Anonymized dataset for analysis.

Background
Coinfection with HIV, hepatitis B virus (HBV) and syphilis increases the risk of vertical transmission. Hence, affecting overall maternal health and child health outcomes. The Tanzanian government is planning to add HBV screening to the existing Prevention of Mother to Child Transmission (PMTCT) of HIV and syphilis program; however, the burden of coinfections in the country is unknown. Therefore, this study aimed to determine the prevalence of HIV, HBV and syphilis coinfections and their associated factors among pregnant women receiving antenatal care in Tanzania.
Methods
A facility-based cross-sectional study design was conducted, utilizing data from the national feasibility study of triple testing for HIV, syphilis and HBV among pregnant women. The data were analysed via STATA version 16.1, and bivariate and multivariate logistic regressions were used to check for associations. Variables with a P value of < 0.05 were considered statistically significant.
Results
A total of 7,828 pregnant women were enrolled, 0.4% (95% CI 0.3–0.6) of whom were coinfected. The prevalence rates for HIV/HBV, HIV/syphilis, HBV/syphilis and HIV/HBV/syphilis coinfections were 0.1% (95% CI 0.1–0.2), 0.2% (95% CI 0.1–0.4), 0.1% (95% CI 0.0–0.2) and 0.0% (95% CI 0.0–0.1), respectively. History of multiple sexual partners (AOR 6.1; 95% CI: 1.3–29.7, P = 0.025) was associated with HIV/HBV coinfection. Age 25–49 years (AOR 13.5; 95% CI 1.8–103.8, P = 0.012) and marital status (AOR 0.2; 95% CI 0.1–0.8, P = 0.018) were associated with HIV/syphilis coinfection. For HBV/syphilis coinfection, marital status (AOR 0.1; 95% CI 0.0–0.9, P = 0.036) and history of multiple sexual partners (AOR 16.8; 95% CI 2.5–114.9, P = 0.004) were independently associated.
Conclusion
Coinfections are present among pregnant women in Tanzania; therefore, it is important to include hepatitis B screening in the existing PMTCT of HIV and syphilis program. Interventions should focus on single, child-bearing women with multiple sexual partners.