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Background: Sub-Saharan Africa (SSA) has the highest sexually transmitted infection (STI) prevalence globally, but information about trends and geographic variation is limited by sparse aetiologic studies, particularly among men. This systematic review assessed chlamydia, gonorrhoea, and trichomoniasis prevalence by sex, sub-region, and year, and estimated male-to-female prevalence ratios for SSA., Methods: We searched Embase, MEDLINE, Global Health, PubMed, and African Index Medicus for studies measuring STI prevalence among general populations from January 1, 2000, to September 17, 2024. We adjusted observations for diagnostic test performance and used log-binomial mixed-effects meta-regressions to estimate prevalence trends and sex-prevalence ratios., Findings: Of 5202 records identified, we included 211 studies from 28 countries. In 2020, estimated prevalence among 15-49-year-olds in SSA for chlamydia was 6.6% (95%CI: 5.0-8.2%, n=169 observations) among females and 4.7% (3.4-6.1%, n=33) among males, gonorrhoea was 2.4% (1.4-3.3%, n=171) and 1.7% (0.7-2.6%, n=31), and trichomoniasis was 6.8% (3.6-9.9%, n=188) and 1.7% (0.7-2.7%, n=19). Male-to-female ratio estimates were 0.61 (0.53-0.71) for chlamydia, 0.81 (0.61-1.09) for gonorrhoea, and 0.23 (0.18-0.28) for trichomoniasis. From 2010-2020, chlamydia prevalence increased by 34.5% (11.1-62.9%) in SSA, while gonorrhoea and trichomoniasis trends were not statistically significant. Chlamydia and gonorrhoea prevalence were highest in Southern and Eastern Africa, whereas trichomoniasis was similar across sub-regions., Interpretation: SSA has a high, geographically varied STI burden, with increasing prevalence of chlamydia. Region-specific sex-prevalence ratios differed from existing global ratios and should be considered in future burden estimates. Enhanced sex-stratified surveillance is crucial to guide national programmes and reduce STI prevalence in SSA., Funding: Gates Foundation, Imperial College London, NIH, UKRI., Competing Interests: Declaration of interests The authors have no competing interests to declare.

Background: Most countries use the Spectrum AIDS Impact Module (Spectrum-AIM), antenatal care routine HIV testing, and antiretroviral treatment data to estimate HIV prevalence among pregnant women. Nonrepresentative program data may lead to inaccurate estimates of HIV prevalence and treatment coverage for pregnant women., Setting: One hundred fifty-four countries and subnational locations across 126 countries., Methods: Using 2023 UNAIDS HIV estimates, we calculated 3 ratios: (1) HIV prevalence among pregnant women to all women 15-49 yrs (prevalence), (2) ART coverage before pregnancy to women 15-49 yrs ART coverage (ART prepregnancy), and (3) ART coverage at delivery to women 15-49 yrs ART coverage (PMTCT coverage). We developed an algorithm to identify and adjust inconsistent results within regional ranges in Spectrum-AIM, illustrated using Burkina Faso estimates., Results: In 2022, the mean regional ratio of prevalence among pregnant women to all women ranged from 0.68 to 0.95. ART coverage prepregnancy ranged by region from 0.40 to 1.22 times ART coverage among all women. Mean regional PMTCT coverage ratios ranged from 0.85 to 1.51. The prevalence ratio in Burkina Faso was 1.59, above the typical range 0.62-1.04 in western and central Africa. Antenatal clinics reported more PMTCT recipients than estimated HIV-positive pregnant women from 2015 to 2019. We adjusted inputted PMTCT program data to enable consistency of HIV prevalence among pregnant women from programmatic routine HIV testing at antenatal clinics with values typical for western and central Africa., Conclusions: These ratios offer Spectrum-AIM users a tool to gauge the consistency of their HIV prevalence and treatment coverage estimates among pregnant women with other countries in the region., Competing Interests: The authors have no conflicts of interest to disclose., (Copyright © 2024 The Author(s). Published by Wolters Kluwer Health, Inc.)

Background: Eliminating HIV vertical transmission (VT) and is a global priority. Estimates of paediatric HIV infections are commonly derived through mathematical models relying on rates of VT stratified by maternal immunological and treatment status from literature, namely the UNAIDS-supported Spectrum AIDS Impact Module (Spectrum-AIM) to assess progress towards eliminating VT. Default VT probabilities were last updated in 2018, since then there have been substantial changes to service delivery and ART regimens., Methods: We aimed to (1) update the systematic review of VT probabilities by maternal status compatible with Spectrum-AIM, (2) conduct a meta-regression to systematically pool studies to estimate VT probabilities with statistical uncertainty, and (3) assess determinants of VT, including maternal viral load. We searched PubMed, Embase, Global Health Database, WHO Global Index Medicus, CINAHL Complete, and Cochrane CENTRAL for peer-reviewed articles in English from all geographic regions with data on VT from randomized controlled trials, cohort studies, or observational studies. We excluded sources that did not stratify VT by maternal treatment or immunological status. We fit four meta-regression models to produce VT probability estimates compatible with stratifications used in Spectrum-AIM and assessed how updated VT probabilities estimated new paediatric infections compared to default parameters in Spectrum-AIM. We conducted subgroup analyses to assess how study inclusion affected model estimates. Finally, we fit a meta-regression model to assess ART class and initiation timing on viral load suppression at delivery., Findings: The updated systematic review identified 24 new studies published between January 2018 and February 2024. Combined with previous review data, 110 studies were included in the meta-regression analysis. Estimates were broadly consistent with previous reviews. For women not receiving PMTCT, the odds of perinatal transmission decreased by 0.20 (0.16-0.25) for each 100 mm 3 increase in median CD4 of the study population. Among women on ART during pregnancy, each additional week on ART before delivery reduced the odds of VT by 5.6% (4.3%-6.8%). ART regimen class affected VT probability; the odds ratio of perinatal VT among WLHIV who initiated an INSTI-based regimen versus a NNRTI-based regimen 20 weeks before delivery was 0.355 (0.140-0.898). However, this effect was confounded by study region. Viral load suppression at delivery was significantly lower among women who started ART late during pregnancy (p=0.02), but did not significantly differ by ART class (p>0.05)., Interpretation: Vertical transmission rates vary substantially according to maternal immunological stage, prophylactic regimen, and timing of treatment initiation. Time of initiation on ART before delivery was strongly associated with viral load suppression at delivery. Our estimates and their uncertainty can be used in Spectrum-AIM to produce estimates of paediatric incidence to inform funding and monitor progress towards eliminating VT., Funding: National Institutes of Health, UNAIDS, and the Medical Research Council., Competing Interests: Conflicts of interest: The authors declare no conflicts of interest. A preliminary analysis of this work was virtually presented in October 2024 to the UNAIDS Reference Group on HIV Estimates, Modelling, and Projections.

Background: Addressing gender inequities could be key to the elimination of vertical transmission of HIV. Women experiencing intimate partner violence (IPV) might be at an increased risk of vertical transmission due to their vulnerability to HIV acquisition and barriers to access to and retention in care. Sub-Saharan Africa, where IPV burden is among the highest globally, accounts for most new paediatric HIV infections. We aimed to examine the proportion of excess vertical transmission attributable to IPV in this region., Methods: In this modelling analysis, we created a probability tree model of vertical HIV transmission among women aged 15-49 years in 46 African countries. We estimated the proportion of vertical transmission attributable to past-year physical or sexual IPV, or both, as an age-standardised population attributable fraction (PAF) and as excess vertical transmission risk per 1000 births among women experiencing IPV. We incorporated perinatal and postnatal vertical transmission among women who acquired HIV before pregnancy, during pregnancy, and during breastfeeding. Fertility, HIV prevalence, HIV incidence, antiretroviral therapy (ART) uptake, and ART retention varied in the model by women's IPV experience. The model was parameterised using UNAIDS' 2023 Spectrum model data, WHO's Global Database on Violence Against Women, and the peer-reviewed literature. Uncertainty intervals (95% UI) were calculated through 1000 Monte Carlo simulations., Findings: Across 46 countries 13% (95% UI 6-21) of paediatric HIV infections in 2022 were attributed to IPV, corresponding to over 22 000 paediatric infections. The PAF ranged from 4% (2-7) in Niger to 28% (13-43) in Uganda. The PAF was highest among girls aged 15-19 years (20%, 8-33) and lowest among women aged 45-49 years (6%, 3-9). In southern Africa, where women's HIV prevalence is highest (23%), IPV led to 11 (5-20) additional infections per 1000 births among women affected by IPV., Interpretation: IPV might be responsible for one in eight paediatric HIV infections in sub-Saharan Africa. Ending IPV could accelerate vertical transmission elimination, especially among young women who bear the highest burden of violence., Funding: Canadian Institutes of Health Research, Canada Research Chair, and Fonds de recherche du Québec-Santé., Translations: For the French, Georgian and Spanish translations of the abstract see Supplementary Materials section., Competing Interests: Declaration of interests MM-G reports contractual arrangements from WHO and UNAIDS, and support for their research programme by a Canada Research Chair (Tier 2) in Population Health Modeling. JWE-I reports research grants from the Bill & Melinda Gates Foundation, the US National Institutes of Health (NIH), UNAIDS, WHO, and the United States Agency for International Development, personal fees from Oxford Policy Management, and support for meeting travel from UNAIDS, BAO Systems, International AIDS Society, and SACEMA, all outside the submitted work. JWE-I and MKW acknowledge funding from National Institute of Allergy and Infectious Diseases of the NIH under award number 1R01AI152721-01A1, and the Medical Research Council (MRC) Centre for Global Infectious Disease Analysis (reference MR/R015600/1), jointly funded by the UK MRC and the UK Foreign, Commonwealth & Development Office (FCDO), under the MRC/FCDO Concordat agreement. The centre is also part of the EDCTP2 programme supported by the EU. M-CB declares funding from The HIV Prevention Trials Network (HPTN) Modelling Centre, which is funded by the NIH (grant number NIH UM1 AI068617) through HPTN, and funding from the MRC Centre for Global Infectious Disease Analysis (reference MR/X020258/1), funded by the UK MRC; this UK funded award is carried out in the frame of the Global Health EDCTP3 Joint Undertaking. M-CB and MM-G acknowledge funding from the Wellcome Trust (grant number WT 226619/Z/22/Z). SK reports contractual arrangements from UNAIDS and is supported by a doctoral award from the Fonds de recherche du Québec-Santé. SD reports a grant from the Canadian Institutes of Health Research, outside the submitted work. WAR reports funding from Canadian Blood Services, Fonds de recherche du Québec, the Association for the Advancement of Blood and Biotherapies Foundation, Canadian Institutes of Health Research, Urgencé Santé, and Natural Sciences and Engineering Research Council of Canada, all outside the submitted work. All other authors declare no competing interests., (Copyright © 2024 Elsevier Ltd. All rights reserved, including those for text and data mining, AI training, and similar technologies.)

Background: Most countries use the Spectrum AIDS Impact Module (Spectrum-AIM), antenatal care routine HIV testing, and antiretroviral treatment data to estimate HIV prevalence among pregnant women. Non-representative programme data may lead to inaccurate estimates HIV prevalence and treatment coverage for pregnant women., Setting: 154 locations in 126 countries., Methods: Using 2023 UNAIDS HIV estimates, we calculated three ratios: (1) HIV prevalence among pregnant women to all women 15-49y (prevalence), (2) ART coverage before pregnancy to women 15-49y ART coverage (ART pre-pregnancy), and (3) ART coverage at delivery to women 15-49y ART coverage (PMTCT coverage). We developed an algorithm to identify and adjust inconsistent results within regional ranges in Spectrum-AIM, illustrated using Burkina Faso's estimates., Results: In 2022, the mean regional ratio of prevalence among pregnant women to all women ranged from 0.68 to 0.95. ART coverage pre-pregnancy ranged by region from 0.40 to 1.22 times ART coverage among all women. Mean regional PMTCT coverage ratios ranged from 0.85 to 1.51. The prevalence ratio in Burkina Faso was 1.59, above the typical range 0.62-1.04 in western and central Africa. Antenatal clinics reported more PMTCT recipients than estimated HIV-positive pregnant women from 2015 to 2019. We adjusted inputted PMTCT programme data to enable consistency of HIV prevalence among pregnant women from programmatic routine HIV testing at antenatal clinics with values typical for Western and central Africa., Conclusion: These ratios offer Spectrum-AIM users a tool to gauge the consistency of their HIV prevalence and treatment coverage estimates among pregnant women with other countries in the region.

Background: Syndromic management is widely used to treat symptomatic sexually transmitted infections in settings without aetiologic diagnostics. However, underlying aetiologies and consequent treatment suitability are uncertain without regular assessment. This systematic review estimated the distribution, trends, and determinants of aetiologies for vaginal discharge, urethral discharge, and genital ulcer in sub-Saharan Africa (SSA)., Methods and Findings: We searched Embase, MEDLINE, Global Health, Web of Science, and grey literature from inception until December 20, 2023, for observational studies reporting aetiologic diagnoses among symptomatic populations in SSA. We adjusted observations for diagnostic test performance, used generalised linear mixed-effects meta-regressions to generate estimates, and critically appraised studies using an adapted Joanna Briggs Institute checklist. Of 4,418 identified records, 206 reports were included from 190 studies in 32 countries conducted between 1969 and 2022. In 2015, estimated primary aetiologies for vaginal discharge were candidiasis (69.4% [95% confidence interval (CI): 44.3% to 86.6%], n = 50), bacterial vaginosis (50.0% [95% CI: 32.3% to 67.8%], n = 39), chlamydia (16.2% [95% CI: 8.6% to 28.5%], n = 50), and trichomoniasis (12.9% [95% CI: 7.7% to 20.7%], n = 80); for urethral discharge were gonorrhoea (77.1% [95% CI: 68.1% to 84.1%], n = 68) and chlamydia (21.9% [95% CI: 15.4% to 30.3%], n = 48); and for genital ulcer were herpes simplex virus type 2 (HSV-2) (48.3% [95% CI: 32.9% to 64.1%], n = 47) and syphilis (9.3% [95% CI: 6.4% to 13.4%], n = 117). Temporal variation was substantial, particularly for genital ulcer where HSV-2 replaced chancroid as the primary cause. Aetiologic distributions for each symptom were largely the same across regions and population strata, despite HIV status and age being significantly associated with several infection diagnoses. Limitations of the review include the absence of studies in 16 of 48 SSA countries, substantial heterogeneity in study observations, and impeded assessment of this variability due to incomplete or inconsistent reporting across studies., Conclusions: In our study, syndrome aetiologies in SSA aligned with World Health Organization guidelines without strong evidence of geographic or demographic variation, supporting broad guideline applicability. Temporal changes underscore the importance of regular aetiologic re-assessment for effective syndromic management., Prospero Number: CRD42022348045., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2024 Michalow et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

Estimates of disease burden are important for setting public health priorities. These estimates involve numerous modeling assumptions, whose uncertainties are not always well described. We developed a framework for estimating the burden of yellow fever in Africa and evaluated its sensitivity to modeling assumptions that are often overlooked. We found that alternative interpretations of serological data resulted in a nearly 20-fold difference in burden estimates (range of central estimates, 8.4 × 10 4 to 1.5 × 10 6 deaths in 2021–2030). Uncertainty about the vaccination status of serological study participants was the primary driver of this uncertainty. Even so, statistical uncertainty was even greater than uncertainty due to modeling assumptions, accounting for a total of 87% of variance in burden estimates. Combined with estimates that most infections go unreported (range of 95% credible intervals, 99.65 to 99.99%), our results suggest that yellow fever’s burden will remain highly uncertain without major improvements in surveillance.