Scottish encephalitis
Introduction
Introduction to Scottish Encephalitis Scottish encephalitis (Scotlandencephalitis) is a natural epidemic disease caused by the Scottish encephalitis virus, which is transmitted by bites and transmitted by humans and animals with central nervous system infection. basic knowledge The proportion of illness: 0.003% Susceptible people: no special people Mode of transmission: blood transmission, contact transmission Complications: coma
Cause
Causes of Scottish encephalitis
(1) Causes of the disease
Scotch encephalitis virus belongs to the genus B virus of the genus Capsididae, 22~27nm in diameter, has cell pathogenic effect in HeLa cell culture, the virus is not heat-resistant, 60°C water bath for 10min and ether, sodium deoxycholate can be inactivated It can survive for several years in the dry state and can survive for 6 months in 50% glycerol.
1. The Scottish encephalitis virus is essentially a genus of the B virus of the genus Drapevirus. It is characterized by a diameter of 22 to 27 nm; the characteristic is that it can survive for several years in a dry state, and can survive for 6 months in 50% glycerol; the virus is not heat-resistant, 60 ° C water bath for 10 min, and diethyl ether and sodium deoxycholate can be inactivated.
2. After infection with the virus, the virus replicates in local tissues and local lymph nodes. Different viruses invade the parts outside the nervous system. Unlike the Venezuelan encephalitis virus, many togaviruses and flaviviruses involve the striated muscle and vascular endothelium.
3. Arbovirus encephalitis has two common pathological changes:
1 damage to nerve cells and glial cells caused by intracellular viral infection;
2 immunocompetent cells enter the peripheral vascular lumen and brain parenchyma.
(two) pathogenesis
After being bitten by infected arthropods, the virus replicates in local tissues and local lymph nodes. The occurrence and persistence of viremia depends on the degree of viral replication in local tissues outside the nervous system, and the speed and specificity of virus clearance by the mononuclear macrophage system. The appearance of antibodies, etc., different viruses invade the parts outside the nervous system, many togaviruses and flaviviruses involve the striated muscle and vascular endothelium, while the Venezuelan encephalitis virus often invades the myeloid and lymphoid tissues, in the viremia phase, nerves Systematic parenchymal cells can be violated, but the way the virus crosses the blood-brain barrier is not fully understood, and may be related to the passive passage of the virus through the vascular membrane and the replication of the virus in the brain capillary endothelial cells, causing an increase in vascular permeability. Factors may contribute to the involvement of the nervous system. Animal experiments have shown that some flaviviruses enter the central nervous system through the olfactory epithelium. There are two common pathological changes in arbovirus encephalitis: 1 nerves caused by intracellular viral infection Cell and glial damage; 2 immune-active cells enter the peripheral vascular lumen and brain In some arbovirus encephalitis may endothelium swelling and proliferation, deep white matter areas of myelin destruction and vasculitis.
Epidemiology
Sheep, grouse and other small mammals carry the virus and are infected by contact with sick sheep or bites of cockroaches. There is also the possibility of transmission through the respiratory tract. The population is generally susceptible, but it is more common with shepherds, wool handlers, slaughter sheep or laboratory workers. The disease is distributed in all hilly grazing areas in Scotland, Northern Ireland, Wales and Ireland. The season is good for summer and autumn.
Prevention
Scottish encephalitis prevention
Mainly from the source of infection and infection to prevent:
1. The focus is on immunization of the flock and killing of the pasture.
2, vaccination, control of transmission
(1) Use inactivated vaccines to produce protective antibodies to the flock.
(2) Recently, a live attenuated vaccine was used to protect the flock; once a shot, sheep and lambs were protected for 1 year.
Complication
Scottish encephalitis complications Complications
Severe coma and death.
Symptom
Scottish encephalitis symptoms common symptoms hypothermia leukopenia leukopenia
The incubation period is 5 to 15 days, which is characterized by flu symptoms. The fever is mild and may have bimodal fever. In the second fever, some patients have severe meningitis symptoms, and the total number of peripheral white blood cells is slightly reduced at the initial stage, and the amount is increased in the late stage. Bacterial meningitis changes (viral).
Examine
Scottish encephalitis check
The total number of peripheral white blood cells decreased slightly at the beginning and increased in the later stage.
Cerebrospinal fluid changes in aseptic cerebrospinal fluid.
Diagnosis
Diagnosis and diagnosis of Scottish encephalitis
It is mainly dependent on the isolation of the virus or the increase in antibody titer of duplicate serum.
Differential diagnosis
Should be noted with aseptic meningitis, other viral encephalitis.
The main clinical symptoms of aseptic meningitis are: onset, fever, headache, vomiting, or rash. Older children have eye pain, neck, back, lower limb pain and pain abnormalities; infants are crying and irritated, but with clear consciousness, no convulsions or stiff neck.
