Molecular evidence of <i>Babesia</i> infections in Spinose ear tick, <i>Otobius</i> <i>megnini</i> infesting stabled horses in Nuwara Eliya racecourse: A case study

Abstract

Spinose ear tick, Otobius megnini (Family Argasidae) is a one-host soft tick that parasitizes domesticated animals and occasionally humans. It causes otoacariasis or parasitic otitis in humans and animals and also known to carry infectious agents. Intra aural infestations of O. megnini is a serious health problem in the well-groomed race horses in Nuwara Eliya. Otobius megnini collected from the ear canal of stabled horses in Nuwara Eliya racecourse were tested for three possible infections, Rickettsia, Theileria and Babesia. Genomic DNA was extracted from 22 ticks collected from 11 horses and then pathogen-specific DNA was amplified using PCR. Ticks from two horses (one thoroughbred and one stallion) tested PCR positive for Babesia but not for other infections. None of the horses however, showed any clinical symptoms of babesiosis. This is the first record of Babesia infections in O. megnini. However, the presence of Babesia DNA in O. megnini doesn’t qualify it as the vector of equine babesiosis, horse blood has to be tested for the presence of parasite DNA or antibodies.

Keywords

• spinose ear tick
• babesiosis
• horses
• otoacariasis
• <i>rickettsia</i>
• <i>theileria</i>