20th Conference on Retroviruses and Opportunistic Infections (CROI)

Select CDC Studies of Interest

CDC scientists will be presenting more than 40 abstracts at CROI 2013. Several studies that may be of particular interest to reporters are briefly summarized below.


Health insurance coverage and type predict durable viral suppression among HIV-infected adults in care in the United States—Medical Monitoring Project, 2009 (Poster Abstract, Session 190, #1028)

  • Overview: HIV-infected adults with healthcare coverage are more likely to have their virus under control, compared to those with no health insurance, according to a new analysis of data from CDC’s Medical Monitoring Project (MMP). Viral suppression is the ultimate goal of HIV care and treatment, as it indicates that a person with HIV can both remain healthy and avoid transmitting the virus. Using data from the MMP, a nationally representative sample of people in HIV care, researchers assessed the relationship between health insurance coverage and viral suppression among HIV-infected adults. They looked at the proportion of people who achieved viral suppression comparing those with insurance coverage to those who had no coverage at all.
    • Of an estimated 4,217 HIV-infected adults in care, 96 percent had coverage within the past 12 months. Medicaid coverage was most common, followed by coverage under the Ryan White HIV/AIDS Program and private insurance.
    • The proportion of insured participants achieving viral suppression was nearly twice that of uninsured participants (62 percent versus 32 percent). Among the insured, people with Medicare and military insurance plans (Tricare, Champus, or Veterans Administration) were more likely to achieve viral suppression than those with other plans.
    • Researchers also discovered associations between viral suppression and several key socioeconomic factors; associations which tended to persist even after adjusting for healthcare coverage and coverage type. For example, controlling for healthcare coverage and type, individuals living at or below the poverty level were less likely to have achieved viral suppression. These findings are in line with previous research showing that complex social, economic, and environmental factors, including poverty, help fuel the epidemic in some communities by limiting access to healthcare and HIV testing and treatment.

    These findings establish a baseline for measuring the future impact of changes in insurance coverage on the health of people with HIV. Authors conclude that expanding coverage to all people with HIV and improving quality of care across coverage types are important to achieve and maintain viral suppression for all.

  • CDC Contact: Jacek Skarbinski

Nationally representative estimates of quality of HIV care in the United States – Data from the Medical Monitoring Project, 2009 (Poster Abstract, Session 191, #1037)

  • Overview: While the majority of HIV-infected adults in care are receiving recommended services for their HIV infection, far too few are receiving the recommended screening and prevention services related to other STD infections, which can threaten their health and facilitate further HIV transmission. Clinical care guidelines for individuals living with HIV include both HIV-specific services, general medical interventions, and other services critical to help slow the spread of HIV, such as STD screening and prevention counseling services. Using data from the Medical Monitoring Project (MMP), which captures a nationally representative sample of people in HIV care, researchers assessed the delivery of nine recommended treatment, screening, immunization, and HIV prevention services in 2009.
    • Most patients in care received recommended HIV-specific services. Among an estimated 421,186 HIV-infected adults in care, 87 percent received adequate CD4 cell monitoring, almost 90 percent were prescribed ART, and 72 percent achieved viral suppression. These findings align with previously published data on the proportion of Americans with HIV receiving treatment and keeping their virus under control.
    • Most also received clinical services important to help people living with HIV remain healthy, including influenza vaccination (79 percent) and cervical cancer screenings (77 percent), and antibiotics to protect against pneumocystis pneumonia (79 percent), if needed.
    • However, the proportion of sexually-active HIV-infected adults in care receiving needed STD screening was low, only 55 percent received screening for syphilis; 23 percent received gonorrhea screening; and 24 percent received chlamydia screening. Further, just 45 percent reported receiving counseling from their provider about preventing HIV and STD transmission.

    While the study shows that delivery of HIV-specific care and some other clinical services is adequate, authors conclude that additional efforts are needed to improve delivery of HIV and STD prevention services including STD testing and prevention counseling.

  • CDC Contact: Jacek Skarbinski


HIV prevalence and awareness of infection in 2008 and 2011 among MSM – 20 cities in the United States (Oral Abstract, Session 25, #90)

  • Overview:Awareness of HIV infection among men who have sex with men (MSM) testing positive for HIV in a 20-city study has increased in recent years, according the latest CDC analysis of data from National HIV Behavioral Surveillance (NHBS). Because awareness of HIV-positive status is a critical first step in obtaining care and treatment and preventing the spread of HIV, researchers examined trends in HIV prevalence and status of awareness among MSM. Using data from CDC’s NHBS, which conducts surveys on HIV-related risk and protective behaviors and provides HIV testing in 20 U.S. cities with high AIDS burden, researchers measured changes in the proportion of MSM testing positive for HIV from 2008 to 2011. In addition, among those testing positive, researchers assessed changes in the proportion who said that they were already aware of their infection due to a previous HIV test.
    • HIV prevalence remained steady during the period – 19 percent of MSM tested positive in 2008, and 18 percent in 2011.
    • The proportion of those testing positive that were already aware of their infection increased from 56 percent in 2008 to 66 percent in 2011. HIV awareness increased in all age categories and across all racial groups. However, the proportion of men aware of their infection remained lowest (54 percent) among black MSM in 2011, though prevalence was highest within this population.

    Since half of all new infections are transmitted by people who are unaware of their HIV-positive status, these increases in awareness are encouraging, but continuing racial/ethnic disparities are concerning. Authors conclude that outreach and testing programs should be sustained and that efforts to reduce disparities remain critical in the fight against HIV.

  • CDC Contact: Cyprian Wejnert


Trend in transmitted HIV-1 antiretroviral drug resistance-associated mutations, 10 HIV surveillance areas, United States, 2007-2010 (Oral Abstract, Session 43, #149)

  • Overview: The proportion of newly infected individuals who are infected with a drug-resistant strain of HIV is holding steady overall at roughly 16 percent, but increases in transmitted resistance, especially to non-nucleoside reverse transcriptase inhibitors (NNRTIs) will be important to monitor over time, according to the latest CDC analysis of resistance among newly diagnosed individuals in the U.S. Because transmission of drug-resistant mutations may limit the effectiveness of HIV treatment regimens, CDC closely monitors resistance mutations in newly diagnosed HIV infections. This analysis is based on blood samples collected in 2007–2010 from 18,144 people who were newly diagnosed with HIV infection and had no evidence of prior antiretroviral use. Researchers examined HIV nucleotide sequences in the blood samples to monitor the percentages of and trends in transmitted drug resistance mutations associated with three classes of drugs: NNRTIs, nucleotide/nucleoside reverse transcriptase inhibitors (NRTIs), and protease inhibitors (PIs). Because these individuals had not yet started antiretroviral drug treatment, the presence of HIV drug resistance mutations in their HIV nucleotide sequences would indicate that the drug-resistant virus was transmitted to them at the time of their infection.
    • Over the entire period, nearly one in six newly diagnosed individuals (16.2 percent) were infected with a drug-resistant strain of HIV. From 2007 through 2010, transmitted drug resistance increased by 3.0 percent per year, but the increase was not statistically significant.
    • The percentage of transmitted mutations resistant to one class of drugs over the entire period was 13.6 percent; two drug classes was 2.1 percent; and three drug classes was 0.5 percent. From 2007 through 2010, there was a statistically significant annual increase in transmitted drug resistance to one class of drugs (4.3 percent).
    • Over the entire period, the percentage of transmitted mutations associated with resistance to NNRTIs was 8.1 percent, NRTIs was 6.7 percent, and PIs was 4.5 percent. The only group in which there was a statistically significant increase in transmitted drug resistance from 2007 through 2010 was NNRTIs, in which resistance increased 5.2 percent.

    While the clinical significance of this level of resistance is not yet clear, researchers believe increases in transmitted resistance could become a public health concern over time if treatment options are threatened in the future. Given that NNRTIs are the most commonly prescribed therapies, authors recommend continued monitoring of resistance to this and other drug classes, as well as additional research to assess whether any adverse impact on HIV treatment options is presently occurring.

  • CDC Contact: David Kim
Page last reviewed: March 6, 2013