Abstract

Pasteurella species are gram-negative coccobacilli belonging to the normal upper respiratory flora of many domestic animals. Human infections are mainly associated with animal bites. Pasteurella invasive infections carry a high short-term mortality. Among this genus, P. multocida accounts for most local and invasive human infections. Other species, including P. canis, P. dagmatis, and P. stomatis, are less commonly implicated. P. canis is mainly associated with localized wound infections following dog bites. Despite some emerging reports of recent sporadic P. canis invasive infections, current evidence is limited just as epidemiology and clinical spectrum. Careful exposure history and prompt microbiological identification can guide early targeted therapy.

I present the case of an 87-year-old comorbid frail woman admitted to our Hospital with heart failure. Blood cultures after a febrile episode resulted positive for P. canis. Response to piperacillin/tazobactam was satisfactory, although she ultimately died from heart failure. She denied being bitten by any dog, therefore we speculated that P. canis spread through respiratory secretions of a dog known to the patient, causing pneumonia (documented at a CT scan) followed by sepsis. She was on chronic immunosuppressive therapy – a known predisposing factor to P. canis infection. In addition, multimorbidity, frailty and immunosenescence contributed to making her more susceptible to sepsis.

The numerosity of household pets in modern societies may contribute to an increased incidence of zoonotic infections. To our knowledge, this is one of the few reports of P. Canis invasive infection worldwide and the first described in Italy.