Fight bite injury: emergency department assessment and management.

Human bite wounds to the hand are relatively common injuries and are associated with high infection rates. Given the unique anatomy of the hand, the bite mechanism and the organisms found in human saliva, even the smallest wound can result in an aggressive infection. Failure to recognise and treat human bite wounds appropriately, can therefore have negative outcomes for patients. This article outlines the diagnostic features of, and complications associated with, bite wounds and discusses the recommended treatment options.

Human and other mammalian bite injuries of the hand: evaluation and management.

The hand is the most common site for bite injuries. Because of specific characteristics of hand anatomy, bite mechanics, and organisms found in human and animal saliva, even small wounds can lead to aggressive infections. Failure to recognize and treat hand bites can result in significant morbidity. Human and animal bites most commonly lead to polymicrobial bacterial infections with a mixture of aerobic and anaerobic organisms. Pasteurella species are commonly found in dog and cat bite wounds, and Eikenella is characteristic of human wounds. Staphylococcus, Streptococcus, and anaerobic bacterial species are common to all mammals. Although public health measures in developed countries have been highly effective at reducing rabies transmission, dog bites remain the most common source of rabies infection worldwide. Human bites can transmit HIV, hepatitis B, or hepatitis C, especially when contaminated blood is exposed to an open wound. Appropriate management of any mammal bite requires recognition, early wound cleansing, evaluation of injured structures, and infection prophylaxis. Structural repair is performed as indicated by the severity and contamination of the injury, and wounds may require delayed closure. Wound infections typically require débridement, empiric antibiotics, and delayed repair or reconstruction.

Acquired macrolide-resistant Treponema pallidum after a human bite.

Syphilis is a systemic disease caused by the spirochete Treponema pallidum that is usually acquired through sexual exposure.

Acute hand infections.

The continued emergence of antibiotic-resistant bacteria and the development of only a few new classes of antibiotics over the past 50 years have made the treatment of acute hand infections problematic. Prompt diagnosis and treatment are important, because hand stiffness, contractures, and even amputation can result from missed diagnoses or delayed treatment. The most common site of hand infections is subcutaneous tissue and the most common mechanism is trauma. An immunocompromised state, intravenous drug abuse, diabetes mellitus, and steroid use all predispose to infections.

Amplification of oral streptococcal DNA from human incisors and bite marks.

Challenges to the evidentiary value of morphometric determinations have led to a requirement for scientifically substantiated approaches to the forensic analysis of bite marks. Human teeth support genotypically distinctive populations of bacteria that could be exploited for forensic purposes. This study explored the feasibility of directly amplifying bacterial DNA from bite marks for comparison with that from teeth. Samples from self-inflicted experimental bite marks (n = 24) and human incisors were amplified by PCR using primers specific for streptococcal 16S ribosomal DNA. Amplicon profiles (resolved by denaturing gradient gel electrophoresis) from bite mark samples aligned significantly more closely with profiles generated from the teeth responsible than with those from other teeth. Streptococcal amplicons were generated from dental samples applied to excised porcine skin for up to 48 h. These findings indicate that streptococcal DNA can be amplified directly from bite marks, and have potential application in bite mark analysis.

Bite wounds to the hand - a review.

Bite wounds occur as a result of bite by an animal or a human. They are relatively frequent due to the growing number of pets living with people, as well as from inadequate human-animal interactions. The knowledge of most surgeons about the management of these injuries is relatively outdated, whereas the current literature points to important changes in this field. The article presents several aspects concerning epidemiology, classification, bacteriology, and characteristics of bite wounds to the hand. Based on the actual literature, detailed rules for the management of these injuries are described. This information may prove useful in the daily practice of surgeons and doctors at emergency departments who are frequently faced with bite wounds.

Management of bite wounds in the head and neck.

An estimated 50% of people in the United States will incur an animal or human bite wound at least once in their lifetimes. Although the majority of these individuals do not seek medical attention, bite wounds to the head and neck are a common reason for emergency department visits. Facial bites are complex injuries due to the functional and cosmetic nature of the area, as well as the unique polymicrobial infection potential that exists. We present a review of the epidemiology and microbiology of bite injuries to the head and neck and provide evidence-based recommendations regarding surgical wound closure and antibiotic therapy.

Emergency management of difficult wounds: part I.

Emergency physicians treat millions of wounds annually in the United States. In 2004 approximately 6.4 million open wounds were seen in United States emergency departments, representing approximately 5.8% of all visits. This article discusses difficult traumatic wounds that emergency physicians encounter on a daily basis, including mammalian bites, puncture and high-pressure wounds, and crush injuries, with special emphasis given to individuals at high risk for infectious complications. Information is provided on epidemiology, pathophysiology, management, and treatment of various complicated wounds. The authors highlight available guidelines, provide the best evidence available, and provide recommendations when data are limited.

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.

Human Bite-induced Cellulitis Due to Streptococcus pyogenes.

The rate of infection after a human bite is 10%-30%. Streptococcus spp. are the most common pathogens that may cause serious infections, such as necrotizing fasciitis. The authors describe a 5-year-old girl admitted to the emergency room with cellulitis due to S. pyogenes after human bites. She presented with fever and pain in her left arm, and her medical history revealed a human bite by her cousin on the arm 3 days prior. The wound culture yielded S. pyogenes. She was successfully treated with intravenous ampicillin-sulbactam regimen. S. pyogenes may cause serious wound infections following human bites. In such cases, the patient should be closely followed. Chemoprophylaxis should be initiated in an appropriate clinical setting to prevent secondary bacterial infections. This case was first reported as cellulitis due to S. pyogenes after a human bite.

Clinical presentation and bacteriologic analysis of infected human bites in patients presenting to emergency departments.

Previous studies of infected human bites have been limited by small numbers of patients and suboptimal microbiologic methodology. We conducted a multicenter prospective study of 50 patients with infected human bites. Seventy percent of the patients and assailants were young adult men. Fifty-six percent of injuries were clenched-fist injuries and 44% were occlusional bites. Most injuries were to the hands. Fifty-four percent of patients were hospitalized. The median number of isolates per wound culture was 4 (3 aerobes and 1 anaerobe); aerobes and anaerobes were isolated from 54% of wounds, aerobes alone were isolated from 44%, and anaerobes alone were isolated from 2%. Isolates included Streptococcus anginosus (52%), Staphylococcus aureus (30%), Eikenella corrodens (30%), Fusobacterium nucleatum (32%), and Prevotella melaninogenica (22%). Candida species were found in 8%. Fusobacterium, Peptostreptococcus, and Candida species were isolated more frequently from occlusional bites than from clenched-fist injuries. Many strains of Prevotella and S. aureus were beta-lactamase producers. Amoxicillin-clavulanic acid and moxifloxacin demonstrated excellent in vitro activity against common isolates.

Lack of transmission of HIV through human bites and scratches.

To examine the relative risk of transmission of the human immuno-deficiency virus (HIV) through bites and scratches, we studied 198 health care workers, 30 of whom were traumatized in this fashion while caring for an aggressive AIDS patient. This violent patient frequently bit or scratched others, his mouth had blood and saliva, while his fingernails were at times soiled with semen, feces, and urine. He was HIV antibody and antigen positive. Although HIV was recovered from his peripheral blood lymphocytes, after 2.5 years of serial follow-up, all traumatized personnel were clinically normal, no HIV was cultured from their blood, and all were HIV antibody and P24 antigen negative. We conclude that this viremic AIDS patient, while producing copious amounts of body fluids, failed to infect those caring for him through bites and scratches. The risk of transmission of HIV through this route under similar conditions should be low.

Microbiology of human and animal bite wounds in children.

Aspirates from bite wounds in 39 children (21 with animal bites and 18 with human bites) were cultured for aerobic and anaerobic bacteria. Aerobic bacteria only were recovered in 7 (18%) wounds, anaerobic bacteria only in 3 (8%) and mixed aerobic and anaerobic bacteria in 29 (74%). A total of 59 isolates was recovered from animal bites (2.8/specimen): 37 aerobes (1.8/specimen); and 22 anaerobes (1.0/specimen). A total of 97 isolates were recovered from human bites (5.4/specimen): 44 aerobes (2.4/specimen); and 53 anaerobes (3.0/specimen). The most frequent isolates in both types of wounds were Staphylococcus aureus, anaerobic cocci and Bacteroides spp. Present only in animal bites were Pasteurella multocida, Pseudomonas fluorescens and M-5. Present only in human bites were Group A streptococci. Eighteen beta-lactamase-producing organisms were isolated in 16 wounds. This study demonstrates the polymicrobial aerobic-anaerobic nature of human and animal bite wounds.

Hand infections. Bacteriology and treatment: a prospective study.

In a prospective, double-blind study, 193 patients hospitalized for established hand infections were randomized to receive either cefamandole intravenously followed by cephalexin by mouth or methicillin intravenously followed by dicloxacillin by mouth. Careful aerobic and anaerobic cultures were performed. Multiple organisms grew in cultures from 84% of the patients (over three isolates per infection on average). Human bite wounds contained anaerobes 43% of the time compared with 12% for other wounds. The majority of wounds (72%) required operative treatment. In 128 patients assessable for treatment outcome, results were unsatisfactory in 11 (9%). There was no difference in outcome between cefamandole (6/59, 10%) and methicillin (5/59, 8%). The presence of anaerobes, Eikenella corrodens, human bites, or an increasing number of organisms was associated with an unsatisfactory response. The presence of Staphylococcus aureus and/or beta-hemolytic streptococci was associated with a favorable response. The incidence of antibiotic-resistant isolates did not correlate with outcome.

Current management of human bites.

Human bites should be considered dangerous injuries with potentially serious complications. Their characteristics vary from an uninfected abrasion to a serious infection such as cellulitis or osteomyelitis. An estimated 10% of the injuries become infected; suspected pathogens include oral and skin flora. Management consists of history and examination, wound care, surgical intervention if necessary, assessment of risk of disease transmission, and appropriate antibiotic prophylaxis or treatment. The best choice for oral or intravenous antibiotic therapy remains the combination of a beta-lactam antibiotic with a beta-lactamase inhibitor. Among the most serious human bites are clenched fist injuries, which often require surgical intervention and intravenous antibiotic therapy.

Analytical pyrolysis of Streptococcus salivarius as an aid to identification in bite-mark investigation.

The use of pyrolysis mass spectrometry (Py-MS) and statistical analysis of mass spectra is introduced as a method for "finger-printing" strains of Streptococcus salivarius. The objective is to provide correlative evidence regarding the identity of suspects in cases of assault or rape involving bite-marks. The results of the analysis of isolates from two individuals are presented, illustrating the differentiation of S. salivarius at strain level according to the origin of the isolate.

The survival of oral streptococci on human skin and its implication in bite-mark investigation.

Ten-microlitre aliquots of whole saliva applied to human skin were sampled for periods up to 6.25 h. The rate of loss of recoverable bacteria was 45-50% per hour. After 6.25 h, viable oral streptococci could be recovered. The implications for using a "fingerprint" typing method for these bacteria with regard to the identification of bite-marks are discussed.

Hand infections.

The diagnosis and treatment of common hand infections are reviewed. A practical approach to the treatment of these conditions is detailed. This approach emphasizes the anatomic compartments of the hand, the microbiology of infecting organisms, and the patient conditions which modify treatment. Prompt and accurate diagnosis, treatment, and rehabilitation are key for optimal outcome.