Zoonotic Orthopoxvirus Infection.

Abstract

Introduction: Cowpox virus (CPXV) is a rare zoonotic orthopoxvirus infection, most commonly transmitted to humans via infected domestic cats. It typically causes necrotic skin lesions accompanied by systemic symptoms such as fever and lymphadenopathy. Diagnosis is confirmed by polymerase chain reaction (PCR) and sequencing, and management is mainly supportive.

Case presentation: A 64-year-old farmer presented with painful, clustered necrotic lesions on the face and neck evolving over 10 days, associated with fever and lymphadenopathy. Due to the facial distribution and severity, broad empirical treatment with intravenous acyclovir and ceftriaxone was initiated. Diagnostic testing for common infectious causes was negative, and bacterial cultures showed no growth. Based on lesion morphology and relevant animal exposure, orthopoxvirus infection was suspected. PCR of skin swab material confirmed orthopoxvirus DNA, and sequencing identified CPXV/catpox virus.

Conclusion: This case highlights CPXV infection in an older host with prominent facial clustering, initially requiring broad empirical therapy. CPXV should be considered in patients with necrotic facial lesions and animal exposure. PCR-based diagnostics are essential for confirmation, and the clinical course is usually benign with supportive management, although residual scarring may occur.