Epidemiology of ovine anaplasmosis (Anaplasma ovis) in sheep on the island of Lesvos, Greece

Abstract

Background: Anaplasma ovis is a tick-borne pathogen that is widely distributed around the world. The primary purpose of this study was to determine the prevalence of A. ovis in sheep as well as in ticks found on these sheep on the island of Lesvos, Greece. This study was also designed to estimate the prevalence of the different tick species found on sheep on Lesvos. Methods: During May, June and October 2015, blood samples and ticks from sheep at a total of 101 farms all over Lesvos were collected. Firstly the ticks were identified. Secondly the blood samples and ticks were analyzed for TBDs using an array of laboratory techniques: DNA extraction, PCR amplification and RLB hybridization. Results: In May and June, the following tick species were found: Rhipicephalus turanicus (89,9%), R. bursa (4,92%), R. sanguineus (2,67%), Hyalomma marginatum (1,73%), H. anatolicum excavatum (0,43%), H. detritum (0,17%), H. detritum scupense (0,09%) and H. rufipes (0,09%). In October the tick species collected differed greatly from May and June. Species found in October were Dermacentor marginatus (48%), Haemaphysalis parva (44,2%), H. punctata (7,46%), H. sulcata (0,19%) and R. sanguineus (0,19%). The 197 blood samples and 171 R. turanicus ticks collected in May and June were analyzed for TBDs. A. ovis was detected in 59,3% of the sheep tested. The prevalence of A. ovis in R. turanicus ticks was 13.4%. The analysis of the October samples still remains to be carried out. Conclusions: The results of this study demonstrate a high prevalence of A. ovis in sheep on Lesvos. Furthermore, sheep were highly infested with ticks in both seasons, including known vectors of A. ovis. These results confirm the importance of further research on the impact of infection with A. ovis on the health and production of these sheep. Moreover, these data support the need to investigate which tick species are able to transmit A. ovis.