Why AIDS destroys the body’s defenses”

　　Why AIDS Will it destroy the human body’s “defenses”? “"Hocktail therapy" has greatly improved the effectiveness of AIDS treatment.

　　There is a spherical virus with a diameter of 1 micron, but it can turn the human world upside down. It is the famous human immunodeficiency virus (HIV) - AIDS virus. Human infection with this virus will lead to immune deficiency and a series of other pathogenic microbial infections and tumors. In severe cases, it can lead to death. caused by HIV disease It is called acquired immune deficiency syndrome, the English abbreviation is AIDS, which is AIDS. How does it hurt us? Please listen to the scientists' explanation.

　　With the help of a microscope, we can discover that the world around us is actually full of dangers: disease-causing microorganisms are everywhere. In order to fight against those "invaders" that threaten survival or uncover "traitors" from the body, the human body has developed a sophisticated and complex defense and surveillance mechanism, which is the immune system. The immune system is responsible for defending its own safety. Under the surface of a peaceful life, the immune guards are always fighting to the death against the enemies in the body.

　　When HIV invades CD4 T lymphocytes, it integrates its own DNA into the DNA of the T lymphocytes.

　　White blood cells are the mainstay of these immune defenders. In fact, white blood cells are just a general term. Within the white blood cell family, they are also divided into many types such as neutrophils, macrophages, lymphocytes, and dendritic cells. They have a clear division of labor and play different roles in different infection situations. For example, in the early stages of infection, neutrophils and macrophages play a major role. They send out messages to recruit more companions while fighting the invaders, striving to engulf and eliminate their opponents. ； After a few days, lymphocytes begin to take on the main responsibility of fighting. They can secrete antibodies, neutralize toxins, and stimulate killer cells in the body to encircle and suppress infected objects. After a battle is won, lymphocytes can also preserve memories so that they can act more quickly and effectively the next time such an invader strikes.

　　However, the intrusion of HIV greatly disrupts and destroys the work of white blood cells. HIV can infect a variety of white blood cells, causing the infected cells to become diseased and die. ； HIV can induce killer cells to attack infected white blood cells, causing the number of white blood cells to decrease. ； In addition, HIV can also interfere with the sight of killer cells, causing them to attack innocent white blood cells, exacerbating the loss of white blood cells. Some HIV viruses are not eager to kill white blood cells, but choose to "lurk" in their bodies, looking for the right time to cause trouble. HIV-carrying white blood cells can also carry the virus to the brain and other parts of the body, causing brain damage.

　　In this way, as the HIV infection becomes more and more serious, the number and function of white blood cells become worse and worse, and the defense ability of the human immune system becomes lower and lower. At this time, once pathogenic microorganisms enter the body, the human body will be unable to stop it ； At the same time, some microorganisms that usually keep their peace will take the opportunity to rebel, causing some infections that are rare under normal circumstances. Because the ability of immune surveillance is reduced and renegade cells in the body can escape more easily, AIDS patients are prone to tumors. Eventually, AIDS patients will die from infections and tumors that are difficult to treat.

　　Can mosquitoes spread AIDS?

　　As early as more than 100 years ago, people discovered that mosquitoes can spread diseases. There are dozens of infectious diseases known to be spread by mosquitoes, including malaria, yellow fever, filariasis, Japanese encephalitis, and dengue fever. Since blood-sucking mosquitoes can spread so many diseases, can they spread AIDS?

　　HIV and Hepatitis B The same as the virus, it is mainly transmitted through mother-to-child, sexual contact and blood. Especially in the blood route, not only the transfusion of HIV-containing blood products can lead to infection, but also the sharing of needles, syringes or other sharp instruments contaminated with HIV can also lead to the spread of HIV. From this point of view, it is really possible for blood-sucking mosquitoes to shuttle among the crowd and carry HIV-containing blood after biting an AIDS patient. healthy On people.

　　The truth is not that simple. The mosquito's mouthparts are not suckable or pushable like a syringe. When the mosquito pierces its mouthparts into the bite target, skin When the mosquito bites, the blood will only be sucked into the mosquito's body in one direction and will not be "injected" into the human body by the mosquito. Most diseases that mosquitoes can spread are caused by mosquitoes "vomiting saliva" when they bite. This means that the pathogen must be able to survive in the mosquito's body and occupy the mosquito's salivary glands for the saliva that the mosquito "vomits" to be infectious. For example, malaria is caused by Plasmodium, which can survive in mosquitoes for 9 to 12 days. When mosquitoes suck blood, saliva containing malaria parasites will contaminate the bite site, causing malaria transmission.

　　This is not the case with HIV. HIV cannot survive in the mosquito's body. After the mosquito sucks blood, HIV is quickly destroyed by the digestive enzymes in the mosquito's body, and naturally cannot enter the mosquito's salivary glands. In this way, the saliva the mosquito vomits does not contain HIV and cannot infect new subjects.

　　Seeing this, you may still have questions: Although mosquito vomit does not contain HIV, the mosquito's blood-sucking "needle" may still be stained with HIV. If these HIV are inserted into the human body when the mosquito sucks blood, won't it lead to HIV transmission? In addition, if a mosquito is slapped to death while sucking blood, wouldn't the HIV that has not been destroyed after being sucked in also lead to HIV transmission?

　　In fact, in order for the human body to be infected, the number of pathogenic microorganisms must reach a certain scale. The scale varies for different diseases. For example, to make a person suffer from dysentery, only a few Shigella dysenteriae bacteria are needed, but AIDS is not the same as dysentery. Even if there are residual HIV on the mosquito's mouthparts, the amount is extremely small and far from being able to cause human infection. Data analysis shows that to infect a healthy person with HIV, it may take tens of millions of mosquitoes that have just bitten an AIDS patient. Even if mosquito bites When he was beaten to death, the amount of HIV in his body was still not enough to cause infection. Therefore, there have been no reports of HIV infection from mosquito bites.

　　Well, now the truth is out: As nasty as they are, mosquitoes do not spread AIDS.

　　Dr. Wei: AIDS’ “cocktail therapy””

　　HIV is very cunning and can easily undergo structural and functional changes after invading the human body, which makes it very difficult to treat AIDS. A single antiviral drug can easily induce HIV to develop drug resistance, and its efficacy will become increasingly poor. In 1996, American scientist He Dayi created "cocktail therapy". Its essence is to use multiple antiviral drugs in combination to target multiple aspects of HIV infection. In this way, not only can HIV be effectively killed, but HIV drug resistance can also be suppressed to the greatest extent. “"Hocktail therapy" has greatly improved the effectiveness of AIDS treatment.