Many HIV Positive Women on Antiretroviral Therapy Have Detectable Virus in Genital Tract

		SUMMARY: As many as half of HIV positive women on effective antiretroviral therapy (ART) still have measurable levels of HIV RNA in the genital tract despite undetectable blood plasma viral load, according to research reported in the October 23, 2010 issue of AIDS. This finding underscores that while treatment can dramatically reduce the likelihood of sexual transmission of HIV, the risk is not eliminated.

By Liz Highleyman

Susan Cu-Uvin from Brown University and colleagues looked at patterns of HIV "shedding" in the genital tract over time among women on antiretroviral therapy with suppressed plasma viral load.

The analysis included 59 HIV positive women who had plasma viral load below 75 copies/mL at least 6 months before study screening. The researchers measured HIV RNA levels in paired plasma and genital tract samples collected every 4 weeks over the course of 1 year.

Participants were classified based on how often they had HIV RNA > 3300 copies/mL in 3 "compartments": the outer cervix (endocervix), the inner cervix (ectocervix), and the vagina.

Persistent shedders had at least 2 consecutive measurements of detectable genital tract viral load paired with undetectable plasma HIV, intermittent shedders had a detectable genital viral load between 2 undetectable tests, and non-shedders never had detectable genital viral load paired with undetectable plasma viral load

Results

	At study entry, 95% of the women had plasma viral load below the level of detection and 98% had undetectable genital tract viral load.
	32 women (54%) had detectable HIV RNA in their genital tracts at least once.
	22 women (37%) women detectable genital tract HIV RNA during a study visit when their plasma viral load was undetectable.
	Observed over time, 7% of the women were persistent shedders, 31% were intermittent shedders, and 46% were non-shedders.
	Sampling all 3 genital compartments increased the likelihood of detecting HIV, compared with a single area.
	Overall, among women without hysterectomies, HIV shedding in any area of the genital tract was observed during about 13% of study visits.
	In this group shedding in at least 1 area was observed during 9% of visits when plasma viral load was undetectable.
	Women who had undergone hysterectomies (19%) were less likely to have detectable genital tract viral load.
	Genital viral load reached high levels in some women, with a maximum of 456,000 copies/mL in the outer cervix, 648,000 copies/mL in the inner cervix, and 480,000 copies/mL in the vagina.

Based on these findings, the researchers concluded, " Women with below-detectable plasma viral load may have less risk of HIV sexual transmission on a population level, but may continue to be infectious on an individual level."

Other investigators have reported a similar phenomenon in men, detectable HIV RNA in the semen even when plasma viral load is undetectable.

Investigator affiliation: Department of Medicine, Miriam Hospital/Alpert Medical School, Brown University, Providence, RI.

12/10/10

Reference
S Cu-Uvin, AK DeLong, KK Venkatesh, and others. Genital tract HIV-1 RNA shedding among women with below detectable plasma viral load. AIDS 24(16): 2489-2497 (Abstract). October 23, 2010.