Babesia diagnosis in cheetahs : preliminary analysis comparing PCR tests and microscopic observations of blood smears

Abstract

Cheetahs are on the list of the most endangered feline species of Africa. To have an effective conservation effort it is important to have a global idea of their health, their behaviour, their environment, and their genetic. This multidisciplinary vision is the leitmotiv of the Cheetah Conservation Fund in Namibia. A lot of African felines have blood and tick-borne subclinical diseases, that can with other infection play a co-morbidity role. That’s why it is important to know the prevalence and importance of Babesia infections in cheetahs. For this, we have different methods, with different sensitivities and specificities. With the help of calculations and graphs, we compared 2 methods, the blood smear microscopic examination, which is the gold standard of Babesia diagnosis, and PCR testing of blood samples. We found that the sensitivity was much higher for PCR, especially considering that blood smear examinations have a very variable sensitivity depending on the experience of the person examining the slide. The specificity is at least as good in a PCR than in a blood smear, if not better because it allows identifying the Babesia subspecies with the right primer. In conclusion, PCR is a good alternative to diagnose Babesia infections, especially for cheetahs who generally have low parasitaemia.