Post Date October, 06 2023
There is a set of calculation formula for AIDS infection. Let's take a look at the formula for calculating the probability of AIDS infection.
What is a sexually transmitted disease? Calculation formula of AIDS infection probability
Probability of HIV infection=probability of infection by the other party × Behavioral infection probability × Probability of missed detection
Instructions for use:
1. Regarding the probability of infection of the other party, if it is determined that the other party is an HIV infected person or patient, it will be calculated at 100%; If it is uncertain whether the other party is infected, there are generally several situations depending on the situation:
① If the other party is a female sex worker, an average of 1% can be considered (there are differences in reports from different regions, with online reports reaching up to 5% in some places);
② If the other party is a male homosexual, a calculation of 5% can be considered (there are reports in the UK that the HIV infection rate among homosexual people in London is as high as 15%. Some experts estimate that the HIV infection rate among male homosexual people in major cities in China may be as high as 5-15%);
③ For the general population, it is calculated as 0.1% (the total population of China is 1.356 billion. By the end of April this year, the mainland has reported a total of 23527 HIV infected people. For the convenience of calculation, we will temporarily enlarge this data by 6.67 times to 1.356 million, so that the population infection rate is 0.1%);
④ If it is an intravenous drug user, it can be calculated based on an average of 10% (the infection rate of intravenous drug users in London is 4.7%, while in the UK it is 2.3%. According to online reports, the infection rate of drug users in parts of China such as Xinjiang, Yunnan, and Sichuan exceeds 50%, and the infection rate of local injection drug users in Ili, Xinjiang is as high as 89%);
⑤ The above situations all have regional characteristics. Generally speaking, the percentage of people who come into contact with and from high-risk areas should be appropriately adjusted according to local conditions.
2. The probability of being infected through various behavioral methods (i.e. behavioral infection rate. Assuming the other party has been identified as an infected person):
① Passive anal intercourse without condom 0.1-3.0%
② 0.06% active anal intercourse without condom
③ Passive vaginal intercourse without condom 0.1-0.2%
④ Active vaginal intercourse without condom 0.03-0.09%
⑤ Unprotected contact between spouses (5 years) 10%
⑥ Multiply the probability of having sexual intercourse by 15%
⑦ Passive oral sex: 0-0.04% (In a study conducted by the University of California on 102 newly infected gay and bisexual men, it was found that 8 of them may have been infected due to unprotected oral sex. Be careful not to interpret this statement as the infection rate of oral sex in the adult population is 8%).
