Infection of lung cavitations in a young dog owner with Hodgkin's lymphoma caused by Pasteurella multocida, without a dog bite: confirmed zoonotic transmission by tagmentation microbiome analysis.

Pasteurella multocida is a known pathogen in humans, mostly reported after animal bite incidents. Atraumatic infections have been described, especially in immunocompromised patients. A 20-year-old patient with a history of stage IV Hodgkin's lymphoma with cavitating pulmonary lesions presented with a bilateral pneumonia. Shortly after finishing antibiotic treatment, she quickly developed the same symptoms of pneumonia. Bronchoscopy showed a large cavity in the right upper lobe and P. multocida was isolated from all bronchial cultures. The transmission route of P. multocida via the patient's dog was confirmed by sampling the full genome of the dog's mouth, which matched the unique P. multocida sequences found in the patient. This case demonstrates the importance of accurately determining the aetiology of the patient's symptoms, and Pasteurella infection should be considered in all immunocompromised patients with domestic animal contact, even without a bite incident.