{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T12:28:11Z","timestamp":1790857691124,"version":"4.1.0"},"reference-count":36,"publisher":"MDPI AG","issue":"3","license":[{"start":{"date-parts":[[2025,2,28]],"date-time":"2025-02-28T00:00:00Z","timestamp":1740700800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Harvard University Center for AIDS Research","award":["HU CFAR NIH\/NAIDS P30-AI 060354"],"award-info":[{"award-number":["HU CFAR NIH\/NAIDS P30-AI 060354"]}]},{"name":"Ragon Institute of MGH, MIT, and Harvard","award":["HU CFAR NIH\/NAIDS P30-AI 060354"],"award-info":[{"award-number":["HU CFAR NIH\/NAIDS P30-AI 060354"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["TropicalMed"],"abstract":"<jats:p>Syphilis and other sexually transmitted infections (STIs) are highly prevalent in most regions experiencing severe human immunodeficiency virus (HIV) epidemics. In sub-Saharan Africa, the region most heavily affected by HIV, the prevalence of syphilis among people living with HIV (PLWH) is notably high. This region accounts for 40% of global STIs and 70% of HIV cases. Despite the high prevalence of syphilis and other STIs among PLWH in the region, there are limited studies on the interplay between the two infections from the region. Most studies on the association between syphilis and HIV transmission\/progression from the region are limited to specific groups of people, such as female sex workers or pregnant women. In this manuscript, we evaluated the association between the two infections using population-based surveys conducted in the region. Statistical methods (such as logistic regression models and propensity score matching) were employed to assess the interplay between the two infections. Our findings indicated that syphilis infection was associated with higher odds of HIV acquisition. Moreover, co-infection with syphilis was associated with higher odds of HIV disease progression among antiretroviral therapy (ART)-treated PLWH, though the association did not reach statistical significance. Our findings suggest that the recognition and treatment of syphilis to reduce the risk of HIV acquisition\/progression should be a public health priority in sub-Saharan Africa, where ART may not be readily available.<\/jats:p>","DOI":"10.3390\/tropicalmed10030065","type":"journal-article","created":{"date-parts":[[2025,2,28]],"date-time":"2025-02-28T08:05:54Z","timestamp":1740729954000},"page":"65","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":9,"title":["The Association Between Syphilis Infection and HIV Acquisition and HIV Disease Progression in Sub-Saharan Africa"],"prefix":"10.3390","volume":"10","author":[{"ORCID":"https:\/\/orcid.org\/0009-0009-6154-9412","authenticated-orcid":false,"given":"Sindhuri","family":"Gandla","sequence":"first","affiliation":[{"name":"Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA 02139, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8352-1204","authenticated-orcid":false,"given":"Raja","family":"Nakka","sequence":"additional","affiliation":[{"name":"Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA 02139, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Ruhul Ali","family":"Khan","sequence":"additional","affiliation":[{"name":"Department of Mathematics, University of Arizona, Tucson, AZ 85721, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0009-5183-6549","authenticated-orcid":false,"given":"Fatemeh","family":"Salboukh","sequence":"additional","affiliation":[{"name":"Department of Engineering and Applied Science, University of Massachusetts, Dartmouth, MA 02747, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8572-1944","authenticated-orcid":false,"given":"Musie","family":"Ghebremichael","sequence":"additional","affiliation":[{"name":"Ragon Institute of MGH, MIT, and Harvard, Cambridge, MA 02139, USA"},{"name":"Harvard Medical School, Massachusetts General Hospital, Cambridge, MA 02115, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,2,28]]},"reference":[{"key":"ref_1","unstructured":"Tudor, M.E., Al Aboud, A.M., Leslie, S.W., and Gossman, W. (2024, October 05). Syphilis, StatPearls [Internet], Available online: https:\/\/www.ncbi.nlm.nih.gov\/books\/NBK534780\/."},{"key":"ref_2","unstructured":"(2024, October 07). Centers for Disease Control and Prevention\u2014Syphilis-Fact Sheet, Available online: https:\/\/www.cdc.gov\/syphilis\/about\/index.html."},{"key":"ref_3","unstructured":"World Health Organization (WHO) (2024, October 08). Syphilis\u2014Overview, Available online: https:\/\/www.who.int\/health-topics\/syphilis#tab=tab_1."},{"key":"ref_4","unstructured":"World Health Organization (WHO) (2024, October 08). Data on Syphilis, Available online: https:\/\/www.who.int\/data\/gho\/data\/themes\/topics\/data-on-syphilis."},{"key":"ref_5","unstructured":"World Health Organization (WHO) (2024, October 09). Sexually Transmitted Infections (STIs): Strategic Information, Available online: https:\/\/www.who.int\/teams\/global-hiv-hepatitis-and-stis-programmes\/stis\/strategic-information."},{"key":"ref_6","unstructured":"World Health Organization (2024, October 09). Implementing the Global Health Sector Strategies on HIV, Viral Hepatitis and Sexually Transmitted Infections, 2022\u20132030: Report on Progress and Gaps 2024, Available online: https:\/\/iris.who.int\/handle\/10665\/378246."},{"key":"ref_7","unstructured":"World Health Organization (2024, October 10). Global Health Sector Strategy on Sexually Transmitted Infections 2016\u20132021 Towards Ending STIs, Available online: https:\/\/iris.who.int\/bitstream\/handle\/10665\/246296\/WHO-RHR-16.09-eng.pdf?sequence=1."},{"key":"ref_8","doi-asserted-by":"crossref","unstructured":"Wu, Y., Zhu, W., Sun, C., Yue, X., Zheng, M., Fu, G., and Gong, X. (2022). Prevalence of syphilis among people living with HIV and its implication for enhanced coinfection monitoring and management in China: A meta-analysis. Front. Public Health, 10.","DOI":"10.3389\/fpubh.2022.1002342"},{"key":"ref_9","doi-asserted-by":"crossref","unstructured":"Wu, Y., Lu, L., Song, X., Liu, X., Yang, Y., Chen, L., Tang, J., Han, Y., Lv, W., and Cao, W. (2024). Clinical and immunological characteristics of HIV\/syphilis co-infected patients following long-term antiretroviral treatment. Front. Public Health, 11.","DOI":"10.3389\/fpubh.2023.1327896"},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"280","DOI":"10.1007\/s11904-021-00564-z","article-title":"The Intersection of HIV and Syphilis: Update on the Key Considerations in Testing and Management","volume":"18","author":"Ren","year":"2021","journal-title":"Curr. HIV\/AIDS Rep."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"525","DOI":"10.1136\/sextrans-2020-054706","article-title":"Effect of syphilis infection on HIV acquisition: A systematic review and meta-analysis","volume":"97","author":"Wu","year":"2021","journal-title":"Sex. Transm. Infect."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Gilbert, L., Dear, N., Esber, A., Iroezindu, M., Bahemana, E., Kibuuka, H., Owuoth, J., Maswai, J., Crowell, T.A., and Polyak, C.S. (2021). Prevalence and risk factors associated with HIV and syphilis co-infection in the African Cohort Study: A cross-sectional study. BMC Infect. Dis., 21.","DOI":"10.1186\/s12879-021-06668-6"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Solomon, H., Moraes, A.N., Williams, D.B., Fotso, A.S., Duong, Y.T., Ndongmo, C.B., Voetsch, A.C., Patel, H., Lupoli, K., and McAuley, J.B. (2020). Prevalence and correlates of active syphilis and HIV co-Infection among sexually active persons aged 15\u201359 years in Zambia: Results from the Zambia Population-based HIV Impact Assessment (ZAMPHIA) 2016. PLoS ONE, 15.","DOI":"10.1371\/journal.pone.0236501"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1296","DOI":"10.1056\/NEJMoa2211934","article-title":"Postexposure Doxycycline to Prevent Bacterial Sexually Transmitted Infections","volume":"388","author":"Luetkemeyer","year":"2023","journal-title":"N. Engl. J. Med."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"308","DOI":"10.1016\/S1473-3099(17)30725-9","article-title":"Post-exposure prophylaxis with doxycycline to prevent sexually transmitted infections in men who have sex with men: An open-label randomised substudy of the ANRS IPERGAY trial","volume":"18","author":"Molina","year":"2018","journal-title":"Lancet Infect. Dis."},{"key":"ref_16","doi-asserted-by":"crossref","unstructured":"Wang, C.L., Gao, S., Li, X.Z., and Martcheva, M. (2023). Modeling Syphilis and HIV Coinfection: A Case Study in the USA. Bull. Math. Biol., 85.","DOI":"10.1007\/s11538-023-01123-w"},{"key":"ref_17","first-page":"e1","article-title":"Syphilis Prevalence Among People Living With and Without HIV in Sub-Saharan Africa: A Systematic Review and Meta-Analysis","volume":"51","author":"Mussa","year":"2024","journal-title":"Sex. Transm. Dis."},{"key":"ref_18","doi-asserted-by":"crossref","unstructured":"He, L., Pan, X., Yang, J., Zheng, J., Luo, M., Cheng, W., and Chai, C. (2024). Current syphilis infection in virally suppressed people living with HIV: A cross-sectional study in eastern China. Front. Public Health, 12.","DOI":"10.3389\/fpubh.2024.1366795"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"ofaa019","DOI":"10.1093\/ofid\/ofaa019","article-title":"Repeated Syphilis Episodes in HIV-Infected Men Who Have Sex With Men: A Multicenter Prospective Cohort Study on Risk Factors and the Potential Role of Syphilis Immunity","volume":"7","author":"Roth","year":"2020","journal-title":"Open Forum Infect. Dis."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"157","DOI":"10.1097\/QAI.0000000000002739","article-title":"HIV Viral Suppression and Pre-exposure Prophylaxis in HIV and Syphilis Contact Tracing Networks: An Analysis of Disease Surveillance and Prescription Claims Data","volume":"88","author":"Billock","year":"2021","journal-title":"J. Acquir. Immune Defic. Syndr."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"1222","DOI":"10.1086\/513427","article-title":"Syphilis and HIV Infection: An Update","volume":"44","author":"Zetola","year":"2007","journal-title":"Clin. Infect. Dis."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"2075","DOI":"10.1097\/00002030-200410210-00012","article-title":"Syphilis increases HIV viral load and decreases CD4 cell counts in HIV-infected patients with new syphilis infections","volume":"18","author":"Buchacz","year":"2004","journal-title":"AIDS"},{"key":"ref_23","unstructured":"(2024, October 11). Population-Based HIV Impact Assessment (PHIA) Project. Available online: https:\/\/phia.icap.columbia.edu\/."},{"key":"ref_24","unstructured":"(2024, October 15). Tanzania Commission for AIDS (TACAIDS); Zanzibar AIDS Commission (ZAC). Tanzania HIV Impact Survey (THIS) 2016\u20132017: Final Report. Dar es Salaam, Tanzania. December 2018. Available online: https:\/\/phia.icap.columbia.edu\/tanzania-final-report\/."},{"key":"ref_25","unstructured":"(2024, October 15). Ministry of Health, Zambia. Zambia Population-Based HIV Impact Assessment (ZAMPHIA) 2016: Final Report. Lusaka, Ministry of Health. February 2019. Available online: https:\/\/phia.icap.columbia.edu\/zambia-final-report\/."},{"key":"ref_26","unstructured":"(2024, October 16). PHIA Data Use Manual. Available online: https:\/\/phia-data.icap.columbia.edu\/storage\/Country\/28-09-2021-22-01-17-615390ad6a147.pdf."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"e1413","DOI":"10.1016\/S2214-109X(24)00234-1","article-title":"Prevalence of syphilis among adults and adolescents in five sub-Saharan African countries: Findings from Population-based HIV Impact Assessment surveys","volume":"12","author":"Farahani","year":"2024","journal-title":"Lancet Glob. Health"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"S6","DOI":"10.1097\/QAI.0000000000002710","article-title":"Population-Based HIV Impact Assessments Survey Methods, Response, and Quality in Zimbabwe, Malawi, and Zambia","volume":"87","author":"Sachathep","year":"2021","journal-title":"J. Acquir. Immune Defic. Syndr."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1","DOI":"10.18637\/jss.v042.i08","article-title":"MatchIt: Nonparametric Preprocessing for Parametric Causal Inference","volume":"42","author":"Ho","year":"2011","journal-title":"J. Stat. Softw."},{"key":"ref_30","unstructured":"R Core Team (2024). R: A Language and Environment for Statistical Computing, R Foundation for Statistical Computing. Available online: https:\/\/www.R-project.org\/."},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Haule, A., Msemwa, B., Mgaya, E., Masikini, P., and Kalluvya, S. (2020). Prevalence of syphilis, neurosyphilis and associated factors in a cross-sectional analysis of HIV infected patients attending Bugando Medical Centre, Mwanza, Tanzania. BMC Public Health, 20.","DOI":"10.1186\/s12889-020-09984-9"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"84","DOI":"10.9734\/ISRR\/2015\/18965","article-title":"Seroprevalence of syphilis among human immunodeficiency virus positive individuals attending immune suppressed syndrome clinic at international hospital Kampala, Uganda","volume":"3","author":"Mboowa","year":"2015","journal-title":"Int. STD Res. Rev."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"562","DOI":"10.12688\/f1000research.17983.1","article-title":"HIV, syphilis and hepatitis B coinfections in Mkushi, Zambia: A cross-sectional study","volume":"8","author":"Katamba","year":"2019","journal-title":"F1000Research"},{"key":"ref_34","doi-asserted-by":"crossref","unstructured":"Ruangtragool, L., Silver, R., Machiha, A., Gwanzura, L., Hakim, A., Lupoli, K., Musuka, G., Patel, H., Mugurungi, O., and Tippett Barr, B.A. (2022). Factors associated with active syphilis among men and women aged 15 years and older in the Zimbabwe Population-based HIV Impact Assessment (2015\u20132016). PLoS ONE, 17.","DOI":"10.1371\/journal.pone.0261057"},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"2851","DOI":"10.2147\/IDR.S320648","article-title":"Consequences of HIV\/Syphilis Co-Infection on HIV Viral Load and Immune Response to Antiretroviral Therapy","volume":"14","author":"Fan","year":"2021","journal-title":"Infect. Drug Resist."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"69","DOI":"10.1186\/s12981-022-00493-w","article-title":"Effects of syphilis infection among HIV-1-positive individuals on suppressive antiretroviral therapy","volume":"19","author":"Chan","year":"2022","journal-title":"AIDS Res. Ther."}],"container-title":["Tropical Medicine and Infectious Disease"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2414-6366\/10\/3\/65\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,9]],"date-time":"2025-10-09T16:44:24Z","timestamp":1760028264000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2414-6366\/10\/3\/65"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,2,28]]},"references-count":36,"journal-issue":{"issue":"3","published-online":{"date-parts":[[2025,3]]}},"alternative-id":["tropicalmed10030065"],"URL":"https:\/\/doi.org\/10.3390\/tropicalmed10030065","relation":{},"ISSN":["2414-6366"],"issn-type":[{"value":"2414-6366","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,2,28]]}}}