The Lung Worm Angiostrongylus Cantonensis of Rodents on Taiwan (Formosa) and the Offshore Islands

Abstract

Summary Approximately 1,650 rodents (Muridae) were examined during a study of the helminth parasites of vertebrates, host-parasite relationships, and reservoir host potentials on Taiwan and the Offshore Islands. Ninety-nine of the rodents examined, including Bandicota indica nemorivaga, Rattus coxinga coxinga, R. losea, R. norvegicus, R. rattus mindanensis and R. rattus subsp. were infected with the metastrongylid lung worm, Angiostrongylus cantonensis. The parasite was found to occur on Lan-yü and in a number of localities on Taiwan. Several species have been added to the list of natural hosts. An examination of sizable population samples of rodents in several localities, and the frequency of infection with A. cantonensis in Bandicota in extensive studies at one site, suggest that hostparasite relationships may be variable and may depend on parasitological potentials in circumscribed areas. The known geographic distribution of A. cantonensis in man and in rodents is presented. Although the first human infection was recorded earlier on Taiwan, angiostrongyliasis is not currently recognised as a clinical entity on the island. Further epidemiological studies are indicated since conditions for propagation of the parasite apparently are ideal and the close association of infected rodents, intermediate hosts and the people of some of the farming communities suggest high potentials for human infection.