Patterns of infection with intestinal parasites in Qatar among food handlers and housemaids from different geographical regions of origin.

Intestinal parasitic infections were surveyed among recently arrived immigrant workers in Qatar destined for employment in food handling occupations. Two overlapping datasets (female workers surveyed in 2005 and 2006, and both sexes in 2006) were analyzed. Seven species were detected, 3 nematodes (Trichuris trichiura, hookworms and Ascaris lumbricoides) and 4 protozoans (Entamoeba histolytica/dispar, non-pathogenic Entamoebae, Blastocystis hominis and Giardia lamblia). Overall prevalence of infections, all species combined was 33.9% (13.6% for nematodes and 24.8% for protozoa). There was a significant female bias in the prevalence of all species combined, all protozoans combined, T. trichiura and A. lumbricoides. Among females, the prevalence of many species fell between 2005 and 2006, but G. lamblia almost tripled and E. histolytica/dispar increased 10-fold. Africa workers were less likely to carry T. trichiura and hookworms but more likely to have gastrointestinal protozoa. The highest overall prevalence of T. trichiura was 26.3% among females from the Philippines in 2005. None of the Indonesian workers were infected with A. lumbricoides whereas those from the Indian sub-continent and the Philippines were more likely to carry hookworms. Quantitative data reflecting abundance of infection (summary statistics are provided), showed the same trends but could not be analyzed further because of the overall low prevalence of each of the species detected. Multiple species infections were not common, although some individuals (0.1%) had 5 species concurrently.