Molecular evidence for trans-stadial and transovarial transmission of Babesia occultans in Hyalomma marginatum and Rhipicephalus turanicus in Turkey

Abstract

A total of 1064 adult ticks identified as Hyalomma marginatum (n=965), Rhipicephalus turanicus (n=86), Haemaphysalis inermis (n=9) and Rhipicephalus bursa (n=4) along with 20 egg masses derived from H. marginatum (n=18) and R. bursa were screened for Babesia occultans. The ticks were combined into 328 pools and infection rates were calculated as the maximum likelihood estimation (MLE) with 95% confidence intervals (CI). Of these pools, 23 (7%) were positive for B. occultans, and the overall MLE was calculated as 2.27% (CI 1.48-3.35). Infection prevalence in tick species was 7.09% for H. marginatum (22/310, MLE 2.41, CI 1.55-3.59) and 7.14% for R. turanicus (1/14, MLE 1.11, CI 0.07-5.18). None of H. inermis and R. bursa was infected with the parasite. Host-seeking H. marginatum females displayed an infection prevalence of 1.68% (2/119, MLE 0.63, CI 0.11-2.06), while no parasite DNA was detected in the males. The prevalence of infection in feeding H. marginatum varied, ranging from 27.27% (9/33, MLE 4.61, CI 2.26-8.52) in males to 25.92% (7/27, MLE 8.22, CI 3.72-15.75) in females. Of the egg masses examined, 4 (22.22%) of H. marginatum and 1 (50%) of R. turanicus were infected with B. occultans. To the best of our knowledge, this is the first time that B. occultans has been detected in R. turanicus.

Keywords: Babesia occultans; Hyalomma marginatum; PCR; Rhipicephalus turanicus.