Persistence of microfilaraemia in peripheral blood and host response against adult Setaria cervi implanted in the peritoneal cavity of white rats

Adult worms and microfilariae survived for 30 and 70 days, respectively in white rats experimentally infected with Setaria cervi which clearly indicates that this parasite of buffalo does not cause severe pathological condition in white rats and the worm do not show any indication of early and complete rejection by the host. It may therefore considered to be the better model for the experimental studies as compared to rabbits and guniea pigs where survival period of both adult worms as well as microfilariae is short. Host reaction was manifested in the form of cell infiltration around the caseated worms. As for differential leucocyte count is concerned there was an early rise in eosinophils and neutrophils with subsequent decline after second and third week, respectively. A reversal mechanism was observed for lymphocytes which showed a decline up to third week followed by a steady rise till eighth week. Neutrophils showed rise in count during first three weeks and there after showed almost uniform decline up to eighth week. Normal blood count was regained after 10–11 weeks.