02151nas a2200229 4500000000100000008004100001653002200042653004100064653001600105653001900121100001000140700001500150700001600165700001100181700001100192700001300203245010300216856008800319300001000407490000600417520149800423 2012 d10aSystematic review10aSoil-transmitted helminth infections10aReinfection10aDrug treatment1 aJia T1 aMelville S1 aUtzinger Ü1 aKing C1 aZhou X1 aCooper P00aSoil-transmitted helminth reinfection after drug treatment: A systematic review and meta-analysis. uhttp://journals.plos.org/plosntds/article/asset?id=10.1371/journal.pntd.0001621.PDF ae16210 v63 a

Infections with soil-transmitted helminths (the roundworm Ascaris lumbricoides, the whipworm Trichuris trichiura, and hookworm) affect over 1 billion people, particularly rural communities in the developing world. The global strategy to control soil-transmitted helminth infections is ‘preventive chemotherapy’, which means large-scale administration of anthelmintic drugs to at-risk populations. However, because reinfection occurs after treatment, ‘preventive chemotherapy’ must be repeated regularly. Our systematic review and meta-analysis found that at 3, 6, and 12 months after treatment, A. lumbricoides prevalence reached 26% (95% confidence interval (CI): 16–43%), 68% (95% CI: 60–76%) and 94% (95% CI: 88–100%) of pretreatment levels, respectively. For T. trichiura, respective reinfection prevalence at these time points were 36% (95% CI: 28–47%), 67% (95% CI: 42–100%), and 82% (95% CI: 62–100%); and for hookworm, 30% (95% CI: 26–34%), 55% (95% CI: 34–87%), and 57% (95% CI: 49–67%). Prevalence and intensity of reinfection were positively correlated with pretreatment infection status. Our results suggest a frequent anthelmintic drug administration to maximize the benefit of preventive chemotherapy. Moreover, an integrated control strategy, consisting of preventive chemotherapy combined with health education and environmental sanitation is needed to interrupt transmission of soil-transmitted helminths.