Studies with Brugia pahangi. 20. An investigation of 23 anthelmintics using different screening techniques.

23 anthelmintics were tested against Brugia pahangi microfilariae and infective larvae in vitro and in Aedes aegypti infected with B. pahagi and jirds (Meriones unguiculatus) infected with a B. pahangi/patei hybrid. There was little correlation between the results obtained in vitro and in infected insects and the results obtained in these tests gave no indication of the activity in jirds. Three of the compounds were macrofilaricidal in jirds and these were tested in cats infected with B. pahangi. One of these--5-benzamido-2(4-thiazolyl)-benzimidazole--was macrofilaricidal in cats and it is suggest that it should be tested in other filarial systems. It is concluded that the insect and in vitro tests are not good primary screens for filaricidal activity.