Mobilization of Dirofilaria immitis Microfilariae in Mice during the Treatment with Diethylcarbamazine

Abstract: The provocative activity of diethylcarbamazine (DEC) on the skin-dwelling mi-crofilariae was examinend by using a mouse-Dirofilaria immitis microfilariae model. The mice were inoculated subcutaneously with 30,000 D. immitis microfilariae and given DEC at dosage of 300mg/kg body weight on 3,4 and 5 days after inoculation. Ten animals treated with DEC and ten control animals were necropsied on the 6 th day after infection in order to recover microfiariae alive. DEC treatment induced the reduction in the total number of microfilariae recovered from a mouse. The remarkable reduction was recog-nized in the number of microfilariae from pelt (p<0.001). On the contrary, the number of microfilariae from viscera was likely to increase, though the difference was not stati-stically significant. These facts suggested that DEC might cause the mobilization of mi-crofilariae into viscera, especially to liver and kidneys. The possible invasion of large number of D. immitis microfilariae into deep organs during the treatment was discussed