Seroprevalence of Toxoplasma gondii in one-humped camels (Camelus dromedarius) of Thal and Cholistan deserts, Punjab, Pakistan

Toxoplasma (T.) gondii is an important zoonotic protozoan infecting humans and a wide range of animals. In this study, we determine the seroprevalence and risk factors associated with the seroprevalence of T. gondii in one-humped camels (Camelus dromedarius) in Pakistan. Camels are still an important mean of transportation in some desert areas in Pakistan. In addition, they are the main source of meat and milk for people in those regions; therefore, they have the potential to transmit T. gondii to humans. In order to estimate the seroprevalence of T. gondii, a total of 897 sera samples were collected from camels in the Thal (n=359) and Cholistan (n=440) deserts, along with other districts of Chakwal (n=44) and Faisalabad (n=54) Punjab, Pakistan, through convenient and snowball sampling techniques. These samples were then analyzed by an indirect enzyme-linked immune-sorbent assay (ELISA) for the presence of T. gondii-specific antibodies, using purified recombinant micronemal protein 3 (MIC3) as an antibody-catching antigen. Our results showed an overall seroprevalence of T. gondii as 40.1% (Thal=45%; Cholistan=35.9%; other districts=33.7%). Risk factor analysis suggested that infection rate was higher in older animals (70.6%). In addition, female camels carried frequent infection (48.8%) than males (22.4%). What's more, female animals having abortion history showed even higher infection rate (75%) compared to pregnant (68.4%) and non-pregnant (42.4%) animals. Our results reported high seroprevelance of T. gondii in camels in Pakistan which provided important information with respect to public health and disease controls.