Researchers are calling it the "astronaut food approach" -- a malaria test on a disposable card small enough to fit into a wallet, with its chemical contents dehydrated so they last for months without refrigeration.

A team at the University of Washington developed the prototype malaria test suitable for developing countries, using funds from the Bill and Melinda Gates Foundation's Grand Challenges in Global Health Initiative.

UNIVERSITY OF WASHINGTON

The malaria test card -- sweet but not edible

The test is printed on a disposable Mylar card, with chemical reagents that researchers managed to stabilize in dry form using a simple ingredient: sugar.

"A pivotal issue in having this technology work is making these tests storable for long periods of time at ambient temperatures," says UW bioengineering professor Paul Yager. "We're saying we can dry the reagents down in order to store them without refrigeration. It's the astronaut-food approach."

Results showed they retained 80 percent to 96 percent of their activity after 60 days of storage at elevated temperatures, according to the UW.

Yager called the cards a critical step in a long-term Grand Challenges project to develop affordable, easy-to-use diagnostic tools for the developing world. The goal is to develop a system in which a drop of a patient's blood on a card can be fed into an instrument that gives a yes/no answer for a panel of infectious diseases in 20 minutes or less.

The prototype automated diagnostic system, dubbed the DxBox, is a team effort by Yager, UW bioengineering professor Patrick Stayton, and collaborators at Seattle non-profit PATH, Redmond-based Micronics and Nanogen of San Diego.

On tiny budgets in harsh conditions, tests for diseases need to be fast and easy to use, since health-care workers in developing countries might have just one visit to diagnose and treat a patient. Malaria kills about a million people a year.

The DxBox includes a portable, fully automatic reader being developed by Micronics to process the card-based disposable tests. Besides malaria, Yager and his team are working toward cards that will test for other diseases, such as dengue fever, influenza, typhoid and measles.

In Zimbabwe, doctors, if they can be found, will have their work cut out for them. Roll Back Malaria, a Geneva-based umbrella group funded by the Gates Foundation to lead global efforts to fight malaria, is warning about a potential surge in malaria deaths in Zimbabwe. The country has managed to control outbreaks in the past through indoor insecticide spraying, bed nets and drug treatment. In 2006, about 1.5 million malaria cases and 1,035 deaths from malaria were reported officially.

But in 2009, the potential for malaria epidemics is much higher for a variety of reasons, says Herve Verhoosel, RBM external relations manager. Zimbabwe health teams were too busy trying to control a cholera outbreak to do the usual indoor malaria spraying, anti-malaria drugs are not reaching rural health clinics because a lack of fuel and vehicles has broken down the distribution system, and health care facilities are facing severe staff shortages because of the country's overall economic crisis.