Soil-Transmitted Helminth (STH) Infections in the MENA Region

Abstract

Soil-transmitted helminths (STHs), or geohelminths, including Ascaris lumbricoides, Trichuris trichiura, Ancylostoma duodenale, Necator americanus, and Strongyloides stercoralis are a group of intestinal nematode parasites transmitted through contaminated soil, vegetables, and water. STH infections are leading neglected tropical diseases that affect the Middle East and North Africa (MENA) region. To conduct this review, publication databases related to STHs in the MENA countries were surveyed. Search engines utilized were PUBMED, SCIRUS, GOOGLE SCHOLAR, IMEMR, The Global Atlas of Helminth Infections, and local sources. Overall the MENA region accounts for less than 10 % of the global number of cases of STH infection. Results show that ascariasis has the lowest rate of infection as 0.02 % in Oman and 56 % as the highest rate in the Palestinian Territories. More than 20 million infections with ascariasis are in the MENA region. As for trichuriasis, a range of 0 % infection in Lebanon to 45 % infection in Somalia was found; overall about seven infections are in the MENA region. For hookworm infection, five to ten million infections are in the MENA region with infection rates ranging between 0 % in Algeria and 50 % in Kuwait (50 %). Minimal data for strongyloidiasis were available, but the estimates range from 0.0 % in Algeria to 15.5 % in the Palestinian Territories. Overall, anthelminthic drug coverage through periodic deworming is extremely low in the MENA region. Here we describe various risk factors in transmission of STHs in the region and report the prevalence of contamination of vegetables with the parasites' eggs. Moreover, different aspects of clinical manifestations, control, prevention, and treatment will be discussed.