This is the 3623rd article of Da Yi Xiao Nursing
1. Can a healthy dog carry rabies virus?
Health here has 2 meanings. One is long-term health, and the other is health at a certain point in time.
(1) Surveys of rabies virus carrying rates in healthy-looking dogs conducted in many places show that although the positive rate is usually not high (at the one-in-a-thousand level), the rabies virus can indeed be detected in healthy-looking dogs (surveys usually from dogs for sale and stray dogs) (using the method of detecting brain tissue after euthanasia).
(2) However, dogs cannot carry rabies virus for a long time without disease, and studies have shown that the incubation period in dogs is up to half a year, so if there is no contact with the outside world within half a year or a dog that has not been bitten by a wild dog or a wild dog, the possibility of carrying rabies virus can be ruled out.
EXPLANATION
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Dogs detected with rabies virus in these brain tissues found in surveillance are in the incubation period of the disease. However, it is important to note that carrying a virus does not mean being contagious at all times. This rabies virus is completely different from other viruses (such as hepatitis virus, chickenpox virus, etc.), which we will continue to discuss below.
2. Is it possible that domestic dogs are the source of rabies infection?
Surveys of rabies patients reported on the mainland in recent years show that more than 90% of the injured animals are dogs, and domestic animals are very common, especially in rural areas, and a large proportion of the diseases are caused after being bitten by their own or neighbor's dogs.
Domestic dogs may be bitten by wild dogs and wild cats, making them a new source of infection, so domestic dogs ≠ not spread rabies.
3. All people who are bitten by dogs will have rabies symptoms, is it just a matter of time?
First, rabies is a disease with a very low incidence and a very high mortality rate. In most cases, the dog that bites or scratches the person does not have a rabies virus in the body (there are many cases of biting, which does not necessarily mean that they have rabies), so in this case, it is impossible to develop the disease.
Second, even if you are bitten by an animal with rabies, you may not be caught. Dogs or cats infected with the rabies virus are generally thought to be intermittently detoxified through salivary glands, i.e. rabies dogs or sick cats do not have the virus in their saliva at all times. If the salivary glands do not detoxify at the time of the bite, then in this case, even if they are not properly disposed of, they will not be infected. That's why not all victims ended up the same in the same mad dog bite.
Even so, we can't be sure whether the virus has entered the human body at the time of the bite, because the case fatality rate of rabies is too high, so we can't take chances, and this phenomenon can't be the basis for refusing to be vaccinated.
4. Is it possible for all people exposed to mad dog saliva to be infected with rabies?
Strictly speaking, the transmission of rabies requires several conditions and is not easy to achieve.
One is that at this time, the dog's salivary glands are in the detoxification stage, and the saliva contains virus.
Second, the virus in saliva should be able to enter the human body. Since the virus cannot penetrate the intact skin, from the perspective of the virus, it requires the rabies animal to inject the virus in the saliva into the new host by biting, scratching, etc.
The essence of this problem is that while paying attention to rabies, we must not panic excessively and become a member of "phobia". Especially if the skin is intact, it is impossible for the virus to penetrate into the human body.
5. Do infectious dogs necessarily show obvious symptoms?
There are 2 types of rabies, one is the manic type, which accounts for about the majority, and the other is paralyzing, which accounts for a relatively low proportion.
Another problem is that a few days before the onset of obvious symptoms, the virus can be detected in the salivary glands of rabies animals, and at this stage it is bitten or it may be infected.
The symptoms at the time of the accident (biting, etc.) alone cannot directly determine whether it is contagious or not.
After being bitten by an animal such as a cat or dog, the most reliable approach is standardized wound management, rabies vaccine/protein use, and it needs to be started as early as possible. Cooperate with your doctor's risk assessment of exposure.
6. Does it have to be caught and bitten by animals to get rabies?
At present, the main route of rabies transmission is bites, the proportion of scratches is relatively small, and other common ways include wound licking.
Other less common paths include:
(1) Aerosol transmission: Laboratory staff who conduct rabies virus-related tests may enter caves where a large number of bats live.
(2) Organ transplantation. The organ donor has a virus in his body, and the donor becomes ill after the transplant.
(3) Dissecting, slaughtering, and skinning rabies animals can occasionally cause infection; while eating raw meat (meat containing rabies virus) of rabies animals that die of rabies is rare.
Ways that will not spread:
(1) Thoroughly cooked animal meat and pasteurized milk will not spread rabies.
(2) Rabies is not transmitted vertically through mother-to-child transmission. Newborn cow dogs do not carry the virus.
Some people tangle with the saliva of rabies animals to the surface of an object, then inadvertently touch their body, and then find that they have wounds on their hands or feet, thus suspecting that they may be infected with rabies. In fact, this panic is very similar to "AIDS phobia". This indirect route of transmission is only theoretically possible, after all, this is a rabies virus, not a respiratory or enterovirus. The main route of normal infection is bites and scratches in dogs and cats that are bloodied.
General Consultant: Professor Jiang Qingwu Medical Consultant: Changning District Center for Disease Control and Prevention Zhao Wensui Chief Physician Cai Enmao Chief Physician
IT technical support: Shanghai Yuemi Information Technology Co., Ltd
Medical content: Zhuang Jianlin Famous Doctor Studio Editor: Zhang Zhan Gao Hui
Funding Project Support:
Shanghai Municipal Science and Technology Commission Science Popularization Project Grant (Project No.: 18dz2300700)
Changning District Fourth Round (2018-2020) Innovation Team (Reserve) (Infectious Disease Prevention and Control Innovation R&D Team Based on Artificial Intelligence and Original IP System)
Changning District Medical Specialty: Department of Acute Infectious Disease Prevention and Control (Monitoring and Prevention of Acute Infectious Diseases in School)
Innovation team of Changning District CDC: Visual Health and Health Science Popularization Team