We treated two elderly patients who contracted amebiasis in a foreign country. They ate a watermelon in Peking, the People's Republic of China. From their account, the watermelon was considered the most probable source of infection.
In Case 1, the patient complained of acute nausea, vomiting, diarrhea and unconsciousness following severe dehydration. The trophozoites of Entamoeba histolytica were found by stool examination. The treatment with metronidazole was not so effective in Case 1 patient with fulminating amebic colitis. In Case 2, he had no subjective symptoms, but the cysts of Entamoeba histolytica were found by stool examination.
Recently, traveling abroad has become popular. The number of travelers has been increasing in Japan from not only urban districts but also rural districts. Therefore, it is necessary to exercise strict rigilance over the imported protozoan parasites and possible mass outbreak of amebiasis in tour groups.