Studies on Malayan Filariasis in Che-Ju Is., Korea

Abstract

Cheju strain of B. malayi was successfully transmitted to three domestic cats by subcutaneous injection of infective-stage larvae obtained from naturally-infected Ae. togoi. The second generation of the strain of B. malayi was established in nine cats which had been inoculated subcutaneously with the infective larvae developed in laboratory-bred Nagasaki strain of Ae. togoi. The third generation was built up by subcutaneous inoculation in two cats through Ae. togoi and four cats through Liverpool strain of Ae. aegypti. The prepatent periods were 91-131 days. The microfilaria counts in the peripheral blood gradually increased in one third to two thirds of successfully transmitted cats. The microfilariae of Cheju strain exhibited a sub-periodic tendency in the cat. The average infection rate of laboratory-bred Nagasaki strain of Ae. togoi was 69.3% with infective larvae of B. malayi. The mean number of larvae per mosquito was 5.8 with the infective larvae. Nagasaki strain of Ar. subalbatus was not susceptible to B. malayi infection. B. pahangi developed to the infective form in both Ae. togoi and Ar. subalbatus.