A rapid diagnostic molecular-based test for the simultaneous detection of the two most recognised pathogens responsible for equine piroplasmosis has painted a picture of the infection’s prevalence in Egypt. Equine piroplasmosis is an infectious disease caused by the blood-dwelling parasites Theileria equiBabesia caballi and the recently identified species Theileria haneyi. The disease is a problem in much of the world. There are more than 30 species of ticks that have been identified as vectors of T. equiB. caballi, or both. Infection with T. equi and B. caballi can cause severe economic losses in the equine industry because of the cost of treatment, especially for acutely infected horses, which, in the absence of appropriate treatment, can die.

Researchers, reporting in the journal Pathogens, tested blood samples from 79 horses and 76 donkeys, collected from different governorates of Egypt, for T. equi and B. caballi. Additionally, they tested for the presence of T. hayeni, first detected in a horse on the US-Mexico border. T. haneyi, which rarely causes clinical signs in field horses, has since been detected in several countries in North and South America, Africa, and Asia.

The testing detected the presence of T. equi in 20.3% of the horses and 13.1% of the donkeys, and B. caballi in 1.2% of the horses. B. caballi was not detected in donkeys in the study. The testing method also detected co-infections with both species in 2.5% of the horses and 1.3% of the donkeys. Their testing revealed, for the first time, the presence of T. haneyi in Egypt, with 53.1% of the horses and 38.1% of the donkeys testing positive. Coinfection with T. haneyi and T. equi was found in 13.5% of the samples, while infection with the three species was found in 1.9% of the samples. The prevalence of T. haneyi may be related to environmental conditions, husbandry, and tick vectors, they said. Differences in sampling size and time of sample collection could also be contributing factors. “The identification of T. haneyi in Egyptian equids is not surprising but warrants further investigation,” they said. The study team comprised Bassma Elsawy, Ahmed Nassar, Heba Alzan, Raksha Bhoora, Sezayi Ozubek, Mona Mahmoud, Omnia Kandil and Olfat Mahdy, from a range of institutions.