A Smart + Strong Site
Subscribe to:
E-newsletters
POZ magazine
JOIN AIDSMEDS YouTube

Back to home » Treatment News » Top Stories

Most Popular Stories
An Almost Normal Life Expectancy for People With HIV?
Undetectable Viral Load Essentially Eliminates Transmission Risk in Straight Couples
A 15-Year Jump in Life Expectancy for People With HIV
Misleading News Reports Suggest HIV Cure Is Near
New HIV Drug Class Shows Promise
Gene Therapy Shows Promise in Controlling HIV
Potential Microbicide Tricks HIV Into Sudden Death
What's That Mean?
(just double-click it!)

If you don't understand one of the words in this article, just double-click it. A window will open with a definition from mondofacto's On-line Medical Dictionary. If the double-click feature doesn't work in your browser, you can enter the word below:

Most Popular Lessons
Aging & HIV
The HIV Life Cycle
Shingles
Herpes Simplex Virus
Syphilis & Neurosyphilis
Treatments for Opportunistic Infections (OIs)
What is AIDS & HIV?
More News

Have medical or treatment news about HIV? Send press releases, news tips and other announcements to news@aidsmeds.com.

Click here for more news


emailprint

August 23, 2011

HIV Linked to False Negative Hep C Results Using Some Rapid Assays

When it comes to testing people living with HIV for hepatitis C virus (HCV) antibodies using rapid assays, some tests appear more accurate than others, according to a U.S. Centers for Disease Control and Prevention (CDC) study of three assays reported in the September 15 issue of the The Journal of Infectious Diseases. OraSure’s OraQuick HCV Rapid Antibody Test was the most accurate of the three in specimens that also contained HIV antibodies, followed by Chembio’s DPP HCV Test and, lastly, by MedMira’s Multiplo Rapid HIV/HCV Antibody Test.

Specimens from people living with HIV were 11 times more likely to have a false result than those from HIV-negative people using the Chembio test, and four times more likely using the MedMira test, Bryce Smith, PhD, of the CDC and his colleagues report. HIV infection was unlikely to affect the accuracy using the OraSure assay.

Much like rapid HIV testing, there is a great deal of interest in “point-of-care” (POC) assays that can document antibodies to HCV within minutes of a sample being collected. With regular antibody tests, which need to be processed by labs and can take a few weeks to yield results, many people do not return for their results. With POC assays, results can be provided while the patient is still present, along with important information such as the need for follow-up testing and care.

Companies have developed POC assays to look for HCV antibodies, which indicate past exposure to the virus and the need for viral load testing to determine whether or not the infection is chronic and potentially causing liver damage. OraSure’s assay has been approved by the U.S. Food and Drug Administration, whereas two other lead contenders—Chembio’s assay and MedMira’s test—have not.

For POC testing and linkage-to-care to be maximally effective, however, the assays need to be both highly sensitive and specific. The more specific the test, the lower the risk of false-positive results. And even more important, as the goal is to capture as many real infections as possible through testing, the more sensitive the assay, the lower the risk of false-negative results.

To explore the accuracy of POC tests for hepatitis C, the researchers tested a panel consisting of 1,100 specimens drawn from 1997 to 1999 from people reporting injection drug use. The specimens were tested with the three rapid assays, along with a standard antibody test conducted by a laboratory known to be highly accurate.
Roughly half of the specimens contained HCV antibodies. Forty-three of the 1,100 specimens contained HIV antibodies.

The sensitivities of the three assays, across the board, were 92.2 to 98 percent for the Chembio test, 86.8 to 88.3 percent for the MedMira test and 97.8 to 99.3 percent for the OraSure test.

False results—both positive and negative—varied. Chembio’s assay had 0.2 percent false positives, and false negatives ranged from 2.2 to 3.9 percent. MedMira had 0.2 percent false positives, and the range of false negatives was from 11.7 to 13.4 percent. And OraSure had a false-positive range from 0.4 to 0.6 percent and a false-negative range from 0.7 to 2.2 percent.

Of particular interest, false results using the Chembio and MedMira assays were strongly associated with the presence of HIV antibodies in the specimens, which suggests these tests are less effective among people living with HIV who require testing for HCV antibodies. Conversely, HIV antibodies were not associated with false results using OraSure’s FDA-approved assay.

Smith’s group noted that finding HCV antibody false-negative results among HIV-positive individuals isn’t a new phenomenon. In fact, the 8.5 percent rate of false-negative results among HIV-positive samples across all three assays compared favorably to a European study that found a false-negative rate of 22.4 percent among people living with HIV when using rapid tests. Even standard antibody tests are associated with false-negative results when testing samples from people living with HIV, on the order of 3.8 to 5.5 percent.

Further exploration of POC assays for HCV antibodies among people living with HIV is needed, the authors conclude. They write that it is necessary to “establish an expected proportion of false-negative results. Also, demonstration projects should be conducted to see how these assays would be implemented in HIV testing settings, including the development and testing of HCV-specific prevention messages.”

Search: hepatitis C, HCV, rapid testing, OraSure, Chembio, MedMira, OraQuick, DPP, Multiplo, false negative, false positive, accuracy, sensitivity, specificity


Scroll down to comment on this story.



Name:

(will display; 2-50 characters)

Email:

(will NOT display)

City:

(will display; optional)

Comment (500 characters left):

(Note: The AIDSmeds team reviews all comments before they are posted. Please do not include ":" "@" "<" ">" in your comment. The opinions expressed by people providing comments are theirs alone. They do not necessarily reflect the opinions of Smart + Strong, which is not responsible for the accuracy of any of the information supplied by people providing comments.)

Comments require captcha.
Please enter this number for verification:

| Posting Rules



Show comments (0 total)


[Go to top]

Quick Links
AIDSmeds en Español
About HIV and AIDS
Lab Tests
Clinical Trials
HIV Meds
Starting Treatment
Switching Treatment
Drug Resistance
Side Effects
Disclosure
Lipodystrophy
Hepatitis & HIV
Women & Children
Fact Sheets
Treatment News
Community Forums
Blogs
Conference Coverage
Health Services Directory
POZ Magazine


    CuteBoyinQns
    Jackson Heights
    New York


    juliar33
    brooklyn
    New York


    Sexynyrican
    Brooklyn
    New York


    jap022964
    el dorado
    Arkansas
Click here to join POZ Personals!
Conference Coverage

21st Conference on Retroviruses and Opportunistic Infections
(CROI 2014)
Boston, MA
March 3 - 7, 2014


7th International AIDS Society Conference on HIV Pathogenesis, Treatment and Prevention
(IAS 2013)
Kuala Lumpur, Malaysia
June 30 - July 3, 2013


20th Conference on Retroviruses and Opportunistic Infections
(CROI 2013)
Atlanta, GA
March 3 - 7, 2013


more conference coverage

[ about AIDSmeds | AIDSmeds advisory board | our staff | advertising policy | advertise/contact us]
© 2014 Smart + Strong. All Rights Reserved. Terms of use and Your privacy.
Smart + Strong® is a registered trademark of CDM Publishing, LLC.