Awareness of human immunodeficiency virus (HIV) serostatus is widely considered a key component in the fight against the spread of HIV/AIDS. The Centers for Disease Control and Prevention (CDC) estimates that 180,900, or 15.8%, of the nearly 1.2 million persons over the age of 13 living with HIV in the United States do not know that they are infected.1 Rapid testing for HIV provides a highly valuable solution for the need to connect at-risk populations and those unaware of their positive status with accessible testing and treatment referrals. Public and private health organizations working to raise HIV status awareness, both in clinical and non-clinical settings, often rely on rapid point-of-care testing (POCT) technology to meet the strategic goals of lowering transmission rates and linking infected patients with care.
Challenges in POCT for HIV
While the speed of an HIV assay might not play as crucial of a role in the laboratory setting, where a greater selection of assays can be performed, it is a critical factor in point-of-care testing sites. In such settings, testing time and quality of care can impact a variety of factors, including whether potential patients hesitate to get tested due to social stigmas, fears, or other concerns often associated with getting tested for HIV. Even when potential patients are tested, however, the Centers for Disease Control and Prevention (CDC) reports that those who initially test for HIV through traditional ELISA methods, which can require up to a week before results are made available, often do not return for results.2
A 2010 report on HIV Testing at CDC-funded sites shows that testing events that included rapid assays that year had a 98% rate of return for receipt of results, in contrast to 47% for those that did not.2 Because results are made available within one to 30 minutes, rapid tests enable public health strategists to implement measures that aim to significantly decrease failure-to-return (FTR) rates in communities or regions where HIV prevalence is high, ultimately providing increased opportunity for linking seropositive patients with care.
When speed matters
Relatively new to the POCT market is an FDA-approved and CLIA-waived one-minute rapid test for the detection of HIV that is already showing promise. Using flow-through technology and ready-made solutions to process the test, this new assay enables results that can be read as soon as the final solution has been absorbed through the membrane, making it much faster than lateral flow testing devices. Organizations that conduct mass testing or mobile campaigns can employ this uniquely rapid technology at large-scale events where a high number of individuals need to be tested within a short amount of time. Speed proves essential in such applications.
On World AIDS Day in 2012, AIDS Healthcare Foundation (AHF) Argentina partnered with Fundación Bienestar to try to better the Guinness World Record for the “Most HIV Tests Given in One City in Multiple Venues in One Day.” A total of 3,733 rapid tests were performed throughout the city of Rosario, Argentina.3 The success of that event illustrates the benefit of speed in contemporary diagnostic POC technology. It also suggests that rapid testing may enable resource-limited clinics and community health organizations to expand efforts, attain growth in serostatus awareness, and meet link-to-care goals, without depending on extensive laboratory services or instruments for early-stage diagnosis.
Other types of facilities that commonly employ rapid tests for HIV screening include hospital emergency departments, drug treatment centers, dental offices, and labor and delivery facilities.4 Such facilities can initially screen with a rapid kit that provides results in 20 minutes after a blood or oral sample is collected. The option of an oral and less invasive assay helps raise the likelihood that high-risk individuals will participate in testing campaigns and routine check-ups due to ease of use.
Confirmation of results
It is highly recommended that any seropositive result detected via any rapid assay be further tested. Rapid tests often provide for more accessible and lower FTR HIV testing, but “it’s very important that preliminary positive POC rapid results are confirmed in the laboratory,” says Berry Bennett, Retrovirology Section Chief at the Florida Department of Health, Bureau of Public Health Laboratories. Most first- and second-generation rapid tests reveal lower sensitivity and specificity than laboratory-based immunoassays, he notes. Those who employ rapid tests as primary screening for HIV should consult with their supporting laboratory to select the most appropriate supplemental testing algorithm in the confirmatory process, including HIV-1/HIV-2 differentiation assays, nucleic acid amplification testing, or even orthogonal rapid testing in some cases. “With that said, in areas or venues where you might not see an individual again [after initial testing], a rapid test is better than no test,” Bennett concludes.
Though it is not recommended that rapid assays be used as the sole method in the screening or early diagnosis of HIV, the technology provides undeniable benefits for a variety of organizations at the POC level. Rapid POCT for HIV plays a key role in raising serostatus awareness in areas and populations where it is most needed and is proving to be an important tool for linking infected patients with care and preventing the spread HIV/AIDS.
Adalto Nascimento serves as a marketing assistant for Bio-Rad Laboratories’ Clinical Diagnostics Division.
References
- CDC. Monitoring selected national HIV prevention and care objectives by using HIV surveillance data—United States and 6 U.S. dependent areas—2011. HIV Surveillance Supplemental Report. 2013;18(5). Published October 2013.
- Centers for Disease Control and Prevention. HIV Testing at CDC-Funded Sites, United States, Puerto Rico, and the U.S. Virgin Islands, 2010. Atlanta, GA: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention; September 2012.
- “Argentinians set new Guinness record with 3,733 HIV tests at World AIDS Day event.” AIDS Healthcare Foundation RSS2. http://www.aidshealth.org/archives/15224. Accessed February 5, 2014.
- National Alliance of State & Territorial AIDS Directors. Update on implementation of HIV rapid testing in health department supported HIV prevention programs. May 2011. http://www.nachc.com/client//NASTAD%202010%20Rapid%20Testing%20Report_May%202011.pdf. Accessed February 11, 2014.
