Arteriviruses are enveloped viruses of 45 to 80 nm in diameter with a spherical appearance due to the shape of the envelope. However, the nucelocapsid that contains the positive-sense single-stranded RNA genome is actually icosohedral. The lipoprotein envelope has ring-like structures on its surface, but there are no gross surface spikes. Arteriviruses have a tropism for macrophages and endothelial cells, where they reproduce in the cytoplasm. The genome is 13Kb in length, and is infectious itself without the capsid or envelope.
Arteriviruses are inactivated by treatment with chloroform or ether. They are very resistant to freezing, althouth infectivity is reduced as temperature rises.
Arteriviruses comprise equine arteritis virus, lactate dehydrogenase-activating virus and the virus of the porcine reproductive and respiratory syndrome.
Morphology
- Small, enveloped, positive sense RNA viruses
Epidemiology
- Aerosol and venereal transfer
- Poor vaccination