Can One Afford Not to Screen for Parasites in High-Risk Immigrant Populations?

The article by Posey et al. [1] in this issue of Clinical Infectious Diseases emphasizes once again the high prevalence of schistosomiais and strongyloidiasis among African refugees. Similar findings have been noted in previous studies of refugees and immigrants from areas where these 2 parasites are endemic. For example, a very high seroprevalence of strongyloidiasis has been noted among refugees from Southeast Asia. In a Canadian study of Southeast Asian refugees, Gyorkos et al. [2] noted that 131 (76.6%) of 171 Kampucheans, 15 (55.6%) of 27 Laotians, and 4 (11.8%) of 34 Vietnamese persons were seropositive. It was interesting to note the lack of association between abdominal pain and the presence of parasites in the studied population. However, this is not at all unexpected, given the fact that the vast majority of persons with parasitic infections remain asymptomatic unless the worm burden is high and/or the long-term damage from a chronic infection has led to pathological changes sufficient to cause illness.