Authors: Li Taisheng (Peking Union Medical College Hospital), Cao Wei (Peking Union Medical College Hospital), Song Xiaojing (Peking Union Medical College Hospital), Liu Xinchao (Peking Union Medical College Hospital), Luo Ling (Peking Union Medical College Hospital)
1. Why do gay men feel more likely to be targeted by AIDS?
The reason why gay men are at high risk of HIV infection is because of their special sexual intercourse - anal sex, as well as many sexual partners but not fixed and other factors.
The sexual lifestyle of anal sex is more likely to cause the spread of the virus: first, due to the rectal morphology and epithelial structure, as well as the violent action of anal sex, the inner wall of the rectum is easily damaged, resulting in the spread of the virus; secondly, the alkaline environment in the rectum is suitable for hive virus survival and reproduction.
In addition, in most cases, men who have sex with men often do not have a fixed sexual partner and are often reluctant to use condoms during anal sex, resulting in cross-infection of AIDS or other sexually transmitted diseases.
2. Is the AIDS test paper sold online reliable? How to detect the most accurately?
The use of the test strip method for the initial screening of HIV infection is easy to operate and more widely used.
Ordinary people can use test strips for self-testing, and many medical institutions will also use test strips for initial screening.
The regular HIV test paper has a production batch number that can be queried by the State Food and Drug Administration, and the accuracy rate is more than 95%, which is a relatively "reliable" preliminary screening choice, but it cannot be used as a diagnostic basis.
If the initial screening of the test strip is positive, it is necessary to go to a regular medical institution as soon as possible for confirmatory tests and other necessary tests to confirm the infection.
It should be noted that the test strip has a clear application time, and it must be used after the WINDOW OF HIV infection (from HIV infection to the appearance of detectable antibodies in the human body) for use.
In most infected people, the window period varies from 2 to 6 weeks. In other words, within 2 weeks after the occurrence of high-risk behaviors, it does not make much sense to repeatedly test strip tests.
If you do not become positive by 3 months after the high-risk behavior, the likelihood of infection is extremely low.
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3. In addition to testing, are there any symptoms that can identify HIV infection?
After HIV enters the human body, there will be three stages, namely the acute stage, the asymptomatic phase and the AIDS phase, and the clinical manifestations of each period are different.
The first stage of acute infection: usually occurs 2 to 4 weeks after the initial infection. Some infected patients present with fever, sore throat, rash, joint pain, and lymphadenopathy.
After entering the asymptomatic period: usually the infected person has no symptoms at this stage.
Finally into the AIDS phase: manifested by various opportunistic infections and tumors, with a variety of clinical manifestations.
When there is long-term diarrhea (more than 3 times per day, > 1 month), significant weight loss (weight loss of more than 10% within 6 months), repeated oral leukoplakia (oral Candida infection); repeated herpes zoster; progressive exacerbation of breathing difficulties; repeated pneumonia; young people have cerebral infarction or neurocognitive decline; progressive visual decline and other clinical manifestations need to be vigilant for HIV infection, it is recommended to go to the hospital in time.
4. What is the "window period", is it that you are infected with HIV but cannot be found?
The window period is the period of time after HIV infection in a human body until a sufficient amount of antibody is produced in the blood that can be detected by detection methods.
During this period, although the human body has been infected with HIV, the indicators of viral infection (p24 antigen and antibodies) in the blood have not yet appeared or are too small to be detected.
Patients in the window phase are highly contagious. All tests have a window period, the length of which is related to the test method, the type of sample detected (plasma, finger blood, saliva, etc.), and whether pre-exposure or post-exposure drugs have been used.
At present, major hospitals in China have widely used the fourth-generation kit recommended by the Anglo-American guidelines to detect HIV infection, and 75% of infected people can be detected by the fourth-generation kit within 24 days after exposure.
Within 44 days of exposure, the fourth-generation kit can detect 99% of HIV-infected people.
The "quick test", which can get the test results immediately, is the second-generation test method, with a longer window period, and 75% of infected people can be detected within 37 days after exposure.
Within 57 days of exposure, 99% of HIV-infected people can be detected.
The above data are based on the detection of plasma. If the test sample refers to blood or saliva, the window period may be several days long.
If the first test is negative, it should be retested 90 days after exposure to HIV.
5. Can I still eat "regret medicine" after a high-risk behavior occurs? Where can I buy?
For healthy people who are not infected with HIV, after exposure to HIV, it is possible to prevent infection by taking antiretroviral drugs, known as post-exposure prophylaxis (PEP).
However, PEP must be started within 72 hours of exposure, the earlier the better, and each hour of medication will be more effective in preventing infection.
PEP is a prescription drug that requires 28 consecutive days of medication to achieve results. If administered correctly, PEP can be effective in preventing HIV, but not 100% effectively.
If you are unsure of your HIV status and have experienced the following in the last 72 hours, you should consult the HIV Focal Point Hospital As soon as possible whether you should use PEP:
Possible exposure to HIV during sexual activity (e.g., anal sex, condom rupture, etc.);
Sharing needles with others for drug use;
Sexually assaulted.
6. Is the "AIDS vaccine" true or a rumor?
Since the first discovery of HIV in 1983, the global scientific community has invested a lot of resources in the study of AIDS vaccines, and there has been no major breakthrough so far, and AIDS vaccines are considered to be one of the most difficult vaccines to overcome.
In recent years, clinical trials of HIV vaccines have been significantly accelerated, such as the trial of the duplicate RV144 vaccine in South Africa, which began in 2016, and the Chinese Center for Disease Control and Prevention and the National Institutes of Health (NIH) jointly carried out the former DNA replication pox virus (rTV).
But there is no effective HIV vaccine.
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7. Have you heard that it is true that some people are born immune to AIDS?
When the HIV virus attacks human immune cells CD4 cells, in addition to identifying CD4 cells, it also needs to recognize the receptors on the surface of CD4 cells.
This receptor is like a door lock of a cell, once successfully paired with the virus, the HIV virus can smoothly enter the interior of the CD4 cell through this door.
There are two main door locks on the surface of CD4 cells, one is called CCR5, the other is called CXCR4, hiv virus mainly enters the cell by opening the CCR5 lock, but there are also a considerable part of the HIV virus by opening CXCR4 into the cell.
Most of the world's human immune cells have these two door locks at the same time, so no matter what kind of "unlocking function" HIV is encountered, immune cells are powerless.
However, a very small number of people, mainly Caucasians, have evolved changes in the structure of CCR5 on the surface of their cells, causing those who specialize in CCR5 to fail to recognize the HIV virus and be turned away, thus appearing "immune" to AIDS.
However, after all, there is still CXCR4 locked in, and the natural immunity of AIDS is not absolute.
8, the three major transmission channels of AIDS seem to have nothing to do with me, is there anything I need to pay attention to in my life?
Being able to name three routes of HIV infection means that you at least have some knowledge of it.
Yes, HIV can only be contracted or transmitted through specific behaviours. The most common scenarios are hive infection or transmission through unsafe sex, sharing needles or syringes.
Remember that only certain bodily fluids, mainly blood, semen, rectal fluid, vaginal fluid and breast milk, can transmit the HIV virus, and these fluids must be in contact with the mucous membranes or damaged tissue, or injected directly into the bloodstream (from a needle or syringe) to spread.
The mucous membranes include the rectum, vagina, penis, and oral mucosa.
In fact, in the clinic, there are three main types of infected people:
Unprotected anal sex or vaginal sex with an HIV-infected person without condom use throughout.
For HIV-negative couples, receiving anal sex is the highest risk of sexual activity, but the party inserting anal sex may also be infected with HIV.
Either party can get HIV through vaginal sex, although this risk is less than the risk of receiving anal sex.
Share needles or syringes with people living with HIV.
Transmission from mother to baby during pregnancy, childbirth, or breastfeeding.
The risk can be high if the mother is infected with HIV but does not take the medicine, but now we have HIV-related testing for all pregnant women and start antiviral therapy as soon as they are detected, which greatly reduces the risk of HIV at birth.
If saliva, tears, or sweat don't mix with the blood of an HIV-positive person, it's safe.
So hugging, shaking hands, sharing toilets, sharing plates, or polite kissing with HIV-positive people and other sexual activities that do not involve fluid exchange (such as touching) do not cause HIV transmission.
9. Can AIDS patients get married and have children?
AIDS patients, like ordinary people, have the right to normal love, marriage, and giving birth to healthy babies.
In terms of marriage and childbirth, there is no legal prohibition, only one is the obligation to inform the partner of the infection. With the informed consent of the other party, it is completely possible to get married and have children.
If only one spouse is hive and wants to try to conceive, the safest method is semen processing (sperm elution) and artificial insemination. Or let the positive party continue to take antiviral drugs to maximize the suppression of the virus, and the negative party can take pre-exposure prophylaxis (PrEP) every day, do not use condoms during the woman's ovulation period, and avoid HIV transmission between partners.
For mothers who are infected with HIV themselves, treatment can be carried out in accordance with the diagnosis and treatment standards of maternal and infant blockade, and the number of viruses in the mother's body can be reduced by taking antiviral drugs, reducing the chance of children contracting AIDS in the womb.
Within 6 hours of the baby's birth, he should also take antiviral drugs (which will be provided free of charge by maternal and child health institutions) and continue to take them for a month and a half.
At the same time, breastfeeding or mixed feeding should be eliminated, artificial feeding should be selected, avoid contact between mother's blood and body fluids and the baby, scientific nursing, and regular physical examination should be carried out to create a good and healthy growth environment for the baby.
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10. Will AIDS patients who receive treatment no longer spread the virus?
In AIDS patients receiving effective antiviral therapy, plasma virus levels can quickly decline if treatment is successful, all the way down to a range that cannot be measured by existing tests.
We call it "below the lower limit of detection, which is a sign of success in antiviral therapy." At this time, the patient's infectivity will be greatly reduced.
Numerous studies have shown that people living with HIV who are on stable antiviral therapy have a very low risk of transmitting HIV if their plasma viral load remains at undetectable levels for more than six months.
However, this does not mean that unprotected sex can be committed. Even if the medication compliance of AIDS patients is very good, 15-25% of patients may have a transient increase in the viral load in the plasma once or several times after the virus is controlled, and this increase is of a short duration and can be relieved on its own, but the reason mechanism behind it is not very clear.
Although scientists and doctors currently believe that this phenomenon does not affect the effect of long-term treatment, after all, it is impossible to monitor the level of the virus in real time, nor can it predict when there will be transient virus fluctuations, so sticking to protective measures is still the best choice.
Therefore, even patients with good viral control after antiviral therapy are still recommended to have protective sex.
*The content of this article is a popularization of health knowledge and cannot be used as a specific diagnosis and treatment recommendation, nor is it a substitute for face-to-face consultation by a practicing physician, for reference only.
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