Reducing the risk of sexual HIV transmission: quantifying the per-act risk for HIV on the basis of choice of partner, sex act, and condom use.
BACKGROUND
Sexual acquisition of HIV is influenced by choice of partner, sex act, and condom use. However, current risk-reduction strategies focus mainly on condom use.


OBJECTIVE
To estimate the contribution of choice of partner, sex act, and condom use on the per-act relative and absolute risks for HIV infection.


METHODS
Per-act relative risk for HIV infection was calculated with use of estimates of HIV prevalence, risk of condom failure, HIV test accuracy, and per-act risk of HIV transmission for different sex acts. Absolute risks were calculated on the basis of these relative risk estimates.


RESULTS
Choosing a partner who tested negative instead of an untested partner reduced the relative risk of HIV infection 47-fold; using condoms, 20-fold; and choosing insertive fellatio rather than insertive anal sex, 13-fold. Choosing one risk-reduction behavior substantially reduces absolute risk of HIV infection for heterosexuals but not for men who have sex with men.


CONCLUSIONS
Clarifying the magnitude of risk associated with different choices may help people make effective and sustainable changes in behavior.
Varghese
Beens
B
Division of HIV/AIDS Prevention-Surveillance and Epidemiology, National Center for HIV, STD, and TB Prevention, Centers for Disease Control and Prevention, Atlanta, Georgia 30333, USA. bav7@cdc.gov
Maher
Julie E
JE
Peterman
Thomas A
TA
Branson
Bernard M
BM
Steketee
Richard W
RW
D017280:Condoms / Q000706:statistics & numerical data; D018562:Disease Transmission, Infectious; D005260:Female; D015658:HIV Infections / Q000517:prevention & control / Q000635:transmission*; D006801:Humans; D008297:Male; D015233:Models, Statistical; D012307:Risk Factors; D012725:Sexual Behavior / Q000706:statistics & numerical data; D012747:Sexual Partners