SEROPREVALENCE OFBORRELIA BURGDORFERISENSU LATO IN ROE DEER (CAPREOLUS CAPREOLUS) FROM NORTHWESTERN SPAIN

Abstract

In the present study, the seroprevalence of Borrelia burgdorferi sensu lato in roe deer in relation to different parameters in northwestern Spain was investigated. A total of 154 roe deer hunted between April 2007 and October 2008 from different localities of Galicia (northwest Spain) were examined. From each animal, a blood sample and all attached ticks found were collected. All the specimens for tick stages (larva, nymph, and adult) were speciated based on reference keys. Antibodies against B. burgdorferi were detected by indirect immunofluorescence (titer > or = 1:64). The percentage of roe deer seropositive for B. burgdorferi was 68.8% (106/ 154), of which 88.7% (94/106) were parasitized by ticks. Ixodes ricinus was the only species identified and was detected in 83.1% of roe deer with a mean (standard deviation [SD]) intensity of 46 +/- 47 ticks. Individual host characteristics such as age or sex did not have any effect on the prevalence of B. burgdorferi, but significant seasonal variation was observed, with higher prevalences in April-July than in August-October. Antibodies against B. burgdorferi were related to the presence of ticks. When analyzing all the factors together, the total number of ticks parasitizing roe deer was found as the most influential factor on B. burgdorferi prevalence. The results of this study have shown that roe deer in the northwest of Spain are highly exposed to B. burgdorferi and that exposure is related to the presence of I. ricinus.

Occurrence of Borrelia and Borreliella species in Ixodes ricinus collected from roe deer in northwestern Spain

“…In total, 8885 ticks were collected; all developmental stages of I. ricinus were found infesting roe deer, with adult females being the most frequent, followed by nymphs, males and larvae (Table 1); these differences were significant by a Kruskal-Wallis test ( 2 = 87 145; P < 0.001). Our results corroborate those of Vázquez et al (2011) and Pato et al (2013), who found that, in addition to adults, deer could also support a high proportion of immature stages. The median number of ticks infesting roe deer was similar in both areas (Table 1) and the differences were not significant using the Kruskal-Wallis test (P > 0.05).…”

“…() and Pato et al . (), who found that, in addition to adults, deer could also support a high proportion of immature stages. The median number of ticks infesting roe deer was similar in both areas (Table ) and the differences were not significant using the Kruskal–Wallis test ( P > 0.05).…”

“…Thus, wild ungulates are among the most important feeding hosts for I. ricinus in Europe. Roe deer is the most abundant cervidae in northwestern Spain (Vázquez et al, 2011;Pato et al, 2013); they are mainly parasitized by I. ricinus (Vázquez et al, 2011) and highly exposed to Borreliella spp. (syn.…”

“…Borrelia burgdorferi s.l.) (Pato et al, 2013). Although roe deer are considered incompetent reservoir hosts for Borreliella species (Kjelland et al, 2011), the abundance of this host significantly affects the population and distribution of ticks and tick-borne pathogens.…”

The wild life of tick-borne pathogens

“…We did not have data on infection prevalence for the largest mammals in our analysis: Red deer (Cervus elaphus) and Roe deer. Studies that were not incorporated in our selection, for reasons outlined above, show that Roe deer have high levels of antibody in their blood, and low infection prevalence in tissues [150][151][152] . These findings support the hypothesis that B. burgdorferi is unable to circumvent the host complement of deer 131,153 , which could also explain the incapability of deer to transmit Borrelia spirochaetes 48 .…”