Lab-on-a-Chip Technology Provides Rapid Diagnosis of Malaria
Lab-on-a-Chip Technology Provides Rapid Diagnosis of Malaria
November 10, 2010 (Atlanta, Georgia) — A diagnostic tool for malaria, using Lab-on-a-Chip (LoC) InCheck (ST Microelectronics) technology, if commercialized, could allow complete and accurate test results in less than an hour.
Lead researcher Lisa Ranford-Cartwright, PhD, from Glasgow University, in the United Kingdom, reported the results of testing of this new diagnostic tool here at the American Society of Tropical Medicine and Hygiene 59th Annual Meeting.
"Current methods of [malaria] diagnosis are pretty old-fashioned," Dr. Ranford-Cartwright told Medscape Medical News. The diagnostic gold standard is microscopy, which requires a high level of expertise and experience, and even then it may not accurately detect low levels of the parasite or correctly identify the species, she said.
According to Dr. Ranford-Cartwright, the ability to determine whether the parasites infecting a patient are drug-resistant will be the "biggest coup" for clinicians. "It will effectively allow more customized treatment of each individual patient, such that they can be treated more accurately and the use of stronger drugs with adverse side effects can be avoided if possible," she said.
More accurate molecular tests, such as polymerase chain reaction (PCR), require expensive equipment and are too time-consuming, said Dr. Ranford-Cartwright. Furthermore, there are currently no tools to determine whether a given infection will be resistant to first-line drug treatments, hindering fast and appropriate clinical decisions for treatment of a disease that can kill within a matter of days.
The integrated LoC InCheck system combines PCR with a microarray-based diagnostic test that then allows the identification of the specific species of malaria parasite and detection of drug resistance. With the current technology, malaria parasite detection will now take just more than 10 minutes.
The species is identified by amplification of the 18S rRNA gene, and drug resistance is determined by amplification of polymorphic regions of genes such as the chloroquine resistance transporter and the cytochrome b gene, which typically confer resistance to common antimalarials including chloroquine and atovaquone and proguanil hydrochloride.
The new system is already being used to diagnose influenza and is being developed for a range of other diseases such as tuberculosis and SARS, said Dr. Ranford-Cartwright.
Researchers at the University of Glasgow are currently testing the sensitivity and specificity of this system in detecting malaria from a range of parasite samples with different levels of infection. They are also testing the performance of the system relative to the currently available diagnostic tools.
According to Dr. Ranford-Cartwright, the system will require the purchase of specialized equipment and single-use chips, but once established, samples can be easily tested by a technician with only minimal experience.
Once clinical trials have been completed, the technology is likely to be initially established in large city hospitals in regions where malaria is endemic, with the potential in the future to be scaled down for use in the field, she said.
Independent commentator Dylan Pillai, MD, PhD, from the University of Toronto, in Canada, noted that microfluidic platforms hold great promise. "They require very little sample, give a rapid result, and require no technical expertise on microbe recognition," he told Medscape Medical News.
"Real-time PCR has become an essential adjunct to microscopy for sensitive diagnosis of malaria," Dr. Pillai added. "The use of microfluidics miniaturizes the platform for PCR, and this [LoC] technology offers a rapid turnaround time, which may be of use in the hospital laboratory to effect quick clinical decision-making."
However, he cautioned that the cost per sample may be prohibitive for endemic settings, and that the "technology requires electrification unless solar- or battery-powered, and may be prone to contamination."
The research was supported by ST Microelectronics. The authors and commentator have disclosed no relevant financial relationships.
American Society of Tropical Medicine and Hygiene 59th Annual Meeting: Abstract 498. Presented November 5, 2010.
November 10, 2010 (Atlanta, Georgia) — A diagnostic tool for malaria, using Lab-on-a-Chip (LoC) InCheck (ST Microelectronics) technology, if commercialized, could allow complete and accurate test results in less than an hour.
Lead researcher Lisa Ranford-Cartwright, PhD, from Glasgow University, in the United Kingdom, reported the results of testing of this new diagnostic tool here at the American Society of Tropical Medicine and Hygiene 59th Annual Meeting.
"Current methods of [malaria] diagnosis are pretty old-fashioned," Dr. Ranford-Cartwright told Medscape Medical News. The diagnostic gold standard is microscopy, which requires a high level of expertise and experience, and even then it may not accurately detect low levels of the parasite or correctly identify the species, she said.
According to Dr. Ranford-Cartwright, the ability to determine whether the parasites infecting a patient are drug-resistant will be the "biggest coup" for clinicians. "It will effectively allow more customized treatment of each individual patient, such that they can be treated more accurately and the use of stronger drugs with adverse side effects can be avoided if possible," she said.
More accurate molecular tests, such as polymerase chain reaction (PCR), require expensive equipment and are too time-consuming, said Dr. Ranford-Cartwright. Furthermore, there are currently no tools to determine whether a given infection will be resistant to first-line drug treatments, hindering fast and appropriate clinical decisions for treatment of a disease that can kill within a matter of days.
The integrated LoC InCheck system combines PCR with a microarray-based diagnostic test that then allows the identification of the specific species of malaria parasite and detection of drug resistance. With the current technology, malaria parasite detection will now take just more than 10 minutes.
The species is identified by amplification of the 18S rRNA gene, and drug resistance is determined by amplification of polymorphic regions of genes such as the chloroquine resistance transporter and the cytochrome b gene, which typically confer resistance to common antimalarials including chloroquine and atovaquone and proguanil hydrochloride.
The new system is already being used to diagnose influenza and is being developed for a range of other diseases such as tuberculosis and SARS, said Dr. Ranford-Cartwright.
Researchers at the University of Glasgow are currently testing the sensitivity and specificity of this system in detecting malaria from a range of parasite samples with different levels of infection. They are also testing the performance of the system relative to the currently available diagnostic tools.
According to Dr. Ranford-Cartwright, the system will require the purchase of specialized equipment and single-use chips, but once established, samples can be easily tested by a technician with only minimal experience.
Once clinical trials have been completed, the technology is likely to be initially established in large city hospitals in regions where malaria is endemic, with the potential in the future to be scaled down for use in the field, she said.
Independent commentator Dylan Pillai, MD, PhD, from the University of Toronto, in Canada, noted that microfluidic platforms hold great promise. "They require very little sample, give a rapid result, and require no technical expertise on microbe recognition," he told Medscape Medical News.
"Real-time PCR has become an essential adjunct to microscopy for sensitive diagnosis of malaria," Dr. Pillai added. "The use of microfluidics miniaturizes the platform for PCR, and this [LoC] technology offers a rapid turnaround time, which may be of use in the hospital laboratory to effect quick clinical decision-making."
However, he cautioned that the cost per sample may be prohibitive for endemic settings, and that the "technology requires electrification unless solar- or battery-powered, and may be prone to contamination."
The research was supported by ST Microelectronics. The authors and commentator have disclosed no relevant financial relationships.
American Society of Tropical Medicine and Hygiene 59th Annual Meeting: Abstract 498. Presented November 5, 2010.
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