RESUMEN
A nonconcurrent, prospective intestinal parasitic disease study in a group of 200 foodhandlers employed in the Panama Canal Area was conducted in mid-1985 as part of an established occupational health medical surveillance program. The study included a review of laboratory testing (i.e., coprological exam), preexisting medical record data, and patient interview information to calculate estimates of incidence and risk factors associated with acquisition of Giardia lamblia and other protozoan/helminthic intestinal parasites. Significant increases in risk of infection were detected for specific native Indian and West Indian employee groups when compared with their Hispanic Panamanian (i.e., Latinos) or North American (i.e., U.S. born) counterparts. A three- to fourfold higher rate of infection was also documented during a one-year period when semiannual rather than annual examinations were conducted. No difference in the therapeutic efficacy of parasitological cure of Metronidazole versus Quinacrine was found when used in the treatment of individuals with asymptomatic G. lamblia infections (85% in both groups). The appropriateness of mass therapy of asymptomatically infected foodhandlers is discussed.