Diagnostic spectrum

Poxvirus (Avipox) see also        ⇒     Avipoxvirus

General information

The genus Orthopoxvirus belongs to the family of Poxviridae. These occupy a special position within the viruses due to their structure and their virus-specific enzymes. Poxviruses are able to mature into viruses capable of infection in the cytoplasm of the host cell without the cooperation of the cell nucleus. Poxviruses have a relatively large genome with a double-stranded linear DNA.

Orthopoxviruses have a broad host spectrum and are therefore alternately called e.g. cowpox, catpox, elephantpox or ratpox. Cattle, carnivores, rodents and humans are particularly susceptible.

In Germany, the authorities must be notified.


An infection with cowpoxvirus can cause catpox in both cats and humans. Cats usually become infected through prey animals such as mice and rats. The virus penetrates the skin through bites or scratches, which are usually localised on the head, neck or forelimbs.To some extent, necrotising, extremely itchy smallpox appears at these sites. In most cases, self-healing occurs after a few weeks, but in immunosuppressed humans and cats (e.g. FIV infection), a systemic infection with severe to fatal pneumonia can develop.

The vaccination against human smallpox, which was carried out until the 1970s, does not provide protection against infection, but seroconversion with the vaccinia virus used for vaccination can probably lead to a weakened clinical picture. These vaccinations were discontinued in the mid-1970s and a clustered occurrence of this infection is again becoming more likely.

A PCR analysis from skin crust material can provide a rapid and reliable diagnosis.

Self-protection during sampling and treatment of an infected cat should not be neglected. In addition, veterinary personnel and, if necessary, the owners should be educated. In most cases, if a person is infected with smallpox, it can be diagnostically evaluated whether or not the pet is a carrier.


The occurrence of Orthopoxvirus bovis infections in pet rats and the resulting transmission to humans has only recently been described. The rats show necrotising lesions on limbs and in the area of the head and tail area.