Epidemiological features of strongyloides infection in Okinawa, Japan: Comparative study with other endemic areas.

Abstract

The epidemiological features of Strongyloides stercoralis infection in Okinawa, Japan, were studied by comparing with those in Thailand, Laos and Brazil. The prevalence rates of Strongyloides infection in the present study were 9.6% (133/1, 380) in Okinawa, 47.6% (99/208) in Chiang Mai, Thailand, 23.8% (106/445) in Khammouane, Laos, and 12.0% (32/267) in Maceio, Brazil, respectively. The age inclination in aged subjects and sex dominance in males were significant features of Strongyloides infection in Okinawa, suggesting that new infection from the environment does not occur in present-day Okinawa. The epidemiological feature was considered to provide a favorable field to investigate therapeutic efficacy unaffected by reinfection from environment after treatment. Absence of helminth infection other than Strongyloides was an additional feature in Okinawa. The features may also be convenient to study host response and pathogenicity in the Strongyloides infection unaffected by concurrent infection with other helminths.