Rapid HIV test: just spit on the test strip
Waiting for the results of a traditional HIV test can seem like an eternity, especially in emergency situations that require an immediate response. In addition, this requires an invasive procedure for taking a blood sample.
Scientists at McGill University (Montreal) have recently successfully completed clinical testing of a new rapid method for detecting HIV in a saliva sample, which allows you to get a result within 20-40 minutes.
The method is based on the analysis of the transudate of the oral mucosa – a fluid secreted at the base of the gums and subsequently converted into saliva. The content of antibodies in this liquid is comparable to the content of antibodies in the blood, which makes it the optimal biological material for diagnosis.
Clinical trials of the method were conducted in the maternity department of the Mahatma Gandhi Institute of Medical Sciences (India). This place was chosen for two reasons. Firstly, many Indian women do not seek prenatal medical care and do not take an HIV test during pregnancy, so testing in the maternity ward is the last chance to detect the disease and prevent infection of the child. Secondly, Indian patients often refuse to donate blood for tests for religious reasons, while collecting saliva is not a problem.
As part of the study, 1,222 women were tested for HIV in the maternity ward using two methods: blood analysis and saliva analysis. The test results matched 100% of the time. In addition, saliva analysis helped to identify several HIV-infected women who did not know about their disease. These women underwent emergency treatment aimed at reducing the likelihood of HIV transmission to newborns.
The method is based on the principle of immunochromatography used in rapid pregnancy tests. Mucosal transudate is applied to a special test strip, which is placed in a test tube with a special solution. Within 20-40 minutes, the antibodies contained in the transudate are aggregated with the antigens included in the test, which, in case of a positive result, gives a color reaction in the form of a purple stripe.
According to the authors, such tests have not yet found their application in Canada due to the general skepticism of the population. However, their effectiveness has been convincingly proven for all subtypes of HIV-1 and HIV-2. The developers believe that the introduction of inexpensive rapid tests into clinical practice will reduce the number of people who do not know about their HIV status. In addition, in the future, the proposed approach can be used to create express tests for home use.
The results of the work are published in PLOS Medicine.
Portal "Eternal youth" www.vechnayamolodost.ru based on the materials of ScienceDaily
08.05.2008