Bratislav Prokić, April 2022
The risk of acquiring HIV depends on the type of exposure (such as sharing needles or having sex without a condom). Some situations pose a greater risk of acquiring HIV than others. The degree of risk is the fact that in some situations the HIV infection will be transmitted (once in 100 cases), but one cannot know whether the infection will occur after one, five or ninety times.
These risk assessments are for informational purposes only and cannot be used as a substitute for HIV testing.
| Unprotected anal sex | Risk assessment |
|---|---|
| Receptive anal sex with ejaculation (passive role) | 1,43% (one in 70) |
| Receptive anal sex without ejaculation (passive role) | 0,65% (one in 154) |
| Insertive anal sex in a circumcised man (active role) | 0,11% (one in 909) |
| Insertive anal sex in an uncircumcised man (active role) | 0,62% (one in 161) |
| Anal sex with a HIV+ person who has immeasurable viral load 0% | 0% |
| Unprotected oral sex | Risk assessment |
|---|---|
| Giving mouth-to-penis oral sex (fellatio) | 0% do 0,04% (one in 2 500) |
| Receiving mouth-to-penis oral sex (fellatio) | 0% do 0,005% (one in 20 000) |
| Receiving or giving oral sex mouth-to-vagina (cunnilingus) | negligible |
| Receiving or giving oral sex mouth-anus (anilingus) | negligible |
| Oral sex with an HIV+ person who has immeasurable viral load 0% | 0% |
| Unprotected vaginal sex | Risk assessment |
|---|---|
| Vaginal sex vagina-penis (from an infected man to a woman) | 0,08% (one in 1234) |
| Vaginal sex vagina-penis (from infected woman to man) | 0,04 (one in 2380) |
| Vaginal sex with an HIV+ person who has immeasurable viral load 0% | 0% |
| From infected mother to child | Risk assessment |
|---|---|
| To a child from a mother not on antiretroviral therapy (ART) | 25% (one in 4) |
| To a child from a mother who started ART two weeks before delivery | 0,8% (one in 125) |
| To a child from a mother who is on ART and has immeasurable viral load | 0,1% (one in 1000) |
| Transmission of HIV via blood | Risk assessment |
|---|---|
| Sharing drug paraphernalia | 0,67% (one in 149) |
| Needlestick injury with contaminated blood | 0,24% (one in 417) |
| Blood transfusion with contaminated blood | 92,5% (9 in 10) |
What else the degree of risk of HIV transmission depends on?
In addition to the type of exposure, the degree of risk also depends on the concentration of the virus in body fluids (blood, sperm, and breast milk). It is higher in the early (acute) and late phase of HIV infection, and HIV is then transmitted more easily. The risk is significantly higher if other sexually transmitted infections, such as syphilis, are present.
What factors can reduce the risk of HIV transmission?
Factors that can reduce the risk of HIV transmission are the use of condoms and/or PrEP (pre-exposure prophylaxis), male circumcision, and the use of antiretroviral therapy.