Syphilis in pregnant women living with HIV/AIDS in Brazil and the relationship between coinfection and mother-to-child transmission of HIV

Mayra Gonçalves Aragón; Leonor Henriette de Lannoy; Pâmela Cristina Gaspar; Ana Paula Betaressi da Silva; Ronaldo de Almeida Coelho; Draurio Barreira; Angélica Espinosa Miranda

doi:10.1186/s12889-025-25338-9

Syphilis in pregnant women living with HIV/AIDS in Brazil and the relationship between coinfection and mother-to-child transmission of HIV

BMC Public Health. 2025 Dec 6;26(1):146. doi: 10.1186/s12889-025-25338-9.

Authors

Mayra Gonçalves Aragón^{1

2}, Leonor Henriette de Lannoy³, Pâmela Cristina Gaspar³, Ana Paula Betaressi da Silva³, Ronaldo de Almeida Coelho³, Draurio Barreira³, Angélica Espinosa Miranda⁴

Affiliations

¹ Department of HIV/AIDS, Tuberculosis, Viral Hepatitis and Sexually Transmitted Infections, Secretariat for Health Surveillance and Environment, Ministry of Health of Brazil, Brasília, Brazil. mayra.aragon@gmail.com.
² Post Graduation Program of Infectious Diseases, Federal University of Espírito Santo, Vitória, Brazil. mayra.aragon@gmail.com.
³ Department of HIV/AIDS, Tuberculosis, Viral Hepatitis and Sexually Transmitted Infections, Secretariat for Health Surveillance and Environment, Ministry of Health of Brazil, Brasília, Brazil.
⁴ Post Graduation Program of Infectious Diseases, Federal University of Espírito Santo, Vitória, Brazil.

Abstract

Background: HIV and syphilis are sexually transmitted infections of concern during pregnancy that affect women and children globally. However, limited data is available regarding the prevalence of syphilis infection among pregnant women living with HIV/AIDS and its influence on mother‒to-child transmission (MTCT) of HIV. The present research aims to analyze HIV and syphilis coinfection during pregnancy through a national analysis of surveillance data from Brazil.

Methods: This retrospective cohort study used secondary data from the Ministry of Health’s information systems. The data included reported cases of pregnant women living with HIV and syphilis, with childbirth between 2016 and 2020, and children with HIV/AIDS with a year of birth from 2016 to 2020. Cross-referencing was performed between notification databases of pregnant women with HIV/AIDS and syphilis and pregnant women with HIV/AIDS and children with HIV/AIDS to identify potential mother‒child pairs. Pregnant women without a paired child with HIV were considered to have no outcome of MTCT for HIV. Logistic regression analysis was performed to estimate the effect of HIV and syphilis coinfection during pregnancy and HIV-MTCT, with a final significance level of 5%.

Results: Among 40,634 pregnant women living with HIV, 2,788 were coinfected with syphilis, yielding a coinfection rate of 6.9%. The MTCT of HIV was significantly greater among HIV-positive pregnant women coinfected with syphilis (2%) than among those without coinfection (1.2%), with an odds ratio of 1.7 (95% CI 1.29–2.25, p ≤ 0.05). Coinfection with HIV and syphilis was more prevalent among young women (aged 10–24), non-white individuals and people with lower educational attainment, and those who did not receive prenatal care and had late laboratory evidence of HIV during pregnancy, indicating a more vulnerable population among the coinfected pregnant women. However, in the multivariable logistic regression analysis, syphilis coinfection did not remain an independent risk factor for MTCT of HIV (p = 0.055).

Conclusions: Compared with HIV-positive pregnant women without syphilis, HIV coinfection with syphilis during pregnancy had higher MTCT rate of HIV. Intersectoral public policies addressing social determinants are essential to achieve the goals of eliminating MTCT.

Keywords: HIV; Mother-to-child transmission; Pregnancy; Syphilis.