Abstract
HIV
HIV Infection Risk Higher for Heterosexuals with Lower Socioeconomic Status
One of every three new cases of HIV infection in the United States is transmitted via heterosexual contact. National HIV Behavioral Surveillance System (NHBS) data collected by the Centers for Disease Control and Prevention (CDC) between 2006–2007 in 24 selected urban areas demonstrates an association between HIV prevalence and socioeconomic status (SES). Of nearly 15,000 heterosexuals included in the survey, 2% were HIV infected. HIV prevalence was higher among individuals with lower SES, characterized by less education (did not complete high school), unemployed, and annual household income at or below the poverty level. The link between SES and HIV prevalence was independent of factors commonly associated with increased risk for HIV infection among heterosexuals, such as use of crack cocaine, sex in exchange for money or drugs, or diagnosis with a sexually transmitted disease. Based on these findings, the CDC suggests that HIV prevention activities targeted at heterosexuals in urban areas with high AIDS prevalence be focused on individuals with lower SES.
Source: Characteristics associated with HIV infection among heterosexuals in urban areas with high AIDS prevalence—24 Cities, United States, 2006–2007. MMWR 2011;60:1045–1049.
HIV Incidence Stable in the United States But Teens and Young Adults Are Disproportionately Affected
Between 2006 and 2009, CDC estimates of the HIV incidence in the United States among persons aged 13 years and older did not change significantly overall from year to year or among specific racial, ethnic, or risk groups. However, researchers from the CDC, in collaboration with The Ginn Group (Peachtree City, Georgia) report that HIV incidence during this time period increased significantly (21%) among people between the ages of 13 and 29 years. This increase was largely attributable to rising incidence rates among young men who have sex with men (MSM). The HIV incidence in this subgroup increased by 34% during the 4-year study period. In particular, there was a significant increase (48%) among young black/African American MSM. In 2009, the majority (61%) of new HIV infections occurred among MSM.
Source: Prejean J, et al. Estimated HIV incidence in the United States, 2006–2009. PLoS ONE 2011;6:e17502.
Comparison of HIV Testing Strategies
A social networking strategy for detecting undiagnosed HIV infection among African American MSM was 3.6 times more effective than an alternative venue testing approach, based on data for New York City that was culled from a larger multisite study. Relying on partner counseling and referral services yielded 2.5 times greater odds for detection of HIV infection than alternative venue testing, according to the study conducted by researchers from New York University.
The authors determined the relative effectiveness of three HIV testing strategies. The HIV-positive detection rate was 19.3% for the social networks strategy, in which HIV-positive or high-risk individuals were recruited and trained to encourage people in their social networks to undergo testing. The detection rate was 14.3% for the partner services strategy, which involved notifying sexual and needle-sharing partners of HIV-infected individuals of their exposure and offering testing, counseling, and referrals. Alternative venue testing involved offering rapid HIV testing at churches, bars, mobile units, and other locations distinct from conventional hospital, clinic, or physician office settings. Based on the study results, the authors conclude that relying on multiple testing strategies might help identify more undiagnosed HIV-positive African American MSM.
Source: Halkitis PN, et al. Evaluation of the relative effectiveness of three HIV testing strategies targeting African American men who have sex with men (MSM) in New York City. Ann Behav Med 2011;17(42) DOI: 10.1007/s12160-011-9299-4.
FDA Approves Complera Three-Drug Combination
The U.S. Food and Drug Administration (FDA) granted market approval to Gilead Sciences' drug Complera, which combines emtricitabine, rilpivirine, and tenofovir DF in a single daily tablet that contains 200, 25, and 300 mg of each drug, respectively. Complera is indicated for the treatment of HIV-1 infection in antiretroviral treatment-naïve patients. FDA approval was based on previous clinical study data for rilpivirine (Edurant™), derived from the ECHO and THRIVE phase 3 trials that compared rilpivirine to efavirenz in antiretroviral-naïve subjects with baseline HIV-1 RNA=5000 copies per milliliter and no resistance to non-nucleoside reverse transcriptase inhibitors. The cost estimate for Complera is about $1700 per month.
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Postexposure HIV Prophylaxis Awareness is Low Among Sample of MSM
Men who have sex with men (MSM) were surveyed at two New York City bathhouses to assess their knowledge of nonoccupational postexposure prophylaxis (nPEP) and postexposure prophylaxis (PrEP). Researchers from New York University School of Medicine, San Francisco Department of Public Health, and Bellevue Hospital Center in New York City found that 63% of the MSM had unprotected sex with a male partner in the previous 90 days, and 7% reported sex with an HIV-infected male partner. Yet less than half of the men surveyed (36%) were aware of nPEP or PrEP or had a primary care provider who was aware of the MSM behavior. Several independent factors were significantly associated with more likely awareness of HIV prophylaxis, including having a primary care provider aware of MSM behavior, previous HIV testing, gay self-identification, higher education level, and reported interaction with the health care system. Multivariate analysis identified a link between knowledge of PrEP and a higher number of sex partners and a weaker link to having a provider aware of their MSM behavior. The findings emphasize the need for better education about nPEP among high-risk MSM and the contributory role health care providers can play.
Source: Mehta SA, et al. Awareness of post-exposure HIV prophylaxis in high-risk men who have sex with men in New York City. Sex Transm Infect 2011;87:344–348.
HIV Serosorting Among HIV-infected MSM Linked to Increase in Bacterial STIs
Serosorting describes the preferential selection of sex partners with concordant HIV status and the preferential use of condoms for sex with partners of discordant HIV status. Serosorting appears to be increasingly common among men who have sex with men (MSM) as a sexual risk management approach (RMA). A study of nearly 3000 MSM in Germany, based on an anonymous, self-administered questionnaire, found that HIV serosorting behavior differs among HIV-positive and HIV-negative respondents and that HIV-infected men who reported serosorting had a threefold increased risk for bacterial sexually transmitted infections (STIs).
Ulrich Marcus, Axel Schmidt, and Osamah Hamouda, from the Robert Koch Institute in Berlin, Germany, distinguished between two types of serosorting strategies: tactical, an event-based decision or strategic, a premeditated search for a seroconcordant partner. They found that for condom use, tactical serosorting ranked second after other RMAs for both HIV-positive and HIV-negative respondents. Tactical serosorting was associated with reduced condom use.
The authors conclude that HIV serosorting may contribute to increased rates of bacterial STI, which could lead to elevated per-contact risk for HIV transmission.
Source: Marcus U, et al. HIV Serosorting among HIV-positive men who have sex with men is associated with increased self-reported incidence of bacterial sexually transmissible infections. Sex Health 2011;8(2): DOI:10.1071SH10053
Uncovering the Scope of HIV Infection Among MSM in the Middle East and North Africa
HIV epidemics are emerging among men who have sex with men (MSM) in some countries in the Middle East and North Africa, and a multinational group of researchers has concluded, “There is an urgent need to expand HIV surveillance and access to HIV testing, prevention, and treatment services in a rapidly narrowing window of opportunity to prevent the worst of HIV transmission among MSM in the Middle East and North Africa.” Based on data collected from a systematic review of HIV status among MSM in this region, the group found that while HIV prevalence generally remains at relatively low levels among MSM groups, in some countries HIV prevalence is approaching 28% for MSM, and MSM transmission of HIV accounts for an increasing proportion of total HIV cases and has exceeded 25% in several countries.
It has historically been difficult to assess HIV prevalence and transmission patterns among MSM in the Middle East and North Africa due to the prevailing stigma associated with this type of sexual behavior. However, this review demonstrates that a substantial amount of data are available. The researchers caution that further spread of HIV among MSM could be fueled by high levels of risky sexual behavior and biomarkers such as herpes simplex virus infection, low rates of consistent condom use, the relative frequency of male sex work, and a substantial overlap with heterosexual risk behavior and injection drug use.
Source: Mumtaz G, et al. Are HIV Epidemics among men who have sex with men emerging in the Middle East and North Africa? A systematic review and data synthesis. PLoS Med 2011;8:e1000444.
New Global Grants Target Mother-to-Child HIV Transmission
One million British pounds (more than $1.6 million) in small grants have been awarded to 82 charitable organizations across 21 countries through the Positive Action for Children Fund to stimulate grassroots community action in support of eliminating mother-to-child transmission of HIV infection. These grants by ViiV Healthcare follows closely on the UNAIDS Global Task Team's June 2011 announcement of its “Global Plan towards the Elimination of New HIV Infections among Children by 2015 and Keeping Their Mothers Alive.” The grants will range from nearly $5,000 to more than $32,000.
Positive Action, the philanthropic arm of U.K.-based ViiV Healthcare is a program aimed at supporting community-based projects to support populations disproportionately affected by HIV infection, and particularly marginalized and vulnerable populations including women and girls, youths, sex workers, injecting drug users, MSM, prisoners, and transgender communities. The program includes multiple ongoing initiatives: Positive Action Southern Initiative, which focuses on reducing disparities in HIV/AIDS care in the southeastern region of the United States; Positive Action at Work, to decrease the stigma and discrimination associated with HIV infection in the workplace; and Positive Action community grants, including the Positive Action for Children Fund, which is aimed at minimizing mother-to-child transmission of HIV by improving primary prevention of HIV infection among women of childbearing age, delivering appropriate and equitable reproductive choices for people with HIV/AIDS, making available interventions to prevent HIV transmission from women living with HIV to their infants, and improving the health and welfare of mothers with HIV and their children and families.
ViiV Healthcare, established in 2009, is an independent company jointly owned by GSK (85%) and Pfizer (15%), with a joint Research Alliance Agreement under which it will invest in R&D into HIV medicines being conducted by both companies.
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Hepatitis C Virus
Early Success of Virus-Like Particle Vaccine Strategy Against Hepatitis C Virus Has Broader Implications
A report from a group of French researchers describes the successful induction of neutralizing antibodies (NAbs) against the hepatitis C virus (HCV) envelope glycoproteins E2 and E1 in mice and macaques. The NAbs were raised against HCV 1a, but were able to cross-neutralize five other genotypes testing (1b, 2a, 2b, 4, and 5), The researchers developed a vaccine development platform based on pseudotyped virus-like particles (VLPs) that contain the retroviral Gag protein. A range of virus envelope glycoproteins could be incorporated into the VLP design, making the vaccine platform broadly applicable across viral diseases. Chronic HCV infection affects more than 200 million people worldwide and can cause life-threatening complications.
Source: Garrone P, et al. A prime-boost strategy using virus-like particles pseudotyped for HCV proteins triggers broadly neutralizing antibodies in macaques. Sci Transl Med 2011;3:94ra71.
Four-Drug HCV Combination Therapy Promising in Early ZENITH Study Results
Vertex Pharmaceuticals (Oxfordshire, UK) released interim results of the ongoing phase 2 ZENITH trial that is assessing the safety and efficacy of a four-drug regimen that includes the Vertex polymerase inhibitor VX-222 in combination with telaprevir (Incivek™), pegylated interferon (Pegasys®) and ribavirin (Copegus®) in people with HCV genotype 1. The 12-week study data indicate the potential for viral cure. Fifteen of 30 (50%) patients who received the four-drug regimen, including a 400 mg dose of VX-222, stopped treatment after 12 weeks, and 14 of 15 (93%) had undetectable HCV at that time. The other 50% of patients that were not eligible to stop treatment after 12 weeks, according to the study design, received an additional 12 weeks of pegylated interferon and ribavirin alone, and after the full 24-week treatment period, 13 of 13 (100%) of these patients had undetectable HCV levels.
VX-222, telaprevir, and ribavirin were administered twice daily. The most common adverse reports among subjects taking the four-drug regimen were mild gastrointestinal symptoms and mild fatigue. An added study arm will evaluate a three-drug regimen including VX-222, telaprevir, and ribavirin in subjects with chronic HCV genotype 1b.
Source: Vertex Pharmaceuticals press release: