Soil-transmitted helminth infections and physical fitness in school-aged Bulang children in southwest China: results from a cross-sectional survey

BACKGROUND: Chronic soil-transmitted helminth (STH) infections have been associated with reduced physical fitness, but available evidence is limited. The aim of this cross-sectional survey was to assess the feasibility of measuring children's physical fitness and to relate it to STH infections. Our study was carried out among school-aged children of the Bulang ethnic group in rural southwest People's Republic of China (P.R. China). Standardized, quality-controlled methods were employed to determine STH infections (Kato-Katz technique), haemoglobin levels, anthropometry (body weight and height) and physical fitness (20-m shuttle run test). RESULTS: A compliance of 87% suggested good acceptance of the methods used. Among 69 children with complete data records, infection prevalence of Trichuris trichiura, Ascaris lumbricoides and hookworm were 81%, 44% and 6%, respectively. The maximum volume of oxygen that can be utilized within 1 min during exhaustive exercise (VO(2 )max estimate) of T. trichiura-infected children was 1.94 ml kg(-1 )min(-1 )lower than that of their non-infected counterparts (P = 0.005). Until exhaustion, T. trichiura-infected children had completed 6.14 20-m laps less (P = 0.004). Additionally, the mean VO(2 )max estimate of stunted children was lowered by 1.63 ml kg(-1 )min(-1 )(P = 0.002) and they completed 5.32 20-m laps less (P = 0.001) compared to children of normal stature. No significant association between stunting and infection with any STH species could be established. CONCLUSIONS: Implementation of physical fitness tests in rural, resource-constraint settings is feasible. The physical fitness of children who are stunted or infected with STHs, particularly T. trichiura, is significantly impaired. We have launched a larger study and will determine the dynamics of school-aged children's physical fitness over a 7-month period after administration of anthelminthic drugs.