Coxiella burnetii in wild mammals: A systematic review

Coxiella burnetii is a multi-host bacterium that causes Q fever in humans, a zoonosis that is emerging worldwide. The ecology of C. burnetii in wildlife is still poorly understood and the influence of host, environmental and pathogen factors is almost unknown. This study gathers current published information on different aspects of C. burnetii infection in wildlife, even in species with high reservoir potential and a high rate of interaction with livestock and humans, in order to partially fill the existing gap and highlight future needs. Exposure and/or infection by C. burnetii has, to date, been reported in 109 wild mammal species. The limited sample size of most of the existing studies could suggest an undervalued prevalence of C. burnetii infection. Knowledge on the clinical outcome of C. burnetii infection in wildlife is also very limited, but currently includes reproductive failure in waterbuck (Kobus ellipsiprymnus), roan antelope (Hippotragus niger), dama gazelle (Nanger dama) and water buffalo (Bubalus bubalis) and placentitis in the Pacific harbor seal (Phoca vitulina richardsi), Steller sea lion (Eumetopias jubatus) and red deer (Cervus elaphus). The currently available serological tests need to be optimised and validated for each wildlife species. Finally, there is a huge gap in the research on C. burnetii control in wildlife, despite of the increasing evidence that wildlife is a source of C. burnetii for both livestock and humans.