Why do person immediately need injection in case of snap bite?

Q 1: What is rabies? Rabies is a disease transmitted from animals to humans, which is caused by a virus. There are two clinical manifestations of rabies – frantic and paralytic. Frantic rabies is most common form of human rabies. Q 2: How is rabies transmitted? The rabies virus invades the nervous system of mammals. It is primarily transmitted from the rabid animal’s saliva when it bites or scratches someone. Licks to wounds or grazed and broken skin, or to 3FREQUENTLY ASKED QUESTIONS ON RABIES the lining of the mouth and nose, can also transmit the disease. Dogs are responsible for 96% of human rabies cases in South-East Asia, but there are also reports of human rabies due to bites of cats, mongooses, jackals, foxes, wolves and other carnivorous animals. Rabies due to monkey and rat bites are rare. Horses and donkeys get aggressive and bite ferociously when they are rabid. Cattle and buffaloes do not bite when they are rabid, but precautions should be taken while examining sick animals that are salivating. Sometimes livestock owners confuse rabies with foot-and-mouth disease, haemorrhagic septicaemia or choking and may attempt to administer drugs by hand, and thus get infected with rabies virus. There are no evidence-based reports of human rabies occurring due to consumption of milk. Individuals or professionals who slaughter rabiesinfected animals and handle brain and other infected 4FREQUENTLY ASKED QUESTIONS ON RABIES material may be at risk, but there are no human cases due to consumption of cooked meat. Human-to-human transmission of rabies through corneal or other organ transplantation is rare but possible. Such transmission has occurred among recipients of transplanted corneas and recently among recipients of solid organs and vascular tissue. Therefore corneas or organs should not be collected from a patient who died due to rabies encephalitis or any undiagnosed neurological disease. Although rabies patients are extremely unlikely to bite other people, caregivers should be watchful and alert when looking after them, and avoid contact with the patient’s saliva. Q 3: How does one treat an animal bite? If a person is bitten by an animal: ● Wounds should be washed and flushed immediately with soap and water for 10–15 minutes. If soap is not available, flush with water alone. This is the most effective first-aid treatment against rabies. ● Wounds should be cleaned thoroughly with 70% alcohol/ethanol or povidone-iodine, if available. ● As soon as possible, take the person to a healthcare facility for further treatment. Q 4: What should not be done with an animal bite wound? Avoid: ● Applying irritants to the wound such as chilli powder, plant juices, acids or alkalis. ● Covering the wound with dressings or bandages. 5FREQUENTLY ASKED QUESTIONS ON RABIES Q 5: How does rabies develop in humans? After entering the human body, the rabies virus progresses from the innermost layer of tissue below the human skin (called subcutaneous tissue), or from muscle, into peripheral nerves (i.e. the nerves in the body which are outside the brain or spinal cord). The virus migrates along nerves to the spinal cord and brain at an estimated speed of 12–24 mm a day. The infected person exhibits behavioural changes and clinical signs when the virus reaches the brain. The incubation period ranges from a few days to several months, and can be as long as 1 year. Q 6: What are the factors that influence development of rabies? Factors that may influence development of rabies infection include: ● type of exposure ● severity of the bite ● the amount of rabies virus introduced ● the animal responsible for the bite ● the immune status of the victim ● site of the bite – head and neck wounds, as well as wounds in highly innervated areas such as fingers, generally have shorter incubation periods due to the proximity of the viral inoculation to nerve tissue. Q 7: How long does it take for dogs and cats to develop rabies, and how long does a rabid animal survive? The incubation period ranges from a few days to several months, whereas the duration of illness – until death – varies from 1 to 7 days. 6FREQUENTLY ASKED QUESTIONS ON RABIES Q 8: What are the clinical features of rabies in dogs? Dog rabies is characterized by changes to its normal behaviour, such as: ● biting without any provocation ● eating abnormal items such as sticks, nails, faeces, etc. ● running for no apparent reason ● a change in sound e.g. hoarse barking and growling or inability to make a sound ● excessive salivation or foaming at the angles of the mouth – but not hydrophobia (fear of water). Q 9: What are the signs and symptoms of rabies in humans? Human rabies has the following signs and symptoms: ● pain or itching at the site of the bite wound (in 80% of cases) ● fever, malaise, headache lasting for 2–4 days. ● hydrophobia (fear of water) ● intolerance to noise, bright light or air ● fear of impending death ● anger, irritability and depression ● hyperactivity ● at a later stage the mere sight of water may provoke spasms in the neck and throat ● the duration of illness is usually 2–3 days, but might stretch to 5–6 days or more when receiving intensive care support. 7FREQUENTLY ASKED QUESTIONS ON RABIES Q 10: Is there any specific treatment for a rabies patient? There is no specific treatment once rabies develops. There is almost nothing that can be done apart from keeping the patient comfortable, and free from physical pain and emotional upset. ● Precautions should be taken by the caregiver to avoid bites and saliva contamination of mucous membranes and wounds by using personal protection equipment. ● Keep the patient in a quiet room with subdued light and protect them from stimuli (e.g. loud noises, cold air) that are likely to increase spasms and convulsions. ● Sedation with diazepam 10 mg every 4–6 hours, supplemented by chlorpromazine 50–100 mg, or intravenous morphine if necessary, will help to control muscular spasms and excitability. ● Feeding orally is usually impossible. Fluids should be given intravenously.