A new [2014] report by the Centers for Disease Control and Prevention (CDC) found that MSM under 30 years old had close to a 19% prevalence of transmitted resistant HIV. MSM accounted for an estimated two thirds of new HIV infections in the United States in 2011, the CDC team observed. Condom-free sex largely accounts for the persistently high HIV incidence in US MSM. Antiretroviral-treated men with poorly controlled viral replication pose a risk of transmitting resistant HIV to partners when they have sex. In other words, close to 20% of gay men who test positive for HIV are carrying a drug-resistant mutation of the disease; that can then be passed on to other men.
To get a better understanding of transmitted resistant HIV prevalence and patterns among MSM, CDC investigators analyzed data from the US National HIV Surveillance System, through which regions submit HIV case data, including demographics, transmission risk, and laboratory and clinical results. Some regions also conduct Molecular HIV Surveillance and HIV Incidence Surveillance, which respectively provide data on resistant virus and timing of newly diagnosed infections as recent or long-standing. The CDC team analyzed HIV sequences in people newly diagnosed with HIV from 2008 through 2011 who had not taken antiretroviral therapy. The researchers calculated prevalence ratios to compare resistance transmission prevalence between groups.
The rate in MSM was 12% higher than in non-MSM. Among MSM, 9.0% of newly diagnosed infections involved nonnucleoside (antiretroviral drugs used in the treatment of human immunodeficiency virus) mutations, 6.6% nucleoside/nucleotide mutations, and 4.6% protease inhibitor mutations. Chances of carrying any resistance mutation were 12% higher in MSM with recent infection and chances of carrying a nonnucleoside resistance mutation were 31% higher in men with recent infection. Compared with MSM 40 to 49 years old, those 13 to 29 had a 17% higher prevalence of any transmitted resistance mutation. Half of all transmitted resistance mutations (50.3%) occurred in 13- to 29-year-old men, though that group also represented almost half of the new HIV diagnoses in the analysis. Resistance mutation prevalence did not vary by race/ethnicity or by year of diagnosis from 2008 through 2011.
*When treating infection, whether bacterial or viral, there is always a risk of the infectious agent to develop drug resistance. The treatment of HIV infection is especially susceptible to drug resistance which is a serious clinical concern in the chemotherapeutic treatment of the infection. Drug resistant HIV-strains emerge if the virus is able to replicate in the presence of the antiretroviral drugs.