Morphological forms of Trypanosoma evansi from blood of Arabian camel [Camelus dromedarius] in the Riyadh metropolitan areas

Trypanosoma evansi is commonly referred to as haemoflagellate infesting camels and other vertebrates. It is causative agent of number of diseases. T. evansi has several morphological forms. We have detected three forms in the blood of camels, slender, transitional and intermediate. The present study is the first investigation on the morphological forms of T. evansi in Arabian camels in Saudi Arabia

Trypanosoma evansi in dromedary camel: with a case report of zoonosis in greater Cairo, Egypt

Trypanosoma evansi [Steel, 1885] Balbiani, is the cause of trypanosomiasis [Surra] which multiples in the blood and body fluids. The incubation period varies from 7-15 days. The mortality rate was up to 20% and fatality rate may reach up to 100% in untreated camels. Three hundred randomly selected camels were 200 males 4-6 years old and 100 females 10-15 years. They were examined clinically and diagnosed by Giemsa stained blood smear, anti-trypanosomiasis-antibodies by ELISA and urine Thymol turbidity test for natural infection with T. evani [Surra]. The results showed that camels were naturally infected with T. evansi as indicated by stained blood film examination and/or ELISA. Infection in males was 6.0% [stained blood smears], 8.0% [ELISA] and 5.0% [urine thymol turbidity test]. In females the infection rate was 9.0%, 24.0% and 12% respectively. By correlation with suggestive clinical manifestations, ELISA proved to be more sensitive and specific [13.3%] than stained blood films [10.0%] and urine Thymol turbidity test [7.3%]. Regarding humans, one out of 30 was positive as indicated by ELISA and stained blood smear but was negative by urine thymol turbidity test. The human case was successfully treated as indicated clinically, parasitologically and serologically. This is the first reported Egyptian human case of trypanosomiasis evansi, a neglected zoonosis

Polymorphism in trypomastigotes of Trypanosoma (Megatrypanum) minasense in the blood of experimentally infected squirrel monkey and marmosets

Experimental infections by Trypanosoma (Megatrypanum) minasense were performed in primates - Saimiri sciureus and Callithrix penicillata - with the objective of searching for morphological variations of the blood trypomastigotes with respect to hosts and time of infection. We carried out morphological and morphometric analysis of blood trypomastigotes. Illustrations are given. Both the squirrel monkey and marmoset became infected after the injection of blood trypomastigotes of T. minasense , although the parasitaemia were briefer in the squirrel monkey. The parasites detected in the later host were narrower and shorter than those found in the inoculated marmoset. In the marmoset, the blood stream parasites derived from culture metacyclic trypomastigotes were considerably smaller than those derived from the inoculation of infected blood. Stronger evidence of polymorphism was found when, at the same time of infection, the blood trypomastigotes found in squirrel monkey had smaller length, body width and the distance from posterior end of the body to the kinetoplast almost four times smaller than the parasite found in the marmoset. Therefore, conflicting results on morphology and morphometry of T. minasense obtained by previous investigators could be due to polymorphism.