Clarence Suh Yah

Dr. Clarence Suh Yah

School of Health Systems and Public Health, Faculty of Health Sciences, University of Pretoria, Pretoria 0002, South Africa
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Representative Publications

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1 October 2014 in Nanomedicine: Nanotechnology, Biology and Medicine
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Journal Article
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MVMelissa A. Vetten
Melissa A. Vetten
CYClarence Suh Yah
Clarence Suh Yah
TSTanusha Singh
Tanusha Singh
MGMary Gulumian
Mary Gulumian

2 September 2015 in DARU Journal of Pharmaceutical Sciences
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Journal Article
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CYClarence Suh Yah
Clarence Suh Yah
GSGeoffrey Simate Simate
Geoffrey Simate Simate
The rapid emergence of antimicrobial resistant strains to conventional antimicrobial agents has complicated and prolonged infection treatment and increased

25 November 2016 in Sexually Transmitted Infections
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Journal Article
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SSSheree Schwartz
Sheree Schwartz
ALAndrew Lambert
Andrew Lambert
RPRefilwe Nancy Phaswana-Mafuya
Refilwe Nancy Phaswana-Mafuya
ZKZamakayise Kose
Zamakayise Kose
MMMfezi Mcingana
Mfezi Mcingana
SBStefan Baral
Stefan Baral
Background Female sex workers (FSWs) are disproportionately affected by HIV, even in the context of broadly generalised HIV epidemics such as South Africa. This has been observed in spite of the individual and population-level benefits of HIV treatment. We characterise the HIV care cascade among FSWs and relationships with antiretroviral therapy (ART) use. Methods FSWs ≥18 years were recruited through respondent-driven sampling into a cross-sectional study in Port Elizabeth, South Africa. Participants completed questionnaires and received HIV and syphilis testing; CD4 counts were assessed among women living with HIV. Engagement in the HIV care cascade is described, and correlates of self-reported ART use among treatment-eligible previously diagnosed FSWs were estimated using robust Poisson regression. Results Between October 2014 and April 2015, 410 FSWs participated in study activities. Overall, 261/410 were living with HIV (respondent-driven sampling-weighted prevalence 61.5% (95% bootstrapped CI 54.1% to 68.0%)). Prior diagnosis of HIV was relatively high (214/261, 82%); however, ART coverage among FSWs living with HIV was 39% (102/261). In multivariate analyses, FSWs were less likely to be on ART if they had not disclosed their HIV status to non-paying partners (adjusted prevalence ratio (aPR) 0.43, 95% CI 0.22 to 0.86, where the reference is FSWs without non-paying partners), and also if they engaged in mobile healthcare services (aPR 0.71, 95% CI 0.57 to 0.89). Conclusions HIV testing and awareness of HIV status were high, but substantial losses in the cascade occur at treatment initiation. Given that FSWs engaged in mobile HIV testing and peer education programmes have unmet HIV treatment needs, models of decentralised treatment provision such as mobile-based ART care should be evaluated.

1 March 2019 in Journal of Infection and Public Health
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Journal Article
Open access
CYClarence Suh Yah
Clarence Suh Yah
ETErnest Tambo
Ernest Tambo
Sub-Saharan Africa (SSA) accounts for more than two thirds of the world's HIV infection. Despite scaled-up prevention of mother-to-child transmission of HIV (PMTCT) programmes, mother to child transmission of HIV (MTCT) continues to escalate. We describe the challenges faced by PMTCT in MTCT in SSA. The study reviewed articles and reports published online. The most common barriers and challenges were non-disclosure of HIV status, late initiation of ARVs treatment/adherence, STIs screening, long clinics waiting time, non-involvement of men in ANC/PMTCT, infant feeding methods and sensitization of community members on ANC/PMTCT programmes. The study highlights the need to expand PMTCT coverage and the implementation of the 90-90-90 programme toward MTCT elimination in SSA. That is " ≥90% of pregnant and breast-feeding mothers must know their HIV status; ≥90% of those that are positive are enrolled on ARVs treatment and care; ≥90% of those on ARVs treatment and care are virally suppressed.

30 September 2015 in Sexually Transmitted Infections
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Journal Article
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SSShauna Stahlman
Shauna Stahlman
LJLisa G Johnston
Lisa G Johnston
CYClarence Suh Yah
Clarence Suh Yah
SKSosthenes Ketende
Sosthenes Ketende
SMSibusiso Maziya
Sibusiso Maziya
SBStefan Baral
Stefan Baral
Objectives Respondent-driven sampling (RDS) is a popular method for recruiting men who have sex with men (MSM). Our objective is to describe the ability of RDS to reach MSM for HIV testing in three southern African nations. Methods Data collected via RDS among MSM in Lesotho (N=318), Swaziland (N=310) and Malawi (N=334) were analysed by wave in order to characterise differences in sample characteristics. Seeds were recruited from MSM-affiliated community-based organisations. Men were interviewed during a single study visit and tested for HIV. χ2 tests for trend were used to examine differences in the proportions across wave category. Results A maximum of 13–19 recruitment waves were achieved in each study site. The percentage of those who identified as gay/homosexual decreased as waves increased in Lesotho (49% to 27%, p<0.01). In Swaziland and Lesotho, knowledge that anal sex was the riskiest type of sex for HIV transmission decreased across waves (39% to 23%, p<0.05, and 37% to 19%, p<0.05). The percentage of participants who had ever received more than one HIV test decreased across waves in Malawi (31% to 12%, p<0.01). In Lesotho and Malawi, the prevalence of testing positive for HIV decreased across waves (48% to 15%, p<0.01 and 23% to 11%, p<0.05). Among those living with HIV, the proportion of those unaware of their status increased across waves in all study sites although this finding was not statistically significant. Conclusions RDS that extends deeper into recruitment waves may be a promising method of reaching MSM with varying levels of HIV prevention needs.

1 October 2020 in Journal of the International AIDS Society
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Journal Article
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PSPatrick S Sullivan
Patrick S Sullivan
RPRefilwe Nancy Phaswana-Mafuya
Refilwe Nancy Phaswana-Mafuya
SBStefan D Baral
Stefan D Baral
RVRachel Valencia
Rachel Valencia
RZRyan Zahn
Ryan Zahn
LBLinda‐Gail Bekker
Linda‐Gail Bekker
Introduction: Men who have sex with men (MSM) and transgender women (TGW) are at increased risk for acquiring HIV, but there are limited HIV incidence data for these key populations in Africa. Understanding HIV prevalence and incidence provides important context for designing HIV prevention strategies, including pre‐exposure prophylaxis (PrEP) programmes. We describe HIV prevalence, awareness of HIV infection, HIV incidence and associated factors for a cohort of MSM and TGW in Cape Town and Port Elizabeth, South Africa.Methods: From 2015 to 2016, MSM and TGW in Cape Town and Port Elizabeth were enrolled and prospectively followed for 12 months, receiving a comprehensive package of HIV prevention services. HIV testing was conducted at baseline and at follow‐up visits (targeted for three, six and twelve months). All HIV‐negative PrEP‐eligible participants were offered PrEP enrolment during the first four months of study participation. We determined HIV prevalence among participants at baseline, and incidence by repeat screening of initially HIV‐negative participants with HIV tests at three, six and twelve months.Results: Among 292 participants enrolled, HIV prevalence was high (43%; 95% CI: 38 to 49) and awareness of HIV status was low (50%). The 167 HIV‐negative participants who were followed prospectively for 144.7 person‐years; nine incident HIV infections were documented. Overall annual incidence was 6.2% (CI: 2.8 to 11.8) and did not differ by city. Annual HIV incidence was significantly higher for younger (18 to 19 years) MSM and TGW (MSM: 21.8% (CI: 1.2 to 100); TGW: 31.0 (CI: 3.7, 111.2)). About half of participants started PrEP during the study; the annual incidence of HIV among 82 (49%) PrEP starters was 3.6% (CI: 0.4, 13.1) and among those who did not start PrEP was 7.8% (CI: 3.1, 16.1).Conclusions: HIV incidence was high among MSM and TGW in the context of receiving a comprehensive package of prevention interventions and offering of PrEP. PrEP uptake was high; the observed incidence of HIV in those who started PrEP was about half the incidence of HIV in those who did not. Future implementation‐oriented studies should focus on decisions to start and continue PrEP for those at highest risk, including young MSM.