People often come across the word “virus”, what virus infection, flu virus, viral encephalitis, computer virus, and so on, and so on, you may know that a virus is a small thing that causes disease, but do you know how small the virus is, smallpox, chicken pox, measles, encephalitis B, hepatitis B, polio, rabies, AIDS are caused by viruses, viruses also cause cancer. Viruses also cause cancer, and “computer viruses” turn out not to be viruses.
If particles are the smallest structure of matter, viruses are the smallest organisms in nature, much smaller than bacteria, and while bacteria can be seen with a microscope magnified a thousand times, viruses can only be seen with an electron microscope magnified tens of thousands of times. Virus structure is very simple, no complete cell structure, only a nucleic acid, can not grow alone, must be parasitic in living cells to grow and reproduce, just like roundworms must survive in the human intestine. Although the virus is small, but the harm to humans is not small, caused by the virus is far more infectious diseases than those caused by bacteria, and the speed of infection, the high incidence rate are more than other pathogens.
Influenza virus is the culprit of influenza, which causes a pandemic every ten to fifteen years, even sweeping the world, and is also an important cause of colds during non-epidemic periods. Mumps virus causes mumps, which is mainly an infectious disease in children and is seen as fever, swollen and painful parotid glands, and sometimes complicates orchitis and causes infertility. Measles virus is the etiology of measles, when there was no measles vaccine in the past, there was a large epidemic every two or three years, as one of the four major evidence of pediatrics, each child must go through a difficult hurdle. The rubella virus causes rubella, and when a woman gets rubella in early pregnancy, the rubella virus can infect the fetus through the placenta causing fetal malformations, commonly deafness, cataracts and congenital heart disease, and in severe cases can cause miscarriage. Polio virus is the cause of poliomyelitis, the virus is most likely to infect children aged one to five years old, invading the central nervous system, causing paralysis, leaving a lifelong disability, and in serious cases, death. China has been promoting the use of live attenuated vaccine pills for prevention since the 1960s, and the incidence has declined significantly, and there is hope that polio will be eradicated in the near future.
Hepatitis B virus is the pathogen of hepatitis B. There are three antigens: surface antigen, core antigen and e antigen. Hepatitis B virus infection of the human body can have three endings: first, the human body is immunocompromised, the virus multiplies in liver cells, and the human body does not produce an immune response, becoming a healthy carrier of hepatitis B virus, manifested as positive surface antigen in the blood, negative surface antibody and normal transaminases; second There are not many viruses infected, and the human body has normal immune function, producing antibodies to destroy the virus and gaining immunity, becoming a recessive infection process, manifested as positive surface antibody in blood and normal transaminases; Third, the virus multiplies in large quantities in liver cells, and the human body’s immune response causes liver cell damage, becoming hepatitis B, manifested as positive surface antigen and elevated transaminases, such as positive core antigen for massive virus multiplication, e antigen positive means that the virus is multiplying, and e antigen positive means that it is highly infectious.
AIDS is a serious disease caused by human acquired immunodeficiency virus. The virus multiplies in human lymphocytes, causing the body’s immune system to collapse, and the patient shows fever, weakness, emaciation, diarrhea and swollen lymph nodes all over the body. The virus is transmitted through sexual intercourse (e.g. homosexuality, promiscuity, prostitution), blood and blood product transfusions, sharing of syringes (mostly among drug users) or razors, etc. Pregnant women with the virus pass it on to their fetuses. AIDS is spreading all over the world, and with the emergence of prostitution and drug abuse, and the increase of foreign exchange, the number of AIDS patients and people with the virus in China is increasing year by year, which cannot be ignored. The main thing is to strengthen the prevention work, to strictly control the blood transfusion and blood products, to strengthen the health quarantine in the country, to strengthen the health propaganda and education, to reject AIDS in the country, to prevent AIDS in the cleanliness.
The close relationship between viruses and tumors has always been valued by the medical profession. Medical experiments have confirmed that more than 30 kinds of animal tumors are caused by viruses, and viruses can be isolated from tumors and cultured, which can cause tumors in susceptible animals; a virus can induce multiple tumors in the same animal, and also in multiple animals. There are many causes of human tumors, and virus is one of the important causes of tumors, such as hepatitis B virus and liver cancer, EB virus and nasopharyngeal cancer, herpes virus and cervical cancer are closely related, so it is important to actively prevent and treat viral diseases to prevent cancer.
Computer viruses are small programs that are artificially prepared to mess up, and they are not similar to biological viruses, but they are called viruses because their characteristics are somewhat like viruses. A small virus can cause great damage to the human body and even death, while a small computer virus can cause the loss of computer data or even destroy the entire system.
At present, the number of antiviral drugs is far inferior to antibiotics, there are only a few, and the quality is not as effective as antibiotics for bacteria.