With the encouragement of “you know my depth, I know your length”, countless men and women are eager to get to know each other’s depth and experience some novel ways of “sexual” experience. However, under this novel “sex” experience, there is a shocking figure. It was recently reported that 2,932 new cases of HIV were reported among college students in Beijing this year. Figures from the CDC also show that the average annual growth rate of HIV infection among young students aged 15-24 has been as high as 35% in the past five years.
Why is AIDS always so difficult to deal with, and why is the spread of the disease becoming more and more oriented to younger and younger people?
This is because the early diagnosis of HIV (AIDS) infection is very difficult. Because of the similarity to the symptoms of the common cold or infectious mononucleosis, when patients do present with symptoms in the acute phase, they are mostly misdiagnosed as having the common cold, and doctors usually tell them that the symptoms will resolve themselves. However, it is this lack of careful questioning, clinical experience, and the complexity and uncertainty of the tests that cause the misdiagnosis of the condition. And the young group experienced some “high-risk” position of the “sex” behavior after, also not convenient to go to the hospital for examination and prevention and control.
Step1: Calculate the probability of infection of each other – by population
If you are sure that the other party is HIV-infected or infected, calculate by 100%.
If it is not certain that the other party is infected, then depending on the situation, there are generally these types of situations
If the other party is a female sex worker, consider calculating at an average of 1 percent
If the other party is a gay male, consider calculating according to 5% (some experts estimate that the HIV infection rate among the gay male population in China’s large cities may be as high as 5%-15%).
If the person is a member of the general population, calculate at 0.1%.
If it is a person with a history of intravenous drug use, consider calculating according to an average of 10% (online reports of Xinjiang, Yunnan, Sichuan and other parts of the drug-using population with infection rates of more than 50%) The above situations all have geographical characteristics, and in general, people in contact with high prevalence areas and people in contact with people from high prevalence areas should be appropriately adjusted upward in percentage according to local conditions.
Step2: Calculating the probability of behavioral infection – assuming that the partner has been identified as infected
condomless passive anal intercourse at 0.1- 3.0%.
condomless active anal intercourse, calculated at 0.06%.
condomless passive vaginal intercourse at 0.1- 0.2 per cent
condomless active vaginal intercourse, calculated at 0.03-0.09%.
unprotected contact between spouses (5 years and more), calculated at 10 per cent
condommed intercourse at 15 per cent multiplied by the above probability
Passive oral sex at 0.04%; (In a study of possible modes of transmission among 102 gay and bisexual men newly infected with HIV, the University of California found that eight of the infections may have been due to having unprotected oral sex. (Note that this should not be interpreted to mean that the infection rate for oral sex in the population was 8 percent)
Have had a blood transfusion or have been exposed to blood at 90- 100%.
Having breastfed, calculated at 20-30%.
Having had a needle stick or piercing act, calculated at 0.3%.
For complex behaviors or multiple behaviors, the probability of infection can be calculated separately and then summed.
Step3: Calculate the probability of missed test
If no HIV antibody test has been performed, calculate at 100%.
If the antibody test is negative one month after high-risk sex, the missed detection rate can be calculated according to 1% for convenience.
If the antibody test is negative three months after high-risk sex, the missed detection rate can be calculated as 0.1%.
If the test is negative after n times, the rate can be calculated according to the nth power of 1% cumulatively.
Step4: Calculate the probability of HIV infection
After calculating the above three steps, the last step can not be missing. By the way, to revisit the calculation formula HIV infection probability = each other infection probability * behavior infection probability * probability of missed detection.