Molecular Detection and Genetic Characterization of Porcine Circovirus 2 (PCV-2) in Black-Backed Jackal (Lupulella mesomelas) in Namibia

SIMPLE SUMMARY: Although often considered host-specific, there is increasing evidence of a broader-than-expected host tropism for different circoviruses, including porcine circovirus 2 (PCV-2). In this study, the presence of PCV-2 in the lung lymph nodes of Namibian jackals has been demonstrated. The complete genome of the viruses was generated, and they were classified as PCV-2b and shown to have a close genetic relationship with South African and Namibian strains collected from domestic pigs. Since contact between jackals and domestic swine is highly unlikely, one of the most plausible explanations for the infection of the jackals with PCV-2b would involve the dispersal of pig-derived products in the wild environment during recreational activities or the scavenging activity of jackals living in peri-urban areas. However, further studies are required to properly assess how PCV-2 is acquired and maintained in the wild canids and its potential impact on other wild and domestic species. ABSTRACT: Members of the genus Circovirus have been identified in several host species. While initially considered host-specific, there is growing evidence of their presence in unexpected hosts. Porcine circovirus 2 (PCV-2) is no exception, having been reported in animals belonging to different orders, including carnivores. Recently, PCV-2 was detected in domestic pigs, warthogs and antelopes in Namibia. Considering the potential contact between these populations and wild carnivores, the presence of PCV-2 was investigated in 32 black-backed jackals (Lupulella mesomelas) shot between February and July 2021 as part of predator control operations in Namibia. Two lung lymph nodes tested positive for PCV-2 by PCR, confirming the broader-than-expected PCV-2 host tropism and the susceptibility of canids. Sequence analysis demonstrated a close association between the PCV-2s identified in the jackals and PCV-2b strains collected from South African domestic pigs. Although several hypotheses regarding the source of the jackal’s infection are proposed, further studies should be performed to properly assess how PCV-2 is acquired and maintained in the wild and its potential impact on wild and domestic species.