The role of wild boar (Sus scrofa) in the eco-epidemiology of R. slovaca in Northeastern Spain.

Rickettsia slovaca is considered the etiological agent of tick-borne lymphadenopathy (TIBOLA), an emerging disease transmitted by tick bites. Dermacentor marginatus constitutes the most important vector and wild boar (Sus scrofa) is the main wild host in our area. The epidemiology of this tick-borne rickettsioses has not been completely clarified. During hunting season 2004, wild boar sera sample were collected from northeastern Spain. Ticks were collected both from wild boar and from flagging vegetation in the same areas where wild boar were hunted. Serologic study was carried out using the immunofluorescent antibody (IFA) technique. Ticks were identified as D. marginatus and Rhipicephalus uranicus. Based on sequence analysis on ompA gene, R. slovaca was identified in 30.5% D. marginatus ticks removed from wild boar and in 33.3% D. marginatus collected from flagging vegetation. Rickettsia sp. RpA4 was identified in 4 specimens of D. marginatus removed from wild boar. Twelve of 23 wild boar were seropositive to R. slovaca. Results suggested wild boar are exposed to R. slovaca infection and this pathogen is well established in the wild cycle of D. marginatus in our area.