Association of nutritional status with the response to infection with Leishmania chagasi.

Outcomes of infection with Leishmania chagasi range from self-resolving infection to visceral leishmaniasis (VL). Risk factors determining development of disease are not totally understood, but probably include environmental influences and host genetics. We assessed whether nutrition influenced the outcome of Leishmania infection by comparing relatives of children with VL with either self-resolving Leishmania spp. infection or apparently uninfected households. We observed a decrease in body mass index (P < 0.0005) and mid-upper arm circumference for age (P = 0.022) z-scores for children with VL. Levels of vitamin A were lower in active children with VL as measured by serum retinol (P = 0.035) and the modified-relative-dose-response test (P = 0.009). Higher birth weight (P = 0.047) and albumin concentrations (P = 0.040) protected against disease. Increased breastfeeding time (P = 0.036) was associated with asymptomatic infection. The results indicate that modifiable nutritional aspects are associated with the outcome of Leishmania spp. infection in humans.