There is a spherical virus, 1 micron in diameter, but it can turn the human world upside down. It is the well-known human immunodeficiency virus (HIV) – HIV.
Human infection with this virus can lead to immune deficiency, and trigger a series of other pathogenic microbial infections and tumors, which can lead to death in severe cases.
The disease caused by HIV is called acquired immunodeficiency syndrome, abbreviated as AIDS, or AIDS.
How did AIDS hurt us?
With the help of a microscope, we can see that the world around us is full of dangers: pathogenic microorganisms are everywhere. In order to confront those “invaders” who threaten survival or “traitors” who pull out of the body, the human body has developed a sophisticated and complex defense and surveillance mechanism, which is the immune system.
The immune system undertakes the task of safeguarding its own security. In a calm and water-like life on the surface, the immune guards always go forward and succeed, constantly fighting with the enemies in the body.
When HIV invades CD4T lymphocytes, it integrates its own DNA into the DNA of T lymphocytes.
White blood cells are the main force of these immune guards. In fact, white blood cells are just a general term. In the large white cell family, they are also divided into neutrophils, macrophages, lymphocytes, dendritic cells and other types. They have a clear division of labor and play different roles in different infections.
In the early stage of infection, neutrophils and macrophages play a major role. They send out messages to greet more peers and fight with invaders to devour and destroy their opponents.
A few days later, lymphocytes began to take on the main responsibility of fighting. They could not only secrete antibodies, neutralize toxins, but also stimulate killer cells in the body to encircle and suppress infected objects.
After the battle is won, lymphocytes can also preserve memories so that they can move faster and more effectively the next time such invaders invade.
However, the invasion of HIV greatly disrupts and destroys the work of white blood cells. HIV can infect many kinds of white blood cells, causing the death of infected cells.
HIV can induce killer cells to attack infected white blood cells, making the number of white blood cells less and less; In addition, HIV can interfere with the sight of killer cells, making them attack innocent white blood cells, aggravating the loss of white blood cells.
Some HIV patients are not eager to kill white blood cells, but choose to “latent” in their bodies, looking for the right time to make waves. White blood cells carrying HIV also carry the virus to parts of the brain, causing brain damage.
In this way, as HIV infection becomes more and more serious, the number and function of white blood cells are getting worse and worse, and the defensive ability of the human immune system is getting worse and worse.
At this time, once pathogenic microorganisms enter the body, the human body will be powerless to block; at the same time, some normally safe microorganisms will take the opportunity to reverse, causing some rare infections under normal circumstances.
As the ability of immune surveillance declines, mutant cells in the body are also more likely to escape, so AIDS patients are prone to tumors. Ultimately, AIDS patients will die of incurable infections and tumors.
Can mosquitoes transmit AIDS?
More than 100 years ago, mosquitoes were found to be able to spread disease. Infectious diseases known to be transmitted through mosquitoes include malaria, yellow fever, filariasis, Japanese encephalitis, dengue fever and so on. Since blood-sucking mosquitoes can spread so many diseases, will they spread AIDS?
Like hepatitis B virus, HIV is transmitted mainly through mother-to-child, sexual contact and blood. Especially in the blood way, not only will the blood products containing HIV cause infection, but also the sharing of needles, needles or other sharp instruments contaminated by HIV will lead to the spread of HIV.
So it seems that the mosquitoes that suck blood in the crowd are really likely to carry HIV-containing blood to healthy people after biting AIDS patients.
The fact is not so simple. Mosquito mouthparts are not as suction-pushing as syringes. When mosquitoes pierce the mouthparts into the skin of the biting object, blood will only be absorbed unilaterally into the mosquito body, instead of being “injected” into the body by the mosquito.
Most diseases transmitted by mosquitoes are caused by the “vomiting saliva” of mosquitoes when they bite. This means that pathogens must be able to survive in mosquitoes and occupy the salivary glands of mosquitoes, so that their “vomiting” saliva is 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 can contaminate the bite site, causing the spread of malaria.
HIV can not survive in mosquitoes. After mosquitoes take blood, HIV is quickly destroyed by digestive enzymes in mosquitoes, and naturally it cannot enter the salivary glands of mosquitoes. In this way, the saliva of mosquitoes vomiting does not contain HIV, so they can not infect new objects.
Although mosquito vomit does not contain HIV, mosquito blood-sucking “needle” may still be infected with HIV, these HIV in mosquito blood-sucking when pierced into the human body, will not lead to the spread of HIV?
If a mosquito is slapped to death when it sucks blood, can HIV that has not been destroyed be sucked in also cause HIV transmission?
In fact, in order to make the human body infected, the number of pathogenic microorganisms must reach a certain scale. The scale of the disease varies from one disease to another.
For example, in order to make people get dysentery, only a few dysentery bacilli can be used, but AIDS is not the same as dysentery. Even if there is residual HIV on mosquito mouthparts, the number is extremely small, far from the scale of human infection.
Data analysis shows that tens of millions of mosquitoes that have just bitten AIDS patients may be needed to infect a healthy person with HIV.
Even if mosquitoes are killed when they bite, the amount of HIV in their bodies is not enough to cause infection. Therefore, no case of HIV infection due to mosquito bites has been reported.
Cocktail Therapy for AIDS
HIV is very cunning, and it is easy to change its structure and function after it invades the human body, which brings great difficulties to the treatment of AIDS. Single antiviral drugs can easily induce HIV resistance, and the efficacy is getting worse and worse.
In 1996, American scientists created Cocktail Therapy. Its essence is to use a variety of antiviral drugs in combination for multiple links of HIV infection. In this way, it can not only effectively kill HIV, but also minimize HIV resistance.