Last data update: May 06, 2024. (Total: 46732 publications since 2009)
Records 1-7 (of 7 Records) |
Query Trace: Thwing JI[original query] |
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SARS-CoV-2 seroprevalence and vaccine uptake among pregnant women at first antenatal care visits in Malawi
Tenthani L , Seffren V , Kabaghe AN , Ogollah F , Soko M , Yadav R , Kayigamba F , Payne D , Wadonda-Kabondo N , Kampira E , Volkmann T , Sugandhi NS , Seydel K , Rogier E , Thwing JI , Gutman JR . Am J Trop Med Hyg 2024 Many SARS-CoV-2 infections are asymptomatic, thus reported cases underestimate actual cases. To improve estimates, we conducted surveillance for SARS-CoV-2 seroprevalence among pregnant women attending their first antenatal care visit (ANC1) from June 2021 through May 2022. We administered a questionnaire to collect demographic, risk factors, and COVID-19 vaccine status information and tested dried blood spots for SARS-CoV-2 antibodies. Although <1% of ANC1 participants reported having had COVID-19, monthly SARS-CoV-2 seroprevalence increased from 15.4% (95% CI: 10.5-21.5) in June 2021 to 65.5% (95% CI: 55.5-73.7) in May 2022. Although COVID-19 vaccination was available in March 2021, uptake remained low, reaching a maximum of 9.5% (95% CI: 5.7-14.8) in May 2022. Results of ANC1 serosurveillance provided prevalence estimates helpful in understanding this population case burden that was available through self-report and national case reports. To improve vaccine uptake, efforts to address fears and misconceptions regarding COVID-19 vaccines are needed. |
Contextual factors to improve implementation of malaria chemoprevention in children: A systematic review
Gatiba P , Laury J , Steinhardt L , Hwang J , Thwing JI , Zulliger R , Emerson C , Gutman JR . Am J Trop Med Hyg 2023 110 (1) 69-78 Malaria remains a leading cause of childhood morbidity and mortality in sub-Saharan Africa, particularly among children under 5 years of age. To help address this challenge, the WHO recommends chemoprevention for certain populations. For children and infants, the WHO recommends seasonal malaria chemoprevention (SMC), perennial malaria chemoprevention (PMC; formerly intermittent preventive treatment in infants [IPTi]), and, more recently, intermittent preventive treatment in school children (IPTsc). This review describes the contextual factors, including feasibility, acceptability, health equity, financial considerations, and values and preferences, that impact implementation of these strategies. A systematic search was conducted on July 5, 2022, and repeated April 13, 2023, to identify relevant literature. Two reviewers independently screened titles for eligibility, extracted data from eligible articles, and identified and summarized themes. Of 6,295 unique titles identified, 65 were included. The most frequently evaluated strategy was SMC (n = 40), followed by IPTi (n = 18) and then IPTsc (n = 6). Overall, these strategies were highly acceptable, although with IPTsc, there were community concerns with providing drugs to girls of reproductive age and the use of nonmedical staff for drug distribution. For SMC, door-to-door delivery resulted in higher coverage, improved caregiver acceptance, and reduced cost. Lower adherence was noted when caregivers were charged with giving doses 2 and 3 unsupervised. For SMC and IPTi, travel distances and inclement weather limited accessibility. Sensitization and caregiver education efforts, retention of high-quality drug distributors, and improved transportation were key to improving coverage. Additional research is needed to understand the role of community values and preferences in chemoprevention implementation. |
Haematological consequences of acute uncomplicated falciparum malaria: a WorldWide Antimalarial Resistance Network pooled analysis of individual patient data
WorldWide Antimalarial Resistance Network Falciparum Haematology Study Group , Hwang J , Plucinski M , Thwing JI . BMC Med 2022 20 (1) 85 BACKGROUND: Plasmodium falciparum malaria is associated with anaemia-related morbidity, attributable to host, parasite and drug factors. We quantified the haematological response following treatment of uncomplicated P. falciparum malaria to identify the factors associated with malarial anaemia. METHODS: Individual patient data from eligible antimalarial efficacy studies of uncomplicated P. falciparum malaria, available through the WorldWide Antimalarial Resistance Network data repository prior to August 2015, were pooled using standardised methodology. The haematological response over time was quantified using a multivariable linear mixed effects model with nonlinear terms for time, and the model was then used to estimate the mean haemoglobin at day of nadir and day 7. Multivariable logistic regression quantified risk factors for moderately severe anaemia (haemoglobin < 7 g/dL) at day 0, day 3 and day 7 as well as a fractional fall ≥ 25% at day 3 and day 7. RESULTS: A total of 70,226 patients, recruited into 200 studies between 1991 and 2013, were included in the analysis: 50,859 (72.4%) enrolled in Africa, 18,451 (26.3%) in Asia and 916 (1.3%) in South America. The median haemoglobin concentration at presentation was 9.9 g/dL (range 5.0-19.7 g/dL) in Africa, 11.6 g/dL (range 5.0-20.0 g/dL) in Asia and 12.3 g/dL (range 6.9-17.9 g/dL) in South America. Moderately severe anaemia (Hb < 7g/dl) was present in 8.4% (4284/50,859) of patients from Africa, 3.3% (606/18,451) from Asia and 0.1% (1/916) from South America. The nadir haemoglobin occurred on day 2 post treatment with a mean fall from baseline of 0.57 g/dL in Africa and 1.13 g/dL in Asia. Independent risk factors for moderately severe anaemia on day 7, in both Africa and Asia, included moderately severe anaemia at baseline (adjusted odds ratio (AOR) = 16.10 and AOR = 23.00, respectively), young age (age < 1 compared to ≥ 12 years AOR = 12.81 and AOR = 6.79, respectively), high parasitaemia (AOR = 1.78 and AOR = 1.58, respectively) and delayed parasite clearance (AOR = 2.44 and AOR = 2.59, respectively). In Asia, patients treated with an artemisinin-based regimen were at significantly greater risk of moderately severe anaemia on day 7 compared to those treated with a non-artemisinin-based regimen (AOR = 2.06 [95%CI 1.39-3.05], p < 0.001). CONCLUSIONS: In patients with uncomplicated P. falciparum malaria, the nadir haemoglobin occurs 2 days after starting treatment. Although artemisinin-based treatments increase the rate of parasite clearance, in Asia they are associated with a greater risk of anaemia during recovery. |
Evidence of non-Plasmodium falciparum malaria infection in Kedougou, Senegal
Daniels RF , Deme AB , Gomis JF , Dieye B , Durfee K , Thwing JI , Fall FB , Ba M , Ndiop M , Badiane AS , Ndiaye YD , Wirth DF , Volkman SK , Ndiaye D . Malar J 2017 16 (1) 9 BACKGROUND: Expanded malaria control efforts in Senegal have resulted in increased use of rapid diagnostic tests (RDT) to identify the primary disease-causing Plasmodium species, Plasmodium falciparum. However, the type of RDT utilized in Senegal does not detect other malaria-causing species such as Plasmodium ovale spp., Plasmodium malariae, or Plasmodium vivax. Consequently, there is a lack of information about the frequency and types of malaria infections occurring in Senegal. This study set out to better determine whether species other than P. falciparum were evident among patients evaluated for possible malaria infection in Kedougou, Senegal. METHODS: Real-time polymerase chain reaction speciation assays for P. vivax, P. ovale spp., and P. malariae were developed and validated by sequencing and DNA extracted from 475 Plasmodium falciparum-specific HRP2-based RDT collected between 2013 and 2014 from a facility-based sample of symptomatic patients from two health clinics in Kedougou, a hyper-endemic region in southeastern Senegal, were analysed. RESULTS: Plasmodium malariae (n = 3) and P. ovale wallikeri (n = 2) were observed as co-infections with P. falciparum among patients with positive RDT results (n = 187), including one patient positive for all three species. Among 288 negative RDT samples, samples positive for P. falciparum (n = 24), P. ovale curtisi (n = 3), P. ovale wallikeri (n = 1), and P. malariae (n = 3) were identified, corresponding to a non-falciparum positivity rate of 2.5%. CONCLUSIONS: These findings emphasize the limitations of the RDT used for malaria diagnosis and demonstrate that non-P. falciparum malaria infections occur in Senegal. Current RDT used for routine clinical diagnosis do not necessarily provide an accurate reflection of malaria transmission in Kedougou, Senegal, and more sensitive and specific methods are required for diagnosis and patient care, as well as surveillance and elimination activities. These findings have implications for other malaria endemic settings where species besides P. falciparum may be transmitted and overlooked by control or elimination activities. |
Clinical determinants of early parasitological response to ACTs in African patients with uncomplicated falciparum malaria: a literature review and meta-analysis of individual patient data
Abdulla S , Adam I , Adjei GO , Adjuik MA , Alemayehu B , Allan R , Arinaitwe E , Ashley EA , Ba MS , Barennes H , Barnes KI , Bassat Q , Baudin E , Berens-Riha N , Bjorkman A , Bompart F , Bonnet M , Borrmann S , Bousema T , Brasseur P , Bukirwa H , Checchi F , Dahal P , D'Alessandro U , Desai M , Dicko A , Djimde AA , Dorsey G , Doumbo OK , Drakeley CJ , Duparc S , Eshetu T , Espie E , Etard JF , Faiz AM , Falade CO , Fanello CI , Faucher JF , Faye B , Faye O , Filler S , Flegg JA , Fofana B , Fogg C , Gadalla NB , Gaye O , Genton B , Gething PW , Gil JP , Gonzalez R , Grandesso F , Greenhouse B , Greenwood B , Grivoyannis A , Guerin PJ , Guthmann JP , Hamed K , Hamour S , Hay SI , Hode EM , Humphreys GS , Hwang J , Ibrahim ML , Jima D , Jones JJ , Jullien V , Juma E , Kachur PS , Kager PA , Kamugisha E , Kamya MR , Karema C , Kayentao K , Kieche JR , Kironde F , Kofoed PE , Kremsner PG , Krishna S , Lameyre V , Lell B , Lima A , Makanga M , Malik EM , Marsh K , Martensson A , Massougbodji A , Menan H , Menard D , Menendez C , Mens PF , Meremikwu M , Moreira C , Nabasumba C , Nambozi M , Ndiaye JL , Ngasala BE , Nikiema F , Nsanzabana C , Ntoumi F , Oguike M , Ogutu BR , Olliaro P , Omar SA , Ouedraogo JB , Owusu-Agyei S , Penali LK , Pene M , Peshu J , Piola P , Plowe CV , Premji Z , Price RN , Randrianarivelojosia M , Rombo L , Roper C , Rosenthal PJ , Sagara I , Same-Ekobo A , Sawa P , Schallig HDFH , Schramm B , Seck A , Shekalaghe SA , Sibley CH , Sinou V , Sirima SB , Some FA , Sow D , Staedke SG , Stepniewska K , Sutherland CJ , Swarthout TD , Sylla K , Talisuna AO , Taylor WRJ , Temu EA , Thwing JI , Tine RCK , Tinto H , Tommasini S , Toure OA , Ursing J , Vaillant MT , Valentini G , Van den Broek I , Vugt MV , Ward SA , Winstanley PA , Yavo W , Yeka A , Zolia YM , Zongo I , WWARN Artemisinin based Combination Therapy (ACT) Africa Baseline Study Group . BMC Med 2015 13 212 BACKGROUND: Artemisinin-resistant Plasmodium falciparum has emerged in the Greater Mekong sub-region and poses a major global public health threat. Slow parasite clearance is a key clinical manifestation of reduced susceptibility to artemisinin. This study was designed to establish the baseline values for clearance in patients from Sub-Saharan African countries with uncomplicated malaria treated with artemisinin-based combination therapies (ACTs). METHODS: A literature review in PubMed was conducted in March 2013 to identify all prospective clinical trials (uncontrolled trials, controlled trials and randomized controlled trials), including ACTs conducted in Sub-Saharan Africa, between 1960 and 2012. Individual patient data from these studies were shared with the WorldWide Antimalarial Resistance Network (WWARN) and pooled using an a priori statistical analytical plan. Factors affecting early parasitological response were investigated using logistic regression with study sites fitted as a random effect. The risk of bias in included studies was evaluated based on study design, methodology and missing data. RESULTS: In total, 29,493 patients from 84 clinical trials were included in the analysis, treated with artemether-lumefantrine (n = 13,664), artesunate-amodiaquine (n = 11,337) and dihydroartemisinin-piperaquine (n = 4,492). The overall parasite clearance rate was rapid. The parasite positivity rate (PPR) decreased from 59.7 % (95 % CI: 54.5-64.9) on day 1 to 6.7 % (95 % CI: 4.8-8.7) on day 2 and 0.9 % (95 % CI: 0.5-1.2) on day 3. The 95th percentile of observed day 3 PPR was 5.3 %. Independent risk factors predictive of day 3 positivity were: high baseline parasitaemia (adjusted odds ratio (AOR) = 1.16 (95 % CI: 1.08-1.25); per 2-fold increase in parasite density, P <0.001); fever (>37.5 degreeC) (AOR = 1.50 (95 % CI: 1.06-2.13), P = 0.022); severe anaemia (AOR = 2.04 (95 % CI: 1.21-3.44), P = 0.008); areas of low/moderate transmission setting (AOR = 2.71 (95 % CI: 1.38-5.36), P = 0.004); and treatment with the loose formulation of artesunate-amodiaquine (AOR = 2.27 (95 % CI: 1.14-4.51), P = 0.020, compared to dihydroartemisinin-piperaquine). CONCLUSIONS: The three ACTs assessed in this analysis continue to achieve rapid early parasitological clearance across the sites assessed in Sub-Saharan Africa. A threshold of 5 % day 3 parasite positivity from a minimum sample size of 50 patients provides a more sensitive benchmark in Sub-Saharan Africa compared to the current recommended threshold of 10 % to trigger further investigation of artemisinin susceptibility. |
Success of Senegal's first nationwide distribution of long-lasting insecticide-treated nets to children under five - contribution toward universal coverage
Thwing JI , Perry RT , Townes DA , Diouf MB , Ndiaye S , Thior M . Malar J 2011 10 86 BACKGROUND: In 2009, the first national long-lasting insecticide-treated net (LLIN) distribution campaign in Senegal resulted in the distribution of 2.2 million LLINs in two phases to children aged 6-59 months. Door-to-door teams visited all households to administer vitamin A and mebendazole, and to give a coupon to redeem later for an LLIN. METHODS: A nationwide community-based two-stage cluster survey was conducted, with clusters selected within regions by probability proportional to size sampling, followed by GPS-assisted mapping, simple random selection of households in each cluster, and administration of a questionnaire using personal digital assistants (PDAs). The questionnaire followed the Malaria Indicator Survey format, with rosters of household members and bed nets, and questions on campaign participation. RESULTS: There were 3,280 households in 112 clusters representing 33,993 people. Most (92.1%) guardians of eligible children had heard about the campaign, the primary sources being health workers (33.7%), neighbours (26.2%), and radio (22.0%). Of eligible children, 82.4% received mebendazole, 83.8% received vitamin A, and 75.4% received LLINs. Almost all (91.4%) LLINs received during the campaign remained in the household; of those not remaining, 74.4% had been given away and none were reported sold. At least one insecticide-treated net (ITN) was present in 82.3% of all households, 89.2% of households with a child < 5 years and 57.5% of households without a child < 5 years. Just over half (52.4%) of ITNs had been received during the campaign. Considering possible indicators of universal coverage, 39.8% of households owned at least one ITN per two people, 21.6% owned at least one ITN per sleeping space and 34.7% of the general population slept under an ITN the night before the survey. In addition, 45.6% of children < 5 years, and 49.2% of pregnant women had slept under an ITN. CONCLUSIONS: The nationwide integrated LLIN distribution campaign allowed household ITN ownership of one or more ITNs to surpass the RBM target of 80% set for 2010, though additional distribution strategies are needed to reach populations missed by the targeted campaign and to reach the universal coverage targets of one ITN per sleeping space and 80% of the population using an ITN. |
Drug dispensing practices during implementation of artemisinin-based combination therapy at health facilities in rural Tanzania, 2002-2005
Thwing JI , Njau JD , Goodman C , Munkondya J , Kahigwa E , Bloland PB , Mkikima S , Mills A , Abdulla S , Kachur SP . Trop Med Int Health 2011 16 (3) 272-9 OBEJCTIVE: To assess the degree to which policy changes to artemisinin-based combination therapies (ACTs) as first-line treatment for uncomplicated malaria translate into effective ACT delivery. METHODS: Prospective observational study of drug dispensing practices at baseline and during the 3 years following introduction of ACT with sulfadoxine-pyrimethamine (SP) plus artesunate (AS) in Rufiji District, compared with two neighbouring districts where SP monotherapy remained the first-line treatment, was carried out. Demographic and dispensing data were collected from all patients at the dispensing units of selected facilities for 1 month per quarter, documenting a total of 271 953 patient encounters in the three districts. RESLTS: In Rufiji, the proportion of patients who received a clinical diagnosis of malaria increased from 47.6% to 57.0%. A majority (75.9%) of these received SP + AS during the intervention period. Of patients who received SP + AS, 94.6% received the correct dose of both. Among patients in Rufiji who received SP, 14.2% received SP monotherapy, and among patients who received AS, 0.3% received AS monotherapy. CONCLUSIONS: The uptake of SP + AS in Rufiji was rapid and sustained. Although some SP monotherapy occurred, AS monotherapy was rare, and most received the correct dose of both drugs. These results suggest that implementation of an artemisinin combination therapy, accompanied by training, job aids and assistance in stock management, can rapidly increase access to effective antimalarial treatment. |
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