There are some pathetic utter morons out there who exercise bareback sex with prostitutes and even advocate it by bringing examples of that catching HIV is less likely than getting hit and killed by a car or a thunderbolt. Although it is true that HIV is difficult to catch the other nasty STIs are VERY PROBABLE to catch especially within a high risk bareback community.
To formally prove what we all sensible punters know I decided I do a little probability calculation of the transmission of each major STI (gathering data from NHS) and here are the results:
1. Probability of STI transmission from an infected female to a non-infected male from one unprotected vaginal sex intercourse: Genital Herpes(if not suppressed): 30%
Genital Herpes(if suppressed) : 10%
Gonorrhea: 25%
Chlamydia: 20%
Syphilis: 20%
HPV/Genital Warts: 10% (suppression does not reduce the average risk)
Hepatitis B: 5%
HIV (if the infected person is NOT in antiretroviral therapy): 0.05%
HIV (if the infected person is in antiretroviral therapy): 0.002%
2. Percentages of UK female population aged 18-25 that are infected with STIs (at any given day):Genital Herpes: 21% (84%)
Gonorrhoea: 3% (12%)
Chlamydia: 10% (40%)
Syphilis: 0.04% (0.16%)
HPV/Genital Warts: 26% (100%)
Hepatitis B: 0.02% (0.08%)
HIV: 0.1% (0.4%)
Note:
For high risk groups (e.g. bareback prostitutes) the percentages are multiplied by 4. The percentages of infected women who belong to high risk groups are shown in brackets.
3. Overall probability of catching an STI from one encounter of unprotected vaginal intercourse with a person of unknown (to you) STI status: Genital Herpes(if not suppressed): 6.3% (25.2%)
Genital Herpes(if suppressed): 2.1% (8.4%)
Gonorrhea: 0.75% (3%)
Chlamydia: 2% (8%)
Syphilis: 0.008% (0.032%)
HPV/Genital Warts: 2.6% (10%)
Hepatitis B: 0.001% (0.004%)
HIV(if NOT in antiretroviral therapy): 0.00005% i.e. 1 in 2 million (0.0002% i.e. 1 in 500 thousand)
HIV (if in antiretroviral therapy): 0.000002% i.e. 1 in 50 million!!! (0.000008 i.e. 1 in 12.5 million)
Notes:
(i) I assume that the woman either does not know her status or she knows it and still continues to have sex (with or without medication). For the curable STIs this is totally irrelevant as the infected person can still transmit the infection until the medication ends (in which case she will be fully cured anyway).
(ii) In brackets it is the probability within a high risk group
4. Probability of catching an STI if you have 10 unprotected intercourses with prostitutes offering bareback:Genital Herpes: 94.5% (if not suppressed)
Genital Herpes: 58.4% (if suppressed)
Gonorrhoea: 7.3%
Chlamydia: 18.3%
Syphilis: 0.32%
HPV/Genital Warts: 65%
Hepatitis B: 0.04%
HIV: 0.002% (i.e. 1 in 50 thousand) (if the not in antiretroviral therapy )
HIV: 0.0008% (i.e. 1 in 125 thousand) (if in antiretroviral therapy)
As you can see if you gamble with your life it is extremely likely to “win” plenty of nasty STIs (Herpes, HPV, Chlamydia and Gonorrhoea). You might also get “very lucky” and even “win” HIV. Yes getting hit and killed by car is 1 in 8000 but many people do get killed by cars every single day. Also the probability of royal flush in poker is only 1/649,740=0.00015%, yet in a large casino it does happens every week.
I would like to conclude with the obvious:
DO NEVER GET COMPLACENT AND ALWAYS USE CONDOMs.
Sources:1.
External Link/Members Only2.
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