For at-risk population, testing reliably for HIV is imperative for timely treatment. However, choices that public health officers can offer patients are restricted to either the pretty convenient yet unreliable saliva test, or the reliable blood tests with low turnout levels.

However, this is about to change.

The new combined testing

A group of chemists from Stanford University in Palo Alto, CA, together with the Alameda County Public Health Laboratory, came up with a new test which integrates the reliability of blood tests with the convenience of saliva tests. The researchers managed to accomplish this by tapping into the conduct of HIV antibodies. Taking into account HIV.GOV statistics, there are over 1.1 million people living with HIV in America, with nearly 14.2% percent of those still unaware of the infection, this emphasizes the significance of early detection.

According to Carolyn Bertozzi PhD, the Anne T. and Robert M. Bass Professor and also a chemistry professor at Stanford, early detection is imperative since with each day the infected may be infecting other people unawares, specifically younger people.

With the new test, a sample of saliva is added with modified bits of HIV linked to a half-piece DNA. If the modified HIV attaches itself onto the HIV in the sample making a full DNA strain, the test is positive. An antibody has a pair of arms which swiftly hangs onto the virus paving way for development of what Bertozzi calls a “purposefully low tech” test.

The test was tried on 44 patients, half of those positive while the other half negative. The test was able to detect the presence of HIV in the group of known HIV-positive patients. With the 22 subjects of known HIV status, the test did not detect anything.
According to Bertozzi, an earlier read would be much better than what they get from oral test, since sensitivity in the new test is suggested to be higher than the current saliva tests. However, the new test still shows slower detection compared to blood testing. Tested during preliminary phase on 8 samples with mixed outcomes from saliva testing, the new test detected 6 positive diagnosis.

Although blood testing is swift in detecting HIV antibodies which are generally abundant in the blood not long after infection, the test is not entirely practical in large populations of patients. According to Cheng-ting Tsai author of the report and a grad student in Bertozzi’s laboratory, blood test cannot reach many inaccessible populations, but with oral fluid tests, the accessibility becomes open.

Still, there are setbacks regarding oral tests considering the saliva does not have as many HIV antibodies as the blood does. The small quantity of antibodies in the saliva consequently makes the oral tests unreliable. According to Bertozzi, by the time HIV is reliably tested via oral test, the infection is usually well spread.

The new test may not only be capable of testing for HIV, but also tuberculosis and typhoid, and it is already under investigation to determine its efficiency. Additionally, the test may also be used in determining the successfulness of measles vaccine.


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