years in the co-trimoxazole plus dihydroartemisinin-piperaquine group versus 77·3 per 100 person-years in the co-trimoxazole plus placebo group (incidence rate ratio 0·32, 95% CI 0·22-0·47, p<0·0001). The number needed to treat to avert one malaria infection per pregnancy was 7 (95% CI 5-10). The incidence of serious adverse events was similar between groups in mothers (17·7 per 100 person-years in the co-trimoxazole plus dihydroartemisinin-piperaquine group [23 events] vs 17·8 per 100 person-years in the co-trimoxazole group [25 events]) and infants (45·4 per 100 person-years [23 events] vs 40·2 per 100 person-years [21 events]). Nausea within the first 4 days after the start of treatment was reported by 29 (7%) of 446 women in the co-trimoxazole plus dihydroartemisinin-piperaquine group versus 12 (3%) of 445 women in the co-trimoxazole plus placebo group. The risk of adverse pregnancy outcomes did not differ between groups. INTERPRETATION: Addition of monthly intermittent preventive treatment with dihydroartemisinin-piperaquine to the standard of care with daily unsupervised co-trimoxazole in areas of high antifolate resistance substantially improves malaria chemoprevention in pregnant women living with HIV on dolutegravir-based cART and should be considered for policy. FUNDING: European and Developing Countries Clinical Trials Partnership 2; UK Joint Global Health Trials Scheme (UK Foreign, Commonwealth and Development Office; Medical Research Council; National Institute for Health Research; Wellcome); and Swedish International Development Cooperation Agency. |
Perceptions and drivers of healthcare provider and drug dispenser practices for the treatment of malaria in pregnancy in the context of multiple first-line therapies in western Kenya: a qualitative study
Osoro CB , Dellicour S , Ochodo E , Young T , Ter Kuile FO , Gutman JR , Hill J . Malar J 2023 22 (1) 274 BACKGROUND: Emergence of Plasmodium falciparum resistance to artemether-lumefantrine in Africa prompted the pilot introduction of multiple first-line therapies (MFT) against malaria in Kenya, potentially exposing women-of-childbearing-age (WOCBAs) to anti-malarials with unknown safety profiles in the first trimester. This qualitative study explored knowledge and perceptions among healthcare providers providing malaria treatment to WOCBAs and pregnant women. METHODS: In-depth interviews were conducted with purposively selected public and private health facility (HF) and drug outlet (DO) providers within and outside the pilot-MFT area. County health managers were interviewed about their knowledge of the national treatment guidelines. Transcripts were coded by content analysis using the World Health Organization health system building blocks (leadership/governance, financing, health workforce, health information systems, access to medicines, and service delivery). RESULTS: Thirty providers (HF:21, DO:9) and three health managers were interviewed. Eighteen providers were from HFs in the pilot-MFT area; the remaining three and all nine DOs were outside the pilot-MFT area. The analysis revealed that providers had not been trained in malaria case management in the previous twelve months. DO providers were unfamiliar with national treatment guidelines in pregnancy and reported having no pregnancy tests. Health managers were unable to supervise DOs due to resource limitations. Providers from HFs and DOs noted poor sensitivity of malaria rapid diagnostic tests (RDTs) and hesitancy among patients who associated malaria-RDTs with HIV testing. Almost all providers reported anti-malarial stock-outs, with quinine most affected. Patient preference was a major factor in prescribing anti-malarials. Providers in HFs and DOs reported preferentially using artemether-lumefantrine in the first trimester due to the side effects and unavailability of quinine. CONCLUSION: Knowledge of malaria case management in drug outlets and health facilities remains poor. Improved regulation of DO providers is warranted. Optimizing treatment of malaria in pregnancy requires training, availability of malaria commodities, and pregnancy tests. |
Post-discharge risk of mortality in children under 5 years of age in western Kenya: A retrospective cohort study
Kwambai TK , Kariuki S , Smit MR , Nevitt S , Onyango E , Oneko M , Khagayi S , Samuels AM , Hamel MJ , Laserson K , Desai M , Ter Kuile FO . Am J Trop Med Hyg 2023 109 (3) 704-712 Limited evidence suggests that children in sub-Saharan Africa hospitalized with all-cause severe anemia or severe acute malnutrition (SAM) are at high risk of dying in the first few months after discharge. We aimed to compare the risks of post-discharge mortality by health condition among hospitalized children in an area with high malaria transmission in western Kenya. We conducted a retrospective cohort study among recently discharged children aged < 5 years using mortality data from a health and demographic surveillance system that included household and pediatric in-hospital surveillance. Cox regression was used to compare post-discharge mortality. Between 2008 and 2013, overall in-hospital mortality was 2.8% (101/3,639). The mortality by 6 months after discharge (primary outcome) was 6.2% (159/2,556) and was highest in children with SAM (21.6%), followed by severe anemia (15.5%), severe pneumonia (5.6%), "other conditions" (5.6%), and severe malaria (0.7%). Overall, the 6-month post-discharge mortality in children hospitalized with SAM (hazard ratio [HR] = 3.95, 2.60-6.00, P < 0.001) or severe anemia (HR = 2.55, 1.74-3.71, P < 0.001) was significantly higher than that in children without these conditions. Severe malaria was associated with lower 6-month post-discharge mortality than children without severe malaria (HR = 0.33, 0.21-0.53, P < 0.001). The odds of dying by 6 months after discharge tended to be higher than during the in-hospital period for all children, except for those admitted with severe malaria. The first 6 months after discharge is a high-risk period for mortality among children admitted with severe anemia and SAM in western Kenya. Strategies to address this risk period are urgently needed. |
Quality of vital event data for infant mortality estimation in prospective, population-based studies: an analysis of secondary data from Asia, Africa, and Latin America
Erchick DJ , Subedi S , Verhulst A , Guillot M , Adair LS , Barros AJD , Chasekwa B , Christian P , da Silva BGC , Silveira MF , Hallal PC , Humphrey JH , Huybregts L , Kariuki S , Khatry SK , Lachat C , Matijasevich A , McElroy PD , Menezes AMB , Mullany LC , Perez TLL , Phillips-Howard PA , Roberfroid D , Santos IS , Ter Kuile FO , Ravilla TD , Tielsch JM , Wu LSF , Katz J . Popul Health Metr 2023 21 (1) 10 INTRODUCTION: Infant and neonatal mortality estimates are typically derived from retrospective birth histories collected through surveys in countries with unreliable civil registration and vital statistics systems. Yet such data are subject to biases, including under-reporting of deaths and age misreporting, which impact mortality estimates. Prospective population-based cohort studies are an underutilized data source for mortality estimation that may offer strengths that avoid biases. METHODS: We conducted a secondary analysis of data from the Child Health Epidemiology Reference Group, including 11 population-based pregnancy or birth cohort studies, to evaluate the appropriateness of vital event data for mortality estimation. Analyses were descriptive, summarizing study designs, populations, protocols, and internal checks to assess their impact on data quality. We calculated infant and neonatal morality rates and compared patterns with Demographic and Health Survey (DHS) data. RESULTS: Studies yielded 71,760 pregnant women and 85,095 live births. Specific field protocols, especially pregnancy enrollment, limited exclusion criteria, and frequent follow-up visits after delivery, led to higher birth outcome ascertainment and fewer missing deaths. Most studies had low follow-up loss in pregnancy and the first month with little evidence of date heaping. Among studies in Asia and Latin America, neonatal mortality rates (NMR) were similar to DHS, while several studies in Sub-Saharan Africa had lower NMRs than DHS. Infant mortality varied by study and region between sources. CONCLUSIONS: Prospective, population-based cohort studies following rigorous protocols can yield high-quality vital event data to improve characterization of detailed mortality patterns of infants in low- and middle-income countries, especially in the early neonatal period where mortality risk is highest and changes rapidly. |
Fetal growth and birth weight are independently reduced by malaria infection and curable sexually transmitted and reproductive tract infections in Kenya, Tanzania, and Malawi: A pregnancy cohort study
Mtove G , Chico RM , Madanitsa M , Barsosio HC , Msemo OA , Saidi Q , Gore-Langton GR , Minja DTR , Mukerebe C , Gesase S , Mwapasa V , Phiri KS , Hansson H , Dodd J , Magnussen P , Kavishe RA , Mosha F , Kariuki S , Lusingu JPA , Gutman JR , Alifrangis M , Ter Kuile FO , Schmiegelow C . Int J Infect Dis 2023 135 28-40 OBJECTIVE: Malaria and sexually transmitted and reproductive tract infections (STIs/RTIs) are highly prevalent in sub-Saharan Africa and associated with poor pregnancy outcomes. We investigated the individual and combined effects of malaria and curable STIs/RTIs on fetal growth in Kenya, Tanzania, and Malawi. METHODS: This study was nested within a randomized trial comparing monthly intermittent preventive treatment for malaria in pregnancy with sulfadoxine-pyrimethamine versus dihydroartemisinin-piperaquine, alone or combined with azithromycin. Fetal weight gain was assessed by serial prenatal ultrasound. Malaria was assessed monthly, and Treponema pallidum, Neisseria gonorrhoeae, Trichomonas vaginalis, Chlamydia trachomatis and bacterial vaginosis at enrolment and in the third trimester. The effect of malaria and STIs/RTIs on fetal weight/birthweight Z-scores was evaluated using mixed-effects linear regression. RESULTS: 1,435 pregnant women had fetal/birth weight assessed 3,950 times. Compared to women without malaria or STIs/RTIs (n=399), malaria-only (n=267), STIs/RTIs-only (n=410) or both (n=353) were associated with reduced fetal growth (adjusted mean difference in fetal/birth weight Z-score [95% CI]: malaria=-0.18 [-0.31,-0.04], p=0.01]; STIs/RTIs=-0.14 [-0.26,-0.03], p=0.01]; both=-0.20 [-0.33,-0.07], p=0.003). Paucigravidae experienced the greatest impact. CONCLUSION: Malaria and STIs/RTIs are associated with poor fetal growth especially among paucigravidae women with dual infections. Integrated antenatal interventions are needed to reduce the burden of both malaria and STIs/RTIs. |
Evaluation of community-based vector surveillance system for routine entomological monitoring under low malaria vector densities and high bed net coverage in western Kenya
Abong'o B , Stanton MC , Donnelly MJ , Ochomo E , Ter Kuile FO , Samuels AM , Kariuki S , Musula G , Oxborough R , Munga S , Torr SJ , Gimnig JE . Malar J 2023 22 (1) 203 BACKGROUND: Entomological surveillance is traditionally conducted by supervised teams of trained technicians. However, it is expensive and limiting in the number of sites visited. Surveillance through community-based collectors (CBC) may be more cost-effective and sustainable for longitudinal entomological monitoring. This study evaluated the efficiency of CBCs in monitoring mosquito densities compared to quality-assured sampling conducted by experienced entomology technicians. METHODS: Entomological surveillance employing CBCs was conducted in eighteen clusters of villages in western Kenya using indoor and outdoor CDC light traps and indoor Prokopack aspiration. Sixty houses in each cluster were enrolled and sampled once every month. Collected mosquitoes were initially identified to the genus level by CBCs, preserved in 70% ethanol and transferred to the laboratory every 2 weeks. Parallel, collections by experienced entomology field technicians were conducted monthly by indoor and outdoor CDC light traps and indoor Prokopack aspiration and served as a quality assurance of the CBCs. RESULTS: Per collection, the CBCs collected 80% fewer Anopheles gambiae sensu lato (s.l.) [RR = 0.2; (95% CI 0.14-0.27)] and Anopheles coustani [RR = 0.2; (95% CI 0.06-0.53)] and 90% fewer Anopheles funestus [RR = 0.1; (95% CI 0.08-0.19)] by CDC light traps compared to the quality assured (QA) entomology teams. Significant positive correlations were however observed between the monthly collections by CBCs and QA teams for both An. gambiae and An. funestus. In paired identifications of pooled mosquitoes, the CBCs identified 4.3 times more Anopheles compared to experienced technicians. The cost per person-night was lower in the community-based sampling at $9.1 compared to $89.3 by QA per collection effort. CONCLUSION: Unsupervised community-based mosquito surveillance collected substantially fewer mosquitoes per trap-night compared to quality-assured collection by experienced field teams, while consistently overestimating the number of Anopheles mosquitoes during identification. However, the numbers collected were significantly correlated between the CBCs and the QA teams suggesting that trends observed by CBCs and QA teams were similar. Further studies are needed to evaluate whether adopting low-cost, devolved supervision with spot checks, coupled with remedial training of the CBCs, can improve community-based collections to be considered a cost-effective alternative to surveillance conducted by experienced entomological technicians. |
Prevalence of and risk factors for microscopic and submicroscopic malaria infections in pregnancy: a systematic review and meta-analysis
van Eijk AM , Stepniewska K , Hill J , Taylor SM , Rogerson SJ , Cottrell G , Chico RM , Gutman JR , Tinto H , Unger HW , Yanow SK , Meshnick SR , Ter Kuile FO , Mayor A . Lancet Glob Health 2023 11 (7) e1061-e1074 BACKGROUND: Malaria infections during pregnancy can cause adverse birth outcomes, yet many infections are undetected by microscopy. We aimed to describe the epidemiology of submicroscopic malaria infections in pregnant women in Asia, the Americas, and Africa using aggregated and individual participant data (IPD). METHODS: For this systematic review and meta-analysis, studies (published Jan 1, 1997 to Nov 10, 2021) with information on both microscopic and submicroscopic infections during pregnancy from Asia, the Americas, or Africa, identified in the Malaria-in-Pregnancy Library, were eligible. Studies (or subgroups or study groups) that selected participants on the basis of the presence of fever or a positive blood smear were excluded to avoid selection bias. We obtained IPD (when available) and aggregated data. Estimates of malaria transmission intensity and sulfadoxine-pyrimethamine resistance, matched by study location and year, were obtained using publicly available data. One-stage multivariable logit and multinomial models with random intercepts for study site were used in meta-analysis to assess prevalence of and risk factors for submicroscopic infections during pregnancy and at delivery. This study is registered with PROSPERO, number CRD42015027342. FINDINGS: The search identified 87 eligible studies, 68 (78%) of which contributed to the analyses. Of these 68 studies, 45 (66%) studies contributed IPD (48 869 participants) and 23 (34%) studies contributed aggregated data (11 863 participants). During pregnancy, median prevalence estimates were 13·5% (range 0·0-55·9, 66 substudies) for submicroscopic and 8·0% (0·0-50·6, 66 substudies) for microscopic malaria. Among women with positive Plasmodium nucleic acid amplification tests (NAATs), the median proportion of submicroscopic infections was 58·7% (range 0·0-100); this proportion was highest in the Americas (73·3%, 0·0-100), followed by Asia (67·2%, 36·4-100) and Africa (56·5%, 20·5-97·7). In individual patient data analysis, compared with women with no malaria infections, those with submicroscopic infections were more likely to present with fever in Africa (adjusted odds ratio 1·32, 95% CI 1·02-1·72; p=0·038) but not in other regions. Among women with NAAT-positive infections in Asia and the Americas, Plasmodium vivax infections were more likely to be submicroscopic than Plasmodium falciparum infections (3·69, 2·45-5·54; p<0·0001). Risk factors for submicroscopic infections among women with NAAT-positive infections in Africa included older age (age ≥30 years), multigravidity, and no HIV infection. INTERPRETATION: During pregnancy, submicroscopic infections are more common than microscopic infections and are associated with fever in Africa. Malaria control in pregnancy should target both microscopic and submicroscopic infections. FUNDING: Bill & Melinda Gates Foundation through the Worldwide Antimalarial Resistance Network. |
Effect of Plasmodium falciparum sulfadoxine-pyrimethamine resistance on the effectiveness of intermittent preventive therapy for malaria in pregnancy in Africa: a systematic review and meta-analysis.
van Eijk AM , Larsen DA , Kayentao K , Koshy G , Slaughter DEC , Roper C , Okell LC , Desai M , Gutman J , Khairallah C , Rogerson SJ , Hopkins Sibley C , Meshnick SR , Taylor SM , Ter Kuile FO . Lancet Infect Dis 2019 19 (5) 546-556 BACKGROUND: Resistance of Plasmodium falciparum to sulfadoxine-pyrimethamine threatens the antimalarial effectiveness of intermittent preventive treatment during pregnancy (IPTp) in sub-Saharan Africa. We aimed to assess the associations between markers of sulfadoxine-pyrimethamine resistance in P falciparum and the effectiveness of sulfadoxine-pyrimethamine IPTp for malaria-associated outcomes. METHODS: For this systematic review and meta-analysis, we searched databases (from Jan 1, 1990 to March 1, 2018) for clinical studies (aggregated data) or surveys (individual participant data) that reported data on low birthweight (primary outcome) and malaria by sulfadoxine-pyrimethamine IPTp dose, and for studies that reported on molecular markers of sulfadoxine-pyrimethamine resistance. Studies that involved only HIV-infected women or combined interventions were excluded. We did a random-effects meta-analysis (clinical studies) or multivariate log-binomial regression (surveys) to obtain summarised dose-response data (relative risk reduction [RRR]) and multivariate meta-regression to explore the modifying effects of sulfadoxine-pyrimethamine resistance (as indicated by Ala437Gly, Lys540Glu, and Ala581Gly substitutions in the dhps gene). This study is registered with PROSPERO, number 42016035540. FINDINGS: Of 1097 records screened, 57 studies were included in the aggregated-data meta-analysis (including 59 457 births). The RRR for low birthweight declined with increasing prevalence of dhps Lys540Glu (p(trend)=0·0060) but not Ala437Gly (p(trend)=0·35). The RRR was 7% (95% CI 0 to 13) in areas of high resistance to sulfadoxine-pyrimethamine (Lys540Glu ≥90% in east and southern Africa; n=11), 21% (14 to 29) in moderate-resistance areas (Ala437Gly ≥90% [central and west Africa], or Lys540Glu ≥30% to <90% [east and southern Africa]; n=16), and 27% (21 to 33) in low-resistance areas (Ala437Gly <90% [central and west Africa], or Lys540Glu <30% [east and southern Africa]; n=30; p(trend)=0·0054 [univariate], I(2)=69·5%). The overall RRR in all resistance strata was 21% (17 to 25). In the analysis of individual participant data from 13 surveys (42 394 births), sulfadoxine-pyrimethamine IPTp was associated with reduced prevalence of low birthweight in areas with a Lys540Glu prevalence of more than 90% and Ala581Gly prevalence of less than 10% (RRR 10% [7 to 12]), but not in those with an Ala581Gly prevalence of 10% or higher (pooled Ala581Gly prevalence 37% [range 29 to 46]; RRR 0·5% [-16 to 14]; 2326 births). INTERPRETATION: The effectiveness of sulfadoxine-pyrimethamine IPTp is reduced in areas with high resistance to sulfadoxine-pyrimethamine among P falciparum parasites, but remains associated with reductions in low birthweight even in areas where dhps Lys540Glu prevalence exceeds 90% but where the sextuple-mutant parasite (harbouring the additional dhps Ala581Gly mutation) is uncommon. Therapeutic alternatives to sulfadoxine-pyrimethamine IPTp are needed in areas where the prevalence of the sextuple-mutant parasite exceeds 37%. FUNDING: US Centers for Disease Control and Prevention, the Malaria in Pregnancy Consortium (funded through a grant from the Bill & Melinda Gates Foundation to the Liverpool School of Tropical Medicine), Worldwide Antimalarial Resistance Network, European and Developing Countries Clinical Trials Partnership. |
Effect of monthly intermittent preventive treatment with dihydroartemisinin-piperaquine with and without azithromycin versus monthly sulfadoxine-pyrimethamine on adverse pregnancy outcomes in Africa: a double-blind randomised, partly placebo-controlled trial
Madanitsa M , Barsosio HC , Minja DTR , Mtove G , Kavishe RA , Dodd J , Saidi Q , Onyango ED , Otieno K , Wang D , Ashorn U , Hill J , Mukerebe C , Gesase S , Msemo OA , Mwapasa V , Phiri KS , Maleta K , Klein N , Magnussen P , Lusingu JPA , Kariuki S , Mosha JF , Alifrangis M , Hansson H , Schmiegelow C , Gutman JR , Chico RM , Ter Kuile FO . Lancet 2023 401 (10381) 1020-1036 BACKGROUND: Intermittent preventive treatment in pregnancy (IPTp) with dihydroartemisinin-piperaquine is more effective than IPTp with sulfadoxine-pyrimethamine at reducing malaria infection during pregnancy in areas with high-grade resistance to sulfadoxine-pyrimethamine by Plasmodium falciparum in east Africa. We aimed to assess whether IPTp with dihydroartemisinin-piperaquine, alone or combined with azithromycin, can reduce adverse pregnancy outcomes compared with IPTp with sulfadoxine-pyrimethamine. METHODS: We did an individually randomised, double-blind, three-arm, partly placebo-controlled trial in areas of high sulfadoxine-pyrimethamine resistance in Kenya, Malawi, and Tanzania. HIV-negative women with a viable singleton pregnancy were randomly assigned (1:1:1) by computer-generated block randomisation, stratified by site and gravidity, to receive monthly IPTp with sulfadoxine-pyrimethamine (500 mg of sulfadoxine and 25 mg of pyrimethamine for 1 day), monthly IPTp with dihydroartemisinin-piperaquine (dosed by weight; three to five tablets containing 40 mg of dihydroartemisinin and 320 mg of piperaquine once daily for 3 consecutive days) plus a single treatment course of placebo, or monthly IPTp with dihydroartemisinin-piperaquine plus a single treatment course of azithromycin (two tablets containing 500 mg once daily for 2 consecutive days). Outcome assessors in the delivery units were masked to treatment group. The composite primary endpoint was adverse pregnancy outcome, defined as fetal loss, adverse newborn baby outcomes (small for gestational age, low birthweight, or preterm), or neonatal death. The primary analysis was by modified intention to treat, consisting of all randomised participants with primary endpoint data. Women who received at least one dose of study drug were included in the safety analyses. This trial is registered with ClinicalTrials.gov, NCT03208179. FINDINGS: From March-29, 2018, to July 5, 2019, 4680 women (mean age 25·0 years [SD 6·0]) were enrolled and randomly assigned: 1561 (33%; mean age 24·9 years [SD 6·1]) to the sulfadoxine-pyrimethamine group, 1561 (33%; mean age 25·1 years [6·1]) to the dihydroartemisinin-piperaquine group, and 1558 (33%; mean age 24·9 years [6.0]) to the dihydroartemisinin-piperaquine plus azithromycin group. Compared with 335 (23·3%) of 1435 women in the sulfadoxine-pyrimethamine group, the primary composite endpoint of adverse pregnancy outcomes was reported more frequently in the dihydroartemisinin-piperaquine group (403 [27·9%] of 1442; risk ratio 1·20, 95% CI 1·06-1·36; p=0·0040) and in the dihydroartemisinin-piperaquine plus azithromycin group (396 [27·6%] of 1433; 1·16, 1·03-1·32; p=0·017). The incidence of serious adverse events was similar in mothers (sulfadoxine-pyrimethamine group 17·7 per 100 person-years, dihydroartemisinin-piperaquine group 14·8 per 100 person-years, and dihydroartemisinin-piperaquine plus azithromycin group 16·9 per 100 person-years) and infants (sulfadoxine-pyrimethamine group 49·2 per 100 person-years, dihydroartemisinin-piperaquine group 42·4 per 100 person-years, and dihydroartemisinin-piperaquine plus azithromycin group 47·8 per 100 person-years) across treatment groups. 12 (0·2%) of 6685 sulfadoxine-pyrimethamine, 19 (0·3%) of 7014 dihydroartemisinin-piperaquine, and 23 (0·3%) of 6849 dihydroartemisinin-piperaquine plus azithromycin treatment courses were vomited within 30 min. INTERPRETATION: Monthly IPTp with dihydroartemisinin-piperaquine did not improve pregnancy outcomes, and the addition of a single course of azithromycin did not enhance the effect of monthly IPTp with dihydroartemisinin-piperaquine. Trials that combine sulfadoxine-pyrimethamine and dihydroartemisinin-piperaquine for IPTp should be considered. FUNDING: European & Developing Countries Clinical Trials Partnership 2, supported by the EU, and the UK Joint-Global-Health-Trials-Scheme of the Foreign, Commonwealth and Development Office, Medical Research Council, Department of Health and Social Care, Wellcome, and the Bill-&-Melinda-Gates-Foundation. |
Malaria in pregnancy (MiP) studies assessing the clinical performance of highly sensitive rapid diagnostic tests (HS-RDT) for Plasmodium falciparum detection.
Ding XC , Incardona S , Serra-Casas E , Charnaud SC , Slater HC , Domingo GJ , Adams ER , Ter Kuile FO , Samuels AM , Kariuki S , Dittrich S . Malar J 2023 22 (1) 60 BACKGROUND: Rapid diagnostic tests (RDTs) are effective tools to diagnose and inform the treatment of malaria in adults and children. The recent development of a highly sensitive rapid diagnostic test (HS-RDT) for Plasmodium falciparum has prompted questions over whether it could improve the diagnosis of malaria in pregnancy and pregnancy outcomes in malaria endemic areas. METHODS: This landscape review collates studies addressing the clinical performance of the HS-RDT. Thirteen studies were identified comparing the HS-RDT and conventional RDT (co-RDT) to molecular methods to detect malaria in pregnancy. Using data from five completed studies, the association of epidemiological and pregnancy-related factors on the sensitivity of HS-RDT, and comparisons with co-RDT were investigated. The studies were conducted in 4 countries over a range of transmission intensities in largely asymptomatic women. RESULTS: Sensitivity of both RDTs varied widely (HS-RDT range 19.6 to 85.7%, co-RDT range 22.8 to 82.8% compared to molecular testing) yet HS-RDT detected individuals with similar parasite densities across all the studies including different geographies and transmission areas [geometric mean parasitaemia around 100 parasites per µL (p/µL)]. HS-RDTs were capable of detecting low-density parasitaemias and in one study detected around 30% of infections with parasite densities of 0-2 p/µL compared to the co-RDT in the same study which detected around 15%. CONCLUSION: The HS-RDT has a slightly higher analytical sensitivity to detect malaria infections in pregnancy than co-RDT but this mostly translates to only fractional and not statistically significant improvement in clinical performance by gravidity, trimester, geography or transmission intensity. The analysis presented here highlights the need for larger and more studies to evaluate incremental improvements in RDTs. The HS-RDT could be used in any situation where co-RDT are currently used for P. falciparum diagnosis, if storage conditions can be adhered to. |
Pregnancy outcomes after first-trimester treatment with artemisinin derivatives versus non-artemisinin antimalarials: a systematic review and individual patient data meta-analysis
Saito M , McGready R , Tinto H , Rouamba T , Mosha D , Rulisa S , Kariuki S , Desai M , Manyando C , Njunju EM , Sevene E , Vala A , Augusto O , Clerk C , Were E , Mrema S , Kisinza W , Byamugisha J , Kagawa M , Singlovic J , Yore M , van Eijk AM , Mehta U , Stergachis A , Hill J , Stepniewska K , Gomes M , Guérin PJ , Nosten F , Ter Kuile FO , Dellicour S . Lancet 2023 401 (10371) 118-130 BACKGROUND: Malaria in the first trimester of pregnancy is associated with adverse pregnancy outcomes. Artemisinin-based combination therapies (ACTs) are a highly effective, first-line treatment for uncomplicated Plasmodium falciparum malaria, except in the first trimester of pregnancy, when quinine with clindamycin is recommended due to concerns about the potential embryotoxicity of artemisinins. We compared adverse pregnancy outcomes after artemisinin-based treatment (ABT) versus non-ABTs in the first trimester of pregnancy. METHODS: For this systematic review and individual patient data (IPD) meta-analysis, we searched MEDLINE, Embase, and the Malaria in Pregnancy Library for prospective cohort studies published between Nov 1, 2015, and Dec 21, 2021, containing data on outcomes of pregnancies exposed to ABT and non-ABT in the first trimester. The results of this search were added to those of a previous systematic review that included publications published up until November, 2015. We included pregnancies enrolled before the pregnancy outcome was known. We excluded pregnancies with missing estimated gestational age or exposure information, multiple gestation pregnancies, and if the fetus was confirmed to be unviable before antimalarial treatment. The primary endpoint was adverse pregnancy outcome, defined as a composite of either miscarriage, stillbirth, or major congenital anomalies. A one-stage IPD meta-analysis was done by use of shared-frailty Cox models. This study is registered with PROSPERO, number CRD42015032371. FINDINGS: We identified seven eligible studies that included 12 cohorts. All 12 cohorts contributed IPD, including 34 178 pregnancies, 737 with confirmed first-trimester exposure to ABTs and 1076 with confirmed first-trimester exposure to non-ABTs. Adverse pregnancy outcomes occurred in 42 (5·7%) of 736 ABT-exposed pregnancies compared with 96 (8·9%) of 1074 non-ABT-exposed pregnancies in the first trimester (adjusted hazard ratio [aHR] 0·71, 95% CI 0·49-1·03). Similar results were seen for the individual components of miscarriage (aHR=0·74, 0·47-1·17), stillbirth (aHR=0·71, 0·32-1·57), and major congenital anomalies (aHR=0·60, 0·13-2·87). The risk of adverse pregnancy outcomes was lower with artemether-lumefantrine than with oral quinine in the first trimester of pregnancy (25 [4·8%] of 524 vs 84 [9·2%] of 915; aHR 0·58, 0·36-0·92). INTERPRETATION: We found no evidence of embryotoxicity or teratogenicity based on the risk of miscarriage, stillbirth, or major congenital anomalies associated with ABT during the first trimester of pregnancy. Given that treatment with artemether-lumefantrine was associated with fewer adverse pregnancy outcomes than quinine, and because of the known superior tolerability and antimalarial effectiveness of ACTs, artemether-lumefantrine should be considered the preferred treatment for uncomplicated P falciparum malaria in the first trimester. If artemether-lumefantrine is unavailable, other ACTs (except artesunate-sulfadoxine-pyrimethamine) should be preferred to quinine. Continued active pharmacovigilance is warranted. FUNDING: Medicines for Malaria Venture, WHO, and the Worldwide Antimalarial Resistance Network funded by the Bill & Melinda Gates Foundation. |
Natural sugar feeding rates of Anopheles mosquitoes collected by different methods in western Kenya
Omondi S , Kosgei J , Agumba S , Polo B , Yalla N , Moshi V , Abong'o B , Ombok M , McDermott DP , Entwistle J , Samuels AM , Ter Kuile FO , Gimnig JE , Ochomo E . Sci Rep 2022 12 (1) 20596 Attractive targeted sugar baits (ATSBs) are a potential vector control tool that exploits the sugar-feeding behaviour of mosquitoes. We evaluated the sugar-feeding behaviour of Anopheles mosquitoes as part of baseline studies for cluster randomised controlled trials of ATSBs. Mosquitoes were collected indoors and outdoors from two villages in western Kenya using prokopack aspirations, malaise tent traps and ultraviolet (UV) light traps. Individual mosquitoes were subjected to the cold anthrone test to assess the presence of sugar. Overall, 15.7% of collected mosquitoes had fed on natural sugar sources. By species and sex, the proportion sugar-fed was 41.3% and 27.7% in male and female Anopheles funestus, 27.2% and 12.8% in male and female An. arabiensis, and 9.7% and 8.3% in male and female An. coustani, respectively. Sugar-feeding was higher in unfed than blood-fed mosquitoes and higher in male than gravid mosquitoes. Anopheles mosquitoes obtained sugar meals from natural sources during all physiological stages, whether they rest indoors or outdoors. These findings offer a potential avenue to exploit for the control of mosquitoes, particularly with the advent of ATSBs, which have been shown to reduce mosquito densities in other regions. |
Temporal trends in molecular markers of drug resistance in Plasmodium falciparum in human blood and profiles of corresponding resistant markers in mosquito oocysts in Asembo, western Kenya.
Zhou Z , Gimnig JE , Sergent SB , Liu Y , Abong'o B , Otieno K , Chebore W , Shah MP , Williamson J , Ter Kuile FO , Hamel MJ , Kariuki S , Desai M , Samuels AM , Walker ED , Shi YP . Malar J 2022 21 (1) 265 BACKGROUND: Over the last two decades, the scale-up of vector control and changes in the first-line anti-malarial, from chloroquine (CQ) to sulfadoxine-pyrimethamine (SP) and then to artemether-lumefantrine (AL), have resulted in significant decreases in malaria burden in western Kenya. This study evaluated the long-term effects of control interventions on molecular markers of Plasmodium falciparum drug resistance using parasites obtained from humans and mosquitoes at discrete time points. METHODS: Dried blood spot samples collected in 2012 and 2017 community surveys in Asembo, Kenya were genotyped by Sanger sequencing for markers associated with resistance to SP (Pfdhfr, Pfdhps), CQ, AQ, lumefantrine (Pfcrt, Pfmdr1) and artemisinin (Pfk13). Temporal trends in the prevalence of these markers, including data from 2012 to 2017 as well as published data from 1996, 2001, 2007 from same area, were analysed. The same markers from mosquito oocysts collected in 2012 were compared with results from human blood samples. RESULTS: The prevalence of SP dhfr/dhps quintuple mutant haplotype C(50)I(51)R(59)N(108)I(164)/S(436)G(437)E(540)A(581)A(613) increased from 19.7% in 1996 to 86.0% in 2012, while an increase in the sextuple mutant haplotype C(50)I(51)R(59)N(108)I(164)/H(436)G(437)E(540)A(581)A(613) containing Pfdhps-436H was found from 10.5% in 2012 to 34.6% in 2017. Resistant Pfcrt-76 T declined from 94.6% in 2007 to 18.3% in 2012 and 0.9% in 2017. Mutant Pfmdr1-86Y decreased across years from 74.8% in 1996 to zero in 2017, mutant Pfmdr1-184F and wild Pfmdr1-D1246 increased from 17.9% to 58.9% in 2007 to 55.9% and 90.1% in 2017, respectively. Pfmdr1 haplotype N(86)F(184)S(1034)N(1042)D(1246) increased from 11.0% in 2007 to 49.6% in 2017. No resistant mutations in Pfk13 were found. Prevalence of Pfdhps-436H was lower while prevalence of Pfcrt-76 T was higher in mosquitoes than in human blood samples. CONCLUSION: This study showed an increased prevalence of dhfr/dhps resistant markers over 20 years with the emergence of Pfdhps-436H mutant a decade ago in Asembo. The reversal of Pfcrt from CQ-resistant to CQ-sensitive genotype occurred following 19 years of CQ withdrawal. No Pfk13 markers associated with artemisinin resistance were detected, but the increased haplotype of Pfmdr1 N(86)F(184)S(1034)N(1042)D(1246) was observed. The differences in prevalence of Pfdhps-436H and Pfcrt-76 T SNPs between two hosts and the role of mosquitoes in the transmission of drug resistant parasites require further investigation. |
Post-discharge morbidity and mortality in children admitted with severe anaemia and other health conditions in malaria-endemic settings in Africa: a systematic review and meta-analysis
Kwambai TK , Mori AT , Nevitt S , van Eijk AM , Samuels AM , Robberstad B , Phiri KS , Ter Kuile FO . Lancet Child Adolesc Health 2022 6 (7) 474-483 BACKGROUND: Severe anaemia is associated with high in-hospital mortality among young children. In malaria-endemic areas, surviving children also remain at increased risk of mortality for several months after hospital discharge. We aimed to compare the risks of morbidity and mortality among children discharged from hospital after recovery from severe anaemia versus other health conditions in malaria-endemic settings in Africa. METHODS: Following PRISMA guidelines, we searched PubMed, Scopus, Web of Science, and Cochrane Central from inception to Nov 30, 2021, without language restrictions, for prospective or retrospective cohort studies and randomised controlled trials that followed up children younger than 15 years for defined periods after hospital discharge in malaria-endemic countries in Africa. We excluded the intervention groups in trials and studies or subgroups involving children with sickle cell anaemia, malignancies, or surgery or trauma, or those reporting follow-up data that were combined with the in-hospital period. Two independent reviewers extracted the data and assessed the quality and risk of bias using the Newcastle Ottawa Scale or the Cochrane Collaboration's tool. The coprimary outcomes were all-cause death and all-cause readmissions 6 months after discharge. This study is registered with PROSPERO, CRD42017079282. FINDINGS: Of 2930 articles identified in our search, 27 studies were included. For children who were recently discharged following hospital admission with severe anaemia, all-cause mortality by 6 months was higher than during the in-hospital period (n=5 studies; Mantel-Haenszel odds ratio 1·72, 95% CI 1·22-2·44; p=0·0020; I(2)=51·5%) and more than two times higher than children previously admitted without severe anaemia (n=4 studies; relative risk [RR] 2·69, 95% CI 1·59-4·53; p<0·0001; I(2)=69·2%). Readmissions within 6 months of discharge were also more common in children admitted with severe anaemia than in children admitted with other conditions (n=1 study; RR 3·05, 1·12-8·35; p<0·0001). Children admitted with severe acute malnutrition (regardless of severe anaemia) also had a higher 6-month mortality after discharge than those admitted for other reasons (n=2 studies; RR=3·12, 2·02-4·68; p<0·0001; I(2)=54·7%). Other predictors of mortality after discharge included discharge against medical advice, HIV, bacteraemia, and hypoxia. INTERPRETATION: In malaria-endemic settings in Africa, children admitted to hospital with severe anaemia and severe acute malnutrition are at increased risk of mortality in the first 6 months after discharge compared with children admitted with other health conditions. Improved strategies are needed for the management of these high-risk groups during the period after discharge. FUNDING: Research Council of Norway and US Centers for Disease Control and Prevention. |
Intermittent screening and treatment with artemisinin-combination therapy versus intermittent preventive treatment with sulphadoxine-pyrimethamine for malaria in pregnancy: a systematic review and individual participant data meta-analysis of randomised clinical trials
Gutman JR , Khairallah C , Stepniewska K , Tagbor H , Madanitsa M , Cairns M , L'Lanziva A J , Kalilani L , Otieno K , Mwapasa V , Meshnick S , Kariuki S , Chandramohan D , Desai M , Taylor SM , Greenwood B , Ter Kuile FO . EClinicalMedicine 2021 41 101160 BACKGROUND: In sub-Saharan Africa, the efficacy of intermittent preventive therapy in pregnancy with sulphadoxine-pyrimethamine (IPTp-SP) for malaria in pregnancy is threatened by parasite resistance. We conducted an individual-participant data (IPD) meta-analysis to assess the efficacy of intermittent screening with malaria rapid diagnostic tests (RDTs) and treatment of RDT-positive women with artemisinin-based combination therapy (ISTp-ACT) compared to IPTp-SP, and understand the importance of subpatent infections. METHODS: We searched MEDLINE and the Malaria-in-Pregnancy Library on May 6, 2021 for trials comparing ISTp-ACT and IPTp-SP. Generalised linear regression was used to compare adverse pregnancy outcomes (composite of small-for-gestational-age, low birthweight (LBW), or preterm delivery) and peripheral or placental Plasmodium falciparum at delivery. The effects of subpatent (PCR-positive, RDT/microscopy-negative) infections were assessed in both arms pooled using multi-variable fixed-effect models adjusting for the number of patent infections. PROSPERO registration: CRD42016043789. FINDINGS: Five trials conducted between 2007 and 2014 contributed (10,821 pregnancies), two from high SP-resistance areas where dhfr/dhps quintuple mutant parasites are saturated, but sextuple mutants are still rare (Kenya and Malawi), and three from low-resistance areas (West-Africa). Four trials contributed IPD data (N=10,362). At delivery, the prevalence of any malaria infection (relative risk [RR]=1.08, 95% CI 1.00-1.16, I(2)=67.0 %) and patent infection (RR=1.02, 0.61-1.16, I(2)=0.0%) were similar. Subpatent infections were more common in ISTp recipients (RR=1.31, 1.05-1.62, I(2)=0.0%). There was no difference in adverse pregnancy outcome (RR=1.00, 0.96-1.05; studies=4, N=9,191, I(2)=54.5%). Subpatent infections were associated with LBW (adjusted RR=1.13, 1.07-1.19), lower mean birthweight (adjusted mean difference=32g, 15-49), and preterm delivery (aRR=1.35, 1.15-1.57). INTERPRETATION: ISTp-ACT was not superior to IPTp-SP and may result in more subpatent infections than the existing IPTp-SP policy. Subpatent infections were associated with increased LBW and preterm delivery. More sensitive diagnostic tests are needed to detect and treat low-grade infections. FUNDING: Centers for Disease Control and Prevention and Worldwide Antimalarial Resistance Network. |
Piperaquine pharmacokinetics during intermittent preventive treatment for malaria in pregnancy
Chotsiri P , Gutman J , Ahmed R , Poespoprodjo JR , Syafruddin D , Khairallah C , Asih PBS , L'Lanziva A , Otieno K , Kariuki S , Ouma P , Were V , Katana A , Price RN , Desai M , Ter Kuile FO , Tarning J . Antimicrob Agents Chemother 2020 65 (3) Background: Dihydroartemisinin-piperaquine (DP) is a long-acting artemisinin combination treatment that provides effective chemoprevention and has been proposed as an alternative antimalarial drug for intermittent-preventive therapy in pregnancy (IPTp). Several pharmacokinetic studies have shown that dose adjustment may not be needed for the treatment of malaria in pregnancy with DP. However, there are limited data on the optimal dosing for IPTp. Objective: This study aimed to evaluate the population pharmacokinetics of piperaquine given as IPTp in pregnant women. Methods: Pregnant women were enrolled in clinical trials conducted in Kenya and Indonesia and treated with standard 3-day courses of DP, administered in 4-8 weeks intervals from the second trimester until delivery. Pharmacokinetic blood samples were collected for piperaquine drug measurements before each treatment round, time of breakthrough symptomatic malaria, and at delivery. Piperaquine population pharmacokinetic properties were investigated using nonlinear mixed-effects modelling with a prior approach. Results: In total data from 366 Kenyan and 101 Indonesian women were analysed. The pharmacokinetic properties of piperaquine were adequately described using a flexible transit absorption (n=5) followed by a three-compartment disposition model. Gestational age did not affect the pharmacokinetic parameters of piperaquine. After three rounds of monthly IPTp, 9.45% (95% CI: 1.8-26.5) of pregnant women had trough piperaquine concentrations below the suggested target concentration (10.3 ng/mL). Translational simulations suggest that providing the full treatment dose of DP at monthly intervals provides sufficient protection to prevent malaria infection. Conclusions: Monthly administration of a DP has the potential to offer optimal prevention of malaria during pregnancy. |
Malaria chemoprevention in the postdischarge management of severe anemia
Kwambai TK , Dhabangi A , Idro R , Opoka R , Watson V , Kariuki S , Kuya NA , Onyango ED , Otieno K , Samuels AM , Desai MR , Boele van Hensbroek M , Wang D , John CC , Robberstad B , Phiri KS , Ter Kuile FO . N Engl J Med 2020 383 (23) 2242-2254 BACKGROUND: Children who have been hospitalized with severe anemia in areas of Africa in which malaria is endemic have a high risk of readmission and death within 6 months after discharge. No prevention strategy specifically addresses this period. METHODS: We conducted a multicenter, two-group, randomized, placebo-controlled trial in nine hospitals in Kenya and Uganda to determine whether 3 months of malaria chemoprevention could reduce morbidity and mortality after hospital discharge in children younger than 5 years of age who had been admitted with severe anemia. All children received standard in-hospital care for severe anemia and a 3-day course of artemether-lumefantrine at discharge. Two weeks after discharge, children were randomly assigned to receive dihydroartemisinin-piperaquine (chemoprevention group) or placebo, administered as 3-day courses at 2, 6, and 10 weeks after discharge. Children were followed for 26 weeks after discharge. The primary outcome was one or more hospital readmissions for any reason or death from the time of randomization to 6 months after discharge. Conditional risk-set modeling for recurrent events was used to calculate hazard ratios with the use of the Prentice-Williams-Peterson total-time approach. RESULTS: From May 2016 through May 2018, a total of 1049 children underwent randomization; 524 were assigned to the chemoprevention group and 525 to the placebo group. From week 3 through week 26, a total of 184 events of readmission or death occurred in the chemoprevention group and 316 occurred in the placebo group (hazard ratio, 0.65; 95% confidence interval [CI], 0.54 to 0.78; P<0.001). The lower incidence of readmission or death in the chemoprevention group than in the placebo group was restricted to the intervention period (week 3 through week 14) (hazard ratio, 0.30; 95% CI, 0.22 to 0.42) and was not sustained after that time (week 15 through week 26) (hazard ratio, 1.13; 95% CI, 0.87 to 1.47). No serious adverse events were attributed to dihydroartemisinin-piperaquine. CONCLUSIONS: In areas with intense malaria transmission, 3 months of postdischarge malaria chemoprevention with monthly dihydroartemisinin-piperaquine in children who had recently received treatment for severe anemia prevented more deaths or readmissions for any reason after discharge than placebo. (Funded by the Research Council of Norway and the Centers for Disease Control and Prevention; ClinicalTrials.gov number, NCT02671175.). |
Cost-effectiveness of intermittent preventive treatment with dihydroartemisinin-piperaquine for malaria during pregnancy: an analysis using efficacy results from Uganda and Kenya, and pooled data
Fernandes S , Were V , Gutman J , Dorsey G , Kakuru A , Desai M , Kariuki S , Kamya MR , Ter Kuile FO , Hanson K . Lancet Glob Health 2020 8 (12) e1512-e1523 BACKGROUND: Prevention of malaria infection during pregnancy in HIV-negative women currently relies on the use of long-lasting insecticidal nets together with intermittent preventive treatment in pregnancy with sulfadoxine-pyrimethamine (IPTp-SP). Increasing sulfadoxine-pyrimethamine resistance in Africa threatens current prevention of malaria during pregnancy. Thus, a replacement for IPTp-SP is urgently needed, especially for locations with high sulfadoxine-pyrimethamine resistance. Dihydroartemisinin-piperaquine is a promising candidate. We aimed to estimate the cost-effectiveness of intermittent preventive treatment in pregnancy with dihydroartemisinin-piperaquine (IPTp-DP) versus IPTp-SP to prevent clinical malaria infection (and its sequelae) during pregnancy. METHODS: We did a cost-effectiveness analysis using meta-analysis and individual trial results from three clinical trials done in Kenya and Uganda. We calculated disability-adjusted life-years (DALYs) arising from stillbirths, neonatal death, low birthweight, mild and moderate maternal anaemia, and clinical malaria infection, associated with malaria during pregnancy. Cost estimates were obtained from data collected in observational studies, health-facility costings, and from international drug procurement databases. The cost-effectiveness analyses were done from a health-care provider perspective using a decision tree model with a lifetime horizon. Deterministic and probabilistic sensitivity analyses using appropriate parameter ranges and distributions were also done. Results are presented as the incremental cost per DALY averted and the likelihood that an intervention is cost-effective for different cost-effectiveness thresholds. FINDINGS: Compared with three doses of sulfadoxine-pyrimethamine, three doses of dihydroartemisinin-piperaquine, delivered to a hypothetical cohort of 1000 pregnant women, averted 892 DALYs (95% credibility interval 274 to 1517) at an incremental cost of US$7051 (2653 to 13 038) generating an incremental cost-effectiveness ratio (ICER) of $8 (2 to 29) per DALY averted. Compared with monthly doses of sulfadoxine-pyrimethamine, monthly doses of dihydroartemisinin-piperaquine averted 534 DALYS (-141 to 1233) at a cost of $13 427 (4994 to 22 895), resulting in an ICER of $25 (-151 to 224) per DALY averted. Both results were highly robust to most or all variations in the deterministic sensitivity analysis. INTERPRETATION: Our findings suggest that among HIV-negative pregnant women with high uptake of long-lasting insecticidal nets, IPTp-DP is cost-effective in areas with high malaria transmission and high sulfadoxine-pyrimethamine resistance. These data provide a comprehensive overview of the current evidence on the cost-effectiveness of IPTp-DP. Nevertheless, before a policy change is advocated, we recommend further research into the effectiveness and costs of different regimens of IPTp-DP in settings with different underlying sulfadoxine-pyrimethamine resistance. FUNDING: Malaria in Pregnancy Consortium, which is funded through a grant from the Bill & Melinda Gates Foundation to the Liverpool School of Hygiene and Tropical Medicine. |
Modelling the incremental benefit of introducing malaria screening strategies to antenatal care in Africa
Walker PGT , Cairns M , Slater H , Gutman J , Kayentao K , Williams JE , Coulibaly SO , Khairallah C , Taylor S , Meshnick SR , Hill J , Mwapasa V , Kalilani-Phiri L , Bojang K , Kariuki S , Tagbor H , Griffin JT , Madanitsa M , Ghani ACH , Desai M , Ter Kuile FO . Nat Commun 2020 11 (1) 3799 Plasmodium falciparum in pregnancy is a major cause of adverse pregnancy outcomes. We combine performance estimates of standard rapid diagnostic tests (RDT) from trials of intermittent screening and treatment in pregnancy (ISTp) with modelling to assess whether screening at antenatal visits improves upon current intermittent preventative therapy with sulphadoxine-pyrimethamine (IPTp-SP). We estimate that RDTs in primigravidae at first antenatal visit are substantially more sensitive than in non-pregnant adults (OR = 17.2, 95% Cr.I. 13.8-21.6), and that sensitivity declines in subsequent visits and with gravidity, likely driven by declining susceptibility to placental infection. Monthly ISTp with standard RDTs, even with highly effective drugs, is not superior to monthly IPTp-SP. However, a hybrid strategy, recently adopted in Tanzania, combining testing and treatment at first visit with IPTp-SP may offer benefit, especially in areas with high-grade SP resistance. Screening and treatment in the first trimester, when IPTp-SP is contraindicated, could substantially improve pregnancy outcomes. |
First trimester use of artemisinin-based combination therapy and the risk of low birth weight and small for gestational age
Augusto O , Stergachis A , Dellicour S , Tinto H , Vala A , Ruperez M , Macete E , Nakanabo-Diallo S , Kazienga A , Valea I , d'Alessandro U , Ter Kuile FO , Calip GS , Ouma P , Desai M , Sevene E . Malar J 2020 19 (1) 144 BACKGROUND: While there is increasing evidence on the safety of artemisinin-based combination therapy (ACT) for the case management of malaria in early pregnancy, little is known about the association between exposure to ACT during the first trimester and the effect on fetal growth. METHODS: Data were analysed from prospective studies of pregnant women enrolled in Mozambique, Burkina Faso and Kenya designed to determine the association between anti-malarial drug exposure in the first trimester and pregnancy outcomes, including low birth weight (LBW) and small for gestational age (SGA). Exposure to anti-malarial drugs was ascertained retrospectively by record linkage using a combination of data collected from antenatal and adult outpatient clinic registries, prescription records and self-reported medication usage by the women. Site-level data synthesis (fixed effects and random effects) was conducted as well as individual-level analysis (fixed effects by site). RESULTS: Overall, 1915 newborns were included with 92 and 26 exposed to ACT (artemether-lumefantrine) and quinine, respectively. In Burkina Faso, Mozambique and Kenya at recruitment, the mean age (standard deviation) was 27.1 (6.6), 24.2 (6.2) and 25.7 (6.5) years, and the mean gestational age was 24.0 (6.2), 21.2 (5.7) and 17.9 (10.2) weeks, respectively. The LBW prevalence among newborns born to women exposed to ACT and quinine (QNN) during the first trimester was 10/92 (10.9%) and 7/26 (26.9%), respectively, compared to 9.5% (171/1797) among women unexposed to any anti-malarials during pregnancy. Compared to those unexposed to anti-malarials, ACT and QNN exposed women had the pooled LBW prevalence ratio (PR) of 1.13 (95% confidence interval (CI) 0.62-2.05, p-value 0.700) and 2.03 (95% CI 1.09-3.78, p-value 0.027), respectively. Compared to those unexposed to anti-malarials ACT and QNN-exposed women had the pooled SGA PR of 0.85 (95% CI 0.50-1.44, p-value 0.543) and 1.41 (95% CI 0.71-2.77, p-value 0.322), respectively. Whereas compared to ACT-exposed, the QNN-exposed had a PR of 2.14 (95% CI 0.78-5.89, p-value 0.142) for LBW and 8.60 (95% CI 1.29-57.6, p-value 0.027) for SGA. The level of between sites heterogeneity was moderate to high. CONCLUSION: ACT exposure during the first trimester was not associated with an increased occurrence of LBW or SGA. However, the data suggest a higher prevalence of LBW and SGA for children born to QNN-exposed pregnancies. The findings support the use of ACT (artemether-lumefantrine) for the treatment of uncomplicated malaria during the first trimester of pregnancy. |
Impact of maternal HIV infection and placental malaria on the transplacental transfer of influenza antibodies in mother-infant pairs in Malawi, 2013-2014
Ho A , Mapurisa G , Madanitsa M , Kalilani-Phiri L , Kamiza S , Makanani B , Ter Kuile FO , Buys A , Treurnicht F , Everett D , Mwapasa V , Widdowson MA , McMorrow M , Heyderman RS . Open Forum Infect Dis 2019 6 (10) ofz383 Background: Maternal influenza vaccination protects infants against influenza virus infection. Impaired transplacental transfer of influenza antibodies may reduce this protection. Methods: We conducted a cross-sectional study of influenza vaccine-naive pregnant women recruited at delivery from Blantyre (urban, low malaria transmission) and Chikwawa (rural, high malaria transmission) in Southern Malawi. HIV-infected mothers were excluded in Chikwawa. Maternal and cord blood antibodies against circulating influenza strains A/California/7/2009, A/Victoria/361/2011, B/Brisbane/60/2008, and B/Wisconsin/1/2010 were measured by hemagglutination inhibition (HAI). We studied the impact of maternal HIV infection and placental malaria on influenza antibody levels in mother-infant pairs in Blantyre and Chikwawa, respectively. Results: We included 454 mother-infant pairs (Blantyre, n = 253; Chikwawa, n = 201). HIV-infected mothers and their infants had lower seropositivity (HAI titer >/=1:40) against influenza A(H1N1)pdm09 (mothers, 24.3 vs 45.4%; P = .02; infants, 24.3 vs 50.5%; P = .003) and A(H3N2) (mothers, 37.8% vs 63.9%; P = .003; infants, 43.2 vs 64.8%; P = .01), whereas placental malaria had an inconsistent effect on maternal and infant seropositivity. In multivariable analyses, maternal HIV infection was associated with reduced infant seropositivity (A(H1N1)pdm09: adjusted odds ratio [aOR], 0.34; 95% confidence interval [CI], 0.15-0.79; A(H3N2): aOR, 0.43; 95% CI, 0.21-0.89). Transplacental transfer was not impaired by maternal HIV or placental malaria. Conclusions: Maternal HIV infection influenced maternal antibody response to influenza A virus infection, and thereby antibody levels in newborns, but did not affect transplacental antibody transfer. |
Menstrual cups and cash transfer to reduce sexual and reproductive harm and school dropout in adolescent schoolgirls: study protocol of a cluster-randomised controlled trial in western Kenya
Zulaika G , Kwaro D , Nyothach E , Wang D , Zielinski-Gutierrez E , Mason L , Eleveld A , Chen T , Kerubo E , van Eijk A , Pace C , Obor D , Juma J , Oyaro B , Niessen L , Bigogo G , Ngere I , Henry C , Majiwa M , Onyango CO , Ter Kuile FO , Phillips-Howard PA . BMC Public Health 2019 19 (1) 1317 BACKGROUND: Adolescent girls in sub-Saharan Africa are disproportionally vulnerable to sexual and reproductive health (SRH) harms. In western Kenya, where unprotected transactional sex is common, young females face higher rates of school dropout, often due to pregnancy, and sexually transmitted infections (STIs), including HIV. Staying in school has shown to protect girls against early marriage, teen pregnancy, and HIV infection. This study evaluates the impact of menstrual cups and cash transfer interventions on a composite of deleterious outcomes (HIV, HSV-2, and school dropout) when given to secondary schoolgirls in western Kenya, with the aim to inform evidence-based policy to improve girls' health, school equity, and life-chances. METHODS: Single site, 4-arm, cluster randomised controlled superiority trial. Secondary schools are the unit of randomisation, with schoolgirls as the unit of measurement. Schools will be randomised into one of four intervention arms using a 1:1:1:1 ratio and block randomisation: (1) menstrual cup arm; (2) cash transfer arm, (3) cups and cash combined intervention arm, or (4) control arm. National and county agreement, and school level consent will be obtained prior to recruitment of schools, with parent consent and girls' assent obtained for participant enrolment. Participants will be trained on safe use of interventions, with all arms receiving puberty and hygiene education. Annually, the state of latrines, water availability, water treatment, handwashing units and soap in schools will be measured. The primary endpoint is a composite of incident HIV, HSV-2, and all-cause school dropout, after 3 years follow-up. School dropout will be monitored each term via school registers and confirmed through home visits. HIV and HSV-2 incident infections and risk factors will be measured at baseline, mid-line and end-line. Intention to treat analysis will be conducted among all enrolled participants. Focus group discussions will provide contextual information on uptake of interventions. Monitoring for safety will occur throughout. DISCUSSION: If proved safe and effective, the interventions offer a potential contribution toward girls' schooling, health, and equity in low- and middle-income countries. TRIAL REGISTRATION: ClinicalTrials.gov NCT03051789 , 15th February 2017. |
Trends in malaria prevalence and health related socioeconomic inequality in rural western Kenya: results from repeated household malaria cross-sectional surveys from 2006 to 2013
Were V , Buff AM , Desai M , Kariuki S , Samuels AM , Phillips-Howard P , Ter Kuile FO , Kachur SP , Niessen LW . BMJ Open 2019 9 (9) e033883 OBJECTIVE: The objective of this analysis was to examine trends in malaria parasite prevalence and related socioeconomic inequalities in malaria indicators from 2006 to 2013 during a period of intensification of malaria control interventions in Siaya County, western Kenya. METHODS: Data were analysed from eight independent annual cross-sectional surveys from a combined sample of 19 315 individuals selected from 7253 households. Study setting was a health and demographic surveillance area of western Kenya. Data collected included demographic factors, household assets, fever and medication use, malaria parasitaemia by microscopy, insecticide-treated bed net (ITN) use and care-seeking behaviour. Households were classified into five socioeconomic status and dichotomised into poorest households (poorest 60%) and less poor households (richest 40%). Adjusted prevalence ratios (aPR) were calculated using a multivariate generalised linear model accounting for clustering and cox proportional hazard for pooled data assuming constant follow-up time. RESULTS: Overall, malaria infection prevalence was 36.5% and was significantly higher among poorest individuals compared with the less poor (39.9% vs 33.5%, aPR=1.17; 95% CI 1.11 to 1.23) but no change in prevalence over time (trend p value <0.256). Care-seeking (61.1% vs 62.5%, aPR=0.99; 95% CI 0.95 to 1.03) and use of any medication were similar among the poorest and less poor. Poorest individuals were less likely to use Artemether-Lumefantrine or quinine for malaria treatment (18.8% vs 22.1%, aPR=0.81, 95% CI 0.72 to 0.91) while use of ITNs was lower among the poorest individuals compared with less poor (54.8% vs 57.9%; aPR=0.95; 95% CI 0.91 to 0.99), but the difference was negligible. CONCLUSIONS: Despite attainment of equity in ITN use over time, socioeconomic inequalities still existed in the distribution of malaria. This might be due to a lower likelihood of treatment with an effective antimalarial and lower use of ITNs by poorest individuals. Additional strategies are necessary to reduce socioeconomic inequities in prevention and control of malaria in endemic areas in order to achieve universal health coverage and sustainable development goals. |
Human direct skin feeding versus membrane feeding to assess the mosquitocidal efficacy of high-dose ivermectin (IVERMAL Trial)
Smit MR , Ochomo EO , Aljayyoussi G , Kwambai TK , Abong'o BO , Bousema T , Waterhouse D , Bayoh NM , Gimnig JE , Samuels AM , Desai MR , Phillips-Howard PA , Kariuki SK , Wang D , Ward SA , Ter Kuile FO . Clin Infect Dis 2018 69 (7) 1112-1119 Background: Ivermectin is being considered for mass-drug-administration for malaria due to its ability to kill mosquitoes feeding on recently treated individuals. In a recent trial, 3-day courses of 300 and 600 mcg/kg/day were shown to kill Anopheles mosquitoes for at least 28 days post-treatment when fed patients' venous blood using membrane-feeding-assays. Direct-skin-feeding on humans may lead to higher mosquito-mortality as ivermectin capillary-concentrations are higher. We compared mosquito-mortality following direct-skin- and membrane-feeding. Methods: We conducted a mosquito feeding study nested within a randomized, double-blind, placebo-controlled trial of 141 adults with uncomplicated malaria in Kenya comparing 3-day ivermectin 0 (n=46), 300 (n=48), or 600 mcg/kg/day (n=47), co-administered with dihydroartemisinin-piperaquine. On post-treatment day-7, direct-skin and membrane-feeding assays were conducted using laboratory-reared Anopheles gambiae s.s.. Mosquito survival was assessed daily for 28-days-post-feeding. Results: Between July-20-2015 and May-7-2016, 69 of 141 patients participated in both direct-skin- and membrane-feeding (placebo n=23, 300mcg/kg/day n=24, 600mcg/kg/day n=22). The 14-day-post-feeding mortality for mosquitoes fed on blood 7-days post-treatment from patients in both ivermectin arms pooled was similar with direct-skin-feeding (n=2,941 mosquitoes) versus membrane-feeding (n=7,380 mosquitoes): cumulative-mortality (RR=0.99, 0.95-1.03, p=0.69) and survival-time (HR=0.96, 0.91-1.02, p=0.19). Results were consistent by sex, body-mass-index, and across the range of ivermectin capillary concentrations studied (0.72-73.9 ng/mL). Conclusions: Direct-skin-feeding and membrane-feeding on day 7 resulted in similar mosquitocidal-effects of ivermectin across a wide range of drug-concentrations, suggesting that the mosquitocidal-effects seen with membrane-feeding accurately reflect those of natural-biting. Membrane-feeding, which is more patient-friendly and ethically acceptable, can likely reliably be used to assess ivermectin's mosquitocidal-efficacy. |
Malaria chemoprevention with monthly dihydroartemisinin-piperaquine for the post-discharge management of severe anaemia in children aged less than 5 years in Uganda and Kenya: study protocol for a multi-centre, two-arm, randomised, placebo-controlled, superiority trial
Kwambai TK , Dhabangi A , Idro R , Opoka R , Kariuki S , Samuels AM , Desai M , van Hensbroek MB , John CC , Robberstad B , Wang D , Phiri K , Ter Kuile FO . Trials 2018 19 (1) 610 BACKGROUND: Children hospitalised with severe anaemia in malaria endemic areas in Africa are at high risk of readmission or death within 6 months post-discharge. Currently, no strategy specifically addresses this period. In Malawi, 3 months of post-discharge malaria chemoprevention (PMC) with monthly treatment courses of artemether-lumefantrine given at discharge and at 1 and 2 months prevented 30% of all-cause readmissions by 6 months post-discharge. Another efficacy trial is needed before a policy of malaria chemoprevention can be considered for the post-discharge management of severe anaemia in children under 5 years of age living in malaria endemic areas. OBJECTIVE: We aim to determine if 3 months of PMC with monthly 3-day treatment courses of dihydroartemisinin-piperaquine is safe and superior to a single 3-day treatment course with artemether-lumefantrine provided as part of standard in-hospital care in reducing all-cause readmissions and deaths (composite primary endpoint) by 6 months in the post-discharge management of children less than 5 years of age admitted with severe anaemia of any or undetermined cause. METHODS/DESIGN: This is a multi-centre, two-arm, placebo-controlled, individually randomised trial in children under 5 years of age recently discharged following management for severe anaemia. Children in both arms will receive standard in-hospital care for severe anaemia and a 3-day course of artemether-lumefantrine at discharge. At 2 weeks after discharge, surviving children will be randomised to receive either 3-day courses of dihydroartemisinin-piperaquine at 2, 6 and 10 weeks or an identical placebo and followed for 26 weeks through passive case detection. The trial will be conducted in hospitals in malaria endemic areas in Kenya and Uganda. The study is designed to detect a 25% reduction in the incidence of all-cause readmissions or death (composite primary outcome) from 1152 to 864 per 1000 child years (power 80%, alpha = 0.05) and requires 520 children per arm (1040 total children). RESULTS: Participant recruitment started in May 2016 and is ongoing. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02671175 . Registered on 28 January 2016. |
Pharmacokinetics-pharmacodynamics of high-dose ivermectin with dihydroartemisinin-piperaquine on mosquitocidal activity and QT-prolongation (IVERMAL)
Smit MR , Ochomo EO , Waterhouse D , Kwambai TK , Abong'o BO , Bousema T , Bayoh NM , Gimnig JE , Samuels AM , Desai MR , Phillips-Howard PA , Kariuki SK , Wang D , Ter Kuile FO , Ward SA , Aljayyoussi G . Clin Pharmacol Ther 2018 105 (2) 388-401 High-dose ivermectin, co-administered for 3-days with dihydroartemisinin-piperaquine (DP), killed mosquitoes feeding on individuals for at least 28-days post-treatment in a recent trial (IVERMAL), while 7-days was predicted pre-trial. The current study assessed the relationship between ivermectin blood concentrations and the observed mosquitocidal effects against Anopheles gambiae. 3-days ivermectin 0, 300, or 600 mcg/kg/day plus DP was randomly assigned to 141 adults with uncomplicated malaria in Kenya. During 28-days follow-up, 1,393 venous and 335 paired capillary plasma samples, 850 mosquito-cluster mortality rates, and 524 QTcF-intervals were collected. Using pharmacokinetic-pharmacodynamic (PK-PD) modeling, we show a consistent correlation between predicted ivermectin concentrations and observed mosquitocidal-effects throughout the 28-day study duration, without invoking an unidentified mosquitocidal metabolite or drug-drug-interaction. Ivermectin had no effect on piperaquine's pharmacokinetics or QTcF-prolongation. The PK-PD model can be used to design new treatment regimens with predicted mosquitocidal effect. This methodology could be used to evaluate effectiveness of other endectocides. This article is protected by copyright. All rights reserved. |
Safety and mosquitocidal efficacy of high-dose ivermectin when co-administered with dihydroartemisinin-piperaquine in Kenyan adults with uncomplicated malaria (IVERMAL): a randomised, double-blind, placebo-controlled trial
Smit MR , Ochomo EO , Aljayyoussi G , Kwambai TK , Abong'o BO , Chen T , Bousema T , Slater HC , Waterhouse D , Bayoh NM , Gimnig JE , Samuels AM , Desai MR , Phillips-Howard PA , Kariuki SK , Wang D , Ward SA , Ter Kuile FO . Lancet Infect Dis 2018 18 (6) 615-626 BACKGROUND: Ivermectin is being considered for mass drug administration for malaria due to its ability to kill mosquitoes feeding on recently treated individuals. However, standard, single doses of 150-200 mug/kg used for onchocerciasis and lymphatic filariasis have a short-lived mosquitocidal effect (<7 days). Because ivermectin is well tolerated up to 2000 mug/kg, we aimed to establish the safety, tolerability, and mosquitocidal efficacy of 3 day courses of high-dose ivermectin, co-administered with a standard malaria treatment. METHODS: We did a randomised, double-blind, placebo-controlled, superiority trial at the Jaramogi Oginga Odinga Teaching and Referral Hospital (Kisumu, Kenya). Adults (aged 18-50 years) were eligible if they had confirmed symptomatic uncomplicated Plasmodium falciparum malaria and agreed to the follow-up schedule. Participants were randomly assigned (1:1:1) using sealed envelopes, stratified by sex and body-mass index (men: <21 vs >/=21 kg/m(2); women: <23 vs >/=23 kg/m(2)), with permuted blocks of three, to receive 3 days of ivermectin 300 mug/kg per day, ivermectin 600 mug/kg per day, or placebo, all co-administered with 3 days of dihydroartemisinin-piperaquine. Blood of patients taken on post-treatment days 0, 2 + 4 h, 7, 10, 14, 21, and 28 was fed to laboratory-reared Anopheles gambiae sensu stricto mosquitoes, and mosquito survival was assessed daily for 28 days after feeding. The primary outcome was 14-day cumulative mortality of mosquitoes fed 7 days after ivermectin treatment (from participants who received at least one dose of study medication). The study is registered with ClinicalTrials.gov, number NCT02511353. FINDINGS: Between July 20, 2015, and May 7, 2016, 741 adults with malaria were assessed for eligibility, of whom 141 were randomly assigned to receive ivermectin 600 mug/kg per day (n=47), ivermectin 300 mug/kg per day (n=48), or placebo (n=46). 128 patients (91%) attended the primary outcome visit 7 days post treatment. Compared with placebo, ivermectin was associated with higher 14 day post-feeding mosquito mortality when fed on blood taken 7 days post treatment (ivermectin 600 mug/kg per day risk ratio [RR] 2.26, 95% CI 1.93-2.65, p<0.0001; hazard ratio [HR] 6.32, 4.61-8.67, p<0.0001; ivermectin 300 mug/kg per day RR 2.18, 1.86-2.57, p<0.0001; HR 4.21, 3.06-5.79, p<0.0001). Mosquito mortality remained significantly increased 28 days post treatment (ivermectin 600 mug/kg per day RR 1.23, 1.01-1.50, p=0.0374; and ivermectin 300 mug/kg per day 1.21, 1.01-1.44, p=0.0337). Five (11%) of 45 patients receiving ivermectin 600 mug/kg per day, two (4%) of 48 patients receiving ivermectin 300 mug/kg per day, and none of 46 patients receiving placebo had one or more treatment-related adverse events. INTERPRETATION: Ivermectin at both doses assessed was well tolerated and reduced mosquito survival for at least 28 days after treatment. Ivermectin 300 mug/kg per day for 3 days provided a good balance between efficacy and tolerability, and this drug shows promise as a potential new tool for malaria elimination. FUNDING: Malaria Eradication Scientific Alliance (MESA) and US Centers for Disease Control and Prevention (CDC). |
Socioeconomic health inequality in malaria indicators in rural western Kenya: evidence from a household malaria survey on burden and care-seeking behaviour
Were V , Buff AM , Desai M , Kariuki S , Samuels A , Ter Kuile FO , Phillips-Howard PA , Kachur SP , Niessen L . Malar J 2018 17 (1) 166 BACKGROUND: Health inequality is a recognized barrier to achieving health-related development goals. Health-equality data are essential for evidence-based planning and assessing the effectiveness of initiatives to promote equity. Such data have been captured but have not always been analysed or used to manage programming. Health data were examined for microeconomic differences in malaria indices and associated malaria control initiatives in western Kenya. METHODS: Data was analysed from a malaria cross-sectional survey conducted in July 2012 among 2719 people in 1063 households in Siaya County, Kenya. Demographic factors, history of fever, malaria parasitaemia, malaria medication usage, insecticide-treated net (ITN) use and expenditure on malaria medications were collected. A composite socioeconomic status score was created using multiple correspondence analyses (MCA) of household assets; households were classified into wealth quintiles and dichotomized into poorest (lowest 3 quintiles; 60%) or less-poor (highest 2 quintiles; 40%). Prevalence rates were calculated using generalized linear modelling. RESULTS: Overall prevalence of malaria infection was 34.1%, with significantly higher prevalence in the poorest compared to less-poor households (37.5% versus 29.2%, adjusted prevalence ratio [aPR] 1.23; 95% CI = 1.08-1.41, p = 0.002). Care seeking (aPR = 0.95; 95% CI 0.87-1.04, p = 0.229), medication use (aPR = 0.94; 95% CI 0.87-1.00, p = 0.087) and ITN use (aPR = 0.96; 95% CI = 0.87-1.05, p = 0.397) were similar between households. Among all persons surveyed, 36.4% reported taking malaria medicines in the prior 2 weeks; 92% took artemether-lumefantrine, the recommended first-line malaria medication. In the poorest households, 4.9% used non-recommended medicines compared to 3.5% in less-poor (p = 0.332). Mean and standard deviation [SD] for expenditure on all malaria medications per person was US$0.38 [US$0.50]; the mean was US$0.35 [US$0.52] amongst the poorest households and US$0.40 [US$0.55] in less-poor households (p = 0.076). Expenditure on non-recommended malaria medicine was significantly higher in the poorest (mean US$1.36 [US$0.91]) compared to less-poor households (mean US$0.98 [US$0.80]; p = 0.039). CONCLUSIONS: Inequalities in malaria infection and expenditures on potentially ineffective malaria medication between the poorest and less-poor households were evident in rural western Kenya. Findings highlight the benefits of using MCA to assess and monitor the health-equity impact of malaria prevention and control efforts at the microeconomic level. |
Prevention of malaria in pregnancy
Desai M , Hill J , Fernandes S , Walker P , Pell C , Gutman J , Kayentao K , Gonzalez R , Webster J , Greenwood B , Cot M , Ter Kuile FO . Lancet Infect Dis 2018 18 (4) e119-e132 Malaria remains one of the most preventable causes of adverse birth outcomes. Intermittent preventive treatment in pregnancy (IPTp) with sulfadoxine-pyrimethamine is used to prevent malaria, but resistance to this drug combination has decreased its efficacy and new alternatives are needed. In Africa, a meta-analysis showed three-course or monthly IPTp with sulfadoxine-pyrimethamine to be safe and more effective than the original two-course sulfadoxine-pyrimethamine strategy, prompting WHO to update its policy in 2012. Although resistance to sulfadoxine-pyrimethamine reduces the parasitological efficacy of IPTp, this drug combination remains associated with reduced incidence of low birthweight in areas where prevalence of parasites with quintuple Plasmodium falciparum dihydrofolate reductase (Pfdhfr) and dihydropteroate synthetase (Pfdhps) mutations is greater than 90%. Nevertheless, its effectiveness is compromised in women infected with sextuple mutant parasites. Six trials of IPTp showed that neither amodiaquine, mefloquine, nor chloroquine-azithromycin are suitable replacements for sulfadoxine-pyrimethamine because of poor tolerability. Furthermore, four trials showed that intermittent screening and treatment with the current generation of malaria rapid diagnostic tests was not a suitable alternative strategy to IPTp with sulfadoxine-pyrimethamine, even in areas with high prevalence of quintuple mutations. Two trials showed that IPTp with dihydroartemisinin-piperaquine was well tolerated, effective, and acceptable for IPTp, with monthly regimens being the most effective. Coverage of IPTp and insecticide-treated nets continues to lag behind targets. The key barriers to uptake are well documented, and many are open to intervention. Outside of Africa, a single trial suggests a potential role for integrated approaches that combine sulfadoxine-pyrimethamine with azithromycin for IPTp in areas of Papua New Guinea where malaria transmission is high. Modelling analysis suggests the importance of the prevention of malaria early in pregnancy and the need to protect pregnant women declines more slowly than the rate at which transmission declines. Improved funding has led to an increase in the number of prevention trials in the past decade, showing the value of more sustained protection with monthly IPTp regimens. There is a need for confirmatory trials of the safety, efficacy, and feasibility of IPTp with dihydroartemisinin-piperaquine, for studies of intermittent screening and treatment with more sensitive rapid diagnostic tests, for studies of integrated strategies for malaria and other co-infections, and for studies of prevention strategies for malaria in pregnant women who are HIV-positive and living outside of Africa. Additional research is required on how to improve uptake of WHO's updated policy on IPTp with sulfadoxine-pyrimethamine and insecticide-treated nets. |
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