Clinical features of pasteurellosis without an animal bite or scratch in comparison with bite/scratch pasteurellosis

Area of Science:

• Infectious Diseases
• Microbiology
• Clinical Medicine

Background:

• Pasteurellosis is a zoonotic infection typically associated with animal bites or scratches (B/S).
• Non-bite/scratch (non-B/S) pasteurellosis represents a less common but significant clinical entity.
• Understanding the distinct clinical features and risk factors for non-B/S pasteurellosis is crucial for accurate diagnosis and management.

Purpose of the Study:

• To compare the clinical characteristics of patients with non-B/S pasteurellosis to those with B/S pasteurellosis.
• To identify the causative agent, Pasteurella multocida, in non-B/S infections.
• To elucidate the predisposing factors and common manifestations of non-B/S pasteurellosis.

Main Methods:

• Retrospective comparison of clinical data from six patients with non-B/S pasteurellosis and 14 patients with B/S pasteurellosis.
• Identification of Pasteurella multocida using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and diagnostic kits.
• Analysis of patient demographics, comorbidities, infection types, and exposure history.

Main Results:

• Pasteurella multocida was identified in all non-B/S cases and most B/S cases.
• Non-B/S infections included pneumonia, skin and soft tissue infections, and bacteremia.
• Patients with non-B/S pasteurellosis had a significantly higher rate of moderate-to-severe comorbidities (100%) compared to B/S cases (14.3%).
• Non-B/S infections occurred in patients with chronic pulmonary disease, ventilator use, open wounds, or compromised immunity, often without a clear animal contact history.

Conclusions:

• Non-bite/scratch pasteurellosis can manifest as pneumonia, soft tissue infections, or bacteremia.
• These infections are frequently associated with underlying chronic diseases and immunocompromised states.
• Non-B/S pasteurellosis should be recognized as an opportunistic infection, distinct from typical B/S pasteurellosis, and considered even without a history of animal exposure.