A team of researchers has developed a portable and low-cost mobile diagnostic tool, utilising a cellphone and nanotechnology, that can detect HIV viruses and monitor their management in resource-limited regions.

The management of HIV, an autoimmune disorder that cripples the immune system by attacking healthy cells, remains a major global health challenge in developing countries that lack infrastructure and trained medical professionals. 

Investigators from Brigham and Women's Hospital have designed this cellphone-based novel platform, described in a paper published in the journal Nature Communications. "This rapid and low-cost cellphone system represents a new method for detecting acute infection, which would reduce the risk of virus transmission and could also be used to detect early treatment failure," said senior author Hadi Shafiee, PhD, Principal Investigator in the Division of Engineering in Medicine and Renal Division of Medicine at the Brigham. 

Traditional virus monitoring methods for HIV are expensive, requiring the use of polymerase chain reaction (PCR). Utilising nanotechnology, a microchip, a cellphone and a 3D-printed phone attachment, Shafiee and his colleagues created a platform that can detect the RNA nucleic acids of the virus from a single drop of blood. 

The device detects the amplified HIV nucleic acids through on-phone monitoring of the motion of DNA-engineered beads without using bulky or expensive equipment.  Researchers found that the platform allowed the detection of HIV with 99.1 per cent specificity and 94.6 per cent sensitivity at a clinically relevant threshold value of 1,000 virus particles/ml -- with results within one hour. 

Notably, the total material cost of the microchip, phone attachment and reagents was less than $5 per test. "Health workers in developing countries could easily use these devices when they travel to perform HIV testing and monitoring. Because the test is so quick, critical decisions about the next medical step could be made right there," said Shafiee. "We could use this same technology as a rapid and low-cost diagnostic tool for other viruses and bacteria as well," said lead author Mohamed Shehata Draz.