HIV test on USB stick could be start of consumer revolution in monitoring disease

What if you could measure the amount of HIV in your blood as easily as you check your weight on the scales in your bathroom or take your blood pressure using a home cuff?

That's the vision of a team of scientists from Imperial College London and DNA Electronics, who announced on Thursday that they had developed a potentially revolutionary gadget to detect an HIV patient's viral load.

The disposable device, which looks very similar to the USB memory stick that you use to move files from computer to computer, is based on a mobile phone chip. It takes a drop of blood and determines the amount of virus in it. It then creates an electrical signal that can be read by your laptop or other device.

The technology, if perfected, could eventually help identify the presence of all sorts of other foreign invaders in your blood, from the hepatitis virus to the presence of bacterial or fungal sepsis. Researchers are also testing ways that the gadget might detect if you've become resistant to certain antibiotics. If they succeed, this would be a major breakthrough in the war against superbugs.

If you've followed health news over the years, you probably know there's a take-home test kit for HIV. So how is the USB stick different from that? The answer is that the kit measures HIV antibodies, which can tell you whether you're infected but not the amount of virus in your body – a measure of the severity of the disease over time. People who are HIV-positive monitor their viral levels constantly so that they can tell if their medication is working or if it's time to move on to something else. The goal for most individuals is to keep the load close to zero, and thanks to a new generation of drugs, those who manage that can live nearly as long as people without HIV.

Graham Cooke, one of the study authors and a clinician scientist in Imperial's Department of Medicine, explained that the stick could help those who are HIV-positive monitor their viral load more regularly. Typically, they now have to go to a doctor or clinic to get blood drawn, then wait while that sample makes its way to a central testing lab and for the numbers to be reported back.

“At the moment, testing often requires costly and complex equipment that can take a couple of days to produce a result. We have taken the job done by this equipment, which is the size of a large photocopier, and shrunk it down to a USB chip,” Cooke said.

The research, reported in the journal Scientific Reports, is in the early stages, so there's still a way to go before the device might be available to consumers. But the results are promising: in 991 blood samples, it was able to determine the amount of virus with 95 per cent accuracy. And that took, on average, a mere 20.8 minutes.

The idea behind the HIV USB stick – of empowering consumers to access information about themselves that previously had been difficult or even impossible to get – is a seductive notion promoted by several prominent companies. One, 23andMe, aims to help people understand their own DNA. Another, Theranos, promised but couldn't deliver on quick and cheap pinprick technology that it envisioned would allow people to bypass doctors for lab tests.

Cooke speculated that the stick could be especially beneficial for people in remote locations where getting to a clinic can be difficult.

One of the most exciting discoveries about DNA in the past two decades is that it can conduct an electrical current. This finding has sparked countless projects to explore whether the material could help us create smaller, faster and more energy-efficient circuits that overcome the limitations of silicon-based electronics.

© Washington Post