Today’s topic is HIV exposure and management, which is how to respond if there is a high risk and how to assess whether there is a risk of infection. Some time ago, in Beijing cab passengers were stabbed incident is boiling, many people to the hospital, consultation, suspected by the needle, will not be infected with HIV, need to go through treatment. So that the majority of netizens friends, or the general public friends, on this aspect of the problem, some knowledge is not too much, today we discuss this issue. What is a highly risky behavior and what is not, and then a problem that needs to be solved, is that if a highly risky behavior occurs, that is, a behavior that may be infected by HIV, how do we face in order to reduce the spread of the virus and the harm brought to us by HIV.
What is HIV exposure? After our broken skin mucous membrane, contact with potentially HIV-infected blood, body fluids, tissue fluids, body fluids containing HIV virus, such a situation is called HIV exposure. We clinically classify exposure into several types. First of all, the problem of HIV exposure, first of all, is in a specific population, that is, occupational exposure, generally refers to doctors, nurses, police officers, these specific occupations, in the work of AIDS prevention and treatment and related management, there is a possibility of accidentally contaminated local skin by the blood and body fluids of HIV-infected people, resulting in such occupational exposure, the other is non- The other is non-occupational exposure, which is the case of HIV exposure in the general population, such as sexual contact, intravenous drug use, and accidental injury, etc.
Today’s focus is on non-occupational exposure, what are the circumstances that will have the problem of HIV exposure. The first is the problem of sexual exposure, through sexual contact, one party may be HIV-infected, through sexual contact, one party may have the problem of HIV infection, another is the sharing of syringes for drug use, this situation is also the occurrence of HIV exposure, and then is the accidental injury, such as pedicure, shaving, sharing some utensils, not well disinfected, this situation may also occur accidental injury The problem of HIV infection may occur, and then there is the case of tattoos, dental cleaning. Then there is the problem of mother-to-child transmission, which means that if a pregnant woman is infected with HIV, the baby or fetus may be infected with HIV, which is also a kind of exposure.
What is the mechanism of HIV exposure in the human body infection, we understand the mechanism, can better explain the post-exposure treatment is not effective, is not able to get a good safety treatment. Generally speaking, patients who are first infected with HIV generally do not show symptoms of systemic infection, leaving a brief window period when HIV acute infection, the virus from the exposed site first after three to five days of active and continuous release, there should be a large amount of virus in the blood, we call the period of viremia, this is the acute infection period, so within 72 hours after exposure, if we Therefore, within 72 hours after exposure, if we have carried out effective treatment, it may be possible to inhibit the replication of the virus, so as to be able to achieve prevention, or to stop the problem of systemic infection, if within a shorter period of exposure, after appropriate treatment, it is possible to prevent HIV infection in humans.
Are there studies that prove the effectiveness of post-exposure prophylaxis? Is it possible for some patients to have side effects, nausea and vomiting during the course of taking the medication, and is it possible to shorten the duration of the medication, and is this okay? Before dealing with this issue, there should be sufficient theoretical basis to support effective treatment, or the issue of the duration of treatment. Before this, there is information to prove that some animal experiments were done, intravenous exposure monkeys, at 48 hours of inoculation, 24 hours were given 4 weeks of antiviral treatment to observe how effective the treatment is, the results showed that if the probability of infection of the virus without treatment is relatively high, antiviral treatment within 24 hours achieved good results. This study also found at the time that if the time of taking the drug is postponed until 48 or 72 hours after exposure, or if the total course of treatment is shortened to 3 to 10 days, it is recurrence to achieve adequate prophylactic treatment, but it is important to go to a professional doctor for consultation, or intervention to reduce the impact of such side effects on themselves.
There are some situations that should not fall under the category of HIV exposure, the first one, is contact with HIV-negative blood and body fluids, is not infected, there is no need to panic about this. The first is that the skin is not broken, there is no wound, a small amount of low concentration of HIV-positive blood in a short period of time, this situation is also not infected. Contact with the sweat, urine, tears, feces, etc. of HIV-infected people is also not infected.
If the gloves are intact, you will not be infected if they come into direct contact with HIV-positive blood or body fluids. There are several ways of HIV transmission, the first is blood transmission, the risk of blood transfusion transmission is 95%, not 100%, and then there is pregnancy transmission, the probability of transmission to the next generation is generally 25%, if a pregnant woman is infected with HIV, after blocking treatment, the risk of infection can be If a pregnant woman is infected with HIV, the risk of infection can be reduced to 8% after effective interruption treatment, plus say, cesarean delivery and artificial feeding, the risk of such transmission will generally be reduced to less than 2%. Another mode of transmission is sexual transmission, sexual transmission in the middle of the male to the female, the probability of once is about 0.2%, if the female is HIV infection, the probability of transmission to the male is 0.1%. The risk of infection in the case of male-to-male anal sex is 0.5% to 3%, and then there is the risk of transmission from needle stick, which is generally around 0.3%. According to WHO statistics, the global incidence of infection through various routes, in the HIV-infected population, the blood transfusion infection caused by 3% to 5%, through the mother-to-child transmission route, perinatal transmission is generally in the range of 10% to 20%, through sexual contact transmission in 70% to 80%, and then the public syringe drug users in the range of 3% to 10%, and then the medical personnel occupational exposure, accounting for 0.01%. The problem, accounting for 0.01%. What is the risk of HIV infection from different sexual contacts, and is the risk of HIV infection the same in different ways, or is there any difference? There are several figures, the probability of infection is 0.1% to 0.3% if one receives anal sex, 0.08% to 0.2% if one receives vaginal sex, 0.67% if one shares syringes, 0.03% for penetrative anal sex, and 0.03 to 0.09% for penetrative vaginal sex. Is the risk of exposure to body fluids high, is it a high-risk situation, or is it related to the concentration of HIV in the body fluids that are exposed to it, how is the concentration of HIV in body fluids a situation, which body fluid HIV concentration is higher and is the most dangerous? In some studies, it is proved that there is a great difference in the concentration of HIV in various body fluids, such as blood and semen, the concentration of HIV in body fluids is relatively high, the highest is blood, then is semen, cerebrospinal fluid, then is the vaginal cervical secretions, than it is lower than urine, feces, saliva, if contact with blood, this risk is relatively high, then is semen.
The first factor that affects HIV transmission through blood is sharing syringes and needles with HIV-infected people to take drugs, which is extremely dangerous, with an infection rate of 0.67%. Then is the amount of blood contact, in the study found that 200 microliters, equivalent to 0.2 ml, this amount is also very small, that is to say 0.2 ml of fresh blood, through the skin needles, through the syringe injection of 0.2 ml of fresh blood, there is a possibility of being infected. Then again, if more than 5 ml of stock blood is injected, it can also be infected with HIV. in addition the longer the blood leaves the body, the risk of infection is also reduced.
Here are a few situations for the majority of users to evaluate the accident, if it happens, the size of this accident risk, we can do our own effective assessment when an accidental injury occurs, and do not be overly alarmed, if the risk is very small, you can do in time to deal with, if the risk is large, you must go to the hospital to do proper treatment. This accidental exposure, first of all, the wound problem, if this wound is small, shallow, this risk is relatively small, if the exposure is a large wound, is a deeper wound, exposure to the HIV environment is relatively large risk. The second is the injury is the cavity of the apparatus, with the virus, this kind of infection is greater, for example, the syringe, which is hollow, there is a large amount of blood or virus inside, the risk is greater. Then there is contact with infected blood or body fluids, or semen, or vaginal secretions, if the amount is relatively large, the risk is higher, if the amount of contact is relatively small, the risk is lower. In another case, if the blood is exposed and has left the body for a long time, the risk is relatively low. The longer the time away from the body, the lower the risk factor is.
There are also some factors, the way of sexual intercourse, unprotected sexual intercourse, such as anal intercourse is relatively high risk, because anal intercourse may bleed, or wound rupture, this situation will increase the risk of HIV infection, will increase the risk of exposure, and then there is vaginal intercourse, is moderate risk, because the amount of vaginal secretions, HIV is not much. The risk of oral sex is relatively low, but if you have sex during your period, the risk is increased because there is a large amount of virus in the blood. The risk of hymen rupture is reduced if a condom is used. If a condom is used safely and correctly, the risk can be reduced by 80%. There are also factors that may increase HIV exposure if accompanied by diseases, such as venereal diseases, such as ulcerative diseases, or inflammatory diseases, such as syphilis, gonorrhea, condyloma acuminata, common clinical sexually transmitted diseases, these diseases may appear ulcers, or pus, surface rupture, condyloma acuminata during sexual intercourse may also This condition increases the risk of HIV exposure, and some sources suggest that it may increase the risk 5 to 10 times. The risk is greater during the acute phase of infection, because the antibodies are not produced during the acute phase of HIV infection, or when they are just produced, there is more virus replication in the body, because the virus content in body fluids is higher. The higher the HIV content, the greater the risk. The higher the HIV level, the greater the risk. The probability of transmission in the latent state is generally smaller, and the amount of virus in the latent stage is relatively low. Then there is the difference in terms of gender, if the risk of transmission from male patients to women is much greater than the risk of transmission from female patients to men, which is five times greater, and the content of HIV in male semen is higher than the content of HIV in female cervical and vaginal secretions, which is a large amount of HIV, the risk of infection is also greater.
Some people know that HIV exposure is graded, divided into primary, secondary and tertiary, when it was in the study of occupational exposure, in the clinic to do an exposure level of treatment and analysis, if the high risk in the general population can also be used as a reference, in the occupational exposure, divided into primary exposure, secondary exposure and tertiary exposure, primary exposure is the source of exposure is body fluids, blood, and body fluids and blood Medical devices. Secondary exposure is body fluids, blood, or medical devices of body fluids and blood, with longer exposure time, larger exposure, or exposure type of needle injury, or cutting injury, but with less damage. The other is the third level of exposure, the exposure source is body fluids, blood, the exposure type is the exposure source stab wounds, cuts, the injury is more serious, the wound is deeper. If there is a high-risk behavior, you can refer to this issue of risk, the higher the level, the greater the risk.
What factors can affect the transmission of the virus? One is breastfeeding, and then there is the question of which disease period the pregnant woman is in. If she is symptomatic, the risk of the next generation being infected with HIV during the symptomatic period is definitely increased, because the virus content in body fluids is higher if there is an episode of symptoms. The longer the mother has been infected, the higher the risk of HIV infection in the newborn. There are also some factors that may increase the probability of mother-to-child transmission of HIV, such as smoking by the mother in early pregnancy, and unprotected sexual contact with multiple partners before or during pregnancy, which can also increase HIV infection and increase the risk of mother-to-child transmission of HIV. If a pregnant woman with HIV infection has a very high level of virus in her blood, this will also increase the probability of mother-to-child products, and if the membranes rupture prematurely during delivery and a cesarean section is not performed in time, this risk is also increased.
If the HIV exposure mentioned above is indeed high-risk or medium-high risk, first of all, don’t panic, we must first assess whether it is HIV exposure and whether the risk of such exposure is great. Hospital is far away, you can also do your own treatment first, if it is skin exposure, contact with HIV-infected blood or body fluids, first you can squeeze the bleeding, to immediately flush the wound with a lot of water and soapy water, the blood and body fluids contaminated by HIV with a lot of water and soapy water to reduce the virus, never use your mouth to suck blood, this situation may increase the risk of HIV infection, and Do not artificially enlarge the wound. Then there is the problem of using a non-irritating disinfectant to disinfect the wound and reduce virus exposure. In the case of mucosal exposure, such as eyelid and oral exposure, rinse with plenty of water or saline. Wound treatment is also very important, and if in the first place, if HIV exposure does occur, this work is certainly best if you can handle it yourself, because it is easier for everyone to operate in this way.
One more issue, after treatment, is indeed high-risk, must go to a professional hospital for the next step, HIV blockade is generally within 72 hours, preferably within 2 hours for HIV blockade. When HIV infection, the virus first reaches the local lymph nodes after three to five days and then releases new virus particles to reach the blood circulation, so it must be treated with antiviral drugs within three days, usually with two or three antiviral drugs, and the treatment time should be four weeks. Prophylactic medication should be applied as early as possible after exposure, preferably within two hours, and not later than 72 hours. If the risk is very high, the exposure to body fluids with high viral content, or the level of exposure is high, even if it exceeds 72 hours, we should also administer prophylactic medication appropriately and observe it in detail in the clinic. Some blocking drugs commonly used in our clinic, lamivudine and so on, we use antiviral drugs will also face the problem of side effects, to observe whether there is anemia, leukopenia, nausea, vomiting, insomnia and other such side effects, lamivudine may appear diarrhea, rash, some may appear pancreatitis, abdominal pain and other side effects, stavudine may appear headache, diarrhea, nausea, pancreatitis, peripheral Neuropathy and other manifestations, if there are side effects of the problem, must be promptly to the hospital for treatment, if it is highly dangerous, must adhere to take the drug for four weeks of time, so as to achieve an effective blockage.
If it is well handled, we should not forget to monitor the antibodies one month, three months, or even six months after exposure to see if the blockade is successful, and to monitor the blood routine before treatment. We will share these related knowledge with you today, and see what questions the netizens have below.
I heard that the medication within 24 hours after HIV occupational exposure can provide 100% protection! I wonder what kind of medication is being taken? If it is within 24 hours after sexual intercourse, is it possible to have 100% protection?
Generally the longest do not exceed 72 hours, preferably within 2 hours, to be able to 100% protection, this is a bit absolute, in the clinical, not after taking the drug will rest easy, we have to observe, for example, after using the drug for a month and three months is not successful in blocking, this use of drugs can only say to reduce the risk of interference, some information said that this risk can be reduced to 80%, must be exposed to the The problem of exposure and drug use must be well understood, not 100%.