Treating Human Bite Wounds
Treating Human Bite Wounds
Human bite injuries are a ubiquitous presentation to emergency departments (ED). They are associated with male predominance, with a male:female ratio of 12:1. In the present study, the ratio was 4:1. Most of the bites occurred during a conflict and were located mostly on fingers and upper extremities. Only 11% of the patients had wounds of the head and face, which is much less than cases reported in the literature.
The risk of local bacterial infection associated with human bites is relatively high. Infection from a human bite is documented to be between 10%–20%. This risk is much higher than any other type of bite injury, since the bacterial load of the human saliva contains more than 900 x 10 organisms/mL. Infection is related to bite location, time of presentation, and systemic diseases, such as diabetes mellitus, splenectomy, and immunosuppression. The infection rate of facial injuries is lower compared to other body parts because of higher vascularity. A factor of increased infection risk is the delayed presentation to the ED of more than 12 hours. The importance of prophylactic antibiotic treatment is described in several reports, and the reduction in the infection rate following prophylactic antibiotics is well documented. In the present study, a majority of patients (60.5%) received prophylactic oral antibiotics for 5 to 10 days, and patients with delayed presentation and infection signs received intravenous antibiotics.
Despite the rare risk of tetanus transmission in these wounds, and the precaution that was taken by administering tetanus vaccine, 2 cases have been reported in the literature, 1 of which was fatal. In this retrospective study, the documentation and administration of tetanus prophylaxis was well recorded. Only three patients' had poor tetanus immunization documentation. The rest received tetanus prophylaxis or booster where required, in accordance to basic surgical principles.
Transmission of viral diseases via human bites remains a controversial issue. Hepatitis B/C and HIV infection can occur as a complication of a human bite. Seventy-five percent of patients with hepatitis B have a detectable antigen in their saliva. Although only 4 cases are reported, the Department of Health (DoH) guidelines acknowledge the risk of hepatitis B transmission through a human bite. Small amounts of HIV are possible to be present in the saliva, but exposure to the saliva alone is not considered a risk factor, unless a mix of saliva and infected blood coexists, along with the required skin breach for bodily fluid exchange. The possibility of viral transmission from an HIV-infected victim to the assailant must be also considered. Five cases of HIV-1 infection following a human bite are reported in the literature. Baseline serology testing for hepatitis B surface antigen, hepatitis C antibody, and HIV antibodies, is appropriate after a human bite, as well as retesting at 3 and 6 months. According to the Centers for Disease Control and Prevention (CDC), the risk appears to be higher if the viral titer of the biter is high. Standard CDC guidelines should be followed for the treatment for exposure to viral diseases. In the present study, the authors noticed that medical records lacked documentation of the biter's viral status in most cases. In an effort to enhance internal documentation and to prevent viral transmission, an algorithm was developed that the authors believe the hospital's ED physicians should follow (Figure 2).
(Enlarge Image)
Figure 2.
Suggested treatment algorithm for human bite wounds.
The timing and the modality of surgical treatment of human bite injuries affects wound infection, as well as cosmetics. Some surgeons prefer primary wound closure, especially when the patient presents early after the injury and they indicate low infection and complication rate. Other surgeons suggest that primary closure improves the cosmetic outcome. Human bite injuries should not be underestimated in order to prevent infection. Adequate irrigation and debridement, along with antibiotic and tetanus prophylaxis, is recommended. Surgical revision must be performed when required, especially when cartilage or joints are exposed and when avulsion with tissue loss is present. In the authors' experience, surgical treatment in the cases where fractures or avulsions had occurred took place within the first 24 hours of a patient's presentation to the ED.
Follow-up documentation seems to be of great importance in order to assess healing and possible complications. Follow-up within 24 to 48 hours is recommended, and according to the authors' collected data, initial follow-up for most of the authors' patients was in line with these recommendations.
Discussion
Human bite injuries are a ubiquitous presentation to emergency departments (ED). They are associated with male predominance, with a male:female ratio of 12:1. In the present study, the ratio was 4:1. Most of the bites occurred during a conflict and were located mostly on fingers and upper extremities. Only 11% of the patients had wounds of the head and face, which is much less than cases reported in the literature.
The risk of local bacterial infection associated with human bites is relatively high. Infection from a human bite is documented to be between 10%–20%. This risk is much higher than any other type of bite injury, since the bacterial load of the human saliva contains more than 900 x 10 organisms/mL. Infection is related to bite location, time of presentation, and systemic diseases, such as diabetes mellitus, splenectomy, and immunosuppression. The infection rate of facial injuries is lower compared to other body parts because of higher vascularity. A factor of increased infection risk is the delayed presentation to the ED of more than 12 hours. The importance of prophylactic antibiotic treatment is described in several reports, and the reduction in the infection rate following prophylactic antibiotics is well documented. In the present study, a majority of patients (60.5%) received prophylactic oral antibiotics for 5 to 10 days, and patients with delayed presentation and infection signs received intravenous antibiotics.
Despite the rare risk of tetanus transmission in these wounds, and the precaution that was taken by administering tetanus vaccine, 2 cases have been reported in the literature, 1 of which was fatal. In this retrospective study, the documentation and administration of tetanus prophylaxis was well recorded. Only three patients' had poor tetanus immunization documentation. The rest received tetanus prophylaxis or booster where required, in accordance to basic surgical principles.
Transmission of viral diseases via human bites remains a controversial issue. Hepatitis B/C and HIV infection can occur as a complication of a human bite. Seventy-five percent of patients with hepatitis B have a detectable antigen in their saliva. Although only 4 cases are reported, the Department of Health (DoH) guidelines acknowledge the risk of hepatitis B transmission through a human bite. Small amounts of HIV are possible to be present in the saliva, but exposure to the saliva alone is not considered a risk factor, unless a mix of saliva and infected blood coexists, along with the required skin breach for bodily fluid exchange. The possibility of viral transmission from an HIV-infected victim to the assailant must be also considered. Five cases of HIV-1 infection following a human bite are reported in the literature. Baseline serology testing for hepatitis B surface antigen, hepatitis C antibody, and HIV antibodies, is appropriate after a human bite, as well as retesting at 3 and 6 months. According to the Centers for Disease Control and Prevention (CDC), the risk appears to be higher if the viral titer of the biter is high. Standard CDC guidelines should be followed for the treatment for exposure to viral diseases. In the present study, the authors noticed that medical records lacked documentation of the biter's viral status in most cases. In an effort to enhance internal documentation and to prevent viral transmission, an algorithm was developed that the authors believe the hospital's ED physicians should follow (Figure 2).
(Enlarge Image)
Figure 2.
Suggested treatment algorithm for human bite wounds.
The timing and the modality of surgical treatment of human bite injuries affects wound infection, as well as cosmetics. Some surgeons prefer primary wound closure, especially when the patient presents early after the injury and they indicate low infection and complication rate. Other surgeons suggest that primary closure improves the cosmetic outcome. Human bite injuries should not be underestimated in order to prevent infection. Adequate irrigation and debridement, along with antibiotic and tetanus prophylaxis, is recommended. Surgical revision must be performed when required, especially when cartilage or joints are exposed and when avulsion with tissue loss is present. In the authors' experience, surgical treatment in the cases where fractures or avulsions had occurred took place within the first 24 hours of a patient's presentation to the ED.
Follow-up documentation seems to be of great importance in order to assess healing and possible complications. Follow-up within 24 to 48 hours is recommended, and according to the authors' collected data, initial follow-up for most of the authors' patients was in line with these recommendations.
