HELMINTHS
Background Soil-transmitted Helminths (STH) infections refer to a group of parasitic diseases caused by nematode worms that are transmitted to humans by fecally-contaminated soil. The STH of major concern to humans are the roundworm (Ascaris lumbricoides), the whip- worm (Trichuris trichiura), and the hookworms (Necator americanus and Ancylostoma duodenale).They are among the most common infections worldwide which heavily affect the poorest and most deprived communities where the sanitation is inadequate and water supplies unsafe. Latest estimates indicate that approximately two billion people (24% of the world's population) are infected with STH infections worldwide. Infections are widely distributed in tropical and subtropical areas, with the greatest numbers occurring in sub-Saharan Africa, the Americas, China and East Asia. Although soil-transmitted helminthiases inflict tremendous disability and suffering, they can be controlled or eliminated. The global estimate of STH in...