on November 12th, 2014 No Comments
When I worked as an epidemiologist, one of my jobs was with a program that prevented perinatal hepatitis B infections. That’s when a woman with a chronic hepatitis B infection passes it on to her baby. Babies are more likely than almost any other group to develop chronic infections that can cause them years of health problems and will most likely cut their lives short.
In the U.S., most states have comprehensive testing programs to detect pregnant women with infections and strict protocols that require delivery hospitals to treat babies born to them with vaccination and antibodies to prevent infection with the virus. But a program like this requires a huge administrative and laboratory investment – and in many poverty-stricken parts of the world, this simply isn’t possible. In fact, in California, the vast majority of cases identified by the prenatal testing program are women who were born outside the United States, including many from Asia.
So when I heard the recent news that a team of four Stanford graduate students had won the Nokia Sensing XCHALLENGE, an international competition to for diagnostic devices, for a mobile test that could detect hepatitis B infections, I was pretty impressed and curious about how it could be implemented in those places. The competition is run by XPrize, the same group that has run several competitions for space exploration, and others for super-fuel efficient vehicles and ocean clean-up efforts.
The mobile version of the winning test was one of five awarded top prizes among 90 entrants. It was developed by engineering PhD candidates Daniel Bechstein, Jung-Rok Lee, Joohong Choi and Adi W. Gani, building on work previously done by Stanford professor of materials science and engineering Shan Wang, PhD, and Stanford immunologist Paul Utz, MD. The device works because magnetic nanoparticles are grafted onto two biological markers: the hepatitis B virus and the antibody that our bodies make in response to the virus. Current tests for hepatitis B requires a full laboratory facility. A Stanford press release describes the device:
The students used a diagnostic strip that takes a finger prick of blood. The patient’s blood flows into a tiny chamber where it mixes with magnetic nanoparticles to form magnetically tagged biomarkers.
The test strip is inserted into a small magnetic detector… The smartphone is plugged into the detector, and its microprocessor helps to perform the test. It takes only a few minutes.
If the test finds the hepatitis B antigen in the blood, the patient is infected and needs treatment. For a newborn with an infected mother, the child needs both vaccination and antibody therapy.