Variant, Atypical, and Resistant HIV Surveillance Project (VARHS)
What is drug resistance surveillance (VARHS)? |
Objective: Variant, atypical and resistant HIV surveillance (VARHS) is an expanded HIV/AIDS surveillance activity funded by the Centers for Disease Control and Prevention (CDC). The objectives of VARHS are to monitor the frequency of important antiretroviral resistance mutations, follow the outcomes of those with and without mutations, and measure the prevalence of different HIV-1 viral strains/types. Methods: VARHS uses genotypic tests to determine viral subtype and the presence of any drug resistant mutations. Leftover sera from HIV positive diagnostic specimens are collected from labs for genotype testing. Additionally, results from clinical practice are also collected from providers and labs. Eligibility for VARHS includes a recent confidential HIV test, being newly diagnosed with HIV (no previous positive tests more than 90 days prior), and being antiretroviral-naïve. Results are returned to the clinician ordering the HIV test so that each individual may have their genotype results to help guide future HAART (highly active antiretroviral therapy) decisions. When this clinician does not provide ongoing HIV primary care, we seek a primary provider from routine CD4/viral load reporting to return the genotype results. Confidentiality of data is of the utmost importance and is protected with a level of security exceeding HIPAA standards. See also: Frequently Asked Questions about VARHS.
Latest statistics on drug resistance as of 7/2009 |
Completeness of VARHS, King County, by diagnosis year
| . |
2003-2004
|
2005-2006
|
2007-2008
|
| Newly diagnosed HIV cases with genotype within 3 months of diagnosis included in VARHS |
16%
|
36%
|
52%
|
Prevalence of high-level antiretroviral drug resistance and HIV-1 subtypes among newly diagnosed HIV cases in King County, by diagnosis year
| . |
|
|
|
| High-level resistance |
| Overall |
11%
|
12%
|
12%
|
| NRTI |
4%
|
3%
|
2%
|
| NNRTI |
9%
|
9%
|
10%
|
| PI |
2%
|
3%
|
3%
|
| 2 or 3 classes |
3%
|
3%
|
2%
|
| HIV-1 subtype |
| B |
93%
|
91%
|
89%
|
| C |
2%
|
3%
|
5%
|
| Other |
5%
|
6%
|
6%
|
Where is VARHS happening? |
Two local laboratories and two large, regional laboratories currently participate in VARHS. At the two local laboratories, leftover blood samples from diagnostic HIV tests of eligible individuals are sent to Stanford University Virology laboratory for a genotypic resistance test. Additionally, one of these laboratories and the two regional laboratories are submitting genotypic test results ordered by health care practitioners. Over half of the sequences included in our drug resistance surveillance system were tested for clinical purposes. Other regions around the country that participate in VARHS include Colorado, Chicago, Connecticut, Florida, Los Angeles, Michigan, New York City, South Carolina, and Texas.
Who is eligible for VARHS? |
All individuals newly and confidentially diagnosed with HIV infection who are antiretroviral naïve are eligible. Thus, people with anonymous HIV tests, those known to be HIV infected for more than 90 days and/or those who have a history of antiretroviral use are not eligible.
What is multi-class drug resistance (MDR)? |
Multi-class drug resistance (MDR) is defined as high level drug resistance in more than one antiretroviral drug class. The three classes which are routinely evaluated for resistance are protease inhibitors (PI), nucleoside reverse transcriptase inhibitors (NRTI) and non-nucleoside reverse transcriptase inhibitors (NNRTI). MDR does not necessarily accelerate disease progression, but high level resistance to more than one drug class may lead to reduced treatment options that can be expensive and difficult to maintain.
Medical providers are encouraged to notify the Public Health – Seattle & King County HIV/AIDS Epidemiology Unit when drug resistance, and especially MDR, is diagnosed in a treatment naïve individual by downloading this form.
Update on multi-class-drug resistant cluster among methamphetamine-using men who have had sex with men (MSM) |
In 2006 and 2007, strains of genetically similar MDR-HIV were identified in seven newly diagnosed ARV-naïve individuals and two treatment-experienced individuals. All nine were men who had sex with men (MSM) and all reported recent use of methamphetamine and sex with multiple, mostly anonymous sex partners. All had resistance tests showing resistance to most protease inhibitors, most non-nucleoside reverse transcriptase inhibitors, and varying levels of resistance to nucleoside reverse transcriptase inhibitors. A manuscript describing the epidemiology and phylogenic analysis of this cluster was published in 2008. In February 2007, Public Health –
Seattle
&
King
County
issued a press release regarding this cluster. This press release resulted in wide coverage in newspapers, radio, and TV. Via the news media, Public Health attempted not only to educate people about the cluster and drug-resistant HIV, but also to encourage HIV prevention. Later that same month Public Health conducted a survey of 325 sexually active men who have sex with men (MSM). Over half (57%) of the MSM surveyed had heard about the MDR cluster, with 90% of these men recalling key points. Almost all (98%) of the MSM interviewed agreed it was important to release information on this cluster to the media.
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