Main transmission routes of rabies virus

Rabies virus mainly exists in the brain tissue and spinal cord of sick animals. There are also large amounts of viruses in the salivary glands and saliva of sick dogs, and they are excreted out of the body with the saliva. From 10 to 15 days before clinical symptoms appear in sick dogs, to 6 to 7 months after the symptoms disappear, the virus can be contained in the saliva. Therefore, when the animal is bitten by a sick animal, it can become infected. The saliva of some seemingly healthy dogs and cats can also contain viruses. When they lick people or other animals, or live with people, they can also infect people.
In addition, many wild animals, such as wolves, foxes, deer, bats, etc., can not only become sick and die after being infected with this disease, but can also spread the disease. For example, some species of bats often attack humans and animals after being infected with rabies virus, causing them to become infected and sick. Air contaminated by respiratory secretions and urine can also cause respiratory infections in humans and animals. Wild animals can become infected through their digestive tract by eating diseased carcasses. Therefore, it can be seen that the infection route of rabies is not just through bite infection as thought in the past.

Key points of diagnosis

1. Epidemiological characteristics: The disease is mostly sporadic, that is, it occurs in one case, and the vast majority of cases have been bitten by rabies. : It usually occurs in spring and summer and is related to the sexual activity of dogs.

2. Clinical characteristics: The sick dog shows violent restlessness and confusion. At the beginning of the disease, the main symptoms are depression and abnormal behavior. For example, the dog does not listen to calls, likes to hide in dark places, has strange habits, and likes to eat gravel, wood, soil and other objects. The sick dog often licks and bites the injured area with its tongue. Soon, they become violent and restless, attacking people and animals, often running around aimlessly. Appearance: The sick dog gradually loses weight, the mandible droops, and the tail droops and is sandwiched between the two hind limbs. Hoarse voice, increased salivation, and difficulty swallowing.
In the later stages, the sick dog developed symptoms of paralysis, difficulty walking, and finally died of systemic failure and respiratory paralysis. Cases with the above typical symptoms, combined with a history of being bitten, can make a preliminary diagnosis. However, not all rabid dogs bite people, and there do exist a considerable number of venom-carrying dogs without clinical symptoms and dogs that excrete the virus before showing clinical symptoms. Therefore, suspected sick dogs that have bitten people or animals should not be killed immediately, but should be captured and quarantined for at least two weeks. If no symptoms of sick dogs appear within two weeks, it is proved that it is not rabies, and the quarantine can be released. If clinical symptoms appear , it is best to conduct an autopsy after natural death. If the stomach is empty or full of foreign matter, the gastric mucosa is obviously inflamed, and there are no specific changes in other organs, the dog brain should be collected and sent to the laboratory for specific examination. Such as endogenous body examination, fluorescent antibodies or enzyme-linked immunosorbent assay (ELISA) in nerve cells to find out whether rabies virus is present in brain tissue. The brain tissue suspension can also be inoculated into rabbits or mice to confirm the diagnosis.

Preventive and control measures

First, domestic dogs should be vaccinated regularly. There are currently two types of rabies vaccines produced in my country:, namely rabies vaccine and rabies attenuated cell freeze-dried vaccine. The dosage of rabies vaccine is: 3 ml for dogs weighing less than 4 kg, and 5 ml for dogs weighing more than 4 kg. Animals bitten by sick dogs should be vaccinated immediately. In this case, only one injection of vaccine is not enough. Two injections should be given at an interval of 3 to 5 months. Vaccinated dogs will be immune for half a year. Another vaccine is rabies attenuated cell freeze-dried vaccine. Before use, it should be diluted with sterile water for injection or physiological saline according to the amount specified on the bottle label. After shaking well, regardless of size, each dog should be injected subcutaneously or intramuscularly with 1 ml to obtain a one-year immunity period. No matter which type of vaccine is injected, dogs generally have no adverse reactions. Sometimes swelling occurs at the injection site, which disappears quickly. However, these two vaccines are not suitable for injection into weak, laboring or postpartum female dogs and young dogs. After injection, dogs should be prevented from being overtrained and their health should be monitored carefully. Pentavalent vaccine for dogs (including rabies vaccine) can also be injected.

Second, strengthen quarantine. When unvaccinated dogs enter the country, in addition to strengthening isolation inspections, they must be vaccinated in time. Otherwise, they are prohibited from entering. Untamed wild dogs and other wild animals should be killed, especially in endemic areas.

Third, sick dogs and livestock that have shown clinical symptoms should be culled immediately and should not be treated. The body should be buried deeply and not eaten.

Newly bitten dogs should be treated promptly. The therapeutic effect depends on the time of treatment and whether the local treatment is complete. At the time of the bite, first allow local bleeding, then fully wash the wound with soap and water to eliminate the virus in the local tissue, and then use o. Disposal with 1% mercury chloride solution or alcohol, iodine, etc. If rabies immune serum is available, it is better to inject it at points around the wound (the dosage is calculated as L 5 ml per kilogram of body weight, preferably within 72 hours after the bite). If serum is not available, emergency vaccination should be carried out promptly with vaccine.

Fourth, for those who are bitten, the wound should be washed quickly with 20% soapy water and treated with 3% iodine. The rabies vaccine should also be promptly vaccinated (on the first, third, seventh, fourteenth and thirty days each) Injection once, followed by a booster injection on the 40th and 50th days) can often achieve control effects.