Cowpox

Cowpox
Electron micrograph of three Cowpox virus particles
Virus classification
(unranked):	Virus
Realm:	Varidnaviria
Kingdom:	Bamfordvirae
Phylum:	Nucleocytoviricota
Class:	Pokkesviricetes
Order:	Chitovirales
Family:	Poxviridae
Genus:	Orthopoxvirus
Species:	Orthopoxvirus cowpox

Cowpox
Cowpox lesions on patient's forearm on day 7 after onset of illness. The hemagglutinin gene of the isolate clustered with a Russian cowpox virus strain, and more distantly with other cowpox and vaccinia virus strains. The patient's dog had orthopoxvirus-specific antibodies, indicating a possible transmission route.
Specialty	Infectious diseases, veterinary medicine

Cowpox is an infectious disease caused by Cowpox virus (CPXV). It presents with large blisters in the skin, a fever and swollen glands, historically typically following contact with an infected cow, though in the last several decades more often (though overall rarely) from infected cats. The hands and face are most frequently affected and the spots are generally very painful.

The virus, part of the genus Orthopoxvirus, is closely related to Vaccinia virus. The virus is zoonotic, meaning that it is transferable between species, such as from cat to human. The transferral of the disease was first observed in dairy workers who touched the udders of infected cows and consequently developed the signature pustules on their hands. Cowpox is more commonly found in animals other than bovines, such as rodents. Cowpox is similar to, but much milder than, the highly contagious and often deadly smallpox disease. Its close resemblance to the mild form of smallpox and the observation that dairy farmers were immune to smallpox inspired the modern smallpox vaccine, created and administered by English physician Edward Jenner.

The first description of cowpox was given by Jenner in 1798. "Vaccination" is derived from the Latin adjective vaccinus, meaning "of or from the cow". Once vaccinated, a patient develops antibodies that make them immune to cowpox, but they also develop immunity to the smallpox virus, or Variola virus. The cowpox vaccinations and later incarnations proved so successful that in 1980, the World Health Organization announced that smallpox was the first disease to be eradicated by vaccination efforts worldwide. Other orthopox viruses remain prevalent in certain communities and continue to infect humans, such as the cowpox virus in Europe and monkeypox virus in Central and West Africa.

The virus is found in Europe, and mainly in the UK. Human cases today are very rare and most often contracted from domestic cats. The virus is not commonly found in cattle; the reservoir hosts for the virus are woodland rodents, particularly voles. From these rodents, domestic cats contract and transmit the virus to humans. The incubation period is 9 to 10 days. The virus is prevalent in late summer and autumn.