Catching up: HIV research round-up

Tuesday, November 4, 2014

I am finally emerging from a monstrous load of urgent freelance work, which is why the blog was silent last week. I was finally able to catch up on global health news last week, so I thought I would post groups of similar studies today and tomorrow. Today's round-up will be HIV-related; tomorrow will feature tuberculosis.

I will kick off with results released yesterday: a study conducted in Uganda and presented at the HIV Drug Therapy Glasgow conference found that the ART efavirenz reduces levels of levenorgestrel, which is used in hormonal implants common in developing countries:
Hormonal contraceptive implants are highly reliable forms of contraception, and have been shown to prevent conception for at least five years with a pregnancy rate of less than 1%. As a form of contraception, implants compare favourably in convenience and reliability to the male condom, and do not require regular clinic visits in order to maintain the contraceptive method.

The disadvantage of progesterone-based hormonal contraceptive implants for women living with HIV lies in the interaction between levenorgestrel and antiretroviral drugs which induce CYP3A4 metabolism. Both efavirenz and nevirapine have been shown to reduce levonorgestrel levels, but the impact has been unclear.

However, a retrospective cohort analysis of unwanted pregnancies among 570 women living with HIV using the Jadelle contraceptive implant in Swaziland, published earlier this year, showed that the only factor associated with unwanted pregnancy was efavirenz treatment.
After adjusting for body weight, levenorgestrel levels in the nevirapine group were 32 to 39% higher than those in the control group during the follow-up period, levenorgestrel levels in the efavirenz group were 40 to 54% lower than those in the control group, and in three cases fell below the minimum recommended concentration for contraceptive efficacy.
The research group concluded that the levonorgestrel implant should be used with nevirapine-based antiretroviral therapy.

A meta-analysis published in AIDS asserts that prevalence of transmitted drug-resistant HIV has doubled in low- and middle-income countries in recent years:
An international team of investigators wanted to establish a better understanding of global trends in rates in transmitted resistance and variations according to world region and risk group.

They therefore conducted a meta-analysis, analysing the results of 212 studies conducted between 1999 and 2013 that reported on rates of transmitted drug resistance.

The authors examined trends in industrialised and low- and middle-income countries. They also compared rates between the main HIV risk groups: men who have sex with men (MSM); people who inject drugs (PWID); and heterosexuals.

Overall, North America was the world region with the highest burden of transmitted drug resistance, which was present in 14% of MSM, 9% of PWID and 11% of heterosexuals.

Western Europe was the next-worst affected region, with transmitted resistance present in 11% of MSM, 6% of PWID and 7% of heterosexuals.

There was also a notable epidemic of transmitted resistance in South America, where prevalence in the key populations were 8% for MSM, 14% in PWID and 8% in heterosexuals.

High rates of transmitted resistance were observed among MSM in Oceania (Australia 16%), Eastern Europe/Central Asia (10%) and East Asia (8%).

A study in AIDS and Behavior by researchers from Brown University School of Public Health examines the male-to-male sex trade as a driver of HIV infection in Mexico, specifically focusing on condom use in MSM in Mexico city:
In his research, including detailed interviews and testing with hundreds of male sex workers on the city's streets and in its clinics, his team estimates that the prevalence of the virus among them could be as high as 40 percent. Because of inconsistent condom use and high degrees of infection among many sex workers, about 8 percent of their customers and other partners become infected each year. Infection can spread further from there.

But out of such seemingly bleak knowledge, Galárraga said, there is also hope. In a new study in AIDS and Behavior, Galárraga, lead author João Filipe G. Monteiro, and colleagues project that a 10-percent increase in condom use by HIV-positive male sex workers would reduce an 8 percent annual infection rate among their partners to 5.2 percent. Meanwhile, increasing the number of HIV-positive sex workers on antiretroviral medications by 50 percent would slash the infection rate among clients to 4.4 percent. More aggressive interventions could cut the rates further.

"There is universal access to HIV treatment in Mexico, so if this is implemented, especially among these key populations, it can really make a dent in the concentrated epidemic that Mexico has," Galárraga said.

NYU researchers examine the link between HIV, drug use, and tourism in the Caribbean, specifically in the Dominican Republic:
Insufficient attention has been paid to the intersection of drugs and tourism as contributing factors for the region's elevated HIV/AIDS risk. Caribbean studies have almost exclusively focused on drug transportation. Seldom acknowledged are the roles which drugs play in tourism areas which may be fueling the Caribbean HIV/AIDS epidemic.

Now a new study, "Illicit drug use and HIV risk in the Dominican Republic: Tourism areas create drug use opportunities," published in Global Public Health addresses this gap by conducting in-depth interviews with 30 drug users in Sosúa, a major sex tourism destination of the DR. The study's results suggest three themes: (1) local demand shifts drug routes to tourism areas, (2) drugs shape local economies and (3) drug use facilitates HIV risk behaviors in tourism areas.

The results of a study published in PLoS One detail how an intervention in South Africa reduced mother-to-child transmission of HIV:
The incidence of HIV infection in South Africa tops that of any nation in the world, with some 6 million of the country's nearly 50 million residents infected. Sadly, young women—and particularly young pregnant women—suffer some of the highest rates of HIV infection. More than one-fourth of pregnant South African women are infected with the virus; in some communities, the infection rates are even higher.

But those infection rates might be reduced—and the overall health of children improved—through community-based peer counseling programs...The study found that having specially trained lay community mothers from the Mentor Mother Programme make regular home visits to pregnant women, and later to those mothers and their infants, led to significantly better health outcomes 18 months later in both the mothers and their children.
Among other outcomes, the study found that Mentor Mother home visits led to a 50 percent improvement by mothers in completing tasks designed to prevent mother-to-child transmission of the HIV virus, compared to mothers in the control group of the study who did not receive home visits, just clinic-based pre- and postnatal care.

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