Seroepidemiology of Bovine Babesiosis due to Babesia divergens in Tunisia

Abstract

Babesia divergens was recently isolated in Tunisia from a bovine of local breed. A serological and parasitic survey was conducted in seven sites, where biotopes were favorable to Ixodes ricinus. Results confirmed the presence of Babesia in several herds. Serum samples were collected from 307 cattle of various ages, spread out throughout the sites. All sera were tested by the indirect immunofluorescence test using B. divergens-infected red cells of gerbils (Meriones unguiculatus) as an antigen. At 1/80 dilution, the prevalence of infection by B. divergens was 44.6%. The prevalence varied according to the site, the herd and the age class of cattle. Direct examination of thin blood smears of these bovines showed intraerythrocytic piroplasms in 28.3% samples. After inoculation of 46 collected samples to gerbils, two B. divergens strains were isolated. The present study shows that B. divergens, which was thought to be confined in Europe up until now, is also present as foci in North Africa, and that a stable endemic situation appears to be established between the local breed (Bos taurus) and this hemoparasite in North Tunisia.