Could Cesarean Delivery Help Prevent Mother-to-Child Transmission of Human T-Lymphotropic Virus Type 1?

BACKGROUND:Mother-to-child transmission (MTCT) of human T-lymphotropic virus type 1 (HTLV-1) is an important route of transmission that can cause lifelong infection. There is high morbidity and mortality due to adult T-cell leukemia/lymphoma, HTLV-1-associated myelopathy (HAM), and other inflammatory disorders. These conditions develop in nearly 10% of people with HTLV-1 infection, with a higher risk if infection occurs early in life. Identification of risk factors can inform targeted measures to reduce HTLV-1 MTCT. This study aimed to investigate the potential of cesarean delivery to prevent HTLV-1 MTCT. METHODS:We performed a review of the cases of women and their offspring under regular follow-up at the HTLV-1 outpatient clinic at the Institute of Infectious Diseases Emilio Ribas. RESULTS:A total of 177 HTLV-1-infected women and 369 adult offspring were investigated. Overall, 15% of the children were positive for HTLV-1 and 85% were negative. Regarding vertical transmission, we found that a breastfeeding duration of >6 months was associated with MTCT. Moreover, maternal proviral load was not associated with transmission, but high educational level and cesarean delivery were identified as protective factors. CONCLUSIONS:HTLV-1 MTCT was associated with mother's age at delivery of >25 years, low educational level, prolonged breastfeeding, and vaginal delivery.