Last data update: Jan 13, 2025. (Total: 48570 publications since 2009)
Records 1-30 (of 146 Records) |
Query Trace: Diallo K[original query] |
---|
Risk of clade II mpox associated with intimate and nonintimate close contact among men who have sex with men and transgender adults - United States, August 2022-July 2023
Chard AN , Dalton AF , Diallo AO , Moulia DL , Deputy NP , Zecca IB , Quilter LAS , Kachur RE , McCollum AM , Rowlands JV , Britton AN , Fisher R , Chai SJ , Licherdell E , Still WL , Morris AL , Castilho JL , Markus TM , Morrow AS , Danza P , Hansen AP , Ali SI , Wegner CW , Weber R , Betancourt GS , Zipprich J , Sutton M , Pathela P , Hawkins S , Wendel KA , Feldstein LR . MMWR Morb Mortal Wkly Rep 2024 73 (40) 896-902 A global outbreak of clade II mpox associated with sexual contact, disproportionately affecting gay, bisexual, and other men who have sex with men (MSM), has been ongoing since May 2022. Information on types of contact most associated with transmission is limited. This report used data from a multijurisdictional vaccine effectiveness case-control study of sexually active persons aged 18-49 years who identified as MSM or transgender, collected during August 2022-July 2023. Odds of mpox associated with selected types of intimate and nonintimate close contact with a person with mpox were estimated. Among 457 case-patients and 1,030 control patients who met minimum data requirements, 150 (32.8%) case-patients and 57 (5.5%) control patients reported close contact with a person with mpox and were included in this analysis. Adjusted odds of mpox were 5.4 times as high among those who reported having condomless receptive anal sex with a person with mpox, compared with participants who reported close contact with a person with mpox and no condomless receptive anal sex with that person (OR = 5.4; p = 0.031). Although the mpox vaccine is highly effective, vaccination coverage remains low; a multifaceted approach to prevention remains important and should include vaccination promotion, safer sex practices, and increasing awareness that mpox continues to circulate. |
Rotavirus vaccine effectiveness against severe acute gastroenteritis: 2009-2022
Diallo AO , Wikswo ME , Sulemana I , Sahni LC , Boom JA , Ramani S , Selvarangan R , Moffatt ME , Harrison CJ , Halasa N , Chappell J , Stewart L , Staat MA , Schlaudecker E , Quigley C , Klein EJ , Englund JA , Zerr DM , Weinberg GA , Szilagyi PG , Albertin C , Johnston SH , Williams JV , Michaels MG , Hickey RW , Curns AT , Honeywood M , Mijatovic-Rustempasic S , Esona MD , Bowen MD , Parashar UD , Gautam R , Mirza SA , Tate JE . Pediatrics 2024 BACKGROUND: Rotavirus was the leading cause of acute gastroenteritis among US children until vaccine introduction in 2006, after which, substantial declines in severe rotavirus disease occurred. We evaluated rotavirus vaccine effectiveness (VE) over 13 years (2009-2022). METHODS: We analyzed data from the New Vaccine Surveillance Network using a test-negative case-control design to estimate rotavirus VE against laboratory-confirmed rotavirus infections among children seeking care for acute gastroenteritis (≥3 diarrhea or ≥1 vomiting episodes within 24 hours) in the emergency department (ED) or hospital. Case-patients and control-patients were children whose stool specimens tested rotavirus positive or negative, respectively, by enzyme immunoassay or polymerase chain reaction assays. VE was calculated as (1-adjusted odds ratio)×100%. Adjusted odds ratios were calculated by multivariable unconditional logistic regression. RESULTS: Among 16 188 enrolled children age 8 to 59 months, 1720 (11%) tested positive for rotavirus. Case-patients were less often vaccinated against rotavirus than control-patients (62% versus 88%). VE for receiving ≥1 dose against rotavirus-associated ED visits or hospitalization was 78% (95% confidence interval [CI] 75%-80%). Stratifying by a modified Vesikari Severity Score, VE was 59% (95% CI 49%-67%), 80% (95% CI 77%-83%), and 94% (95% CI 90%-97%) against mild, moderately severe, and very severe disease, respectively. Rotavirus vaccines conferred protection against common circulating genotypes (G1P[8], G2P[4], G3P[8], G9P[8], and G12[P8]). VE was higher in children <3 years (73% to 88%); protection decreased as age increased. CONCLUSIONS: Rotavirus vaccines remain highly effective in preventing ED visits and hospitalizations in US children. |
Monovalent rotavirus vaccine effectiveness and long-term impact among children <5 years old in Antananarivo, Madagascar, 2010-2022
Raboba JL , Rahajamanana VL , Rakotojoelimaria HE , Masembe YV , Martin PR , Weldegebriel GG , Diallo AO , Burnett E , Tate JE , Parashar UD , Mwenda JM , Seheri M , Magagula N , Mphahlele J , Robinson AL . Vaccine 2024 42 (26) 126321 BACKGROUND: Monovalent rotavirus vaccine substantially reduced rotavirus disease burden after introduction (May 2014) in Madagascar. We examined the effectiveness and long-term impact on acute watery diarrhea and rotavirus-related hospitalizations among children <5 years old at two hospitals in Antananarivo, Madagascar (2010-2022). METHODS: We used a test-negative case-control design to estimate monovalent rotavirus vaccine effectiveness (VE) against laboratory-confirmed rotavirus hospitalizations among children age 6-23 months with documented vaccination status adjusted for year of symptom onset, rotavirus season, age group, nutritional status, and clinical severity. To evaluate the impact, we expanded to children age 0-59 months with acute watery diarrhea. First, we used admission logbook data to compare the proportion of all hospitalizations attributed to diarrhea in the pre-vaccine (January 2010-December 2013), transition period (January 2014-December 2014), and post-vaccine (January 2015-December 2022) periods. Second, we used active surveillance data (June 2013-May 2022) to describe rotavirus positivity and detected genotypes by vaccine introduction period and surveillance year (1 June-31 May). RESULT: Adjusted VE of at least one dose against hospitalization due to rotavirus diarrhea among children age 6-23 months was 61 % (95 % CI: -39 %-89 %). The annual median proportion of hospitalizations attributed to diarrhea declined from 28 % in the pre-vaccine to 10 % in the post-vaccine period. Rotavirus positivity among hospitalized children age 0-59 months with acute watery diarrhea was substantially higher during the pre-vaccine (59 %) than the post-vaccine (23 %) period. In the pre-vaccine period, G3P[8] (76 %) and G2P[4] (12 %) were the dominant genotypes detected. Although genotypes varied by surveillance year, G1P[8] and G2P[4] represented >50 % of the genotypes detected post-introduction. CONCLUSIONS: Rotavirus vaccine has been successfully implemented in Madagascar's routine childhood immunization program and had a large impact on rotavirus disease burden, supporting continued use of rotavirus vaccines in Madagascar. |
Two decades of molecular surveillance in Senegal reveal rapid changes in known drug resistance mutations over time
Ndiaye YD , Wong W , Thwing J , Schaffner SF , Brenneman KV , Tine A , Diallo MA , Deme AB , Sy M , Bei AK , Thiaw AB , Daniels R , Ndiaye T , Gaye A , Ndiaye IM , Toure M , Gadiaga N , Sene A , Sow D , Garba MN , Yade MS , Dieye B , Diongue K , Zoumarou D , Ndiaye A , Gomis JF , Fall FB , Ndiop M , Diallo I , Sene D , Macinnis B , Seck MC , Ndiaye M , Ngom B , Diedhiou Y , Mbaye AM , Ndiaye L , Sy N , Badiane AS , Hartl DL , Wirth DF , Volkman SK , Ndiaye D . Malar J 2024 23 (1) 205 BACKGROUND: Drug resistance in Plasmodium falciparum is a major threat to malaria control efforts. Pathogen genomic surveillance could be invaluable for monitoring current and emerging parasite drug resistance. METHODS: Data from two decades (2000-2020) of continuous molecular surveillance of P. falciparum parasites from Senegal were retrospectively examined to assess historical changes in malaria drug resistance mutations. Several known drug resistance markers and their surrounding haplotypes were profiled using a combination of single nucleotide polymorphism (SNP) molecular surveillance and whole genome sequence based population genomics. RESULTS: This dataset was used to track temporal changes in drug resistance markers whose timing correspond to historically significant events such as the withdrawal of chloroquine (CQ) and the introduction of sulfadoxine-pyrimethamine (SP) in 2003. Changes in the mutation frequency at Pfcrt K76T and Pfdhps A437G coinciding with the 2014 introduction of seasonal malaria chemoprevention (SMC) in Senegal were observed. In 2014, the frequency of Pfcrt K76T increased while the frequency of Pfdhps A437G declined. Haplotype-based analyses of Pfcrt K76T showed that this rapid increase was due to a recent selective sweep that started after 2014. DISCUSSION (CONCLUSION): The rapid increase in Pfcrt K76T is troubling and could be a sign of emerging amodiaquine (AQ) resistance in Senegal. Emerging AQ resistance may threaten the future clinical efficacy of artesunate-amodiaquine (ASAQ) and AQ-dependent SMC chemoprevention. These results highlight the potential of molecular surveillance for detecting rapid changes in parasite populations and stress the need to monitor the effectiveness of AQ as a partner drug for artemisinin-based combination therapy (ACT) and for chemoprevention. |
Impact of malaria diagnostic choice on monitoring of Plasmodium falciparum prevalence estimates in the Democratic Republic of the Congo and relevance to control programs in high-burden countries
Diallo AO , Banek K , Kashamuka MM , Bala JAM , Nkalani M , Kihuma G , Nseka TM , Atibu JL , Mahilu GE , McCormick L , White SJ , Sendor R , Sinai C , Keeler C , Herman C , Emch M , Sompwe E , Thwai KL , Dinglasan RR , Rogier E , Juliano JJ , Tshefu AK , Parr JB . PLOS Glob Public Health 2023 3 (7) e0001375 Malaria programs rely upon a variety of diagnostic assays, including rapid diagnostic tests (RDTs), microscopy, polymerase chain reaction (PCR), and bead-based immunoassays (BBA), to monitor malaria prevalence and support control and elimination efforts. Data comparing these assays are limited, especially from high-burden countries like the Democratic Republic of the Congo (DRC). Using cross-sectional and routine data, we compared diagnostic performance and Plasmodium falciparum prevalence estimates across health areas of varying transmission intensity to illustrate the relevance of assay performance to malaria control programs. Data and samples were collected between March-June 2018 during a cross-sectional household survey across three health areas with low, moderate, and high transmission intensities within Kinshasa Province, DRC. Samples from 1,431 participants were evaluated using RDT, microscopy, PCR, and BBA. P. falciparum parasite prevalence varied between diagnostic methods across all health areas, with the highest prevalence estimates observed in Bu (57.4-72.4% across assays), followed by Kimpoko (32.6-53.2%), and Voix du Peuple (3.1-8.4%). Using latent class analysis to compare these diagnostic methods against an "alloyed gold standard," the most sensitive diagnostic method was BBA in Bu (high prevalence) and Voix du Peuple (low prevalence), while PCR diagnosis was most sensitive in Kimpoko (moderate prevalence). RDTs were consistently the most specific diagnostic method in all health areas. Among 9.0 million people residing in Kinshasa Province in 2018, the estimated P. falciparum prevalence by microscopy, PCR, and BBA were nearly double that of RDT. Comparison of malaria RDT, microscopy, PCR, and BBA results confirmed differences in sensitivity and specificity that varied by endemicity, with PCR and BBA performing best for detecting any P. falciparum infection. Prevalence estimates varied widely depending on assay type for parasite detection. Inherent differences in assay performance should be carefully considered when using community survey and surveillance data to guide policy decisions. |
Case management of imported Crimean-Congo hemorrhagic fever, Senegal, July 2023
Gueye YB , Sall Y , Roka JL , Diagne I , Sow KD , Diallo A , Dièye PS , Diallo JP , Diop B , Pasi O . Emerg Infect Dis 2024 30 (4) 805-807 We report an imported Crimean-Congo hemorrhagic fever case in Senegal. The patient received PCR confirmation of virus infection 10 days after symptom onset. We identified 46 patient contacts in Senegal; 87.7% were healthcare professionals. Strengthening border crossing and community surveillance systems can help reduce the risks of infectious disease transmission. |
Predictors of severity and prolonged hospital stay of viral acute respiratory infections (ARI) among children under five years in Burkina Faso, 2016-2019
Ilboudo AK , Cissé A , Milucky J , Tialla D , Mirza SA , Diallo AO , Bicaba BW , Charlemagne KJ , Diagbouga PS , Owusu D , Waller JL , Talla-Nzussouo N , Charles MD , Whitney CG , Tarnagda Z . BMC Infect Dis 2024 24 (1) 331 BACKGROUND: Viruses are the leading etiology of acute respiratory infections (ARI) in children. However, there is limited knowledge on drivers of severe acute respiratory infection (SARI) cases involving viruses. We aimed to identify factors associated with severity and prolonged hospitalization of viral SARI among children < 5 years in Burkina Faso. METHODS: Data were collected from four SARI sentinel surveillance sites during October 2016 through April 2019. A SARI case was a child < 5 years with an acute respiratory infection with history of fever or measured fever ≥ 38 °C and cough with onset within the last ten days, requiring hospitalization. Very severe ARI cases required intensive care or had at least one danger sign. Oropharyngeal/nasopharyngeal specimens were collected and analyzed by multiplex real-time reverse-transcription polymerase chain reaction (rRT-PCR) using FTD-33 Kit. For this analysis, we included only SARI cases with rRT-PCR positive test results for at least one respiratory virus. We used simple and multilevel logistic regression models to assess factors associated with very severe viral ARI and viral SARI with prolonged hospitalization. RESULTS: Overall, 1159 viral SARI cases were included in the analysis after excluding exclusively bacterial SARI cases (n = 273)very severe viral ARI cases were common among children living in urban areas (AdjOR = 1.3; 95% CI: 1.1-1.6), those < 3 months old (AdjOR = 1.5; 95% CI: 1.1-2.3), and those coinfected with Klebsiella pneumoniae (AdjOR = 1.9; 95% CI: 1.2-2.2). Malnutrition (AdjOR = 2.2; 95% CI: 1.1-4.2), hospitalization during the rainy season (AdjOR = 1.71; 95% CI: 1.2-2.5), and infection with human CoronavirusOC43 (AdjOR = 3; 95% CI: 1.2-8) were significantly associated with prolonged length of hospital stay (> 7 days). CONCLUSION: Younger age, malnutrition, codetection of Klebsiella pneumoniae, and illness during the rainy season were associated with very severe cases and prolonged hospitalization of SARI involving viruses in children under five years. These findings emphasize the need for preventive actions targeting these factors in young children. |
Assessment of the performance of the plasma separation card for HIV-1 viral load monitoring in South Africa
Chimoyi L , Hans L , Oladimeji M , Kindra G , Diallo K , Ayalew K , Setswe GK , Carmona S . J Clin Microbiol 2024 e0164923 Scaling up of newer innovations that address the limitations of the dried blood spot and the logistics of plasma monitoring is needed. We employed a multi-site, cross-sectional assessment of the plasma separation card (PSC) on blood specimens collected from all consenting adults, assenting young and pediatric patients living with HIV from 10 primary healthcare clinics in South Africa. Venous blood for EDTA-plasma samples was collected and analyzed according to the standard of care assay, while collected capillary blood for the PSC samples was analyzed using the Roche COBAS AmpliPrep/Cobas TaqMan (CAP/CTM) HIV-1 Test at the National Reference laboratories. McNemar tests assessed the differences in concordance between the centrifuged plasma and dried plasma spots. The usability of PSC by blood spotting, PSC preparation, and pre-analytical work was assessed by collecting seven-point Likert-scale data from healthcare and laboratory workers. We enrolled 538 patients, mostly adults [n = 515, 95.7% (95% CI: 93.7%-97.1%)] and females [n = 322, 64.2% (95% CI: 60.0%-68.1%)]. Overall, 536 paired samples were collected using both PSC- and EDTA-plasma diagnostics, and 502 paired PSC- and EDTA-plasma samples assessed. Concordance between the paired samples was obtained for 446 samples. Analysis of these 446 paired samples at 1,000 copies per milliliter threshold yielded an overall sensitivity of 87.5% [95% CI: 73.2%-95.8%] and specificity of 99.3% [95% CI: 97.9%-99.8%]. Laboratory staff reported technical difficulties in most tasks. The usability of the PSC by healthcare workers was favorable. For policymakers to consider PSC scale-up for viral load monitoring, technical challenges around using PSC at the clinic and laboratory level need to be addressed. IMPORTANCE: Findings from this manuscript emphasize the reliability of the plasma separation card (PSC), a novel diagnostic method that can be implemented in healthcare facilities in resource-constrained settings. The agreement of the PSC with the standard of care EDTA plasma for viral load monitoring is high. Since the findings showed that these tests were highly specific, we recommend a scale-up of PSC in South Africa for diagnosis of treatment failure. |
Evaluating the performance of Plasmodium falciparum genetic metrics for inferring National Malaria Control Programme reported incidence in Senegal
Wong W , Schaffner SF , Thwing J , Seck MC , Gomis J , Diedhiou Y , Sy N , Ndiop M , Ba F , Diallo I , Sene D , Diallo MA , Ndiaye YD , Sy M , Sene A , Sow D , Dieye B , Tine A , Ribado J , Suresh J , Lee A , Battle KE , Proctor JL , Bever CA , MacInnis B , Ndiaye D , Hartl DL , Wirth DF , Volkman SK . Malar J 2024 23 (1) 68 BACKGROUND: Genetic surveillance of the Plasmodium falciparum parasite shows great promise for helping National Malaria Control Programmes (NMCPs) assess parasite transmission. Genetic metrics such as the frequency of polygenomic (multiple strain) infections, genetic clones, and the complexity of infection (COI, number of strains per infection) are correlated with transmission intensity. However, despite these correlations, it is unclear whether genetic metrics alone are sufficient to estimate clinical incidence. METHODS: This study examined parasites from 3147 clinical infections sampled between the years 2012-2020 through passive case detection (PCD) across 16 clinic sites spread throughout Senegal. Samples were genotyped with a 24 single nucleotide polymorphism (SNP) molecular barcode that detects parasite strains, distinguishes polygenomic (multiple strain) from monogenomic (single strain) infections, and identifies clonal infections. To determine whether genetic signals can predict incidence, a series of Poisson generalized linear mixed-effects models were constructed to predict the incidence level at each clinical site from a set of genetic metrics designed to measure parasite clonality, superinfection, and co-transmission rates. RESULTS: Model-predicted incidence was compared with the reported standard incidence data determined by the NMCP for each clinic and found that parasite genetic metrics generally correlated with reported incidence, with departures from expected values at very low annual incidence (< 10/1000/annual [‰]). CONCLUSIONS: When transmission is greater than 10 cases per 1000 annual parasite incidence (annual incidence > 10‰), parasite genetics can be used to accurately infer incidence and is consistent with superinfection-based hypotheses of malaria transmission. When transmission was < 10‰, many of the correlations between parasite genetics and incidence were reversed, which may reflect the disproportionate impact of importation and focal transmission on parasite genetics when local transmission levels are low. |
Evaluation of a dried blood and plasma collection device, SampleTanker(®), for HIV type 1 drug resistance genotyping in patients receiving antiretroviral therapy.
Diallo K , Lehotzky E , Zhang J , Zhou Z , de Rivera IL , Murillo WE , Nkengasong J , Sabatier J , Zhang G , Yang C . AIDS Res Hum Retroviruses 2014 30 (1) 67-73 Whatman 903 filter paper is the only filter paper that has been used for HIV drug resistance (HIVDR) genotyping in resource-limited settings. In this study, we evaluated another dried blood specimen collection device, termed SampleTanker(®) (ST), for HIVDR genotyping. Blood specimens from 123 antiretroviral therapy (ART)-experienced patients were used to prepare ST whole blood and ST plasma specimens; they were then stored at ambient temperature for 2 or 4 weeks. The remaining plasma specimens were stored at -80°C and used as frozen plasma controls. Frozen plasma viral load (VL) was determined using the Roche Amplicor HIV-1 Monitor test, v.1.5 and 50 specimens with VL ≥3.00 log10 copies/ml were genotyped using the broadly sensitive genotyping assay. The medium VL for the 50 frozen plasma specimens with VL ≥3.00 log10 was 3.58 log10 copies/ml (IQR: 3.32-4.11) and 96.0% (48/50) of them were genotyped. Comparing to frozen plasma specimens, significantly lower genotyping rates were obtained from ST whole blood (48.98% and 42.85%) and ST plasma specimens (36.0% and 36.0%) stored at ambient temperature for 2 and 4 weeks, respectively (p<0.001). Nucleotide sequence identity and resistance profile analyses between the matched frozen plasma and ST whole blood or ST plasma specimens revealed high nucleotide sequence identities and concordant resistance profiles (98.1% and 99.0%, and 96.6% and 98.9%, respectively). Our results indicate that with the current design, the ST may not be the ideal dried blood specimen collection device for HIVDR monitoring for ART patients in resource-limited settings. |
Use of supervision data to improve quality of care for malaria in pregnancy: Experience in six African countries
Wolf K , Mostel J , Oseni L , Gomez P , Kibuka T , Emerson C , Gutman JR , Malpass A , Youll S , Mukamba JY , Tchinda E , Achu D , Tjek P , Assa JL , Silue M , Tanoh MA , Kokrasset-Yah C , Babanawo F , Asiedu A , Komey M , Boateng P , Mabiria M , Ngindu A , Njiru P , Omar AH , Sidibe FA , Diallo C , Kamate B , Kone A , Elisha S , Maiga AD , Mayaki AI , Tidjani Issa Gana F , Tetteh G . Am J Trop Med Hyg 2023 Malaria in pregnancy (MiP) intervention coverage, especially intermittent preventive treatment in pregnancy (IPTp), lags behind other global malaria indicators. In 2020, across Africa, only 32% of eligible pregnant women received at least three IPTp doses, despite high antenatal care attendance. We conducted a secondary analysis of data collected during outreach, training, and supportive supervision visits from 2019 to 2020 to assess quality of care and explore factors contributing to providers' competence in providing IPTp, insecticide-treated nets, malaria case management, and respectful maternity care. Data were collected during observations of provider-patient interactions in six countries (Cameroon, Cote d'Ivoire, Ghana, Kenya, Mali, and Niger). Competency scores (i.e., composite scores of supervisory checklist observations) were calculated across three domains: MiP prevention, MiP treatment, and respectful maternity care. Scores are used to understand drivers of competency, rather than to assess individual health worker performance. Country-specific multilinear regressions were used to assess how competency score was influenced by commodity availability, training, provider gender and cadre, job aid availability, and facility type. Average competency scores varied across countries: prevention (44-90%), treatment (78-90%), and respectful maternity care (53-93%). The relative association of each factor with competency score varied. Commodity availability, training, and access to job aids correlated positively with competency in multiple countries. To improve MiP service quality, equitable access to training opportunities for different cadres, targeted training, and access to job aids and guidelines should be available for providers. Collection and analysis of routine supervision data can support tailored actions to improve quality MiP services. |
Seroprevalence to schistosoma soluble egg antigen among nomadic pastoralists residing in Northern Senegal
Seck MC , Badiane AS , Thwing J , Ndiaye M , Diongue K , Ndiaye IM , Diallo MA , Sy M , Gomis JF , Ndiaye T , Gaye A , Lee YM , Secor WE , Ndiaye D , Rogier E . J Parasitol 2023 109 (6) 580-587 Urinary and intestinal schistosomiasis are endemic in Senegal, with prevalence heterogeneous throughout the country. Because of their way of life, nomadic pastoralists are not typically included in epidemiological surveys, and data on the prevalence of schistosomiasis in Senegalese nomadic populations are largely non-existent. The purpose of this study was to determine the seroprevalence of schistosomiasis in Senegalese nomadic pastoralists. A modified snowball sampling survey was conducted among 1,467 nomadic pastoralists aged 6 mo and older in 5 districts in northern Senegal. Dried blood spots from participants of all ages and data regarding demographics were collected to assess IgG antibody responses against Schistosoma mansoni soluble egg antigen (SEA) using a bead-based multiplex assay. Out of 1,467 study subjects, 1,464 (99.8%) provided IgG serological data that cleared quality assurance. Of the participants with appropriate data, 56.6% were male, the median age was 22 yr, and 31.6% were under 15 yr of age. The overall anti-SEA IgG seroprevalence was 19.1% (95% confidence interval [CI]: 17.1-21.1%) with the highest estimates observed in Dagana (35.9%) and the lowest observed in Podor nomadic groups (3.4%). Antibody responses increased significantly with age except for the oldest age groups (>40 yr of age), which saw lower levels of antibody response compared to younger adults. When controlling for age and location by multivariate regression, the male sex was associated with a 2-fold greater odds of anti-SEA IgG seropositivity (aPOR: 2.0; 95% CI: 1.5-2.7). Serosurveys for anti-SEA IgG among nomadic peoples in northern Senegal found a substantial percentage of individuals with evidence for current or previous Schistosoma spp. infection with the highest levels of exposure in the district adjacent to the Diama dam along the Senegal River. With IgG prevalence increased by age except in the older adults, and the male sex significantly associated with seropositivity, these data point toward sex-associated behavioral practices and human environmental modification as risk factors for Schistosoma exposure. |
Evaluating the performance of Plasmodium falciparum genetics for inferring National Malaria Control Program reported incidence in Senegal
Wong W , Schaffner SF , Thwing J , Seck MC , Gomis J , Diedhiou Y , Sy N , Ndiop M , Ba F , Diallo I , Sene D , Diallo MA , Ndiaye YD , Sy M , Sene A , Sow D , Dieye B , Tine A , Ribado J , Suresh J , Lee A , Battle KE , Proctor JL , Bever CA , MacInnis B , Ndiaye D , Hartl DL , Wirth DF , Volkman SK . Res Sq 2023 Genetic surveillance of the Plasmodium falciparum parasite shows great promise for helping National Malaria Control Programs (NMCPs) assess parasite transmission. Genetic metrics such as the frequency of polygenomic (multiple strain) infections, genetic clones, and the complexity of infection (COI, number of strains per infection) are correlated with transmission intensity. However, despite these correlations, it is unclear whether genetic metrics alone are sufficient to estimate clinical incidence. Here, we examined parasites from 3,147 clinical infections sampled between the years 2012-2020 through passive case detection (PCD) across 16 clinic sites spread throughout Senegal. Samples were genotyped with a 24 single nucleotide polymorphism (SNP) molecular barcode that detects parasite strains, distinguishes polygenomic (multiple strain) from monogenomic (single strain) infections, and identifies clonal infections. To determine whether genetic signals can predict incidence, we constructed a series of Poisson generalized linear mixed-effects models to predict the incidence level at each clinical site from a set of genetic metrics designed to measure parasite clonality, superinfection, and co-transmission rates. We compared the model-predicted incidence with the reported standard incidence data determined by the NMCP for each clinic and found that parasite genetic metrics generally correlated with reported incidence, with departures from expected values at very low annual incidence (<10/1000/annual [‰]). When transmission is greater than 10 cases per 1000 annual parasite incidence (annual incidence >10 ‰), parasite genetics can be used to accurately infer incidence and is consistent with superinfection-based hypotheses of malaria transmission. When transmission was <10 ‰, we found that many of the correlations between parasite genetics and incidence were reversed, which we hypothesize reflects the disproportionate impact of importation and focal transmission on parasite genetics when local transmission levels are low. |
More frequent HIV viral load testing with point-of-care tests detects elevated viral load earlier in postpartum HIV-positive women in a randomized controlled trial in two clinics in Johannesburg, South Africa
Fairlie L , Sawry S , Pals S , Sherman G , Williamson D , Le Roux J , Ngeno B , Berrie L , Diallo K , Cox MH , Mogashoa M , Chersich M , Modi S . J Acquir Immune Defic Syndr 2023 94 (5) 412-420 BACKGROUND: Elevated maternal HIV viral load (VL) increases vertical transmission risk for breastfeeding children. This randomized controlled trial in Johannesburg primarily evaluated whether 3-monthly point-of-care testing, with laboratory-based standard-of-care testing (arm 2), compared with 6-monthly laboratory-based VL testing (arm 1) in postpartum women living with HIV receiving first-line tenofovir-emtricitabine-efavirenz antiretroviral treatment improved VL suppression, factors associated with nonsuppression, and drug resistance in those with virologic failure. METHODS: Mother-child pairs were enrolled July 2018-April 2019 at the child's 6/10/14-week clinic visit. Women were randomized 1:1 to arm 1 or 2. Trained staff performed point-of-care VL testing using the Cepheid's Xpert HIV-1 VL assay. We fitted a generalized linear mixed model with VL suppression (<50 copies/mL (cps/mL) and <1000 cps/mL) at enrollment and 6, 12, and 18 months postpartum as the outcome and indicator variables for time, study site, study arm, and interaction variables. The final model tested for a difference by study arm, pooling across time points. RESULTS: Of 405 women enrolled (204 arm 1 and 201 arm 2), 249 (61%) remained in follow-up through 18 months. There was no difference in VL suppression between arms at 6, 12, or 18 months. VL suppression rate (<50 cps/mL) at 18 months was 64.8% in arm 1 and 63.0% in arm 2 (P = 0.27). On bivariate analysis, there was an association with late antenatal booking and being in arm 2 for nonsuppressed VL, but no significant association with breastfeeding. HIV drug resistance was found in 12 of 23 participants (52.2%). CONCLUSION: We found no significant difference in VL suppression with more frequent VL testing in postpartum women living with HIV receiving first-line efavirenz-based antiretroviral treatment. |
Malaria surveillance reveals parasite relatedness, signatures of selection, and correlates of transmission across Senegal
Schaffner SF , Badiane A , Khorgade A , Ndiop M , Gomis J , Wong W , Ndiaye YD , Diedhiou Y , Thwing J , Seck MC , Early A , Sy M , Deme A , Diallo MA , Sy N , Sene A , Ndiaye T , Sow D , Dieye B , Ndiaye IM , Gaye A , Ndiaye A , Battle KE , Proctor JL , Bever C , Fall FB , Diallo I , Gaye S , Sene D , Hartl DL , Wirth DF , MacInnis B , Ndiaye D , Volkman SK . Nat Commun 2023 14 (1) 7268 We here analyze data from the first year of an ongoing nationwide program of genetic surveillance of Plasmodium falciparum parasites in Senegal. The analysis is based on 1097 samples collected at health facilities during passive malaria case detection in 2019; it provides a baseline for analyzing parasite genetic metrics as they vary over time and geographic space. The study's goal was to identify genetic metrics that were informative about transmission intensity and other aspects of transmission dynamics, focusing on measures of genetic relatedness between parasites. We found the best genetic proxy for local malaria incidence to be the proportion of polygenomic infections (those with multiple genetically distinct parasites), although this relationship broke down at low incidence. The proportion of related parasites was less correlated with incidence while local genetic diversity was uninformative. The type of relatedness could discriminate local transmission patterns: two nearby areas had similarly high fractions of relatives, but one was dominated by clones and the other by outcrossed relatives. Throughout Senegal, 58% of related parasites belonged to a single network of relatives, within which parasites were enriched for shared haplotypes at known and suspected drug resistance loci and at one novel locus, reflective of ongoing selection pressure. |
Social Contact Patterns and Implications for Infectious Disease Transmission: A Systematic Review and Meta-Analysis of Contact Surveys (preprint)
Mousa A , Winskill P , Watson OJ , Ratmann O , Monod M , Ajelli M , Diallo A , Dodd PJ , Grijalva CG , Kiti MC , Krishnan A , Kumar R , Kumar S , Kwok KO , Lanata CF , Le Polain de Waroux O , Leung K , Mahikul W , Melegaro A , Morrow CD , Mossong J , Neal EF , Nokes DJ , Pan-Ngum W , Potter GE , Russell FM , Saha S , Sugimoto JD , Wei WI , Wood RR , Wu JT , Zhang J , Walker PG , Whittaker C . medRxiv 2021 BACKGROUND: Transmission of respiratory pathogens such as SARS-CoV-2 depends on patterns of contact and mixing across populations. Understanding this is crucial to predict pathogen spread and the effectiveness of control efforts. Most analyses of contact patterns to date have focussed on high-income settings. METHODS: Here, we conduct a systematic review and individual-participant meta-analysis of surveys carried out in low- and middle-income countries and compare patterns of contact in these settings to surveys previously carried out in high-income countries. Using individual-level data from 28,503 participants and 413,069 contacts across 27 surveys we explored how contact characteristics (number, location, duration and whether physical) vary across income settings. RESULTS: Contact rates declined with age in high- and upper-middle-income settings, but not in low-income settings, where adults aged 65+ made similar numbers of contacts as younger individuals and mixed with all age-groups. Across all settings, increasing household size was a key determinant of contact frequency and characteristics, but low-income settings were characterised by the largest, most intergenerational households. A higher proportion of contacts were made at home in low-income settings, and work/school contacts were more frequent in high-income strata. We also observed contrasting effects of gender across income-strata on the frequency, duration and type of contacts individuals made. CONCLUSIONS: These differences in contact patterns between settings have material consequences for both spread of respiratory pathogens, as well as the effectiveness of different non-pharmaceutical interventions. FUNDING: This work is primarily being funded by joint Centre funding from the UK Medical Research Council and DFID (MR/R015600/1). |
Two decades of molecular surveillance in Senegal reveal changes in known drug resistance mutations associated with historical drug use and seasonal malaria chemoprevention (preprint)
Ndiaye YD , Wong W , Thwing J , Schaffner SS , Tine A , Diallo MA , Deme A , Sy M , Bei AK , Thiaw AB , Daniels R , Ndiaye T , Gaye A , Ndiaye IM , Toure M , Gadiaga N , Sene A , Sow D , Garba MN , Yade MS , Dieye B , Diongue K , Zoumarou D , Ndiaye A , Gomis J , Fall FB , Ndiop M , Diallo I , Sene D , Macinnis B , Seck MC , Ndiaye M , Badiane AS , Hartl DL , Volkman SK , Wirth DF , Ndiaye D . medRxiv 2023 26 Drug resistance in Plasmodium falciparum is a major threat to malaria control efforts. We analyzed data from two decades (2000-2020) of continuous molecular surveillance of P. falciparum parasite strains in Senegal to determine how historical changes in drug administration policy may have affected parasite evolution. We profiled several known drug resistance markers and their surrounding haplotypes using a combination of single nucleotide polymorphism (SNP) molecular surveillance and whole-genome sequence (WGS) based population genomics. We observed rapid changes in drug resistance markers associated with the withdrawal of chloroquine and introduction of sulfadoxine-pyrimethamine in 2003. We also observed a rapid increase in Pfcrt K76T and decline in Pfdhps A437G starting in 2014, which we hypothesize may reflect changes in resistance or fitness caused by seasonal malaria chemoprevention (SMC). Parasite populations evolve rapidly in response to drug use, and SMC preventive efficacy should be closely monitored. Copyright The copyright holder for this preprint is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY-NC-ND 4.0 International license. |
Malaria surveillance reveals parasite relatedness, signatures of selection, and correlates of transmission across Senegal (preprint)
Schaffner SF , Badiane A , Khorgade A , Ndiop M , Gomis J , Wong W , Ndiaye YD , Diedhiou Y , Thwing J , Seck MC , Early A , Sy M , Deme A , Diallo MA , Sy N , Sene A , Ndiaye T , Sow D , Dieye B , Ndiaye IM , Gaye A , Ndiaye A , Battle KE , Proctor JL , Bever C , Fall FB , Diallo I , Gaye S , Sene D , Hartl DL , Wirth DF , MacInnis B , Ndiaye D , Volkman SK . medRxiv 2023 17 Parasite genetic surveillance has the potential to play an important role in malaria control. We describe here an analysis of data from the first year of an ongoing, nationwide program of genetic surveillance of Plasmodium falciparum parasites in Senegal, intended to provide actionable information for malaria control efforts. Looking for a good proxy for local malaria incidence, we found that the best predictor was the proportion of polygenomic infections (those with multiple genetically distinct parasites), although that relationship broke down at very low incidence. The proportion of closely related parasites in a site was more weakly correlated with incidence while the local genetic diversity was uninformative. Study of related parasites indicated their potential for discriminating local transmission patterns: two nearby study areas had similarly high fractions of relatives, but one area was dominated by clones and the other by outcrossed relatives. Throughout the country, most related parasites proved to belong to a single network of relatives, within which parasites were enriched for shared haplotypes at known and suspected drug resistance loci as well as at one novel locus, reflective of ongoing selection pressure. Copyright The copyright holder for this preprint is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. All rights reserved. No reuse allowed without permission. |
Evaluation of the Performance of the Routine Epidemiological Surveillance System in the Health District of Tambacounda (Senegal) in 2020 (preprint)
Gadiaga T , Ba MF , Sagna S , Cisse B , Diallo A , Ndiaye S , Diop B , Ndiaye M , Ndoye B , Ba MS , Sall Y , Sougou NM , Diegane Tine JA , Mbacke Leye MM . medRxiv 2022 02 Introduction: Epidemiological surveillance (ES) which is a continuous systematic process of data collection, analysis and interpretation for decision-making is of paramount importance for a good health system. Thus, to contribute to the improvement of the health system in Senegal, a study of the functioning of the routine epidemiological surveillance system was conducted in Tambacounda from S1 to S53 of the year 2020. Methodology: A descriptive and analytical cross-sectional study was conducted from 1 to 17 July 2021. Comprehensive recruitment of the district's 44 health care points was carried out. Data collection was carried out through a questionnaire prepared, pre-tested and administered to the 44 heads of public and non-public health facilities. The analyses were carried out with R software version 4.0.5. Result(s): Of the 44 health facilities surveyed, 64% were public and 36% were non-public. The completeness and timeliness of the data were 100% and 97.5%, respectively. Suspected cases of tuberculosis were the most reported. For the providers surveyed (n=44), only 65.9% had knowledge of disease under epidemiological surveillance (DUES) and 93.2% managed suspected cases. On-site data analysis is only performed by 20.5% of providers. Only 38.6% of the service delivery point (SDP) had a health area card and the ES was under the responsibility of 77.3% of the paramedics. The training of ES officials was effective for only 45.5% of them. Despite the availability of dry tubes (69.8%), only 29.5% of PSD had COVID sampling equipment. The contribution of local authorities and technical and financial partners (TFP) to the SE was 22.7% and 29.5% respectively. There was a statistically significant link between public SDP with knowledge of DUES (p <0.001), display of case definitions (p <0.001), feedback of reported cases, knowledge of indicators (p <0.001), existence of a health area map (p <0.001), advocacy with authorities (p=0.003), staff training (p=0.002), availability of DUES vaccines (p <0.001), availability of notification form (p <0.001) and partner contribution to ES activities. Conclusion(s): Staff training, regular monitoring of ES activities with greater involvement of nonpublic structures, and the availability of inputs applied to the six pillars of the health system, are essential elements on which action must be taken. for an efficient ES system in the Tambacounda health district for the benefit of the country's health system. Copyright The copyright holder for this preprint is the author/funder, who has granted medRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY 4.0 International license. |
Characteristics and prescribing patterns of clinicians waivered to prescribe buprenorphine for opioid use disorder before and after release of new practice guidelines
Jones CM , Olsen Y , Ali MM , Sherry TB , McAninch J , Creedon T , Juliana P , Jacobus-Kantor L , Baillieu R , Diallo MM , Thomas A , Gandotra N , Sokolowska M , Ling S , Compton W . JAMA Health Forum 2023 4 (7) e231982 IMPORTANCE: In April 2021, the US Department of Health and Human Services (HHS) released practice guidelines exempting educational requirements to obtain a Drug Addiction Treatment Act (DATA) waiver to treat up to 30 patients with opioid use disorder with buprenorphine. OBJECTIVE: To compare demographic and practice characteristics of clinicians who received traditional DATA waivers before and after release of the education-exempted HHS practice guidelines and those who were approved under the guidelines. DESIGN, SETTING, AND PARTICIPANTS: This survey study was conducted electronically from February 1 to March 1, 2022. Eligible survey recipients were US clinicians who obtained an initial DATA waiver between April 2020 and November 2021. EXPOSURE: DATA waiver approval pathway. MAIN OUTCOME AND MEASURES: The outcomes were clinician demographic and practice characteristics, buprenorphine prescribing barriers, and strategies to treat patients with opioid use disorder, measured using χ2 tests and z tests to assess for differences among the waivered groups. RESULTS: Of 23 218 eligible clinicians, 4519 (19.5%) responded to the survey. This analysis was limited to 2736 respondents with a 30-patient limit at the time of survey administration who identified their DATA waiver approval pathway. Among these respondents, 1365 (49.9%; female, 831 [61.9%]; male, 512 [38.1%]) received their DATA waiver prior to the education-exempted practice guidelines (prior DATA waiver), 550 (20.1%; female, 343 [63.4%]; male, 198 [36.6%]) received their waiver after guidelines were released but met education requirements (concurrent DATA waiver), and 821 (30.0%; female, 396 [49.2%]; male, 409 [50.8%]) received the waiver under the education-exempted guidelines (practice guidelines). Among practice guidelines clinicians, 500 (60.9%) reported that traditional DATA waiver educational requirements were a reason for not previously obtaining a waiver. Demographic and practice characteristics differed by waiver approval type. Across all groups, a large minority had not prescribed buprenorphine since obtaining a waiver (prior DATA waiver, 483 [35.7%]; concurrent DATA waiver, 226 [41.2%]; practice guidelines, 359 [44.3%]; P < .001). Clinicians who prescribed buprenorphine in the past 6 months reported treating few patients in an average month: 27 practice guidelines clinicians (6.0%) prescribed to 0 patients and 338 (75.1%) to 1 to 4 patients compared with 16 (2.2%) and 435 (59.9%) for prior and 11 (3.6%) and 166 (55.0%) for concurrent DATA waiver clinicians, respectively (P < .001). Across waiver types, clinicians reported multiple challenges to buprenorphine prescribing. CONCLUSIONS AND RELEVANCE: In this survey of DATA-waivered clinicians, clinician- and systems-level challenges that limit buprenorphine prescribing were observed, even among clinicians approved under the education-exempted guidelines pathway. The findings suggest that as implementation of legislation removing the DATA waiver begins, addressing these barriers could be essential to increasing buprenorphine access. |
Estimated effectiveness of JYNNEOS vaccine in preventing Mpox: A Multijurisdictional Case-Control Study - United States, August 19, 2022-March 31, 2023
Dalton AF , Diallo AO , Chard AN , Moulia DL , Deputy NP , Fothergill A , Kracalik I , Wegner CW , Markus TM , Pathela P , Still WL , Hawkins S , Mangla AT , Ravi N , Licherdell E , Britton A , Lynfield R , Sutton M , Hansen AP , Betancourt GS , Rowlands JV , Chai SJ , Fisher R , Danza P , Farley M , Zipprich J , Prahl G , Wendel KA , Niccolai L , Castilho JL , Payne DC , Cohn AC , Feldstein LR . MMWR Morb Mortal Wkly Rep 2023 72 (20) 553-558 As of March 31, 2023, more than 30,000 monkeypox (mpox) cases had been reported in the United States in an outbreak that has disproportionately affected gay, bisexual, and other men who have sex with men (MSM) and transgender persons (1). JYNNEOS vaccine (Modified Vaccinia Ankara vaccine, Bavarian Nordic) was approved by the Food and Drug Administration (FDA) in 2019 for the prevention of smallpox and mpox via subcutaneous injection as a 2-dose series (0.5 mL per dose, administered 4 weeks apart) (2). To expand vaccine access, an Emergency Use Authorization was issued by FDA on August 9, 2022, for dose-sparing intradermal injection of JYNNEOS as a 2-dose series (0.1 mL per dose, administered 4 weeks apart) (3). Vaccination was available to persons with known or presumed exposure to a person with mpox (postexposure prophylaxis [PEP]), as well as persons at increased risk for mpox or who might benefit from vaccination (preexposure mpox prophylaxis [PrEP]) (4). Because information on JYNNEOS vaccine effectiveness (VE) is limited, a matched case-control study was conducted in 12 U.S. jurisdictions,(†) including nine Emerging Infections Program sites and three Epidemiology and Laboratory Capacity sites,(§) to evaluate VE against mpox among MSM and transgender adults aged 18-49 years. During August 19, 2022-March 31, 2023, a total of 309 case-patients were matched to 608 control patients. Adjusted VE was 75.2% (95% CI = 61.2% to 84.2%) for partial vaccination (1 dose) and 85.9% (95% CI = 73.8% to 92.4%) for full vaccination (2 doses). Adjusted VE for full vaccination by subcutaneous, intradermal, and heterologous routes of administration was 88.9% (95% CI = 56.0% to 97.2%), 80.3% (95% CI = 22.9% to 95.0%), and 86.9% (95% CI = 69.1% to 94.5%), respectively. Adjusted VE for full vaccination among immunocompromised participants was 70.2% (95% CI = -37.9% to 93.6%) and among immunocompetent participants was 87.8% (95% CI = 57.5% to 96.5%). JYNNEOS is effective at reducing the risk for mpox. Because duration of protection of 1 versus 2 doses remains unknown, persons at increased risk for mpox exposure should receive the 2-dose series as recommended by the Advisory Committee on Immunization Practices (ACIP),(¶) regardless of administration route or immunocompromise status. |
Mosquito microevolution drives Plasmodium falciparum dynamics.
Gildenhard M , Rono EK , Diarra A , Boissière A , Bascunan P , Carrillo-Bustamante P , Camara D , Krüger H , Mariko M , Mariko R , Mireji P , Nsango SE , Pompon J , Reis Y , Rono MK , Seda PB , Thailayil J , Traorè A , Yapto CV , Awono-Ambene P , Dabiré RK , Diabaté A , Masiga D , Catteruccia F , Morlais I , Diallo M , Sangare D , Levashina EA . Nat Microbiol 2019 4 (6) 941-947 Malaria, a major cause of child mortality in Africa, is engendered by Plasmodium parasites that are transmitted by anopheline mosquitoes. Fitness of Plasmodium parasites is closely linked to the ecology and evolution of its anopheline vector. However, whether the genetic structure of vector populations impacts malaria transmission remains unknown. Here, we describe a partitioning of the African malaria vectors into generalists and specialists that evolve along ecological boundaries. We next identify the contribution of mosquito species to Plasmodium abundance using Granger causality tests for time-series data collected over two rainy seasons in Mali. We find that mosquito microevolution, defined by changes in the genetic structure of a population over short ecological timescales, drives Plasmodium dynamics in nature, whereas vector abundance, infection prevalence, temperature and rain have low predictive values. Our study demonstrates the power of time-series approaches in vector biology and highlights the importance of focusing local vector control strategies on mosquito species that drive malaria dynamics. |
Resistance is common in paediatric patients failing ART in South Africa
Hunt GM , Yousif M , Levin L , Ledwaba J , Steegen K , Kufa T , Zwane H , Kalimashe M , Kana V , Aynalem G , Perlman J , Ayalew K , Kindra G , Diallo K , Carmona S , Sherman G , Raizes EJ . J Antimicrob Chemother 2023 78 (5) 1160-1167 BACKGROUND: Minimal data exist on HIV drug resistance patterns and prevalence among paediatric patients failing ART in resource-limited settings. We assessed levels of HIV drug resistance in children with virological failure. METHODS: This cross-sectional study, performed from March 2017 to March 2019 in South Africa, enrolled HIV-positive children aged ≤19 years, receiving ART through public health facilities with recent evidence suggestive of virological failure (at least one viral load ≥1000 copies/mL), across 45 randomly selected high-volume clinics from all nine provinces. Resistance genotyping was performed using next-generation sequencing technologies. Descriptive analysis taking into account survey design was used to determine outcomes. RESULTS: Among 899 participants enrolled, the adjusted proportion of HIV drug resistance among children with virological failure was 87.5% (95% CI 83.0%-90.9%). Resistance to NNRTIs was detected in 77.4% (95% CI 72.5%-81.7%) of participants, and resistance to NRTIs in 69.5% (95% CI 62.9%-75.4%) of participants. Overall, resistance to PIs was detected in 7.7% (95% CI 4.4%-13.0%) of children. CONCLUSIONS: HIV drug resistance was highly prevalent in paediatric patients failing ART in South Africa, with 9 in 10 patients harbouring resistance to NNRTIs and/or NRTIs. PI-based regimens are predicted to be highly efficacious in achieving virological suppression amongst patients failing NNRTI-based regimens. Scaling up resistance testing amongst patients would facilitate access to second- and third-line regimens in South Africa. |
Use of epidemiology surge support to enhance robustness and expand capacity of SARS-CoV-2 pandemic response, South Africa
Taback-Esra R , Morof D , Briggs-Hagen M , Savva H , Mthethwa S , Williams D , Drummond J , Rothgerber N , Smith M , McMorrow M , Ndlovu M , Adelekan A , Kindra G , Olivier J , Mpofu N , Motlhaoleng K , Khuzwayo L , Makapela D , Manjengwa P , Ochieng A , Porter S , Grund J , Diallo K , Lacson R . Emerg Infect Dis 2022 28 (13) S177-s180 As COVID-19 cases increased during the first weeks of the pandemic in South Africa, the National Institute of Communicable Diseases requested assistance with epidemiologic and surveillance expertise from the US Centers for Disease Control and Prevention South Africa. By leveraging its existing relationship with the National Institute of Communicable Diseases for >2 months, the US Centers for Disease Control and Prevention South Africa supported data capture and file organization, data quality reviews, data analytics, laboratory strengthening, and the development and review of COVID-19 guidance This case study provides an account of the resources and the technical, logistical, and organizational capacity leveraged to support a rapid response to the COVID-19 pandemic in South Africa. |
HIV viral load scale-up among children and adolescents: Trends in viral load suppression, sample type and processing in 7 PEPFAR countries, 2015-2018
Hrapcak S , Pals S , Itoh M , Peters N , Carpenter D , Hackett S , Prao AK , Adje-Toure C , Eboi E , Mutisya I , Nyabiage Omoto L , Ondondo RO , Bowen N , Nyanya W , Kayira D , Kaba MD , Mwenda R , Deus MI , Almeida J , Cuco RMM , Boylan A , Beard S , Ashikoto S , van Rooyen G , Kindra G , Diallo K , Carmona S , Nazziwa E , Mwangi C , Ntale J , Ssewanyana I , Nabadda SN , Nabukenya M , Ellenberger D , Rivadeneira E . Pediatr Infect Dis J 2023 42 (4) e102-e104 HIV-positive children and adolescents face gaps in viral load (VL) testing. To understand trends in pediatric/adolescent VL testing, 7 countries collected data from Laboratory Information Management Systems. Results showed increasing proportion of VL tests done through dried blood spot (DBS) and decreased sample rejection rates for DBS compared with plasma, supporting use of DBS VL when skilled phlebotomy is unavailable. |
Retention and predictors of attrition among HIV-infected children on antiretroviral therapy in Cte d'Ivoire between 2012 and 2016
Touré F , Etheredge GD , Brennan C , Parris K , Diallo MO , Ouffoue AF , Ekra A , Prao H , Assamoua NV , Gnongoue C , Kone F , Koffi C , Kamagaté F , Rivadeneira E , Carpenter D . Pediatr Infect Dis J 2023 42 (4) 299-304 BACKGROUND: An estimated 21,000 children aged 0-14 years were living with HIV in Côte d'Ivoire in 2020, of whom only 49% have been diagnosed and are receiving antiretroviral therapy (ART). Retention in HIV care and treatment is key to optimize clinical outcomes. We evaluated pediatric retention in select care and treatment centers (CTCs) in Côte d'Ivoire. METHODS: We retrospectively reviewed medical records using 2-stage cluster sampling for children under 15 years initiated on ART between 2012 and 2016. Kaplan-Meier time-to-event analysis was done to estimate cumulative attrition rates per total person-years of observation. Cox proportional hazard regression was performed to identify factors associated with attrition. RESULTS: A total of 1198 patient records from 33 CTCs were reviewed. Retention at 12, 24, 36, 48 and 60 months after ART initiation was 91%, 84%, 74%, 72% and 70%, respectively. A total of 309 attrition events occurred over 3169 person-years of follow-up [266 children were lost to follow-up (LTFU), 29 transferred to another facility and 14 died]. LTFU determinants included attending a "public-private" CTC [adjusted hazard ratio (aHR) 6.05; 95% confidence interval (CI): 4.23-8.65], receiving care at a CTC without an on-site laboratory (aHR: 4.01; 95% CI: 1.70-9.46) or attending a CTC without an electronic medical record (EMR) system (aHR: 2.22; 95% CI: 1.59-3.12). CONCLUSIONS: In Cote d'Ivoire, patients attending a CTC that is public-private, does not have on-site laboratory or EMR system were likely to be LTFU. Decentralization of laboratory services and scaling use of EMR systems could help to improve pediatric retention. |
Improving water, sanitation, and hygiene (WASH), with a focus on hand hygiene, globally for community mitigation of COVID-19
Berendes D , Martinsen A , Lozier M , Rajasingham A , Medley A , Osborne T , Trinies V , Schweitzer R , Prentice-Mott G , Pratt C , Murphy J , Craig C , Lamorde M , Kesande M , Tusabe F , Mwaki A , Eleveld A , Odhiambo A , Ngere I , Kariuki Njenga M , Cordon-Rosales C , Contreras APG , Call D , Ramay BM , Ramm RES , Paulino CJT , Schnorr CD , Aubin M , Dumas D , Murray KO , Bivens N , Ly A , Hawes E , Maliga A , Morazan GH , Manzanero R , Morey F , Maes P , Diallo Y , Ilboudo M , Richemond D , Hattab OE , Oger PY , Matsuhashi A , Nsambi G , Antoine J , Ayebare R , Nakubulwa T , Vosburgh W , Boore A , Herman-Roloff A , Zielinski-Gutierrez E , Handzel T . PLOS Water 2022 1 (6) Continuity of key water, sanitation, and hygiene (WASH) infrastructure and WASH practices-for example, hand hygiene-are among several critical community preventive and mitigation measures to reduce transmission of infectious diseases, including COVID-19 and other respiratory diseases. WASH guidance for COVID-19 prevention may combine existing WASH standards and new COVID-19 guidance. Many existing WASH tools can also be modified for targeted WASH assessments during the COVID-19 pandemic. We partnered with local organizations to develop and deploy tools to assess WASH conditions and practices and subsequently implement, monitor, and evaluate WASH interventions to mitigate COVID-19 in low- and middle-income countries in Latin America and the Caribbean and Africa, focusing on healthcare, community institution, and household settings and hand hygiene specifically. Employing mixed-methods assessments, we observed gaps in access to hand hygiene materials specifically despite most of those settings having access to improved, often onsite, water supplies. Across countries, adherence to hand hygiene among healthcare providers was about twice as high after patient contact compared to before patient contact. Poor or non-existent management of handwashing stations and alcohol-based hand rub (ABHR) was common, especially in community institutions. Markets and points of entry (internal or external border crossings) represent congregation spaces, critical for COVID-19 mitigation, where globally-recognized WASH standards are needed. Development, evaluation, deployment, and refinement of new and existing standards can help ensure WASH aspects of community mitigation efforts that remain accessible and functional to enable inclusive preventive behaviors. |
Optimising courier specimen collection time improves patient access to HIV viral load testing in South Africa
Girdwood SJ , Crompton T , Cassim N , Olsen F , Sejake P , Diallo K , Berrie L , Chimhamhiwa D , Stevens W , Nichols B . Afr J Lab Med 2022 11 (1) 1725 BACKGROUND: South Africa uses a courier network for transporting specimens to public laboratories. After the daily collection of specimens from the facility by the courier, patients not yet attended to are unlikely to receive same-day blood draws, potentially inhibiting access to viral load (VL) testing for HIV patients. OBJECTIVE: We aimed to design an optimised courier network and assess whether this improves VL testing access. METHODS: We optimised the specimen transport network in South Africa for 4046 facilities (November 2019). For facilities with current specimen transport times (n = 356), we assessed the relationship between specimen transport time and VL testing access (number of annual VL tests per antiretroviral treatment patient) using regression analysis. We compared our optimised transport times with courier collection times to determine the change in access to same-day blood draws. RESULTS: The number of annual VL tests per antiretroviral treatment patient (1.14, standard deviation: 0.02) was higher at facilities that had courier collection after 13:36 (the average latest collection time) than those that had their last collection before 13:36 (1.06, standard deviation: 0.03), even when adjusted for facility size. Through network optimisation, the average time for specimen transport was delayed to 14:35, resulting in a 6% - 13% increase in patient access to blood draws. CONCLUSION: Viral load testing access depends on the time of courier collection at healthcare facilities. Simple solutions are frequently overlooked in the quest to improve healthcare. We demonstrate how simply changing specimen transportation timing could markedly improve access to VL testing. |
Lessons learned for surveillance system strengthening through capacity building and partnership engagement in post-Ebola Guinea, 2015-2019
Hemingway-Foday JJ , Diallo BI , Compaore S , Bah S , Keita S , Diallo IT , Martel LD , Standley CJ , Bah MB , Bah M , Camara D , Kaba AK , Keita L , Kone M , Reynolds E , Souare O , Stolka KB , Tchwenko S , Wone A , Worrell MC , MacDonald PDM . Front Public Health 2022 10 715356 The 2014-2016 Ebola outbreak in Guinea revealed systematic weaknesses in the existing disease surveillance system, which contributed to delayed detection, underreporting of cases, widespread transmission in Guinea and cross-border transmission to neighboring Sierra Leone and Liberia, leading to the largest Ebola epidemic ever recorded. Efforts to understand the epidemic's scale and distribution were hindered by problems with data completeness, accuracy, and reliability. In 2017, recognizing the importance and usefulness of surveillance data in making evidence-based decisions for the control of epidemic-prone diseases, the Guinean Ministry of Health (MoH) included surveillance strengthening as a priority activity in their post-Ebola transition plan and requested the support of partners to attain its objectives. The U.S. Centers for Disease Control and Prevention (US CDC) and four of its implementing partners-International Medical Corps, the International Organization for Migration, RTI International, and the World Health Organization-worked in collaboration with the Government of Guinea to strengthen the country's surveillance capacity, in alignment with the Global Health Security Agenda and International Health Regulations 2005 objectives for surveillance and reporting. This paper describes the main surveillance activities supported by US CDC and its partners between 2015 and 2019 and provides information on the strategies used and the impact of activities. It also discusses lessons learned for building sustainable capacity and infrastructure for disease surveillance and reporting in similar resource-limited settings. |
Seroprevalence of anti-SARS-CoV-2 antibodies in Senegal: a national population-based cross-sectional survey, between October and November 2020.
Talla C , Loucoubar C , Roka JL , Barry MA , Ndiaye S , Diarra M , Thiam MS , Faye O , Dia M , Diop M , Ndiaye O , Tall A , Faye R , Mbow AA , Diouf B , Diallo JP , Keita IM , Ndiaye M , Woudenberg T , White M , Ting J , Diagne CT , Pasi O , Diop B , Sall AA , Vigan-Womas I , Faye O . IJID Reg 2022 3 117-125 OBJECTIVES: A nationwide cross-sectional epidemiological survey was conducted to capture the true extent of coronavirus disease 2019 (COVID-19) exposure in Senegal. METHODS: Multi-stage random cluster sampling of households was performed between October and November 2020, at the end of the first wave of COVID-19 transmission. Anti-severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies were screened using three distinct ELISA assays. Adjusted prevalence rates for the survey design were calculated for each test separately, and thereafter combined. Crude and adjusted prevalence rates based on test performance were estimated to assess the seroprevalence. As some samples were collected in high malaria endemic areas, the relationship between SARS-CoV-2 seroreactivity and antimalarial humoral immunity was also investigated. RESULTS: Of the 1463 participants included in this study, 58.8% were female and 41.2% were male; their mean age was 29.2 years (range 0.20-84.8.0 years). The national seroprevalence was estimated at 28.4% (95% confidence interval 26.1-30.8%). There was substantial regional variability. All age groups were impacted, and the prevalence of SARS-CoV-2 was comparable in the symptomatic and asymptomatic groups. An estimated 4 744 392 (95% confidence interval 4 360 164-5 145 327) were potentially infected with SARS-CoV-2 in Senegal, while 16 089 COVID-19 RT-PCR laboratory-confirmed cases were reported by the national surveillance. No correlation was found between SARS-CoV-2 and Plasmodium seroreactivity. CONCLUSIONS: These results provide a better estimate of SARS-CoV-2 dissemination in the Senegalese population. Preventive and control measures need to be reinforced in the country and especially in the south border regions. |
- Page last reviewed:Feb 1, 2024
- Page last updated:Jan 13, 2025
- Content source:
- Powered by CDC PHGKB Infrastructure