Man's best friend: life threatening sepsis after minor dog bite

Capnocytophaga sepsis causing purpura fulminans in a 50-year-old man with chronic opioid use

We present a case of polymicrobial sepsis with Capnocytophaga spp. complicated by purpura fulminans following a dog-bite in a 50-year-old-man with an extensive history of opioid use disorder. Generally, severe Capnocytophaga cases are thought to occur in patients with underlying immune deficiencies. However, this case highlights the importance of maintaining clinical suspicion for Capnocytophaga infection in immunocompetent patients, and we discuss the role of chronic opioid-use in severe infection.

Microbiology of animal bite wound infections

The microbiology of animal bite wound infections in humans is often polymicrobial, with a broad mixture of aerobic and anaerobic microorganisms. Bacteria recovered from infected bite wounds are most often reflective of the oral flora of the biting animal, which can also be influenced by the microbiome of their ingested prey and other foods. Bacteria may also originate from the victim's own skin or the physical environment at the time of injury. Our review has focused on bite wound infections in humans from dogs, cats, and a variety of other animals such as monkeys, bears, pigs, ferrets, horses, sheep, Tasmanian devils, snakes, Komodo dragons, monitor lizards, iguanas, alligators/crocodiles, rats, guinea pigs, hamsters, prairie dogs, swans, and sharks. The medical literature in this area has been made up mostly of small case series or case reports. Very few studies have been systematic and are often limited to dog or cat bite injuries. Limitations of studies include a lack of established or inconsistent criteria for an infected wound and a failure to utilize optimal techniques in pathogen isolation, especially for anaerobic organisms. There is also a lack of an understanding of the pathogenic significance of all cultured organisms. Gathering information and conducting research in a more systematic and methodical fashion through an organized research network, including zoos, veterinary practices, and rural clinics and hospitals, are needed to better define the microbiology of animal bite wound infections in humans.

Capnocytophaga canimorsis a cause of septicaemia following a dog bite: a case review

Described in this study is the case of a 53-year-old woman who developed a life-threatening infection caused by the bacterium Capnocytophaga canimorsus (C. canimorsus), subsequent to being bitten by a dog. The patient presented to an Emergency Department with a 24-h history of diarrhoea and vomiting with dehydration but within 36 h of presentation developed an overwhelming severe sepsis with septic shock, disseminated intravascular coagulation, acute renal failure, metabolic acidosis and threatened acute respiratory failure requiring urgent intensive care intervention. At subsequent questioning her husband volunteered that she had been bitten on the wrist by the family dog 24h prior to the onset of symptoms; this bite had been extremely minor, requiring no treatment at the time and leaving only a very superficial wound. The causative organism was finally identified two weeks later as C. canimorsus, a common commensal in the oral flora of dogs. C. canimorsus has been reported as a rare cause of severe infection in susceptible individuals; however this case is of particular interest as there were no apparent predisposing factors conferring risk of severe infection. This case also raised significant practice issues for the treating hospital.

Dental follicle infection following a dog bite

Animal bite wounds and their subsequent infection are relatively common. Incidence rates for dog bites are significantly higher among children aged 0-9 years, especially among boys. Although bite wounds may initially look innocuous, they frequently lead to serious infection with a potential for life-threatening complications. The microbiology of dog bite wounds is usually polymicrobial, typically including anaerobes, Staphylococcus aureus and Pasteurella species. A case is described of a 22-month-old boy who, subsequent to a dog bite over the left maxilla, suffered infection of the dental follicle of the primary maxillary canine with Pasteurella multocida. The infection proved difficult to treat, requiring several attempts at incision and drainage of the abscess together with systemic antibiotics, and resulted in the eventual loss of the tooth.

Facial bite wounds: management update

Bite wounds are frequently located on the face; injuries inflicted by dogs are most common, especially in children. Bacteriology of infected dog and cat bite wounds includes Pasteurella multocida, Staphylococcus aureus, viridans streptococci, Capnocytophaga canimorsus, and oral anaerobes. Infected human bites yield a similar spectrum of bacteria except for Pasteurellae and C. canimorsus; instead human bites are frequently complicated by Eikenella corrodens. Antibiotic therapy against these bacteria is indicated both for infected bite wounds and fresh wounds considered at risk for infection. Amoxicillin-clavulanate (and other combinations of extended-spectrum penicillins with beta-lactamase inhibitors) and moxifloxacin offer the best in vitro coverage of the pathogenic flora. Initial wound management consisting in irrigation and debridement is at least equally important with antibiotics for prevention of infection. The need for prophylaxis against systemic infectious complications, particularly tetanus, should also be evaluated. Primary surgical repair is the treatment of choice for most clinically uninfected facial bite wounds, whereas delayed closure should be reserved for certain high risk or already infected wounds. Avulsive injuries with significant tissue loss represent the most difficult cases for definitive management and are also those most likely to require hospitalization.

Capnocytophaga canimorsus Sepsis with Purpura Fulminans and Symmetrical Gangrene following a Dog Bite in a Shelter Employee

The authors describe a fatal case of purpura fulminans with symmetrical peripheral gangrene and sepsis caused by Capnocytophaga canimorsus in a 45-year-old, previously healthy woman who was bitten by a dog at an animal shelter where she was employed. Absent in this patient were the usual risk factors, including immunosuppression, alcohol abuse, corticosteroid therapy, and splenectomy. The patient's presentation to the emergency room late in the course of the infection probably effected her death. C canimorsus should be strongly suspected in any case of septicemia following a dog bite. Prompt therapy may influence the potentially fatal course of systemic infection. Employees and/or volunteers who work in animal shelters should be cognizant of the potential risks of a dog or cat bite and follow recommended procedures when such an incident occurs.

Dog Bites: Bacteriology, Management, and Prevention

Dog bites are among the most frequent causes of non- fatal injuries in the United States. Most dog bites involve children and young adults. Infected wounds are polymicrobial in nature; the most prevalent organisms are Pasteurella, streptococci, staphylococci, and Fusobacterium, Bacteroides, and Porphyromonas species. Musculoskeletal and neurovascular injuries, as well as systemic infections, can be complications of dog-bite wounds. Treatment includes thorough cleansing of the wound, with copious irrigation. Abscesses, when present, should undergo incision and drainage. Suitable antibiotics for the initial empiric and expectant therapy include amoxicillin-potassium clavulanate, a penicillin with a first generation cephalosporin, or clindamycin and a fluoroquinolone (eg, for patients allergic to penicillins). Preventive strategies should be aimed at public awareness of basic animal safety and responsible pet ownership.

Injuries to the hand from dog bites

A review of dog bite injuries referred to one surgeon over a 12 month period demonstrated a significant association between a delay in referral and a prolonged period of subsequent in-patient treatment. Two patients sustained injuries when delivering material through a letter-box.

Life-threatening Capnocytophaga canimorsus infection after dog bite

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Managing animal bite wounds

A review of specific features associated with bite wounds occurring as a result of human fights or attacks by dogs and other animals