Contemporary Human and Animal Infections with Cowpox Virus: Recommendations for Preventing Zoonotic Transmission
Cowpox was long considered enzootic in cattle with occasional transmission to humans.1 Today the virus is known to infect a broad range of species throughout Europe and western Asia. The first case of human cowpox in the United States was recently reported. Although this infection was acquired in a laboratory setting, the 2003 U.S. monkeypox outbreak serves as a reminder that cowpox could enter the U.S. via importation of infected animals. The numerous reports from Europe of cowpox in zoologic collections and companion animals indicate that veterinarians, zoo personnel, and wildlife professionals would be among the first to encounter cowpox virus and, therefore, should be familiar with cowpox epidemiology, transmission, clinical signs, and personal protective measures. Wild rodents are considered the reservoir, but the species appear to differ based on geographic location.4 The virus is usually transmitted to humans through direct contact and infections are typically self-limiting in immunocompetent hosts. Clinical disease typically manifests as dermal lesions in animals and humans; however, a pulmonary form has been described in felids.2,3 Clinical cowpox has been recognized most often in Felidae sp., namely the domestic cat, but has also been described in elephants, okapis, anteaters, and others.5-7 In these instances, infections are often more severe and more frequently fatal than what is seen in the domestic cat. Early recognition of disease, adherence to quarantine procedures, and the use of gloves when handling rodents and animals with skin lesions may diminish risks for human infection.
The findings and conclusions in this report are those of the authors and do not necessarily represent the official position of the Centers for Disease Control and Prevention.
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