Subfamily: Chordopoxvirinae

Genus: Capripoxvirus

Distinguishing features

Members of the genus Capripoxvirus cause economically important, notifiable diseases in domesticated cattle, sheep and goats. In cattle, milk drop, secondary mastitis, abortion and infertility can occur, although mortality is usually <10%, whereas lambs and young goats are highly susceptible to infection and mortality can be up to 50%. While lumpy skin disease virus distribution is confined mainly to Africa and the Middle East, both goatpox virus and sheeppox virus have a much wider distribution across Africa and Asia. Viruses can be transmitted mechanically by arthropods and by direct contact or fomites (Babiuk et al., 2008). There is extensive DNA cross-hybridization between species, and serological cross-reaction and cross-protection between the viruses. Sheeppox and goatpox viruses have a narrow host range, whereas lumpy skin disease virus has been found in a number of wildlife species across Africa. There is no evidence of the capripoxviruses being zoonotic.

Virion

Virions are brick-shaped, about 300 × 270 × 200 nm. Infectivity is sensitive to trypsin and ether.

Genome organization and replication

The dsDNA genome is approximately 150–154 kbp, encoding 147–156 genes; G + C content is approximately 26%. The central core of the capripoxvirus genome is co-linear with the other chordopoxviruses with genes at both ends predicted to confer host range and immunomodulating activities (Tulman et al., 2001). In pairwise comparisons, the capripoxviruses are most like the leporipoxviruses and the yatapox viruses. Members of the species Goatpox virus and Sheeppox virus are entirely co-linear along the whole length of the genome with all 147 genes present being found in members of the species Lumpy skin disease virus (Tulman et al., 2002). This latter species has an additional 9 genes that are extensively disrupted in members of the species Goatpox virus and Sheeppox virus and thus are thought to be involved in defining the bovine host.

For replication please see discussion under family description.

Species demarcation criteria

The general chordopoxvirus criteria of <98% nucleotide identity across the central core of the genome is used to delineate species, whereas >98% identity would indicate separate strains of the same species.