When bitten by a rabid animal, the pathogenic virus present in the animal’s saliva can cause rabies. The incubation period after a rabid animal bite can range from 10 days to several months, typically between 30 and 60 days. In the early stages of the disease, numbness and pain may appear around the wound, gradually spreading to the entire limb. This is followed by symptoms such as fever, irritability, excitability, fatigue, difficulty swallowing, hydrophobia, and pharyngeal spasms, accompanied by drooling, excessive sweating, and rapid heart rate. Eventually, muscle paralysis, coma, circulatory failure, and death may occur. The biting animal should be closely observed and isolated; if the animal survives for more than 10 days, rabies can generally be ruled out.
Treatment
Superficial wounds may be treated with routine disinfection. Deep and extensive wounds require immediate debridement to remove foreign material and necrotic tissue, followed by irrigation with normal saline or diluted povidone-iodine solution, and then rinsing with 3% hydrogen peroxide solution. The wound should remain open for drainage, and primary closure is generally not recommended.
Administration of 1,500 IU of tetanus antitoxin is indicated, and antibiotics should be given prior to debridement to prevent infection.
Rabies vaccination should be provided. Rabies immune globulin (RIG, 20 IU/kg) should be administered via infiltration around the wound. If animal-derived RIG is used, an allergy test should be performed beforehand; if the test is positive, epinephrine should be administered before giving RIG. If human-derived RIG is used, anti-allergy medication is not necessary. Active immunization with rabies vaccine should follow a five-dose schedule, with doses administered on the day of the injury and on days 3, 7, 14, and 28 after injury. For individuals who have previously received a full course of active immunization, passive immunization is not required after a bite; instead, booster doses of the rabies vaccine should be given on the day of the injury and again on day 3. Because rabies has a poor prognosis and a high fatality rate, prevention should be emphasized. Infants may receive combined vaccines that include protection against rabies. Dogs should be strictly managed and routinely immunized.