USA - Treatment as Prevention
posted: 10/12/2009
The USA has joined the list of countries producing national statements about how effective HIV treatment can make passing on HIV during sex very unlikely.
The USA statement uses much the same evidence as the earlier Swiss, French and German statements on HIV treatment as prevention that we have reported. However, it is a lot more cautious, urging continued consistent condom use.
"In summary, for couples in which one member is HIV-infected, treatment of the infected partner with effective ART and suppression of viral load to undetectable levels should greatly reduce the risk of transmission to the uninfected partner. However, this risk is not eliminated and it may not be maximally reduced at all times due to some of the factors discussed above. Moreover, the likelihood of transmission may be expected to increase with repeated exposures over time."
"In a model which estimated transmission risk in the setting of suppressed viral load (<50 copies/mL) without intercurrent STIs, the number of expected transmission events occurring within a population of 10,000 serodiscordant couples over 10 years was estimated to be 215 for female-to-male transmission, 425 for male-to-female transmission, and 3,524 for male-to male transmissions [31]."
"In a meta-analysis of data from 11 cohorts including 5,021 heterosexual couples observed no transmissions among persons receiving ART with a viral load of <400 copies/mL; however, analysis of the data was compatible with the possibility of one event per 70 person-years [32]. For this reason, it is important that individual couples recognize the risk, and use additional preventive methods (e.g., condoms) in order to further minimize the chance of transmission."
So they advise condoms for heterosexual couples to prevent a 1 in 70 person years possibility of transmission.
This statement and advice comes from the US Centers for Disease Control.
Effective HIV treatment where the viral load is undetectable reduces the risk of HIV transmission but some slight risk remains. The risk is higher for gay men than most heterosexual people, and sexually transmitted infections especially raise the risk of transmission.
US Centers for Disease Control statement Effect of Antiretroviral Therapy on Risk of Sexual Transmission of HIV Infection and Superinfection [read on webpage] OR download it as a pdf
French statement
German statement
Swiss statement
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