Pseudocowpoxvirus

Pseudocowpoxvirus is a species of virus in the family Poxviridae, genus Parapoxvirus. It is a large, enveloped, brick-shaped double-stranded DNA virus that infects cattle and other ruminants. The virus causes bovine pseudocowpox, a contagious dermatitis of the teats and udders, and can also produce lesions in the oral mucosa of affected animals. In humans, zoonotic infection can occur after contact with infected cattle, commonly presenting as milker’s nodules on the hands or fingers.

Taxonomy and genome

Pseudocowpoxvirus belongs to the genus Parapoxvirus within the family Poxviridae. Parapoxviruses have relatively large, linear double-stranded DNA genomes, typically about 134–140 kilobase pairs, and replicate in the cytoplasm of infected cells. Virions are brick-shaped, characteristic of poxviruses.

Hosts, transmission, and clinical signs

Primary hosts are cattle, with possible infection of other ruminants. In cattle, the disease manifests as nodular to ulcerative lesions on the teats, udders, and occasionally oral mucosa; lesions are usually self-limiting but can be painful and may predispose to secondary bacterial infections, reducing milk yield. In humans, contact with infected animals or contaminated equipment can cause localized nodules on the hands or fingers that heal without complication over weeks.

Diagnosis and management

Laboratory confirmation is via molecular methods such as PCR targeting parapoxvirus DNA, sequencing, or virus isolation; electron microscopy and serology may support diagnosis. Treatment is primarily supportive and aimed at preventing secondary infections; analgesics may be used for pain, and good herd hygiene reduces transmission. There is no widely used commercial vaccine for pseudocowpox in cattle.

Epidemiology

Pseudocowpoxvirus is found worldwide, with outbreaks linked to dairy husbandry practices and milking equipment hygiene. Zoonotic cases are reported among dairy workers and veterinarians.