Risk of intestinal helminth and protozoan infection in a refugee population

With continuing emigration from endemic countries, screening for parasitic infections remains a priority in U.S. communities serving refugee and immigrant populations. We report the prevalence of helminths and protozoa as well as demographic risk factors associated with these infections among 533 refugees seen at the Santa Clara County, California, Refugee Clinic between October 2001 and January 2004. Stool parasites were identified from 14% of refugees, including 9% found to have one or more protozoa and 6% found to have at least one helminth. Most common protozoan infections were Giardia lamblia (6%) and Dientamoeba fragilis (3%), and for helminths, hookworm (2%). Protozoa were more frequent in refugees < 18 years of age (OR: 2.2 [1.2-4.2]), whereas helminths were more common in refugees from South Central Asia (OR: 8.0 [2.3-27.7]) and Africa (OR: 5.9 [1.6-21.6]) when compared with refugees from Eastern Europe and the Middle East. Among helminths, Ascaris lumbricoides and hookworm were concentrated among South Central Asians (6 of 7 and 10 of 11 cases, respectively), whereas Strongyloides stercoralis was predominantly found in Africans (5 of 7 cases). Although predeparture empirical treatment programs in Saharan Africa may have helped to reduce prevalence among arriving refugees from this region, parasitic infection is still common among refugees to the United States with helminth infections found in more specific populations. As refugees represent only a fraction of recent immigrants from endemic countries, current studies in nonrefugee groups are also needed.