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.