Studies have shown that the efficacy of antiretroviral treatment dramatically reduces the risk of HIV transmission following - a concept known as "treatment and prevention" - PrEP and reduced the risk of infection over 90% is taken consistently.
The initial HIV negative partners of the PrEP study in heterodiscordant heterosexual couples who Dr Baeten initially presented to the conference the International AIDS Society conference in 2011, were randomly assigned in Kenya and Uganda to receive tenofovir / emtricitabine (components of Truvada), tenofovir without co-formulation or placebo. (At the time this occurred World Health Organization guidelines and the country recommended initiating ART based on CD4 cell count and not all diagnosed with HIV).
Follow up with the Partner Study demonstration and PrEP, the purpose of showing whether a integrated combination of PrEP negative partners plus positive partner ART could further reduce the risk of HIV transmission. At the time this study was started in November of 2012 there was ample evidence that both PrEP and treatment as prevention (Tasp - Acronym for Treatment as Prevention) were effective, so that all participants received the two interventions on an open source (non-random) basis.
The demonstration project was conducted in four centers in Kenya and Uganda which hosted the initial partners of the study randomized to PrEP, but were inscribed a new cohort of 1013 serodiscordant heterosexual couples in which neither partner had ever taken antiretrovirals.
The average age of participants was 30 years. In two-thirds of the couples the woman was the HIV-positive partner. Positive partners had a mean CD4 cell count of 436 cells / mm3 and the mean viral load in more than 37.000 copies / ml. Most (65%) said they had sexually unprotected sex last month.
After enrollment, the HIV-positive partner was offered the ART combination in accordance with national guidelines - less than 350 cells / mm3 until mid-2013 and then universal treatment thereafter - while the HIV-negative partner was offered daily Truvada. PrEP was continued while the positive partner delayed the initiation of treatment in the first six months after initiation of HAART, allowing the passage of time so that the viral load became undetectable; PrEP was extended if the positive partner had treatment interruptions or known poor adherence.
The demonstration project measured the couples selected based on an algorithm of risk scores that were 1 10 to depending predictors of risk of HIV infection, including young couples in cohabitation arrangements rather than marriage, recent unprotected sex, uncircumcised male partners, and positive partners with a high viral load; couples with a score equal to 5 or above were eligible for the study.
At the 2015 Conference on Retroviruses and Opportunistic Infections (Ends), Dr. Baeten reported interim results, showing that two HIV-negative partners initially seroconverted. Instead of a placebo arm, the researchers used the incidence rate in the original placebo arm of random partners from the PrEP study to estimate that 40 new infections would have been expected in the absence of ART and PrEP - a reduction of risk of 96%.
This week Dr Baeten showed results updated with final data through June 2016, reflecting approximately 1700 person-year follow-up.
By this time, 91% of the positive partners had started ART and almost all had achieved viral suppression (<400 copies / ml) - (Editor's Note: It is visible disrespect to the Helsinki Treaty which provides the subject of the research with the best treatment (20%) of the negative partners to whom it was offered PrEP accepted it.Results in solitary ART (...) were in 97% of the follow-up time, solitary PrEP in 39%, overlap of TARV and PrEP for 20%, and neither TARV nor PrEP for 33%.
At the end of the follow-up of four new HIV infections occurred, compared to expected 83 without ART or PrEP, for a relative risk reduction of 95%. Protection was similar regardless of gender, age or pre-treatment of viral load. Adherence to both PrEP and ART was good during the demonstration project. Among partners of HIV-negative patients who started PrEP and were randomly selected to test for serum level of drug concentration, 82% of blood samples showed detectable levels of tenofovir
However, none of the newly infected individuals actually make use of HAART and PrEP consistently - and in fact they were in couples who did not use these recursosá
A woman had broken with its positive partner and stopped PrEP, while a second woman had a partner who has not wanted to start treatment and she stopped PrEP; nor the woman had a detectable serum concentrations of tenofovir in your blood sample at the time of infection. A third woman was a sex worker making inconsistent use of PrEP. The only man who had the infection had decreased the use of PrEP and had multiple sexual partners.
"In this open design to demonstrate the integrated delivery of ARV treatment and PrEP for HIV prevention among discordant couples, We observe the virtual elimination of HIV incident, "The researchers concluded.
"Interventions like this could have a substantial effect on the HIV epidemic," Dr. Baeten told the AIDS Conference news conference at 2016:
"As far as PrEP ART are extremely important interventions
could virtually eliminate HIV transmission(Sic). "
There is more to be seen on this link and I advise you to read
Posted in AIDSMAP at: 21 July 2016
Translated Claudio Souza in 04's August 2016 of the original at: PrEP can further reduce the risk of HIV infection after a partner starts treatment. Reviewed by Mara Macedo