Epidemiological drivers of mother to child HIV transmission in West Bengal, India: A retrospective cohort study.

Background: HIV transmission through vertical route can be reduced to a large extent with combination of medical interventions. Apart from maternal HIV status several other epidemiological attributes determine this transmission dynamics. The objective of this study was to identify various associated factors that determine and modify the risk of HIV transmission from a mother living with HIV to her child. A retrospective cohort-study was conducted with 518 HIV-positive pregnant women with delivering live babies between April 2016 - September 2018. The HIV status of the children was ascertained with polymerase chain reaction. A number of socio-demographic and medical attributes were compared between HIV-positive (41) and HIV-negative babies (477) using bivariate and multivariate methods to identify disease modifying factors.

Results: Maternal HIV detection during the postnatal period (AOR = 11.2; 5.2 - 23.8), low birth weight (AOR = 2.7; 1.2 - 5.9), and vaginal delivery (AOR = 2.8; 1.01 - 7.7) were significantly associated with vertical transmission of HIV. Lower duration of maternal antiretroviral treatment and higher maternal age (>25 years) were also associated in bivariate analysis.

Conclusion: The battery of PPTCT (Prevention of Parent to Child Transmission) interventions should be tailored in such a way to address all the epidemiological attributes influencing vertical transmission.