Rabies is a dreaded infectious disease that is spread due to a bite or saliva of an infected animal. The rabies virus affects the central nervous system and progressively damages the spinal cord and brain. If untreated, rabies is fatal. Rabies can be contracted from infected wild animals such as raccoons, skunks, bats and foxes. Sometimes domesticated animals such as cats and dogs can become infected unless they are vaccinated against rabies.
Symptoms of rabies appear within a month of exposure to an infected animal. The severity of the exposure and bite determine the appearance of symptoms. The patient suffering from rabies is likely to have fever and headache. There might confusion and hallucinations. A person suffering from rabies will have excessive salivation. There might be difficulty in swallowing. Fear of water (hydrophobia) is another symptom. Paralysis and breathlessness may result.
Testing for rabies includes blood and saliva tests and examination of the brain tissue and spinal fluid. The wound site must be carefully cleaned with a virus-killing cleanser. Treatment for rabies includes a dose of human rabies immune globulin (HRIG) and five doses of rabies vaccine over a 28-day period. It is essential to be vaccinated with the rabies vaccine immediately after exposure. While the immune globulin is injected around the site of the bite, the rabies vaccine is injected into the upper arm.
Rabies vaccine is administered to persons who have been exposed to an infected animal. It is also given to persons at higher risk of exposure to rabies. Animal handlers, laboratory workers and veterinarians are usually vaccinated against rabies as they might be frequently in contact with rabid animals. Rabies vaccine helps the infected person's body start production of antibodies. While rabies immune globulin provide initial antibodies, the ones produced by the body provide lasting protection. The rabies vaccine is administered in 5 doses - days 1, 3, 7, 14 and 28. Along with the first dose, the exposed person is given a shot of human rabies immune globulin. There might be mild reaction to the vaccine such as swelling and tenderness the site of the injection. There might be fever, nausea and headache.
Animal bites are one of the most reported causalities with adults and children. In addition to the emergency measures to stop bleeding in the event of an animal bite, physicians need to look for potential pathogens such as bacteria or virus that can cause further damage to the patient.
Dog and cat bite
It is one of the common forms of animal bites. A dog that attacks or bites has pre-existing tendency of abnormal temperament, which triggers its proactive nature to bite an individual. However, dogs, which are kept as pets that have been vaccinated, are not dangerous when they leave minor scratches with their teeth. Dogs, which are affected by rabies, are more dangerous and can be lethal. An attack by a rabid dog can be traumatizing leading to many physiological and psychological conditions. Immunoglobulin and anti-rabies vaccines are given immediately to the victim to prevent the multiplication of the rabies virus. If ignored, rabies virus can be fatal causing adverse complications such as hydrophobia and sometimes death. Similar approach is taken with respect to cats. In case of cat scratch, immunoglobulin along with antimicrobial such as tetracycline are used to prevent associated bacterial infections caused by Pasteurella and Bartonella species.
Rodent bites are rare but are equivalently dangerous as they are potential carriers of rabies virus along with bacterial species such as Leptospira and streptobacillus SP. In the event of a rodent bite, immediate medical attention is required. The proximity of the bite region to the brain is very significant as it is associated with the rapid propagation the virus.
The most common form of reptile bites is snakebites. These bites are fatal and require immediate medical attention. Snake bites are widely studied and depending upon the type of snake and the potential venom it produces, the anti-venom is administered. Some snakes such as the black mamba and Cobra seen in Africa and Asia produce venom that is neurotoxic. Other snakes such as vipers, rattle snakes and kraits produce venom that is toxic to the circulatory system. Anti-venom administration is followed by patient observation for a period of 24 hours is essential to ensure positive prophylaxis.
In addition, other animals such as raccoons, coyotes, foxes, skunks which fall under the wild mammal categories are also treated with anti-rabies vaccines and tetanus shots.
Management of animal bites
Animal bites have to be effectively analyzed in order to manage them well. The history and the demography of the animal are recorded along with appearance and behavior traits. Evidence-based conclusions are drawn to confirm that the animal especially if it's a mammal is rabid. All wounds have to be cleaned thoroughly to prevent cross infection and sepsis. All puncture wounds ranging from mild to severe have to be treated with respective vaccines and antimicrobial drugs. The most common drugs used are Augmentin, tetracycline, clindamycin and in some cases cefuroxime and metronidazole. This prevents the onset of tissue necrosis by the bacteria. Azithromycin is recommended in case of cat scratch as it prevents the growth of Bartonella.
Bibliography / Reference
Collection of Pages - Last revised Date: March 18, 2019