Separate research projects at University of Washington and in the United Kingdom are producing handheld diagnostic devices to accurately detect Malaria
Two new handheld, point-of-care test (POC) devices for malaria could save millions of lives in third-world countries. At the same time, these POC devices may lead to inexpensive alternatives for diagnosing common diseases in developed nations as well.
Clinical laboratory test developers see a big opportunity in developing assays to detect Malaria. That is because an estimated 200 million cases of malaria are diagnosed annually, resulting in the death of about 100 million people each year.
Recently, two organizations released news about the specific testing devices they have developed to detect malaria. One group is at the University of Washington in Seattle, Washington. The other group is NanoMal, a biotechnology company located in the United Kingdom.
UW Bioengineers Develop Card-sized Mobile Test Device for Malaria
Bioengineering researchers at the University of Washington (UW) have developed a wallet-sized malaria test on a Mylar card that contains dehydrated reagents that do not require refrigeration and lasts for months. This effort is funded by the Bill and Melinda Gates Foundation.
This malaria test prototype is part of an automated diagnostic system—unofficially called DxBox—designed to overcome major challenges associated with providing medical laboratory services in poor, rural areas of developing nations, noted an article published on ScienceDaily.com.
The DxBox team is led by Paul Yager, Ph.D., UW Professor of Bioengineering. It also includes UW colleague Patrick Stayton, Ph.D. , and students, as well as external collaborators. The development project included Micronics, Inc., of Redmond, Washington, which developed an automatic reader to process the card-based disposable tests.
‘Astronaut Food Approach’ Makes Tests Storable at Ambient Temperatures
Writing in a journal article, published in December 2012 by Lab on a Chip, Yager said his team used an “astronaut-food approach. A pivotal issue in having this technology work is making these tests storable for long periods at ambient temperatures,” he stated. “Normally people work with wet reagents…we can dry the regents down in order to store them without refrigeration.”
The research team developed a method to stabilize reagents in dry form by mixing them with sugar, explained Sciencedaily.com. The malaria antibodies, when dried in sugar matrices, retained 80% to 96% of their activity at elevated temperatures after 60 days of storage.
How the University of Washington’s Dxbox System Works
To use this system, clinicians spot a drop of the patient’s blood onto the card, which is fed into the reader. The reader indicates intensity of disease by the hue of the colored spots on the card. Using an immunoassay, or antibody-based, approach, the instrument gives a yes/no answer in less than nine minutes, noted the Sciencedaily.com report.
The UW prototype cards use microfluidics, the manipulation of liquids at very small scales, to process results. This saves space and resources. It also allows the researchers to do “things that are only possible at that very small scale,” observed Yager, noting that the DxBox system runs faster than conventional tests, in part because the liquids involved behave differently.
The prototype card currently only looks for the presence of malarial proteins. The team is also working on card tests for five other diseases that cause high fever. These include:
• Rickettsial diseases
The “fever panel” of six diseases, however, is just a starting point. Yager noted that the technology could be adapted to other diseases in the future. While these test cards will only look for disease proteins, the team is also developing tests that look for the pathogen’s DNA or RNA.
NanoMal’s Mobile Device Diagnoses Type of Malaria
Meanwhile, NanoMal, a United Kingdom-based biotechnology company, has developed a hand-held device that does two things. It will diagnose malaria and will use the disease’s DNA markers to indicate antimalarial drugs that would provide the most effective treatment, noted a report published on Gizmag.com.
NanoMal’s point-of-care testing device performs a full malaria screening panel. This includes identification of which of the five parasite species is involved, along with levels of drug resistance to be expected.
Funded by the European Union, the Nanomal project involves researchers at St. George’s University in London, the University of Tuebingen in Germany, and the Karolinska Institute in Sweden, as well as the Newcastle-based biotech company QuantuMDx. Clinical trials for this device are expected to begin within three years.
Innovative Technology Provides Quick, Accurate, Inexpensive Results
The Nanomal test takes less than 20 minutes. This compares favorably to the several days required by a medical laboratory, noted the Gizmag.com article. The test device is expected to cost about as much as a smartphone.
“The simple-to-use, handheld Nanomal device will bring complex drug resistance analysis to the remotest areas, where malaria often goes undetected because of the lack of facilities,” said St. George University Professor Dr. Sanjeev Krishna, lead researcher for the project, in a news article published on the Bionow website.
“There is also great value in being able to collect drug resistance information from parasites and for that information to become centrally available through communication technologies, so that drug resistance markers can be assessed in a community …,” noted Krishna.
Test Can Identify Best Treatment for Drug-Resistant Organisms
Malarial parasites in southeast Asia and sub-Saharan Africa have mutated and are increasingly resistant to artemisinins, the most powerful class of antimalarial drugs, according to Oman Daily Observer. Research has established that certain combinations of genes in a parasite’s DNA is associated with drug resistance.
This mobile device extracts the parasite’s malarial DNA using a drop of the patient’s blood and then sequences the parasite’s DNA to detect the specific mutations linked to drug resistance using a nanowire biosensor.
Why These Technologies Will Eventually Gain Universal Use
While NanoMal’s point-of-care malaria test device will initially be used to combat malarial epidemics in third-world and developing nations, it is adaptable to diagnosis and treatment of other diseases too.
Both of these hand-held, POC devices grew out of the need for rapid and low-cost healthcare solutions in poor, third-world and developing nations. However, as they demonstrate clinical accuracy and reliability, each is likely to find its way back to developed nations because of lower cost, acceptable accuracy, quick time to answer, and convenience of use in near-patient settings.
Mobile medical devices, such as the two examples presented here, are expected to eventually be disruptive to the current medical laboratory model. For that reason, in vitro diagnostics (IVD) manufacturers are keeping a watchful eye on this developing field.
Meanwhile, pathologists and clinical laboratory managers will want to track the development and introduction of these and similar devices. Although clinical use is still years away, the potential of these diagnostic technologies to perform assays that are equally sensitive to traditional medical laboratory tests—and at a price that is substantially cheaper—is why many experts are labeling this POC technology as disruptive to existing models of clinical laboratory operations.
—by Patricia Kirk