What reason is Oriental equine encephalitis caused by?

summary

Oriental equine encephalitis (OEE) is a typical zoonotic viral disease. It belongs to group a arbovirus (arbovirus group A, enveloping virus family a) and contains a single strand RNA. The virus was first isolated from the diseased equine brain tissue, hence its name. Subsequently, the same virus was isolated from the brain tissue of the patient. The symptoms of human encephalitis caused by the virus are very critical and dangerous. Its clinical manifestations are very similar to those of Japanese encephalitis. The mortality rate is about 35%. At present, the virus is one of the main types of anti bioterrorism in the international community, and it is a kind of managed virus in China.

What reason is Oriental equine encephalitis caused by?

Oriental equine encephalitis is a kind of viral encephalitis. Oriental equine encephalitis virus (EEEV) is a member of the envelop virus family α Virus is a member of the family, and it is very similar to Venezuelan equine encephalitis virus. It is defined as a kind of strain because of its many chances of laboratory infection, high possibility of disease after infection, severe symptoms and life-threatening, lack of effective prevention methods, strong infectivity and great harm to people. The storage host of EEEV is birds. In North America, antibodies to the virus were found in 39 species of birds, and equine encephalitis virus was isolated from purple white headed bentgrass, tit and migratory birds. Most of the wild birds did not get sick after infection, only appeared different degrees of viremia, but could carry and spread the virus.

It is estimated that more than 1000 cases of "viral encephalitis of unknown origin" are clinically diagnosed every year in Fujian Province. Most of them are of unknown etiology and affect the treatment. EEEV is transmitted from horses to humans by the bite of an infected mosquito. The incubation period is about 15 May. Like humans, horses can be infected and even die. But the main transmission chain is between birds and mosquitoes. Not all mosquitoes transmit EEEV, and there are more than 60 species. In order to maintain the transmission chain of endemic animal diseases, the most important mosquito is cercidus melanocephalus. Residents and tourists in epidemic areas, as well as those engaged in outdoor work and recreational activities, are the high risk groups, and most of them are over 50 years old and less than 15 years old.

The typical manifestations of the disease are rapid influenza like symptoms, such as headache and fever, and even convulsions, disturbance of consciousness and meningeal irritation. If not treated, with central nervous system damage, poor prognosis, may lead to 35% of the cases died. The prognosis of Oriental equine encephalitis is related to the extent and severity of the disease. Brain lesions are limited and do not invade the "life center". When the condition is mild, the prognosis is often good. If coma lasts for a long time, or has frequent convulsions, brain hypoxia and pathological changes aggravate, prognosis is poor, easy to leave nerve, mental sequelae.

matters needing attention

Although there are drugs for various types of encephalitis in infected horses, there is no good symptomatic treatment for infected people. Relatively speaking, the best medical methods, including hospitalization and supportive treatment, such as specialist care, respiratory support, prevention of secondary bacterial infection, and physical therapy, are mainly used to reduce the risk of fever and relieve the pressure on the brain and spinal cord. Due to the relative lack of treatment measures, prevention is the main method.