14 DAY TRIAL // A breakthrough in testing for HIV has been achieved: no more blood analysis is required, since a new saliva-based test comes with results in just 20 minutes, as described in the PLoS Medicine journal. The new technique uses the oral mucosal transudate (OMT), a liquid released at the base of the gums that later turns into saliva.
OMT has the same antibody amounts like blood plasma and immunochromatography is the same methodology employed for pregnancy tests. The OMT antibodies are aggregated and exposed to the HIV antigens (molecules that are attacked by antibodies). The presence of anti-HIV antibodies will cause a reaction.
The OMT is collected using a stick, just like in pregnancy tests, which is dipped in a small tube containing a special solution. 20 to 40 minutes later, a purple line will be seen at the top of the stick if the saliva proves HIV positive. Clinical trials were made at the Mahatma Gandhi Institute of Medical Sciences in Sevagram, Maharastra, India.
"In such cases, it is vital to determine the HIV status of the mother very quickly to prevent transmission to the child during delivery. Many Indian women do not receive prenatal care and therefore do not get tested for HIV during pregnancy. Testing in the labor ward is the last chance to prevent HIV transmission to the newborn baby. Also Indian patients often refuse blood collection, while saliva collection poses no problem," said co-author Dr Nitika Pant Pai from McGill University Health Center.
HIV tests based on both saliva and blood samples were performed on 1,222 Indian mothers. The blood and saliva tests matched in 100% of cases. The saliva test detected several HIV infected mothers-to-be unaware of their infection. These subjects later underwent treatments in order to reduce the risk of HIV infection in their unborn children.
Further development of the method could lead to an over-the-counter HIV test for home use.