Zoonotic Poxviruses Associated with Companion Animals

Abstract

Understanding the zoonotic risk posed by poxviruses in companion animals is important for protecting both human and animal health. The outbreak of monkeypox in the United States, as well as current reports of cowpox in Europe, point to the fact that companion animals are increasingly serving as sources of poxvirus transmission to people. In addition, the trend among hobbyists to keep livestock (such as goats) in urban and semi-urban areas has contributed to increased parapoxvirus exposures among people not traditionally considered at high risk. Despite the historic notoriety of poxviruses and the diseases they cause, poxvirus infections are often missed. Delays in diagnosing poxvirus-associated infections in companion animals can lead to inadvertent human exposures. Delays in confirming human infections can result in inappropriate treatment or prolonged recovery. Early recognition of poxvirus-associated infections and application of appropriate preventive measures can reduce the spread of virus between companion animals and their owners. This review will discuss the epidemiology and clinical features associated with the zoonotic poxvirus infections most commonly associated with companion animals.

Keywords: companion animals; cowpox; monkeypox; orf; orthopoxvirus; parapoxvirus; poxvirus; zoonoses.

Figure 1

Clinical presentation of cowpox lesions on rats and humans during an outbreak in Germany, 2009. (A) Pet rat with lesions on the right hind limb; and (B) Neck lesions on a girl [10] (Photos originally printed in Emerging Infectious Diseases by Campe, H.; et al.).

Figure 2

Clinical signs of monkeypox in experimentally prairie dogs. (A) Nasal discharge; (B) Blepharitis and (C) Disseminated skin lesions (Photos associated with the study available at http://libproxy.cdc.gov:2073/science/article/pii/S0042682210001650).

Figure 3

Clinical presentations of orf lesions in a human and a sheep. (A) Lesions at the site of a bite from a sheep on day 19 postinoculation [83]; (B) Proliferative lesions involving the lips and muzzle of a goat infected with orf. (Photo A courtesy of Scottish Medical Journal Copyright 2011 Royal Society of Medicine Press; Photo B provided by Callis, J.J.; and Mahy, B.W.J. courtesy of CDC Public Health Image Library http://phil.cdc.gov/phil/home.asp).

Figure 4

Electron microscope photos of (A) orthopox (monkeypox) and (B) parapox (orf) viruses (Photo A provided by Humphrey, C.D.; Morehead, T.; and Regnery, R.; Photo B taken by Goldsmith, C.; and provided by Likos, A.; both images courtesy of CDC Public Health Image Library http://phil.cdc.gov/phil/home.asp).