ABSTRACTThe control of multihost pathogens, such asCoxiella burnetii, should rely on accurate information about the roles played by the main hosts. We aimed to determine the involvement of the red deer (Cervus elaphus) in the ecology ofC. burnetii. We predicted that red deer populations from broad geographic areas within a European context would be exposed toC. burnetii, and therefore, we hypothesized that a series of factors would modulate the exposure of red deer toC. burnetii. To test this hypothesis, we designed a retrospective survey of 47 Iberian red deer populations from which 1,751 serum samples and 489 spleen samples were collected. Sera were analyzed by enzyme-linked immunosorbent assays (ELISA) in order to estimate exposure toC. burnetii, and spleen samples were analyzed by PCR in order to estimate the prevalence of systemic infections. Thereafter, we gathered 23 variables—within environmental, host, and management factors—potentially modulating the risk of exposure of deer toC. burnetii, and we performed multivariate statistical analyses to identify the main risk factors. Twenty-three populations were seropositive (48.9%), andC. burnetiiDNA in the spleen was detected in 50% of the populations analyzed. The statistical analyses reflect the complexity ofC. burnetiiecology and suggest that although red deer may maintain the circulation ofC. burnetiiwithout third species, the most frequent scenario probably includes other wild and domestic host species. These findings, taken together with previous evidence ofC. burnetiishedding by naturally infected red deer, point at this wild ungulate as a true reservoir forC. burnetiiand an important node in the life cycle ofC. burnetii, at least in the Iberian Peninsula.
Estimating the Efficacy of a Commercial Phase I Inactivated Vaccine in Decreasing the Prevalence of Coxiella burnetii Infection and Shedding in Red Deer (Cervus elaphus)
