Venezuelan Equine Encephalitis
Introduction
Introduction to Venezuelan equine encephalitis Venezuelan equine encephalitis (Venezuelaanequineencephalitis) is a natural epidemic disease caused by the Venezuelan equine encephalitis virus, a mosquito-borne, zoonotic central nervous system infection. In 1938, the disease was prevalent in the Venezuela horse herd, and this was the first time that a virus was isolated from the tissue of the diseased horse. basic knowledge The proportion of illness: 0.006% Susceptible people: no special people Mode of infection: contact spread Complications: respiratory failure
Cause
Causes of equine encephalitis in Venezuela
Infection (35%):
Venezuelan encephalitis virus is an arbovirus group A virus, the antigen is divided into 6 subtypes, causing the main pathogenicity of human and horse epidemics is subtype IA, IB and IC, causing human sporadic and local epidemics of mammals. Type II.
Pathology (30%):
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, the speed at which the mononuclear-macrophage system clears the virus, and the specificity. The emergence of sexual antibodies, etc., different viruses invade the parts outside the nervous system, many togaviruses and flaviviruses involve the striated muscle and blood management of the working endothelium, while the Venezuelan encephalitis virus often invades the myeloid and lymphoid tissues in viremia The neuronal 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 across the vascular membrane and the replication of the virus in the brain capillaries.
Increased vascular permeability (15%):
Factors that cause increased vascular permeability may contribute to nervous system involvement, and animal experiments have shown that certain flaviviruses enter the central nervous system through the olfactory neuroepithelial pathway.
Prevention
Venezuelan equine encephalitis prevention
Livestock captive, anti-mosquito, anti-mosquito and horse immunization can prevent the spread of the disease. Inoculated with TC83 live attenuated vaccine in adults, laboratory workers and high-risk groups, can prevent IA, IB, IC subtype infection, ID, IE subgroup also has a certain preventive effect.
Complication
Venezuelan equine encephalitis complications Complications, respiratory failure
Venezuelan equine encephalitis can be complicated by respiratory failure.
Symptom
Venezuelan horse brain symptoms common symptoms myalgia flu-like symptoms tachycardia nausea central fever drowsiness coma convulsions
The incubation period is 2 to 5 days, most of which are manifested as flu-like symptoms, chills, fever, headache, myalgia (the following back and legs are obvious) and nausea, vomiting, etc., may have tachycardia, conjunctivitis and non-exudative pharynx The symptoms of gorging and other symptoms disappeared in about 4 to 6 days. Only a few patients had typical manifestations of encephalitis such as lethargy, coma, convulsions, spastic paralysis and central respiratory failure. The peripheral white blood cells were slightly elevated and had brain. Inflammatory manifestations of cerebrospinal fluid are characterized by viral encephalitis.
Examine
Venezuela equine encephalitis check
The total number of white blood cells in the peripheral blood is normal or slightly low, and the virus is easily isolated in the throat swab specimen.
Diagnosis
Diagnosis and identification of equine encephalitis in Venezuela
It is clinically easy to distinguish from influenza, acute infectious gastritis and leptospirosis.
1. Influenza (infuenza), referred to as influenza, is an acute respiratory infection caused by influenza virus. The pathogens are influenza A, B, and C. They spread through droplets and are clinically hot and weak. Whole body muscle aches and mild respiratory symptoms, short duration, self-limiting, middle-aged people and patients with chronic respiratory diseases or heart disease are prone to pneumonia, the most prominent epidemiological characteristics of influenza: sudden outbreak, rapid spread It has a wide range of coverage and has a certain seasonality (popularity in northern China, generally occurring in winter).
2. Acute gastritis (acute gestritis) is an acute inflammation of the gastric mucosa caused by no cause. It can be divided into simple, erosive, corrosive and suppurative, and simplest is the most common.
