Review of 59 patients hospitalized with animal bites

Staphylococcus intermedius infections: case report and literature review

Staphylococcus intermedius is part of the normal skin and oral flora of dogs. Case reports of human infections are rare, but the true incidence is unknown because the pathogen is frequently misidentified as Staphylococcus aureus. Reported cases range from soft tissue infections to brain abscess. Most reported cases in humans have been related to dog exposure. We report a case of a 73 year old female with S. intermedius surgical wound infection one month following a left elbow total arthroplasty. This is the first reported human case of S. intermedius infection of a mechanical prosthesis. The presumed source of infection was the patient’s dog. The patient was treated with vancomycin, then switched to cefazolin and rifampin once susceptibilities were known. Case reports suggest that patients generally respond well to tailored antibiotics with complete or near-complete recovery. S. intermedius should be included in the differential diagnosis of invasive infection amongst patients with close contact with dogs.

Risk Factors, Prevention and Prophylaxis of Dog Bites for Disaster Response Personnel in the United States

It commonly is rumored that in large scale disasters, packs of dogs present a human health hazard because of dog bites. However, it is likely that factors other than pack behavior comprise greater risk factors for dog bites in disaster-response personnel. Important risk factors include: 1) the density of the human population, which in turn, determines the number of dogs at a disaster site; 2) territorial behavior of dogs at their site of residence, which determines the frequency with which dogs may bite; and 3) whether rabies is present at endemic or epidemic levels within the area in which the disaster is occurring, which determines the likelihood of fatal outcomes. Persons bitten by a dog should seek medical attention as contraction of rabies may result in a fatal outcome from a dog bite. It is recommended that disaster response personnel obtain pre-exposure vaccination against rabies. Vaccinated or not, they immediately should seek post-exposure treatment for rabies following potential exposure.

Bear attack--A unique fatality in Finland

Fatalities due to animal bites, the vast majority of which are associated with dogs and big cats, are relatively uncommon and rarely described in the literature. Especially rare are fatal bear attacks on humans. We herein present a forensic investigation of a fatal assault, involving numerous bites on a 42-year-old man in Finland by an European brown bear (Ursus arctos arctos).

Death secondary to a donkey's bites

We present a unique case of death due to the assault and bites of a donkey on a 65-year-old man. The farmer, found dead in his farmyard, had a very deep wound in the anterior region of the neck, with a sharp transection of the trachea and severe bleeding by several minor vessels wall disruptions. The cause of death was established to be massive bleeding combined with asphyxia due to aspiration of the blood. Moreover, multiple contusions with associated skin abrasions and perforations were present. The general impression of the injuries was consistent with an animal's bite marks. Herbivorous or omnivorous bite attacks on humans are rare; instead, these animals attack by kicking, trampling, and kneeling, resulting in secondary blunt injuries. The donkey is usually a docile animal, but its behavior can be aggressive during the mating season, and the possibility of biting should not be underestimated, as illustrated by the 2 cases published previously as well as by the case presented here.

[Bite injuries of the hand]

Bite injuries of the hand have a clearly increased risk for infection compared with other regions. Surgical treatment of the wound is indicated, and the debridement must be done thoroughly and with consideration of the wound closure. Antibiotic therapy may be indicated in addition to the surgery if signs of infection exist. Antibiotics alone are not a suitable treatment. Common complications in cases of deficient primary therapy are flexor tenosynovitis, purulent arthritis, and phlegmons of the dorsal hand. These are emergencies and need immediate surgical intervention.

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.

National survey of owner-directed aggression in English Springer Spaniels

OBJECTIVE

To determine prevalence of owner-directed aggression and identify associated environmental and genetic factors in English Springer Spaniels.

DESIGN

Prevalence survey.

ANIMALS

1,053 adult English Springer Spaniels.

PROCEDURE

A mail survey was sent to 2,400 randomly selected owners of adult American Kennel Club-registered English Springer Spaniels. Dogs with a history of aggression to family members and familiar humans were compared with dogs without such a history.

RESULTS

1,053 questionnaires (56.1% of the 1,877 delivered) were completed. A history of owner-directed growling or more intense aggression was reported in 510 (48.4%) dogs. Two hundred seventy-seven (26.3%) dogs had bitten a human in the past; 65.2% of bites were directed at familiar (owner or nonowner) adults and children. Variables associated with owner-directed aggression included sex of dog (male), neuter status (neutered, regardless of sex), show or bench lines, age > 4 years, aggression to unfamiliar adults and children, acquisition from a hobby breeder, less responsiveness to obedience cues, and a specific kennel and 1 popular sire from that kennel in a 4-generation pedigree.

CONCLUSIONS AND CLINICAL RELEVANCE

Owner-directed aggression in adult English Springer Spaniels was associated with a number of environmental, sex-related, and inherited factors. To reduce the risk of aggression, prospective owners might seek a female, hunting-type English Springer Spaniel from an experienced breeder. However, because risk factors are broad and varied, there are limitations to the extent to which behavior can be predicted and further study is needed of the inheritance of aggression in this breed.

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.

Management of lacerations in the emergency department

The goals of wound management are simple: avoid infection and achieve a functional and aesthetically pleasing scar. This is achieved by reducing tissue contamination, debriding devitalized tissue, and restoring perfusion in poorly perfused wounds, in conjunction with a well-approximated skin closure.

The Management of Dog Bites

Objective

To review the contemporary management of dog bites with an emphasis on clinical presentation, wound care, microbiology, antimicrobial prophylaxis, and treatment.

Data Sources

The published literature was searched by use of MEDLINE (1990-December 2000) and bibliographic reviews of relevant textbooks and review articles.

Data Selection and Extraction

Review articles, case reports, appropriate meta-analyses, and relevant textbook chapters dealing with mammalian bites and their management were evaluated. All pertinent information was synthesized and incorporated into the present review.

Data Synthesis

The incidence of serious and fatal dog bites has increased because of the acquisition of larger, more aggressive breeds. School-age children and young adults are at the highest risk. Most bites occur on the upper extremities, although head and neck bites are also common. The risk of infection is greatest for crush injuries, puncture wounds, and hand wounds. Infection tends to develop within 24–36 hours of the injury. Complications include osteomyelitis, septic arthritis, tenosynovitis, and septicemia. Most infections are polymicrobial and involve organisms isolated from the skin of the patient and the indigenous oral flora of the dog. Bites should be initially managed under accepted wound care protocols. Wound closure remains controversial and should be reserved for facial and head wounds. Immobilization and elevation are essential for therapeutic success. Prophylactic antibiotics should be reserved for bites at high risk for infection and the immunocompromised host. Whether for prophylaxis or treatment, empiric antimicrobial therapy should be directed against the most common bacteria: Pasteurella spp., streptococci, staphylococci, and anaerobes. Duration and route are dependent on the location and severity of the wound.

Conclusions

Dogs remain the major cause of mammalian bites in the US. It is important for clinicians to have an understanding of the contemporary management of dog bites. Good wound care is central to the prevention and treatment of complications. Appropriate antimicrobial therapy should be directed against both aerobic and anaerobic flora. Careful monitoring is imperative, and antibiotic changes should be made based on clinical response and, if appropriate, the results of culture and sensitivity reports.

Hospitalization due to Pasteurella multocida-infected animal bite wounds: correlation with inadequate primary antibiotic medication

Over a 10-y period, patients hospitalized with Pasteurella-induced cat or dog bite-associated wound infection were analysed retrospectively with regard to preceding antibiotic medication. In 10/14 cases, hospitalization was necessitated in spite of prophylactic or therapeutic administration of oral antibiotics. In 1 case, phenoxymethylpenicillin and flucloxacillin had been prescribed. The other patients received flucloxacillin (7 patients), erythromycin, or cefadroxil (1 patient each), agents that are not consistently active against Pasteurella. In conclusion, hospitalization due to Pasteurella-induced animal bite-associated wound infection seemed to be related to the prescription of suboptimal oral antibiotic therapy at a preceding medical consultation.

Treating mammalian bite wounds

The incidence of dog, cat and human bites has been increasing steadily and represents an important cause of morbidity and mortality in the United States. Approximately half of all Americans will suffer a bite wound during their lifetime, and the annual medical costs of managing these injuries has been estimated to be over $100 million. Possible complications may include disfigurement, dismemberment and infection. Effective management requires rapid medical evaluation and may necessitate surgical intervention and prophylactic antibiotic therapy. As bite wounds are microbiologically diverse and most often polymicrobial in nature, selection of an appropriate antibiotic regimen requires knowledge of common pathogens. Close clinical follow-up is recommended to minimize the risk of late complications.

Bacteriologic analysis of infected dog and cat bites. Emergency Medicine Animal Bite Infection Study Group

BACKGROUND AND METHODS

To define better the bacteria responsible for infections of dog and cat bites, we conducted a prospective study at 18 emergency departments. To be eligible for enrollment, patients had to meet one of three major criteria for infection of a bite wound (fever, abscess, and lymphangitis) or four of five minor criteria (wound-associated erythema, tenderness at the wound site, swelling at the site, purulent drainage, and leukocytosis). Wound specimens were cultured for aerobic and anaerobic bacteria at a research microbiology laboratory and, in some cases, at local hospital laboratories.

RESULTS

The infected wounds of 50 patients with dog bites and 57 patients with cat bites yielded a median of 5 bacterial isolates per culture (range, 0 to 16) at the reference laboratory. Significantly more isolates grew at the reference laboratory than at the local laboratories (median, 1; range, 0 to 5; P<0.001). Aerobes and anaerobes were isolated from 56 percent of the wounds, aerobes alone from 36 percent, and anaerobes alone from 1 percent; 7 percent of cultures had no growth. Pasteurella species were the most frequent isolates from both dog bites (50 percent) and cat bites (75 percent). Pasteurella canis was the most common isolate of dog bites, and Past. multocida subspecies multocida and septica were the most common isolates of cat bites. Other common aerobes included streptococci, staphylococci, moraxella, and neisseria. Common anaerobes included fusobacterium, bacteroides, porphyromonas, and prevotella. Isolates not previously identified as human pathogens included Reimerella anatipestifer from two cat bites and Bacteroides tectum, Prevotella heparinolytica, and several porphyromonas species from dog and cat bites. Erysipelothrix rhusiopathiae was isolated from two cat bites. Patients were most often treated with a combination of a beta-lactam antibiotic and a beta-lactamase inhibitor, which, on the basis of the microbiologic findings, was appropriate therapy.

CONCLUSIONS

Infected dog and cat bites have a complex microbiologic mix that usually includes pasteurella species but may also include many other organisms not routinely identified by clinical microbiology laboratories and not previously recognized as bite-wound pathogens.

Antibiotics in the management of pediatric skin disease

An increasingly large number of antibiotics are available for the treatment of uncomplicated skin and skin structure infections in children. Primary factors in the choice among these agents are the antibiotic resistance profile of the target pathogen(s), and the antibiotic's spectrum of activity, pharmacologic properties, potential adverse reactions and interactions and propensity to select for the emergence of resistant organisms. Based on a consideration of these principles, this article provides a practical guide to the use of antibiotics in the management of common cutaneous infections in the pediatric population.

Anticipatory guidance: having a dog in the family

Pediatric nurse practitioners frequently provide families with anticipatory guidance. An area often discussed is safety as it relates to growth and development. One topic that may not be covered is safety with dogs. Dog bites, especially by the family pet, are a common occurrence among children. This article assists the nurse practitioner to learn about the unique characteristics of the canine, what to teach families and children about safety around dogs, responsible dog ownership, and dog training.

Pasteurella multocida septicemia and subsequent Pasteurella dagmatis septicemia in a diabetic patient

Pasteurella species may cause zoonotic infections of humans. Serious systemic infections with these organisms are unusual, but they may occur in individuals with predisposing underlying illnesses. Occurrences of bacteremia due to P. multocida are infrequent, and P. dagmatis bacteremia is even rarer. We report independent occurrences of P. multocida and P. dagmatis septicemia in the same diabetic patient after contact with two pet dogs. We review the history of Pasteurella species and discuss the biochemical and clinical features of its association with zoonosis.

[Infectious diseases transmitted by animal bites]

The animal population, and most of all pets, entail a high risk of bites, some of them severe, which may lead to complications among which infection is a major one. Epidemiological data about the germs liable to grow (Pasteurellae, pyogenic germs, anareobes...) are helpful to guide curative, and even more, prophylactic approaches to treatment.

Cat bite wounds: risk factors for infection

STUDY OBJECTIVE

In the last ten years, many emergency medicine specialists have studied animal bite wounds. The majority of these studies have addressed the controversies of prescribing prophylactic antibiotics or suturing wounds. This study was undertaken to determine risk factors for cat bite wound infections.

DESIGN

Prospective survey.

SETTING

Community hospital emergency medicine residency program.

TYPE OF PARTICIPANTS

One hundred eighty-six consecutive patients with 216 cat bite/scratch wounds over a two-year period.

INTERVENTIONS

A standardized wound cleaning protocol with debridement and suturing, if indicated, was used. Variables analyzed included patient age and gender; wound age, type, number, location, and depth; prehospital therapy; emergency department therapy; and antibiotics used.

RESULTS

The mean patient age was 19.5 +/- 15.9 years. The mean time interval from wounding to ED treatment was 10.2 +/- 39.2 hours. By anatomical sites, there were 33 (15%) head/neck, 48 (22%) arm, 97 (45%) hand, ten (5%) truncal, and 28 (13%) lower extremity wounds. By wound type, there were 122 (56%) punctures, 54 (25%) abrasions, 37 (17%) lacerations, and two (1%) avulsions. One hundred fifty (71%) of the wounds were partial thickness, and 62 (29%) were full thickness. Twenty-four (12.9%) of the patients had clinical evidence of wound infection on arrival to the ED. Five (2.7%) developed clinical evidence of infection despite ED treatment. None of the 14 (7.5%) patients with only "claw" injuries developed infection. The overall patient infection rate for those with cat "bites" was 15.6%. Factors associated with wound infections included older age (P less than .001), longer time intervals until ED treatment (P less than .0001), wounds inflicted by "pet" cats (P = .001), attempting wound care at home (P = .0004), having a more severe wound (P = .01), and having a deeper wound (P = .0001). Data from 148 patients who had only "bite" wounds and did not have clinical evidence of infection on initial presentation to the ED also were analyzed for wound infection risk factors. Wound infections were more likely to develop in patients with lower extremity wounds who did not receive prophylactic oral antibiotics (P = .071) and those with puncture wounds who did not receive prophylactic oral antibiotics (P = .085).

CONCLUSION

In this study, wound type and wound depth were the most important factors in determining the likelihood of developing wound infection regardless of whether the patient was prescribed prophylactic oral antibiotics.

Bite wounds to the upper extremity

The complications secondary to mismanaged or neglected bite wounds to the upper extremity can be devastating to upper extremity functioning. An organized approach to treatment can prevent infection and permanent disability.

Erythromycin failure with subsequent Pasteurella multocida meningitis and septic arthritis in a cat-bite victim

We report the case of a 75-year-old woman who developed Pasteurella multocida meningitis and septic arthritis while being treated for a cat-bite wound infection with erythromycin. Review of the literature revealed that erythromycin has poor in vitro activity against this bacterium and has been associated with serious clinical failures. We recommend that erythromycin not be prescribed for empiric therapy of established animal-bite infections. Suggestions for optimal empiric therapy of animal-bite infections and the differential diagnosis of severe cat-bite-associated sepsis are discussed.

Management of human and animal bite wounds

Bite wounds, usually by dogs, cats, and human beings, affect one of two Americans during his or her lifetime and 1 to 2 million Americans annually. Despite the relative frequency of bite wounds, there are few prospective studies to define optimal care; consequently, diverse methods are used. In this article I review the incidence, bacteriology, clinical spectrum, complications, and treatment of animal and human bite wounds. The spectrum of pathogenic bacteria that cause bite infections is broader than is generally appreciated and includes both aerobic and anaerobic bacteria. Pasteurella multocida is found in only 20% to 25% of dog bite wounds. In choosing empiric antimicrobial therapy, clinicians must consider the diverse causative bacteria and their characteristic susceptibility patterns. Liberal irrigation and elevation of the injured part are also cornerstones of therapy. Early, aggressive medical and surgical management can minimize, if not prevent, complications.

Staphylococcus intermedius: clinical presentation of a new human dog bite pathogen

Staphylococcus intermedius is a Gram-positive, coagulase-positive coccus that can be distinguished from Staphylococcus aureus by routine microbiological testing. Whereas S intermedius is recognized as flora and pathogen of dogs, it has never been isolated from human infections. We hypothesized that S intermedius may cause human dog bite wound infections and that it has been previously misidentified as S aureus. Fourteen isolates from clinically infected dog bite wounds that were originally identified as S aureus were subjected to further testing; three (22%) were found to be S intermedius. The clinical and microbiological characteristics of these three S intermedius cases are described. All three patients were nonimmunocompromised persons seen within 24 hours for bites on the upper extremity. All patients developed cellulitis within one to three days. All S intermedius isolates were distinguished from S aureus by the lack of acetoin production and by the presence of beta-galactosidase activity. S intermedius was susceptible to a wide range of antibiotics; one isolate was resistant to penicillin. Two patients were treated with penicillin, one with amoxicillin-clavulanate, and all were clinically cured. These are the first three reported human infections involving S intermedius. Further study is necessary to define its clinical importance as a potential human pathogen.

Dysgonic fermenter-2: a clinico-epidemiologic review

In the literature to date, there have been 44 confirmed cases of infection with the Dysgonic Fermenter-2 (DF-2) bacterium. DF-2 infections appear to demonstrate a strong association with dog bites (or recent exposure to dogs) and have a predilection for patients with defective host defenses although immunocompetent individuals are also susceptible. Recently, the first two cases of documented DF-2 infection following cat bite have been reported. Of the cases reported, 42 of the 44 blood cultures grew DF-2. In one of the two cases where blood culture failed to grow DF-2, the bacterium was isolated at the time of operation from an infected myxoma of the tricuspid valve. In the other case, the organism was isolated from the eyelid margin of a case of angular blepharitis. Peripheral blood smears also afford an effective and practical clinical tool for early diagnosis; 9 of 10 patients for whom smears were done tested positive. This paper reviews the epidemiologic, microbiological, and clinical features of this relatively new illness and also offers general guidelines to physicians for clinical management. Health professionals, especially those providing care for high risk groups, should be alerted to this potentially fatal infection.

The politics of immunization in public health

The role of socio-political and psychological factors in the decision to immunize is explored using data collected in a county health department in the United States. Decisions regarding the administration of post-exposure immunizations for hepatitis A and rabies are described, and a tendency toward unnecessary use noted. At times these interventions function more to reduce the anxiety of a patient or clinician than they do to prevent an infection. These findings may have implications for analyses of clinical decision making that involve other types of interventions.

Staphylococcus intermedius in canine gingiva and canine-inflicted human wound infections: laboratory characterization of a newly recognized zoonotic pathogen

Staphylococcal gingival flora was characterized in cultures from 135 dogs. Staphylococcus intermedius was isolated in 39% of the cultures, S. aureus was isolated in 10%, and both were isolated in 2.0%. S. aureus was isolated more often from dogs of working breeds with weights of greater than 40 lb (ca. 18 kg) and with outdoor habitats than was S. intermedius, which was associated with dogs of nonworking breeds with weights of less than 40 lb and indoor habitats. S. intermedius was distinguished from S. aureus by the following characteristics: coagulation of rabbit plasma at 4 h (26 versus 100%, respectively), hemolysis of sheep blood at 24 h (30 versus 79%, respectively), and mannitol fermentation at 24 h (4 versus 93%, respectively). A clear separation of the two species was apparent only with the acetoin (modified Voges-Proskauer) reaction (100% of the S. aureus isolates versus 0% of the S. intermedius isolates) and beta-galactosidase activity on the API Staph-Ident strip (0% of the S. aureus isolates and 100% of the S. intermedius isolates). Susceptibilities of S. intermedius and S. aureus were 72 and 7%, respectively, to penicillin G, and 100% of both species to oxacillin. Fourteen previously collected strains of coagulase-positive staphylococci from infected canine-inflicted human wounds were reanalyzed; 3 of 14 (21%) isolates were S. intermedius. We conclude that S. intermedius is a common canine gingival flora and is responsible for some canine-inflicted human wound infections, thus representing a newly recognized zoonotic pathogen.

Eikenella corrodens in human mouth flora

The incidence of Eikenella corrodens in the human mouth was studied in 229 individuals. Six (2.6%) had positive cultures. The incidence of positive cultures for the saliva group was 0.6% and for the tooth-scraping group it was 8.2%. When 11 isolates were tested against 33 antimicrobials by disc-agar diffusion, 82% were susceptible to penicillin, cephalothin, and cefoperazone. Susceptibility to the remaining second- and third-generation cephalosporins studied was 100%. We suggest that the use of a second- or third-generation cephalosporin only is appropriate empiric therapy for human bite injuries.

Co-isolation of Pasteurella dagmatis and Pasteurella multocida from cat-bite wounds

Two cases of cat-bite wounds where Pasteurella multocida and Pasteurella dagmatis were isolated together are reported. The possibility of overlooking one species is discussed.

Lack of in vitro efficacy of oral forms of certain cephalosporins, erythromycin, and oxacillin against Pasteurella multocida

The in vitro susceptibility of human isolates of Pasteurella multocida to oral antimicrobial agents from our current study and from a review of the literature suggests that dicloxacillin (oxacillin), erythromycin, clindamycin, cephalexin, cefaclor, and cefadroxil should not be used for empiric therapy of animal bite wounds. Agents that were consistently active against P. multocida were penicillin, ampicillin, amoxicillin-clavulanic acid, tetracycline, minocycline, chloramphenicol, trimethoprim-sulfamethoxazole, and cefuroxime. Possible reasons for the confusion regarding the activity of oral cephalosporins are addressed.