Two Distinct Clinical Courses of Human Cowpox, Germany, 2015

Area of Science:

• Veterinary Medicine
• Infectious Diseases
• Virology

Background:

• Cowpox virus (orthopoxvirus genus) can cause zoonotic infections in humans.
• Clinical presentation and outcomes of human cowpox are influenced by factors such as vaccination history and treatment.
• Understanding cowpox virus transmission and pathogenesis is crucial for public health.

Observation:

• Two human cases of cowpox virus infection with differing clinical courses are presented.
• Case 1: An unvaccinated veterinary assistant developed a severe ulcer and lymphadenitis after contact with an infected cat, with prolonged healing.
• Case 2: A smallpox-vaccinated farmer experienced a mild cowpox infection with a small eschar and rapid healing.

Findings:

• Virus isolation, PCR, and serology confirmed cowpox virus infection in both cases.
• The unvaccinated individual showed a severe, prolonged clinical course, while the vaccinated individual had a mild presentation.
• Evidence suggests zoonotic transmission from a cat with a PCR-positive swab and high anti-orthopoxvirus antibodies.

Implications:

• Cowpox virus infection can lead to severe morbidity, particularly in unvaccinated individuals.
• Smallpox vaccination may offer protection against severe cowpox disease.
• Prompt diagnosis and management are essential for optimizing patient outcomes in zoonotic orthopoxvirus infections.