Morphological Studies On Trypanosome Lewisi In Wild Rats

During the survey which was carried out on the wild rats in Kafer El-Sheikh. Governorate, 196 wildrats were collected ; 61 ( 31.12%) were found to be infected with T • lewisi. The infection rate was varied in various rat species. Summer season showed the highest infestation rate ( 26.2%) than the other seasons •, the infection rate with 1. lewisiamong females (44.6%) was much higher than males (21.2%). Also, the infection rate increased in juvenile rats (100 - 300 gms. ) but decreased amongrats more than 300 gms. body weight.With respect to. the fleas infestation rate ,it was 50.5~ whereas , the fleas-index was 2.60.Summer seasons represented the highest infesta- tion rate with fleas (66.7%) than in the other seasons •. relative humidity and the temperature during the different seasons were taken in consideration •The infestation rate with fleas was differed in di fferent ra t hosts as it was 83.3% in Ar. nilottcus but