HIV risk wen exposure happen many times

Each act na im own chance

Di risk for each act na average. Wit partner wey get HIV and e no dey take treatment, dem estimate one act of receptive vaginal sex at 0.08% (around 1 out of 1,200). If you repeat am, di chances go join:

• 10 acts: 0.8% (around 1 out of 130)
• 100 acts: 7.7% (around 1 out of 13)

For receptive anal sex (di person wey dem enter), di type of sex wey get di highest risk, di same partner go give 1.4% (around 1 out of 72) for one act and 13% (around 1 out of 8) for ten.

Di total small pass di risk for each act times di number of acts, becos each act na separate chance and infection fit happen only one time. E no be countdown too: HIV fit pass di first time, or e no go pass at all even afta many acts.

One regular partner vs different partners

Wen you no know partner status, two questions dey: dis person get HIV, and e pass am? How dem two dey join depend on weda na one person or many.

Wit one regular partner, im status na either positive or negative, and e dey di same every time. If di person no get HIV, no number of acts fit pass am. So di risk go climb first, then e go flat, and e no fit ever pass di chance say dis one person get HIV.

Wit different partners, each new person na anoda draw: anoda chance say person get HIV. Di risk go dey rise wit each new partner.

For man wey dey do vaginal sex without condom wit women wey e no know dia status for United States:

• One act: <0.0001% (around 1 out of 1,500,000)
• 100 acts wit di same partner: 0.0067% (around 1 out of 15,000)
• 100 acts wit different partners: 0.0069% (around 1 out of 15,000)

And for man wey be bottom without condom wit men wey e no know dia status for United States:

• 10 acts wit di same partner: 0.47% (around 1 out of 210)
• 10 acts wit different partners: 0.5% (around 1 out of 200)

For dis number of acts, di two dey close, becos each act get small risk. Di gap go dey wide as di acts dey add up.

Even acts wey get very low risk dey add up wit time. Oral sex (to use mouth for private part) wit partner wey get HIV go reach 0.5% (around 1 out of 200) over 50 acts.

Wetin dey change wit time

• Treatment. If partner wey get HIV start treatment and im viral load (how much HIV dey di blood) dey undetectable (di HIV for blood don low reach where test no fit see am) all di time, e go stop to pass HIV through sex. To reach undetectable fit take up to six months. See U=U.
• New infection. If regular partner get HIV from anoda person, im viral load go high well-well for di first weeks. Di calculator dey raise di estimate 10 times for partner wey just get infection.
• Oda STIs. STIs (sexually transmitted infection, wey be infection wey dey pass through sex) dey make HIV pass easy. Di calculator dey multiply di estimate by 2.
• Condoms and PrEP. Condoms dey reduce risk by about 80% for real life use. PrEP (pre-exposure prophylaxis: HIV medicine wey you dey take before any exposure to protect yourself), if you take am di way dem prescribe, dey reduce di risk from sex by about 99% for anal sex and about 90% for vaginal sex. Ten acts of receptive anal sex wit PrEP wey you dey take well, wit partner wey get HIV: 0.14% (around 1 out of 730).

Wetin to do now

1. Do test now. One test fit cover every exposure wey don pass di window period (di time afta infection wen test neva fit show HIV). Lab antigen/antibody test (blood wey dem draw from vein) dey give final negative result for anytin wey happen more than 45 days ago.
2. Test again for di recent exposures. If some happen inside di window, test again wen di window don pass. See how accurate test be week by week.
3. Tok wit your regular partner about to do test together. If una two know una status, and weda partner wey get HIV don undetectable, most of di doubt go clear.
4. Ask about PrEP if you expect more exposures. E dey protect you for all of dem, no be just one. CDC also recommend make you test at least once every year if you don get more than one sex partner since your last test. See our HIV testing guide.