Phones to be used to test for HIV soon

Dar es Salaam. Are you worried about how to tell your HIV status or that of your partner? Are you troubled by the idea of voluntarily visiting a health centre to test your HIV status or that of your partner?

Now, there’s good news for you—especially if you have a smartphone. Very soon, you will be testing your HIV status or that of your partner through your mobile phone.

You will not have to visit any hospital to know whether you are HIV-positive or negative, thanks to US medical researchers who have developed a low-cost smartphone accessory that can perform a point-of-care test that simultaneously detects three infectious disease markers—HIV and syphilis—from a finger prick of blood in just 15 minutes. The device replicates, for the first time, all mechanical, optical, and electronic functions of a lab-based blood test without requiring any stored energy. The necessary power is drawn from the smartphone.

A team of researchers, led by Samuel Sia, an associate professor of biomedical engineering at Columbia Engineering, has found a way to turn a common smartphone into a quick and easy device to conduct field tests for HIV and syphilis.

According to a report published yesterday by Science Translational Medicine, by using an attachment that costs Sh61,200 ($34) to make —a far cry from the standard Sh30.6 million ($18,000) for diagnostic tests — blood drops are tested for the antibodies in minutes instead of hours.

When plugged into a smartphone’s audio jack, scientists said, it mimicked the enzyme-linked immune-sorbent assay (ELISA), a well-known test for HIV, and “performed almost as well”.

The initial study, involving 96 women in Rwanda, is published in the journal Science Translational Medicine. During the field testing in Rwanda, health care workers were given 30 minutes of training, which included a user-friendly interface to aid the user through each test, step-by-step pictorial directions, built-in timers to alert the user to next steps, and records of test results for later review.

Following the field study, the vast majority of patients (97 per cent) said they would recommend the dongle because of its fast turn-around time, ability to offer results for multiple diseases and simplicity of procedure.

Experts hope that this lab-on-a-chip device could be a helpful tool, especially in places where field clinics are set up to help remote or underserved populations.

Clinical trials

The team, led by Samuel Sia, an associate professor of biomedical engineering, is aiming for larger clinical trials first. “Our work shows that a full laboratory-quality immunoassay can be run on a smartphone accessory,” said Sia. “Coupling microfluidics with recent advances in consumer electronics can make certain lab-based diagnostics accessible to almost any population with access to smartphones. This kind of capability can transform how health care services are delivered around the world.”

The study was funded by a Saving Lives at Birth transition grant—which is backed by the US Agency for International Development (USAID), the Gates Foundation, the government of Norway, Grand Challenges Canada, the World Bank and the Wallace H. Coulter Foundation.

The device replicates—for the first time—all mechanical, optical, and electronic functions of a lab-based blood test. Specifically, it performs an enzyme-linked immune-sorbent assay (ELISA) without requiring any stored energy: all necessary power is drawn from the smartphone. It performs a triplexed immunoassay not currently available in a single test format: HIV antibody, treponemal-specific antibody for syphilis, and non-treponemal antibody for active syphilis infection.

Additional reporting by AFP