Bacteremia From an Unlikely Source
An unusual infection caused by contact with a pet reinforces the importance of educating patients about proper postoperative wound care.
Pasteurella multocida septicemia commonly occurs in patients with an immune-compromised status, but septicemia in healthy individuals has also been reported.15,16 Apart from local skin and soft-tissue infections, P multocida can cause upper respiratory tract infections, lower respiratory tract infections leading to pneumonia, trachea-bronchitis, lung abscess, and empyema, usually in individuals with underlying pulmonary disease. Pasteurella multocida meningitis has been associated with cat licks and bites occurring on the face in both the young and the elderly.17-19
Gram stains of purulent material or other fluid specimens, including blood, sputum, and cerebrospinal fluid, may show small, Gram-negative, nonmotile, non–spore-forming pleomorphic coccobacilli. Wright, Giemsa, and Wayson stains enhance bipolar staining. The quickest and most accurate method for confirming an active P multocida infection is molecular detection using polymerase chain reaction.20 Evaluations of tenosynovitis, septic arthritis, osteomyelitis, and meningeal enhancement, when appropriate, should be done with CT scans or MRIs.
In < 10% of cases, localized infection by P multocida may lead to bacteremia. The most common predisposing factors associated with bacteremia identified in a review of cases over 20 years at an urban medical center included old age and chronic medical conditions.21 Chronic medical conditions involved most commonly were diabetes mellitus, hypertension, and congestive heart failure. Liver dysfunction has also been reported as a significant risk factor in cases of P multocida bacteremia. The most common antibiotics used to treat the patients with bacteremia were ampicillin/sulbactam, cephalosporins, and fluoroquinolones.
A brief review of the literature of 21 cases of bacteremia showed that the most common antibiotics used for treatment were penicillins (ampicillin, amoxicillin, and piperacillin) in 11 of 21 cases. After penicillin, ciprofloxacin was the most commonly used antibiotic to treat bacteremia secondary to P multocida. The review also identified chronic medical conditions, such as diabetes mellitus, hypertension, congestive heart failure, and chronic obstructive pulmonary disease, as the most common risk factors associated in these cases with bacteremia.
In 17 of 20 cases, patients reported being present in an environment with pets, mostly cats and dogs. Twelve out of 17 patients reported having contact with pet cats and dogs, mostly in the form of bites or pets licking their wounds, and 3 of these were postoperative patients with external wounds.22-24
This patient reported that after discharge from the hospital following surgery for his spreading melanoma, domestic cats at his home repeatedly licked the postoperative wound. This almost certainly was the source of the infection and bacteremia in this patient. These findings stress the importance of educating patients about proper postoperative wound care and precautions needed if there is potential exposure to domestic animals, such as cats and dogs.
CONCLUSIONS
Pasteurella multocida is an unusual cause of postoperative wound infection. The most common method of acquiring a P multocida infection is through contact with pet animals, mostly cats and dogs. Infection can occur not only with animal bites and scratches, but also with licking of open wounds. The rate of infections can be decreased significantly by educating patients about the mode of transmission of infection, its complications, and safety measures needed if they have pets at home.
Author disclosures
The authors report no actual or potential conflicts of interest with regard to this article.
Disclaimer
The opinions expressed herein are those of the authors and do not necessarily reflect those of Federal Practitioner, Frontline Medical Communications Inc., the U.S. Government, or any of its agencies. This article may discuss unlabeled or investigational use of certain drugs. Please review the complete prescribing information for specific drugs or drug combinations—including indications, contraindications, warnings, and adverse effects—before administering pharmacologic therapy to patients.
