New HIV detector on a USB chip?


A tiny USB chip could soon be the new way to monitor HIV patients’ health. Thanks to a research team from Imperial College London, the type of HIV technology that normally requires a laboratory and a machine the size of a desktop computer has been condensed into a device barely larger than your thumbnail.

It’s the most crucial test to see whether the medications are working…
— Dr. Roy Steigbigel

This chip offers an alternative to traditional viral load testing, which is a measure of how much of the HIV virus is present in a patient’s blood. “It’s the most crucial test to see whether the medications are working,” says Dr. Roy Steigbigel, director of the Stony Brook HIV Treatment Development Center in New York. Regular monitoring helps to detect treatment failure as early as possible, which is essential to prevent the emergence of a drug-resistant virus.

There are 39 million individuals worldwide that are affected by HIV-1, and the majority of them live in sub-Saharan Africa where the structures and facilities needed for effective healthcare are limited. This means that if a person wants to be tested for HIV, they have to travel to a central clinic that is likely far from their home, and in many cases wait for up to three days for test results.

The USB chip works by placing a drop of blood on the stick, and has embedded heaters and sensors that help to amplify the nucleic acid found in DNA. These sensors are pH sensitive and can detect the hydrogen ions produced during DNA replication.

The chip contains three chambers, each of which function independently. When the pH of a chamber changes, it generates an electric signal, producing a result that doesn’t require anything other than a hand held device to read. During the research, these results were produced in less than 30 minutes, a huge improvement upon the three days currently required for lab results.

Because of its multiple chambers, this technology has the potential to assess several samples at once, and has an 88.8% detection rate. This could theoretically reduce the costs of HIV detection and expand its availability in non-clinical settings, such as remote locations in certain African countries. Dr. Steigbigel points out, however, that while this new technology is helpful, it’s far from a major solution. Without proper follow up care and counseling, HIV positive patients would not know how to deal with their diagnosis.

While scientists and medical professionals hope to find a cure someday, the biggest hurdle right now is reaching out to populations that don’t know they’re infected and encouraging people who have risk behaviors to get tested. This chip could present a means to overcome that obstacle by allowing for better monitoring than is currently available.