Impact of small reductions in plasma HIV RNA levels on the risk of heterosexual transmission and disease progression.
OBJECTIVE
To estimate the impact of small changes in plasma levels of HIV-1 RNA on the risk of heterosexual transmission or disease progression to an AIDS-defining event or death.


METHODS
We systematically reviewed the published literature for studies that evaluated small viral load changes among antiretroviral-therapy-naive, adult populations. We modeled relative risk estimates for viral transmission and disease progression according to 0.3, 0.5, and 1.0 log10 increments of HIV load.


RESULTS
We calculated that the likelihood of transmitting HIV by heterosexual contact increased, on average, by 20% and that the annual risk of progression to an AIDS-defining illness or related death increased by 25% with every 0.3 log10 increment in HIV RNA. A 0.5 log10 increment in HIV RNA was associated with 40% greater risk of heterosexual transmission and 44% increased risk of progression to AIDS or death. A 1.0 log10 increment in HIV RNA was associated with 100% greater risk of heterosexual transmission and 113% increased risk of progression to AIDS or death.


CONCLUSIONS
Antiretroviral therapy continues to be unavailable or not-yet-indicated for 72% of the world's HIV-infected persons. Mounting evidence that treatment of coinfections may reduce HIV viral load, even modestly, suggests the priority of improved adjunctive care for HIV-infected persons even without antiretroviral therapy, both to slow disease progression and to reduce infectiousness.
Modjarrad
Kayvon
K
Department of Medicine, Institute for Global Health, Vanderbilt University, Nashville, Tennessee 37203-1738, USA. kayvon.modjarrad@vanderbilt.edu
Chamot
Eric
E
Vermund
Sten H
SH
D000163:Acquired Immunodeficiency Syndrome / Q000821:virology; D018450:Disease Progression; D005260:Female; D015658:HIV Infections / Q000635:transmission* / Q000821:virology; D015497:HIV-1 / Q000302:isolation & purification*; D020010:Heterosexuality; D006801:Humans; D008297:Male; D012367:RNA, Viral / Q000097:blood*; D018570:Risk Assessment; D019562:Viral Load
D012367:RNA, Viral