According to a recent study published in The Lancet Infectious Diseases, saliva-based HIV test results may be only two per cent less accurate than conventional HIV blood tests.
The research, led by Dr. Nitika Pant Pai, a medical scientist at the Research Institute of McGill University Health Centre (RI-MUHC), compared results of blood tests and an oral fluid test, OraQuick HIV ½, taken from field research data from five worldwide databases. Researchers found that the saliva test is 99 per cent accurate for detecting HIV in high-risk populations, and about 97 per cent accurate in low-risk populations. The traditional blood test detects the virus at a success rate of 99.8 percent.
“The beauty of it is you can get your results in 20 minutes. Apart from speed, self-testing is non-invasive, provides privacy, and convenience,” Pai said. “As we have proven, it is also fairly accurate.”
The FDA-approved OraQuick HIV ½ works in three simple steps: the patient swabs a cotton stick around the gum lines of the mouth, puts the stick in a provided solution, and waits 20 minutes before reading the result via an indicator line on the device. The whole process can be done privately and does not require any medical personnel.
The device was developed to address the stigma that often accompanies more public forms of HIV screening. Many are uncomfortable being seen in a public testing facility due to fears of ostracization. For many individuals, the time taken journeying to testing facilities, waiting, and returning for follow-up visits has a negative economic impact. In many ways, HIV testing is viewed similarly to a trip to the dentist—deemed tedious unless absolutely necessary.
Pai summarized the problem succinctly.
“People don’t want to show up. And there is no way they are going to show up without encouragement,” she said. “If you look at the bigger picture, the more untested people are out there, the more likely that they are going to infect others.”
Pai hopes that the new test, following the latest findings which have proven its efficacy, combined with the attractive confidential setting, will encourage more people to get tested, and aid in acquiring timely information about antibodies in the blood.
The public health sector, however, is reluctant to embrace the notion of HIV self-testing. Despite proof of its accuracy, results from OraQuick HIV ½ are still considered to be only ‘preliminarily positive,’ and the public is encouraged to follow up with a confirmatory lab test. Another concern is that the solitary self-test is not accompanied by ample support in the event of potential adverse psychological outcomes such as stress, depression, or emotional breakdowns. From a public health perspective, self-tests pose difficulty in tracking HIV data for annual surveillance. There are also fears that the test could make public health efforts redundant by empowering people to self-diagnose their disease. Despite these concerns, Pai contends that the efficacy of the system requires a positive attitude.
“Once you adopt the optimistic attitude, self-testing can work if public health settings are willing to absorb it,” she said. “It can help provide linkages with, for example, support systems like perpetually-open counselling hotlines and medical personnel advice. It is all about creating an alternative paradigm. Coupling with self-tests will, in fact, strengthen the traditional lab-based testing. You are tapping into groups that never even bothered to get tested before, who now visit facilities to do follow-ups.”
Dr. Pai’s next project furthers her vision of the future of HIV testing.
“We’re looking at creating an Internet app for mobile phones. From the app, users can obtain reliable information on HIV, watch videos on how to do [a] self-test, and access counsellors—all in a confidential setting.”
This innovative project, which combines HIV self-testing with the power of the Internet, has won Dr. Pai one of 2011’s Grand Challenges Canada’s Rising Stars in Global Health awards, along with a $100,000 grant.
