Co-trimoxazole Prophylaxis, Asymptomatic Malaria Parasitemia, and Infectious Morbidity in Human Immunodeficiency Virus–Exposed, Uninfected Infants in Malawi: The BAN Study

Background: Human immunodeficiency virus (HIV)-exposed infants are disproportionately at risk of morbidity and mortality compared with their HIV-unexposed counterparts. The role of co-trimoxazole preventive therapy (CPT) in reducing leading causes of infectious morbidity is unclear. Methods: We used data from the Breastfeeding, Antiretrovirals and Nutrition (BAN) clinical trial (conducted 2004-2010, Malawi) to assess the association of (1) CPT and (2) asymptomatic malaria parasitemia with respiratory and diarrheal morbidity in infants. In June 2006, all HIV-exposed infants in BAN began receiving CPT (240 mg) from 6 to 36 weeks of age, or until weaning occurred and HIV infection was ruled out. All HIV-exposed, uninfected infants (HEIs) at 8 weeks of age (n = 1984) were included when CPT was the exposure. A subset of HEIs (n = 471) were tested for malarial parasitemia using dried blood spots from 12, 24, and 36 weeks of age. Cox proportional hazards models for recurrent gap-time data were used to examine the association of time-varying exposures on morbidity. Results: CPT was associated with a 36% reduction in respiratory morbidity (hazard ratio [HR], 0.64 [95% confidence interval {CI}, .60-.69]) and a 41% reduction in diarrheal morbidity (HR, 0.59 [95% CI, .54-.65]). Having asymptomatic malaria parasitemia was associated with a 40% increase in respiratory morbidity (HR, 1.40 [95% CI, 1.13-1.74]) and a 50% increase in diarrheal morbidity (HR, 1.50 [95% CI, 1.09-2.06]), after adjusting for CPT. Conclusions: CPT may have an important role to play in reducing the leading global causes of morbidity and mortality in the growing population of HEIs in malaria-endemic resource-limited settings.