Breastfeeding is associated with decreased pneumonia incidence among HIV-exposed, uninfected Kenyan infants

Abstract

<bold>Background:</bold> HIV-exposed uninfected (HIV-EU) infants have higher infectious disease morbidity and mortality than their unexposed peers. Pneumonia is a leading cause of infant mortality worldwide, and identifying characteristics that predict pneumonia among HIV-EU infants may enable early identification of those at highest risk. We sought to determine the incidence of pneumonia in a cohort of HIV-EU infants as well as risk factors. <bold>Methods:</bold> HIV-EU infants participating in a Kenyan perinatal HIV-1 cohort study enrolled between 1999-2002 were followed monthly from birth to 12 months. Clinician-diagnosed pneumonia episodes were recorded at monthly study visits and at sick-child visits. The incidence of pneumonia was estimated using total person-years of observation and instances of physician-diagnosed pneumonia, with a 14-day window for new episodes. Cox proportional hazards regression was used to identify predictors of first pneumonia occurrence. <bold>Results:</bold> Among 365 HIV-EU infants with 323 person-years of follow-up, the incidence of pneumonia was 89.8/100 child-years (95% CI: 80.1-100.8). Crowding in the home [HR=1.4 (95% CI 1.0-2.0)], maternal HIV viral load at 32 weeks' gestation [HR=1.2 (1.0-1.5) per log10 difference] and being underweight (WAZ<-2) at the previous visit [HR=1.9 (1.2-3.0)] were associated with increased risk of pneumonia. Infants whose mothers reported breastfeeding had a 47% lower risk of pneumonia than those who never breastfed [HR=0.53 (0.39-0.73)]. <bold>Conclusions:</bold> The incidence of pneumonia in this cohort of HIV EU infants was high. Our observations suggest that maternal viral suppression and breastfeeding may reduce the burden of pneumonia among HIV-EU children.