Background
The relationship between mastitis and antiretroviral therapy among HIV-positive, breastfeeding women is unclear.
Methods
In the Breastfeeding, Antiretrovirals, and Nutrition (BAN) study, conducted in Lilongwe, Malawi, 2369 mother-infant pairs were randomized to a nutritional supplement group and to one of three treatment groups: maternal antiretroviral therapy (ART), infant nevirapine (NVP) or standard of care for 24 weeks of exclusive breastfeeding and 4 weeks of weaning. Among 1,472 HIV-infected women who delivered live infants between 2004 and 2007, we estimated cumulative incidence functions and sub-distribution hazard ratios (HR) of mastitis or breast inflammation comparing women in maternal ART (n=487) or infant nevirapine (n=492) groups to the standard of care (n=493). Nutritional supplement groups (743 took, 729 did not) were also compared.
Results
Through 28-weeks post-partum, 88 of 1472 women experienced at least one occurrence of mastitis or breast inflammation. The 28-week risk was higher for maternal ART (RD 4.5, 95% confidence interval (CI): 0.9, 8.1) and infant NVP (RD: 3.6, 95%CI: 0.9-6.9) compared to standard of care. The hazard of late-appearing mastitis or breast inflammation (from week 5-28) was also higher for maternal ART (HR: 6.7, 95%CI: 2.0, 22.6) and infant NVP (HR: 5.1, 95%CI: 1.5, 17. 5) compared to the standard of care.
Conclusions
Mastitis or breast inflammation while breastfeeding is a possible side effect for women taking prophylactic ART and women whose infants take NVP, warranting additional research in the context of postnatal HIV transmission.