Schistosomiasis japonica and childhood nutritional status in northeastern Leyte, the Philippines: A randomized trial of praziquantel versus placebo

The hypothesis that infection with Schistosoma japonicum causes decreased nutritional status was studied in a randomized trial among 170 males and females, mean (SD) age 11.4 (3.5) years, residing in an endemic region of northeastern Leyte, Philippines. The S. japonicum-infected children were randomized to receive praziquantel or placebo and followed-up six months after randomization. Stature, weight, triceps, subscapular, and calf skinfold thicknesses and their sum, and hemoglobin level were measured at baseline and follow-up. Schistosoma japonicum eggs were detected in Kato-Katz stool smears and the intensity of infection was assessed by quantitative egg count. Intensities of hookworm, ascaris, and trichuris infections were also measured, The six-month levels of the anthropometric measures and hemoglobin were adjusted for age and their baseline levels and then compared between the praziquantel and placebo groups. Treatment interactions were also analyzed by sex, Baseline anthropometric and hemoglobin levels and parasite infection intensities were the same in the two groups. At six months, the praziquantel group had significantly higher hemoglobin levels (P < 0.001) and sum of skinfolds (P < 0.001) than the placebo group. Males had a significantly greater increase in hemoglobin levels with treatment than did females. The hemoglobin increase was not due to changes in hookworm intensity. The results show that schistosomiasis japonica caused decreased nutritional status in children and probably is partly responsible for the malnutrition and reduction in growth for age described in prior cross-sectional studies.