Apr 12 2007
A convenient, easy to use, and rapid alternative to blood-based HIV testing may become the new standard for field testing according to a new MUHC study.
The study shows that the oral fluid-based OraQuick HIV1/2 test is 100 per cent accurate and patients' preferred choice.
Senior and lead author Dr. Nitika Pai, a postdoctoral fellow at the McGill University Health Centre (MUHC), and her colleagues tested 450 individuals for HIV infection at the Mahatma Gandhi Institute of Medical Sciences in Sevagram India. Thirty two percent were found to be HIV positive. Researchers compared the diagnostic accuracy of the OraQuick test from two samples - one obtained from oral fluid (saliva) and the other from a blood-based finger stick - with traditional blood tests. They demonstrated that the oral fluid test had 100 per cent accuracy versus the finger-stick blood test, which showed one false positive (99.7 per cent specificity). There was little reported discomfort during sample collection for the oral test, but 66 per cent of the individuals reported discomfort with the finger testing.
Although the oral OraQuick test has been approved by the US Food and Drug Administration, some previous studies had indicated that it was not sufficiently precise. As a result, the Centre for Disease Control (CDC) called for more definitive studies leading to this study in rural India.
"Based on our findings, the oral test is the preferred choice for HIV field testing by rural Indians," says Dr. Pai, a physician epidemiologist supported by the Canadian HIV Trials Network. "The other advantages are that results are available within 40 minutes compared to the standard blood test, which takes up to two weeks. This test can also be performed by health workers with minimal training, eliminating the need for specialist laboratory technicians."
"Rapid point of care HIV testing is a very important component of HIV control initiatives and programs. In particular, non-invasive, simple, accurate oral fluid-based, rapid tests have the potential to make a big impact on HIV screening. They open the door to the possibility of home-based HIV testing," she says.