To prevent Japanese encephalitis, it is time to show the real technology

Epidemic encephalitis B (JE), also known as Japanese encephalitis, is an acute infectious disease of the central nervous system caused by JE virus, with inflammation of the brain parenchyma as the main lesion. The disease is transmitted by mosquito bites and is more common in summer and autumn (July-September), with an incubation period of 10-14 days. Most patients are asymptomatic after being infected with JE virus, and only a few have symptoms of the central nervous system. The clinical symptoms are high fever, impaired consciousness, convulsions, pathological reflexes and meningeal irritation signs. The mortality rate is high, and severe patients may have sequelae such as language disorders, mental abnormalities, intellectual impairment, paralysis, or death.

Treatment: Patients should be hospitalized and the ward should be equipped with mosquito-proof and cooling equipment. The condition should be closely monitored and careful care should be provided to prevent complications and sequelae, which is of great significance to improving the efficacy.

At present, there is no specific antiviral drug to treat Japanese encephalitis. Active symptomatic and supportive treatment should be adopted to maintain the water and electrolyte balance in the body, focus on treating critical symptoms such as high fever, convulsions, controlling cerebral edema and respiratory failure, reduce the mortality rate and the occurrence of sequelae.

How is Japanese encephalitis transmitted?

Japanese encephalitis is a natural zoonotic disease. Livestock and poultry such as pigs, cattle, horses, sheep, chickens, and ducks that have a close relationship with humans can be infected with Japanese encephalitis by being bitten by mosquitoes. At the same time, they are also the source of infection of Japanese encephalitis, that is, mosquitoes bite these sick animals and then bite humans, which can transmit Japanese encephalitis to humans. Usually, in the first few weeks before Japanese encephalitis becomes prevalent in the human population, it has already been widely spread through the cycle of mosquitoes → livestock and poultry → mosquitoes. Therefore, livestock and poultry are the main sources of infection of Japanese encephalitis.

When a person is bitten by a mosquito carrying the Japanese encephalitis virus, the virus enters the body through the mosquito's saliva. After a latent period of 4-21 days, the virus first grows and multiplies in the cells at the site of the bite, then travels through the blood to the lymph nodes and other reticuloendothelial systems to multiply in large quantities, and then returns to the blood to form viremia. After humans are infected with Japanese encephalitis, there is only a short (about 1 week) period of viremia, and the amount of virus in the blood is also low, so human Japanese encephalitis patients are not the main source of infection for Japanese encephalitis.

The disease has a strict seasonality, with 80-90% of cases concentrated in July, August, and September. However, the epidemic season varies slightly with different geographical environments. The peak of epidemic in South China is from June to July, in North China from July to August, and in Northeast China from August to September, which is consistent with the mosquito density curve.

Prevention of Japanese encephalitis

(1) When killing and preventing mosquitoes, pay attention to killing overwintering mosquitoes and early spring mosquitoes.

(2) Proper management of livestock such as pigs and horses and good environmental hygiene in livestock sheds can reduce the virus transmission rate in animal pens, thereby protecting susceptible populations.

(3) Vaccination: Timely injection of Japanese encephalitis vaccine can improve the immunity of susceptible people and is one of the most important measures to prevent this disease.

(4) Drug prevention: During the epidemic season of Japanese encephalitis, decocting 15 grams each of isatis indigotica, isatis root and honeysuckle in water, one dose per day for 7 consecutive days, also has a certain preventive effect.

(5) Physical fitness: Pay attention to strengthening children’s physical fitness and improving their disease resistance.

(6) Carry out health education to popularize knowledge on the prevention of Japanese encephalitis so that everyone is clearly aware of the preventive measures for this disease, promptly identify patients, isolate them early, diagnose them early, and treat them early, so as to minimize the harm of Japanese encephalitis to human health.

At the same time, we explain the knowledge of Japanese encephalitis prevention to family members and patients, and tell them that they should be vaccinated during the Japanese encephalitis epidemic season, carry out mosquito prevention and control work, and develop good hygiene habits. If they have fever, headache, or impaired consciousness, they should go to a regular hospital immediately to improve their self-protection awareness and reduce the incidence rate.

Popular Science Physician: Chen Xiaoli

Workplace: Xiyangdian Town Health Center, Pingyu County

Original title: "Prevention and treatment of epidemic encephalitis B"