HIV screening: How we can do better

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Applied Evidence

HIV screening: How we can do better

J Fam Pract. 2014 July;63(7):383-387

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References

1. amFAR. Thirty years of HIV/AIDS: Snapshots of an epidemic. amfAR, The Foundation for AIDS Research Web site. Available at: http://www.amfar.org/thirty-years-of-hiv/aids-snapshots-of-anepidemic. Accessed May 9, 2014.

2. Centers for Disease Control and Prevention. HIV Surveillance Report, 2011. Vol. 23. Centers for Disease Control and Prevention Web site. Available at: http://www.cdc.gov/hiv/pdf/statistics_2011_HIV_Surveillance_Report_vol_23.pdf. Published February 2013. Accessed October 19, 2013.

3. Centers for Disease Control and Prevention. HIV in the United States: At a glance. Centers for Disease Control and Prevention Web site. Available at: http://www.cdc.gov/hiv/statistics/basics/ataglance.html. Accessed May 9, 2014.

4. The White House Office of National AIDS Policy. National HIV/ AIDS Strategy for the United States. AIDS.gov Web site. Available at: http://aids.gov/federal-resources/national-hiv-aids-strategy/nhas.pdf. Accessed October 25, 2013.

5. Branson BM, Handsfield HH, Lampe MA, et al; Centers for Disease Control and Prevention (CDC). Revised recommendations for HIV testing of adults, adolescents, and pregnant women in health-care settings. MMWR Recomm Rep. 2006;55(RR-14):1-17;quiz CE1-CE4.

6. Centers for Disease Control and Prevention (CDC). Vital signs: HIV testing and diagnosis among adults-- United States, 2001-2009. MMWR Morb Mortal Wkly Rep. 2010;59:1550-1555.

7. Moyer VA; U.S. Preventive Services Task Force. Screening for HIV: U.S. Preventive Services Task Force recommendation statement. Ann Intern Med. 2013;159:51-60.

8. Brown M. AAFP, USPSTF recommend routine HIV screening but differ on age to begin. Available at: http://www.aafp.org/news/health-of-the-public/20130429hivscreenrecs.html. Accessed August 17, 2013.

9. Bayer R, Oppenheimer GM. Routine HIV testing, public health, and the USPSTF--an end to the debate. N Engl J Med. 2013;368:881-884

10. Cornett JK, Kirn TJ. Laboratory diagnosis of HIV in adults: a review of current methods. Clin Infect Dis. 2013;57:712-718.

11. Baron EJ, Miller MJ, Weinstein MP, et al. A guide to the utilization of the microbiology laboratory for diagnosis of infectious diseases: 2013 recommendations by the Infectious Diseases Society of America (IDSA) and the American Society for Microbiology (ASM)(a). Clin Infect Dis. 2013;57:e22-e121.

12. Delaney KP, Branson BM, Uniyal A, et al. Evaluation of the performance characteristics of 6 rapid HIV antibody tests. Clin Infect Dis. 2011;52:257-263.

13. FDA. FDA approves first rapid diagnostic test to detect both HIV-1 antigen and HIV-1/2 antibodies [press release]. US Food and Drug Administration Web site. Available at: http://www.fda.gov/newsevents/newsroom/pressannouncements/ucm364480.htm. Silver Spring, MD: US Food and Drug Administration; August 8, 2013. Accessed October 26, 2013.

14. Chavez P, Wesolowski L, Patel P, et al. Evaluation of the performance of the Abbott ARCHITECT HIV Ag/Ab Combo Assay. J Clin Virol. 2011;52:S51-S55.

15. Centers for Disease Control and Prevention (CDC). Rapid HIV testing in emergency departments—three U.S. sites, January 2005-March 2006. MMWR Morb Mortal Wkly Rep. 2007;56:597-601.

16. Napierala Mavedzenge S, Baggaley R, Corbett EL. A review of self-testing for HIV: research and policy priorities in a new era of HIV prevention. Clin Infect Dis. 2013;57:126-138.

17. Centers for Disease Control and Prevention (CDC). Detection of acute HIV infection in two evaluations of a new HIV diagnostic testing algorithm - United States, 2011-2013. MMWR Morb Mortal Wkly Rep. 2013;62:489-494.

18. Nasrullah M, Wesolowski LG, Meyer WA 3rd, et al. Performance of a fourth-generation HIV screening assay and an alternative HIV diagnostic testing algorithm. AIDS. 2013;27:731-737.

When rapid tests are most useful. Rapid tests can be particularly useful for testing women presenting in labor who have not been screened for HIV as part of prenatal care. They also can be used to determine the need for postexposure prophylaxis in the event of a needlestick injury. According to manufacturer’s data, the sensitivity of rapid tests ranges from 99.3% to 100% and specificity from 99.7% to 99.9%.¹² However, in real-world experience these numbers have been slightly lower.¹² By comparison, the sensitivity and specificity of the fourth-generation EIAs are 99.4% and 99.5%, respectively.¹⁴

The downside... A disadvantage of rapid HIV testing is that under current FDA-approval status and CDC guidance, tests performed on oral fluid must have serologic confirmation. In addition, patients tested during the “window period” of seroconversion (after infection occurs but before antibodies are detectable) will test negative with rapid HIV tests and must be reminded that repeat testing should be done within 4 to 6 weeks of their last potential exposure to the virus. In high-prevalence settings such as urban emergency departments (EDs), rapid HIV tests have detected a significant number of new infections.¹⁵ However, ED physicians and urgent care providers have been reluctant to perform HIV tests due to the lack of follow-up for most patients treated in these settings.

Over-the-counter (OTC) tests. Approved by the FDA in 2012, the OraQuick In-Home HIV Test is the only available OTC test for use at home. Patients can go to the company’s Web site at www.oraquick.com to learn more about HIV and testing, and the company offers 24-hour phone support. It’s not clear how many patients are taking advantage of this home testing option. The test costs approximately $40 and several studies suggest that this price may deter patients from using it.¹⁶ In addition, it is not clear how patients who test positive using an OTC test will access medical care or get appropriate medical follow-up.

New testing algorithm eliminates Western blot

Historically, a patient with a reactive (positive) EIA result would undergo the Western blot assay as a confirmatory test. Although the Western blot for HIV is highly specific (99.7%), it tests only for the IgG antibody. This could lead to a false negative test in a patient in whom IgG seroconversion has not yet occurred. Additionally, the time for HIV confirmation with the Western blot often is one week or longer.

When speaking with a patient who tests positive on a rapid test, consider using the phrase "preliminary positive" results.Recently, the CDC has made available for public comment a diagnostic algorithm that removes the Western blot as a recommended test (FIGURE 2).¹⁷ This algorithm replaces the Western blot with an assay to differentiate HIV-1 and HIV-2 antibodies. Patients for whom this test is negative should undergo additional testing for HIV RNA to determine if HIV-1 is present. Positive HIV RNA would indicate acute or more recent infection. Studies suggest that this new algorithm is better than the existing algorithm at detecting HIV infections, and many reference labs have already adapted it.^17,18

Choosing your words carefully when giving patients their results

Patients can be given the results of a rapid HIV test during their visit, but a positive result on a rapid test should be confirmed by serologic testing. When speaking with a patient who tests positive on a rapid test, consider using the phrase “preliminary positive” results. This allows the patient to more easily process the results, knowing that a confirmatory blood draw will be done. State laws vary regarding how patients can receive HIV test results. Most states allow negative serologic test results to be given over the telephone (or electronically). For positive tests, it is preferable to give these results at a face-to-face consultation so that you can ensure the patient will have access to medical care. For more on HIV testing and lab reporting laws by state, see http://www.cdc.gov/hiv/policies/law/states/index.html.

CORRESPONDENCE
Jeffrey T. Kirchner, DO, FAAFP, AAHIVS, Family and Community Medicine, Lancaster General Hospital, 555 N. Duke Street #3555, Lancaster, PA 17602; jtkirchn@lghealth.org