Soil-transmitted Helminthiasis in the United States: a systematic review--1940-2010.

The epidemiology of soil-transmitted helminth infections (hookworm, Trichuris trichiura, Ascaris lumbricoides, and Strongyloides stercoralis) in the United States is poorly understood. To gain understanding of the status of disease, a systematic review was performed to assess the prevalence of soil-transmitted helminth infections in the United States. Of all studies reviewed, 14 were designated as high-quality. High-quality studies were published from 1942 to 1982 and showed that infection was prevalent throughout the southern United States and Appalachia as recently as 1982, finding that hookworm (19.6%), T. trichiura (55.2%), A. lumbricoides (49.4%), and S. stercoralis (3.8%) affected significant percentages of the population. However, because the most recent high-quality studies were published over 25 years ago, the literature does not provide sufficient data to assess current endemic transmission. Because the status of disease remains unclear, there is a need for additional studies to determine if soil-transmitted helminths remain endemic in the United States.