Quicker, more appropriate HIV test just needs spit

Currently, public health officials have a tough choice to create when it comes to screening people for HIV: administer a trusted blood test that may detect infections in early stages, but that few people will volunteer for, or give people an easy test using saliva that's less reliable during the initial stages of infection. The new test could change that.

By far the most typical way to check for HIV infection is to try looking in a blood sample for antibodies, proteins that the immune protection system custom-builds to attack the virus and react against infection. That test is far more convenient than a direct search for the virus, simply because antibodies are relatively abundant in the bloodstream after the first stages of infection.

Yet there's an important drawback, especially for public health officials and researchers who want—and sometimes need—to obtain lots of people tested quickly to greatly help retain the spread of the condition: needles.

But oral fluid tests have their own problems. While you will find HIV antibodies in saliva, they do not accumulate at the levels they do in blood, or at the exact same speed—and thus there just aren't that many present, especially early on.

By the full time oral fluid tests can reliably detect HIV, Bertozzi says, "you've waited an extended time"—and in the period, the infection could spread.

The team's job, then, was to determine steps to make it easier to detect the little bit of antibodies present in the saliva of someone with HIV. To accomplish this, they took an indirect approach. As opposed to searching for the antibodies themselves, they looked for what antibodies could do.

The team took advantage of a key feature of antibodies—they have two arms, each which easily latches onto a virus like HIV. They took components of HIV and attached them to 1 or another half of a little bit of DNA. They then added the modified HIV bits to the saliva sample.

If the sample contained HIV antibodies, their two arms would grab hold of the tagged HIV, bringing the two halves of the DNA together in to a continuous strand. Once the DNA piece is made whole it is simple to detect using standard lab techniques.

That will all be done without requiring a blood sample or much technology to process the samples.

Although the researchers say it can take more studies to ensure the outcomes, the very first experiments show that it is useful: the test correctly diagnosed 22 those who took part in a Alameda County screening effort, every one of whom had tested positive for HIV using other methods. When you have any kind of concerns with regards to where by and the best way to make use of HIV test kit, it is possible to call us on our website. Importantly, the test did not falsely detect HIV in the 22 additional HIV-negative participants.

It might also work earlier compared to other saliva tests, while not earlier than existing blood tests. In a couple of eight samples that had produced mixed results with the current standard saliva test, six resulted in positive with the new HIV test, and one of those was confirmed using a blood test. Although those results are preliminary, they claim that the newest test is more sensitive and could pick up HIV infection prior to others.

Beyond HIV, she and Tsai says, the same principles might be ideal for allergy testing and screening for typhoid and tuberculosis infection. The team is also investigating the strategy as a way to test the efficacy of measles vaccination efforts, Bertozzi says.