Detection of Tick-Borne Pathogens in Red Deer (Cervus elaphus), United Kingdom

Abstract

Deer represent a major vertebrate host for all feeding stages of the hard tick Ixodes ricinus in the United Kingdom (UK), and could play a role in the persistence of tick-borne pathogens. However, there have been few studies reporting the presence of Babesia spp. and Anaplasma phagocytophilum in deer in the UK, and those that detected Babesia were unable to confirm the species. To address this, we have investigated blood samples from red deer (Cervus elaphus) for the presence of tick-borne pathogens. Total DNA was extracted from haemolysed blood that was removed from clotted blood sampled from culled, captive red deer. Babesia spp. were detected with a pan-piroplasm PCR that amplifies a fragment of the 18S rRNA gene. Species were identified based on identity with published sequences. Anaplasma phagocytophilum was detected with a probe-based PCR targeting the msp2 gene. In addition, residual serum samples from a subset of animals were tested for the presence of anti-flavivirus antibodies. Of 105 red deer samples tested from three locations in the United Kingdom, 5 were positive for piroplasm and 5 were positive for A. phagocytophilum. Co-infection with both pathogens was detected in two samples from one location. No evidence for antibodies against West Nile virus were detected. However, 12% of sera tested were positive for tick-borne encephalitis virus antibodies.

Transmission Cycle of Tick-Borne Infections and Co-Infections, Animal Models and Diseases

“…In nature, TBPs have been reported in different species ranging from small to large animals worldwide (Table 1) as listed for the US [70], Canada [72], South America [65,74], Europe [28,63,68,69,75], Australia [76] Africa [77] and China [78]. Despite tick blood meal being the most common transmission mode of TBPs, oral engulfment of infected ticks by animals, carnivorism, animal bites, and transplacental routes also occur to cause wildlife infection [2].…”