This Week in HIV Research: The Ubiquity, and Diversity, of Substance Use

Use of psychoactive substances, cigarette smoking, and drinking excessive amounts of alcohol are much more common among people living with HIV, a cross-sectional study published in AIDS found.

Researchers analyzed questionnaires completed by 1018 people, 76.8% of whom were men, at an HIV clinic in Montpellier, France. During the prior three months, 37.8% reported substance use, 22% excessively consumed alcohol, and 44.6% smoked -- with 29.1% of smokers classified as high dependence.

Substance use was more common among men who have sex with men (MSM) than heterosexual men when both groups were compared to women. Smoking or being on opioid maintenance therapy were associated with detectable viral loads, as was being an MSM. Using psychoactive substances was not correlated with higher viral loads, even though 12.5% of substance users reported missing antiretroviral doses due to their substance use.

Study authors noted that provider screening for alcohol, drug and cigarette use was well received. They recommended incorporating such questions into routine clinical care for PLWH.

The incidence of progressive multifocal leukoencephalopathy (PML) has dropped significantly since the advent of combination antiretroviral therapy, but some groups are still at higher risk for this traditionally AIDS-associated disease, a data analysis published in Clinical Infectious Diseases shows.

In particular, people living with both HIV and hepatitis C (HCV), people who inject street drugs, and people who are still in their first six months of initial HIV treatment are at greater risk for PML, the study found. This latter factor may be caused by antiretroviral therapy-induced immune reconstitution that uncovers a preclinical stage of the disease, study authors hypothesized.

The study was based on 15 years of data in a French database; the researchers examined data on 92,477 people living with HIV, 14,091 of whom were originally from sub-Saharan Africa.

Despite relatively fewer reports of PML from people of sub-Saharan African origin, no genetic protection against PML was found. Researchers theorized that people living with HIV in that region may die from other causes before PML symptoms appear, and that diagnosing PML may be hampered by a lack of equipment.

The study authors called for further research into the correlation between PML and HCV or intravenous drug use, especially heroin.

Tenofovir (TFV) pharmacokinetics differed substantially between pre- and post-menopausal women who used a vaginal gel containing the medication, a small clinical trial published in Journal of Acquired Immune Deficiency Syndrome showed.

Tenofovir-containing gel is one of several experimental strategies for biomedical HIV prevention in women. The 20 pre-menopausal women who volunteered for this study had significantly higher TFV concentrations in their cervical tissue after using two doses of 1% tenofovir vaginal gel than the 17 post-menopausal volunteers. After the post-menopausal group was treated with E2, which stimulates epithelial growth, their levels of the study drug were the same as those in the pre-menopausal women.

Among all participants, the thicker the vaginal epithelium, the higher the TFV concentration. However, despite overall TFV level differences, levels of its active metabolite, TFV-DP, were similar between the two arms. This conflicts with findings from an earlier study, which found lower TFV-DP levels in explants from post-menopausal women. The current study's finding might be explained by activated immune cells converting TFV at greater rates and more of the unconverted drug flowing out, study authors hypothesized.

One thing authors believe is clear, though: The vaginal mucosal environment affects both the risk of HIV acquisition and the efficacy of biological prevention.

Overall global health care spending has risen over the past decade by 3.1% per year, to a total of US$9.7 trillion in 2015 -- but money for HIV/AIDS has begun to decline since its peak of US$49.7 billion in 2013, an analysis published in The Lancet showed.

Per capita spending for health varied widely across the world, from US$28 in the Central African Republic to US$9,839 in the U.S. (2015 estimates). In sub-Saharan Africa, home to the largest number of people living with HIV, 63.9% of HIV outlays were financed by development aid. While such assistance grew substantially between 2000-2010, annual aid for health has leveled off since then, even for countries with high HIV burdens. "Reliance on development assistance to fight HIV/AIDS in high-prevalence countries leaves them susceptible to fluctuations in the external resources available for HIV/AIDS," lead author Joseph Dieleman, Ph.D., said in a related press release.

While national averages are useful, health care spending is not uniformly distributed within countries. Tracking intra-country variations could help assess the connection between spending patterns and disease outcomes, study authors noted.