From the Guidelines
The causative organism of hand infections due to human bites is most commonly Eikenella corrodens (answer D). This gram-negative facultative anaerobic bacillus is part of the normal oral flora in humans and is frequently isolated from human bite wound infections, as noted in the study by 1. Human bite wounds to the hand are particularly concerning because they can introduce this organism deep into the tissues, joints, or tendon sheaths. Eikenella corrodens produces a unique infection characterized by slow progression, indolent course, and purulent discharge that may have a distinctive odor. These infections often require both surgical debridement and appropriate antibiotic therapy. Treatment typically includes antibiotics that cover both Eikenella and other oral flora, such as amoxicillin-clavulanate or a combination of penicillin and a beta-lactamase inhibitor, as recommended by 1. While other organisms like Staphylococcus aureus may also be present in human bite infections, Eikenella corrodens is considered the characteristic pathogen specifically associated with human oral flora introduced through bites. Some key points to consider in the management of human bite wounds include:
- The importance of prompt treatment to prevent complications such as abscesses, septic arthritis, and osteomyelitis, as highlighted by 1.
- The need for empirical antibiotic therapy that covers a broad range of pathogens, including Eikenella corrodens, as noted by 1.
- The potential for antibiotic resistance, particularly among gram-negative rods, and the need for careful selection of antibiotics, as discussed by 1. Overall, the management of human bite wounds requires a comprehensive approach that includes prompt treatment, empirical antibiotic therapy, and careful consideration of the potential pathogens involved.
From the Research
Causative Organism of Hand Infection due to Human Bite
- The causative organism of hand infection due to a human bite is Eikenella corrodens 2, 3, 4.
- Eikenella corrodens is a microaerophilic gram-negative rod that is a normal inhabitant of human mucosal surfaces, particularly the oral cavity 3.
- It is commonly found in human bite wounds and can cause serious infection in both normal and immunocompromised hosts 3, 4.
- Other organisms such as Staphylococcus, Streptococcus, and anaerobic bacterial species can also be present in human bite wounds, resulting in polymicrobial infections 2.
- Eikenella corrodens is resistant to certain antibiotics, including clindamycin, and requires specific treatment with antibiotics such as penicillin, tetracycline, and chloramphenicol 3, 5, 6.