Plasma and rectal viral load correlated in HIV-positive gay men: supports use of treatment as prevention

via European AIDS Treatment Group, by Michael Carter

Viral load in the blood and rectal secretions of HIV-positive gay men are highly correlated, according to US research published in the September 1st edition of the Journal of Infectious Diseases. The study also showed that the presence of sexually transmitted infections did not increase rectal viral load.

Individuals with a plasma viral load above 1000 copies/ml were significantly more likely to have detectable virus in the rectum.

“Our data add substantially to the few published studies of HIV shedding in rectal secretions of MSM [men who have sex with men],” comment the investigators, “we were able to quantify HIV RNA in rectal secretions, demonstrate the linear correlation between increasing plasma load and rectal viral load and determine a threshold plasma viral load that distinguished detectable from undetectable rectal viral load.”

They also believe that their findings have important implications for current debates about the use of HIV treatment as prevention, commenting: “Combination antiretroviral therapy will have a similar effect on reducing HIV transmission in MSM, as seen in studies of heterosexual discordant couples.”

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[If an item is not written by an IRMA member, it should not be construed that IRMA has taken a position on the article's content, whether in support or in opposition.]

Is treatment really reducing infections?

via Aidsmap, by Gus Cairns

Moupali Das of the San Francisco Department of Public Health presented evidence to show that the city’s intensive testing and treatment policy was beginning to result in a declining HIV infection rate there. Similar evidence was presented from the province of British Columbia in Canada.

The evidence presented still leaves some questions unanswered, however.

• Is the reduction in viral load in the HIV-positive population (the 'community viral load' or CVL) really the cause of the decreased level of diagnoses seen in San Francisco in the last few years, or is it due to the success of prevention campaigns and reductions in risky behaviour?
  
• Do reduced diagnoses really indicate reduced incidence of infection?
  
• Is reducing the average viral load of diagnosed people a good indicator of the average infectiousness of people with HIV in the community – or do high viral loads in the minority who remain undiagnosed make this an unreliable indicator?

The answers to these questions are crucial as the future direction of HIV prevention policy may depend on them, in particular whether to concentrate on suppressing viral load or on behaviour change as the mainspring of prevention.

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[If an item is not written by an IRMA member, it should not be construed that IRMA has taken a position on the article's content, whether in support or in opposition.]

Eradication of smallpox may have set the stage for HIV pandemic, study says

via Los Angeles Times, by Thomas H. Maugh II

"While these results are very interesting and hopefully may lead to a new weapon against the HIV pandemic, they are very preliminary and it is far too soon to recommend the general use of vaccinia immunization for fighting HIV," Weinstein said in a statement. Given the great difficulties researchers have encountered in trying to develop an HIV vaccine, the ironic fact is that we may once have had a vaccine that is more effective against the virus than anything that has since been developed, and we threw it away.

Laboratory tests suggest that immunity to smallpox triggered by the vaccinia (smallpox) vaccine can inhibit the replication of the AIDS virus. Such vaccination could have kept HIV transmission partially under control in the early days of the outbreak, but withdrawal of the smallpox vaccine in the 1950s would have freed it to spread unfettered, the researchers said.

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Theory Explains Why Some With HIV Survive Longer

via Physorg.com by, Jason Socrates Bardi

A group of researchers in Boston announced a new theory this week that may help to explain a longstanding mystery in AIDS research: why some people with HIV survive for decades without ever developing AIDS.

About one out of every 200 people who catch HIV are considered "long-term non-progressors" or "elite controllers" because they can live for many years with the virus without developing AIDS. Even the most sensitive tests often cannot detect the virus in their bloodstream.

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Gay men’s risk of acquiring HIV is similar to the pre-HAART era despite widespread use of HAART

via Aidsmap, by Roger Pebody

"It may be possible that HIV transmission by anal intercourse is not as closely related to viral load as it is in vaginal transmission. There is a paucity of data on HIV transmission at low viral loads, and there are almost no data on transmission and viral load in homosexual men."

Although the widespread use of antiretroviral therapy could be expected to make HIV-positive gay men less likely to pass on HIV during unprotected sex than in the early 1990s, the risk of transmission per-sexual-act is actually quite similar, Australian researchers report in AIDS.

The authors put forward a number of suggestions to explain this surprising finding - that transmission during primary infection is a more significant factor than before 1996, that sexually transmitted infections are now more common, or that viral load is a less important factor for anal transmission than for vaginal transmission.

Their study also suggests that circumcised men who have unprotected insertive sex are less likely to acquire HIV than men who are not circumcised, and that ejaculation inside the rectum increases the risk of transmission during unprotected receptive anal intercourse.

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Sexual transmission of HIV according to viral load and antiretroviral therapy: systematic review and meta-analysis

Attia, Suzanna; Egger, Matthias; Müller, Monika; Zwahlen, Marcel; Low, Nicola

AIDS: 17 July 2009 - Volume 23 - Issue 11 - p 1397-1404

Objectives: To synthesize the evidence on the risk of HIV transmission through unprotected sexual intercourse according to viral load and treatment with combination antiretroviral therapy (ART).

Design: Systematic review and meta-analysis.

Methods: We searched Medline, Embase and conference abstracts from 1996-2009. We included longitudinal studies of serodiscordant couples reporting on HIV transmission according to plasma viral load or use of ART and used random-effects Poisson regression models to obtain summary transmission rates [with 95% confidence intervals, (CI)]. If there were no transmission events we estimated an upper 97.5% confidence limit.

Results: We identified 11 cohorts reporting on 5021 heterosexual couples and 461 HIV-transmission events. The rate of transmission overall from ART-treated patients was 0.46 (95% CI 0.19-1.09) per 100 person-years, based on five events. The transmission rate from a seropositive partner with viral load below 400 copies/ml on ART, based on two studies, was zero with an upper 97.5% confidence limit of 1.27 per 100 person-years, and 0.16 (95% CI 0.02-1.13) per 100 person-years if not on ART, based on five studies and one event. There were insufficient data to calculate rates according to the presence or absence of sexually transmitted infections, condom use, or vaginal or anal intercourse.

Conclusion: Studies of heterosexual discordant couples observed no transmission in patients treated with ART and with viral load below 400 copies/ml, but data were compatible with one transmission per 79 person-years. Further studies are needed to better define the risk of HIV transmission from patients on ART.

Testing Formula to Better Predict Treatment Failure/Drug Resistance

via Deborah Baron
IRMA Steering Committee Member

The Journal of the International AIDS Society published an article on a recent study testing a formula to better predict ARV treatment failure and possible drug resistance in the absence of viral load testing. According to a New York Times article on the study, "Scientists from Makerere University’s hospital in Kampala, Uganda, along with American and Belgian scientists, have developed a formula, based on close questioning of patients, for predicting which ones are most likely to have treatment failure."

The researches then compared their formula with the existing WHO guidelines, which relies on clinical and immunological criteria to identify treatment failure. They concluded that although "the WHO guidelines are used as a standard across many RLS [resource-limited setting, i]t is our view that this standard of care needs to be improved to reduce the late detection of viral failure and to minimize unnecessary switching of patients to second-line ART."

This formula could help provide useful insight to the ARV-based prevention research field, as it prepares for possible scenarios and challenges (if and when a product proves effective) around scaling up ARV-based prevention.

Check it out "Development and evaluation of a clinical algorithm to monitor patients on antiretrovirals in resource-limited settings using adherence, clinical and CD4 cell count criteria."

You can also link to the New York Times article on this study, "AIDS: Questions Help Find AIDS Patients Who Are Vulnerable to Drug Resistance"

Prevention for HIV serodiscordant couples: it's more than just condoms

via Aidsmap, by Michael Carter

Promoting 100% condom use may not be the most appropriate HIV prevention strategy for serodiscordant couples, according to research presented to the Fifteenth Conference of the British HIV Association. However, researchers found that there was little awareness or use of other methods of HIV prevention, such as post-exposure prophylaxis (PEP) or the impact of viral load on infectiousness.

Investigators recruited 38 serodiscordant couples (where one partner is HIV-positive, the other HIV-negative) to a prospective study lasting three years. Most (30) of the couples were gay men. To be included in the study the couples had to have been in their relationship for at least two years and to have engaged in at least 20 separate episodes of unprotected anal or vaginal sex in the previous twelve months.

The couples were interviewed about their understanding of issues such as PEP, viral load and infectiousness, and the reasons why they engaged in unprotected sex. The investigators hypothesised that there were likely to be three factors underlying unprotected sex in relationships: failure to understand the mechanisms of HIV transmission; emotional reasons; and a low concern about the consequences of HIV transmission.

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