lymphocytic choriomeningitis
Introduction
Introduction to lymphocytic choriomeningitis Lymphocytic choroidal meningitis (lymphocyticchoriomeningitis) is an acute infectious disease caused by lymphocytic choriomeningitis virus. The clinical manifestations of this disease are different. It can be a latent infection, or like a flu, with acute onset and fever. , headache, myalgia is the main performance. Typical manifestations are lymphocytic meningitis syndrome. In severe cases, meningoencephalitis can occur. The disease is generally self-limiting and has a good prognosis. basic knowledge Sickness ratio: 0.0001% Susceptible people: no special people Mode of infection: non-infectious Complications: lymphocytic choriomeningitis, abortion
Cause
Causes of lymphocytic choriomeningitis
(1) Causes of the disease
Lymphocytic choriomeningitis virus belongs to the RNA virus. During the epidemic of arbovirus encephalitis in 1934, a patient who had been diagnosed with St. Louis encephalitis died, and the specimen collected from the central nervous system was inoculated into the monkey. After continuous passage, the virus was isolated. One year later, the virus was also found in the cerebrospinal fluid of two patients with viral meningitis. Its status on human etiology was quickly determined. It belongs to the Arenavirus in terms of virus taxonomy.
The size of lymphocytic choriomeningitis virus is 40-60 nm. The virus is very unstable. It is easily destroyed in ether and below pH 7. It can be killed at 56 ° C for 1 h. At room temperature, the virus is in brain tissue suspension. It is also unstable, but it can be stored for a long time in 50% glycerol at -70 °C. The virus can grow in chicken embryo or rat embryo fibroblast tissue culture. In addition to rats, laboratory infections can also be used in guinea pigs, dogs and monkeys.
After human infection with the virus, blood circulation antibodies can be produced regardless of clinical symptoms. Immunofluorescence is a rapid and sensitive method for detecting human lymphocytic choriomeningitis virus antibody. After clinical symptoms appear 1~ The antibody can be detected in 6 days, then the antibody level gradually decreases within a few months to several years, the complement-binding antibody appears within 2 to 3 weeks, and is maintained for several months; the neutralizing antibody is produced in about 2 months, which lasts for many years.
(two) pathogenesis
There are few cases of pathological changes in this disease, so there are few reports of pathological changes. The main findings are brain swelling, atrophy of the arachnoid membrane, lymphocytes, mononuclear cell infiltration, capillary hemorrhage, necrosis, perivascular inflammatory infiltration, focal inflammation. Lymph node nodules, etc., but there have been atypical deaths, no pathological changes were found in the central nervous system, and lesions were found only in organs such as the lungs, liver, kidneys and adrenal glands.
Prevention
Lymphocytic choroid plexus meningitis prevention
Because there is no discovery of human-to-human transmission, patients do not need to be isolated, and the laboratory and animal room related to the virus should be guarded against, so as not to cause laboratory outbreaks.
Complication
Lymphocytic choroid plexus meningitis complications Complications lymphocytic choroidal meningitis abortion
It has been reported that infection of this disease in early pregnancy is related to spontaneous abortion. Late pregnancy infection may also have serious consequences. A mother infected the disease 8 days before giving birth, the child died 12 days after birth, and the cerebrospinal fluid was separated into lymphocytes. Choroidal plexus meningitis virus.
Symptom
Lymphocytic choroid plexus meningitis symptoms common symptoms meningeal irritation nausea and vomiting back pain lymph nodes meningitis diarrhea muscle sore throat sore throat
The clinical manifestations of this disease are diversified. After infection with this virus, the performance can be from asymptomatic infection, influenza-like systemic disease, meningoencephalitis and even severe meningoencephalitis, but there is no clear dividing line between the different types. Whether the clinical manifestations are related to different strains is not yet certain.
Influenza-like systemic symptoms are the most common clinical manifestations. The incubation period is generally 8 to 12 days. The onset is acute and the fever can be as high as 39.5 °C. It is accompanied by back pain, headache, and sore muscles. Some patients have sore throat, cough and other things. Symptoms of respiratory infections, a few may also have rash, swollen lymph nodes and tenderness, nausea, vomiting and diarrhea, the course of the disease is usually around 2 weeks, some patients, after a period of time, may have a second, and even occasionally Three similar episodes, but the symptoms were often mild and lasted for a short period of time, with most patients recovering gradually and some developing meningitis.
Meningitis patients may have flu-like systemic symptoms at the beginning of the disease, or they may start with headache, neck stiffness, vomiting, back muscle pain and other meningeal irritation as the main features, but the condition is not as serious as purulent meningitis, cerebrospinal fluid The examination is consistent with the characteristics of lymphocytic meningitis. The course of the disease usually lasts for 1 to 2 weeks, and the change of cerebrospinal fluid is later than the recovery of symptoms.
Occasionally, the lesions affect the parenchyma of the brain and the manifestations of meningoencephalitis. The patient may have personality changes, paralysis, lethargy, and even coma. There may also be sensory loss and dyskinesia of the cranial nerve and peripheral nerves, changes in tendon reflexes, etc. In severe cases, it can be fatal.
Patients with only influenza-like systemic symptoms, due to the clinical lack of meningitis, no indication for lumbar puncture, the diagnosis can only rely on the tips of epidemiological data, as well as evidence of viral serological diagnosis, such patients may have abnormalities in cerebrospinal fluid examination .
In patients with meningitis, cerebrospinal fluid examination is helpful, and the number of cells in the cerebrospinal fluid is increased (even in the early stage of the disease, lymphocytes are still the majority), and the sugar content is slightly lower, which has certain hints for the diagnosis of this disease, however, Cerebrospinal fluid changes are also non-specific and difficult to distinguish from other causes of lymphocytic meningitis.
Examine
Examination of lymphocytic choriomeningitis
Peripheral blood leukocytes and differential counts are usually normal, occasionally visible atypical lymphocytes, erythrocyte sedimentation is normal.
The cerebrospinal fluid examination looks normal, the pressure is normal or slightly increased, the number of cells is about 500×106/L, the lymphocytes can be as high as 80% to 90%, the protein is often up to about 1g/L, the sugar can be normal or slightly lower, chlorine The compound is normal.
Diagnosis
Diagnosis and differentiation of lymphocytic choriomeningitis
diagnosis
The patient needs to have evidence of virus isolation or serum antibody detection. In the acute febrile phase, lymphocytic choriomeningitis virus can be isolated from the blood or cerebrospinal fluid of the patient. In the acute phase and the recovery phase, the serum antibodies are detected in duplicate serum, which is helpful for identification. Acute infection, immunofluorescence technology can detect antibodies in the early stage of the disease, is a rapid and sensitive diagnosis method, in the case of only a single serum sample, high-cost complement-binding antibodies may be an indication of recent infection. Since neutralizing antibodies can persist in serum for many years, only neutralizing antibodies are positive, which is not sufficient to determine the diagnosis of this disease.
Differential diagnosis
Mainly consider lymphocytic (sterile, viral) meningitis caused by other causes, such as meningitis caused by mumps virus, rubella virus, enterovirus and other viruses, and sometimes with tuberculous meningitis Identification.
