Carnivore parvovirus ecology in the Serengeti ecosystem: vaccine strains circulating and new host species identified

Carnivore parvoviruses infect wild and domestic carnivores and cross- species transmission is believed to occur. However, viral dynamics are not well understood nor the consequences to wild carnivore populations of the introduction of new strains into wild ecosystems. To clarify the ecology of these viruses in a multi-host system such as the Serengeti ecosystem and identify potential threats for wildlife conservation we analyzed, through real-time PCR, 152 samples belonging to 14 wild carnivore species and 62 samples from healthy domestic dogs. We detected parvovirus DNA in several wildlife tissues. Of the wild carnivore and domestic dog samples tested, 13% and 43%, respectively, were positive for carnivore parvovirus infection, but little evidence of transmission between the wild and domestic carnivores was detected. Instead, we describe two different epidemiological scenarios with separated routes of transmission: first, an endemic feline parvovirus (FPV) route of transmission maintained by wild carnivores inside the Serengeti National Park (SNP); and second, a canine parvovirus (CPV) route of transmission among domestic dogs living around the periphery of the SNP. Twelve FPV sequences were characterized, new host-virus associations involving wild dogs, jackals and hyaenas were discovered and our results suggest mutations in the fragment of the gene were not required to infect different carnivore species. In domestic dogs, six sequences belonged to the CPV-2a strain, whilst 11 belonged to the CPV-2 vaccine-derived strain. This is the first description of a vaccine-derived parvovirus strain being transmitted naturally. IMPORTANCE: Carnivore parvoviruses are widespread among wild and domestic carnivores, which are vulnerable to severe disease under certain circumstances. The findings from this study, which further the understanding of carnivore parvovirus epidemiology, suggest that feline parvoviruses are endemic in wild carnivores in the Serengeti National Park (SNP); further, that canine parvoviruses are present in the dog population living around the SNP, with little evidence of transmission into wild carnivore species; and finally, that the detection of vaccine-derived virus (described here for the first time circulating naturally in domestic dogs) highlights the importance of performing epidemiological research in the region