Basic studies on the laboratory assessment of macrofilaricides using Brugia malayi in the jird, Meriones unguiculatus. 2. Establishment and evaluation of a new method of macrofilaricide assessment.

Jird infected subcutaneously with infective stage larvae (L3) of Brugia malayi were evaluated as an animal model for assessing macrofilaricides using a method of observing the change in microfilaria (mf) density but not by recovering adult worms. The animals were treated with a test compound followed by diethylcarbamazine (DEC) at 50 mg/kg for 5 consecutive days for clearing the existing mf from the blood stream. A continuous decrease in mf density was observed when jirds were treated with flubendazole. Nevertheless, slow recovery of mf density was observed in the jirds which were given suramin or Mel W, indicating that mf productivity of female worms was continuing after DEC treatment. The results obtained by monitoring microfilaremia corresponded with those obtained by recovery of adult worms at autopsy, suggesting that the system of L3-induced B. malayi jird model is useful for testing macrofilaricides.