New wallet-sized disposable cards with dehydrated chemical contents could be used to detect malaria in developing countries, according to researchers from the University of Washington, PATH, Micronics and Nanogen, the Seattle Times "Business of Giving" blog reports.
The researchers developed the cards using funds from the Bill & Melinda Gates Foundation's Grand Challenges in Global Health Initiative, which aims to develop inexpensive and easy-to-use diagnostic tools for developing countries. According to "Business of Giving," diagnostic tools in resource-limited settings must be fast and easy to use, in part because many health workers must diagnose and treat a patient in a single visit.
The new diagnostic system, called the DxBox, contains malaria tests printed on disposable Mylar cards with chemical reagents stabilized in a dry form using sugar. The DxBox also contains a portable, automatic reader developed by Micronics to process the cards.
According to the university, evaluations of the tests demonstrated that the cards retained 80% to 96% of their activity after 60 days of storage at high temperatures. The team hopes these cards will lead to the development of a system in which an instrument can read a card containing a drop of a patient's blood and provide diagnostic results for a series of infectious diseases in 20 minutes or less. Paul Yager, a bioengineering professor at the university, said creating tests that are "storable for long periods of time at ambient temperatures" is a "pivotal issue" in creating successful diagnostic tools for developing countries.
Yager added that the researchers dried the chemical reagents so that the tests would not require refrigeration.
