Epstein-Barr virus infection
Introduction
Introduction to EB virus infection Epstein-Barr virus (EBV) is a member of the herpesvirus family of lymphoblastic viruses, which is distributed throughout the world and is carried by more than 95% of adults. EBV is the causative agent of infectious mononucleosis. More importantly, EBV is closely related to the occurrence of nasopharyngeal carcinoma and childhood lymphoma, and is listed as one of the human tumor viruses that may cause cancer. basic knowledge The proportion of illness: 1.3% Susceptible people: more common in children 3 to 5 years old Mode of infection: digestive tract spread, blood transmission Complications: meningitis peripheral neuritis
Cause
Epstein-Barr virus infection etiology
(1) Causes of the disease
EBV is spherical, 180 to 200 nm in diameter, and the genome is DNA. It belongs to the genus Herpesvirus and its morphological structure is similar to other herpesviruses under electron microscope. EBV has the biological properties of specifically infecting humans and certain primate B cells in vitro and in vivo. Humans are hosts of EBV infection and are mainly transmitted through saliva. Asymptomatic infections occur mostly in young children. According to serological investigation, the positive rate of EBV vca-lgG antibody in children aged 3 to 5 years in China is over 90%. Epstein-Barr virus has very special growth requirements and needs to be cultured and separated in African lymphoma cells, blood of infectious mononucleosis patients, leukemia cells and healthy human brain cells.
Epstein-Barr virus is widely transmitted in the human population, mainly through saliva, and can also be transmitted through blood transfusion.
(two) pathogenesis
There are three different ways for EBV to enter the body: First, EBV infects human B lymphocytes and proliferates, infiltrating infected cells; second, EB virus is latent in lymphocytes, free in the cytoplasm as circular DNA, and integrated into chromosomes. In the third, EBV can be inactivated and re-infected, re-infecting cells or transmitting the virus to another individual in the original way. The initial site of replication of EBV is the oropharynx, which grows in B lymphocytes and oral epithelial cells, and then infects B lymphocytes, which enter the bloodstream and cause systemic infection. It can be lurking in human lymphoid tissue for a long time. When the immune function of the body is low, the latent Epstein-Barr virus activation forms a recurrent infection.
Prevention
EB virus infection prevention
1. According to the characteristics of EBV mainly through saliva infection, it should develop good personal hygiene habits and prohibit spitting.
2. It is strictly forbidden to feed the baby by mouth.
3. Vaccination against EB virus vaccine (developed in China).
Complication
Epstein-Barr virus infection complications Complications meningitis peripheral neuritis
About 50% of cases have infectious mononucleosis, and nasopharyngeal carcinoma mostly occurs in middle-aged and older people over 40 years old.
Children aged 5 to 12 years may have lymphoma in children in Africa.
Nervous system infection can occur with viral meningitis, peripheral neuritis, and the like. The respiratory system can manifest as viral pneumonia. The cardiovascular system can manifest as viral myocarditis.
Symptom
Symptoms of Epstein-Barr virus infection Common symptoms Loss of appetite, diarrhea, hepatosplenomegaly, nausea, lymphadenopathy
The incubation period is about 4 to 7 weeks. The infection can involve various organs of the whole body. The clinical manifestations are complex and diverse. Generally, there are fever, loss of appetite, nausea, vomiting, diarrhea, swollen lymph nodes, hepatosplenomegaly, rash, etc. There may also be neurological symptoms, and the recovery period of this disease is longer, usually takes 2 to 4 weeks.
Examine
EB virus infection check
1. The presence of EB virus genome and its expression products (RNA, protein) in cells can be detected by nucleic acid hybridization and PCR.
2. Serological examination is still the most effective method for the diagnosis of CMV infection.
(1) Heterophilic antibody agglutination test: It is mainly used for the auxiliary diagnosis of infectious mononucleosis. The patient may have lgM type antibody in the early stage of the disease, which can agglutinate sheep red blood cells. The antibody titer of more than 1:100 has diagnostic significance. However, only 60-80% of cases are positive.
(2) Detection of EBV-specific antibodies: using immunoenzymatic staining or immunofluorescence techniques.
Diagnosis
EB virus infection diagnosis and identification
The disease must be differentiated from cytomegalovirus infection.
Cytomegalovirus infection is a sexually transmitted disease caused by cytomegalovirus (cmv). Twenty percent have no symptoms at birth, but also have drowsiness, difficulty breathing and convulsions shortly after birth and die within days or weeks. Other symptoms include conscious dyskinesia, mental retardation, hepatosplenomegaly, deafness, and central nervous system symptoms.
