A rapid malaria test kit that could aid diagnosis in developing countries

Close-up of the prototype of NTU's rapid malaria test kit. Credit: NTU SingaporeThe test kit was developed by scientists at Nanyang Technological University (NTU Singapore). It delivers results within 30 minutes. This kit is expected to make it easier to diagnose malaria in the field. It's lightweight, portable, and easy to use.According to the World Health Organisation (WHO), malaria affected an estimated 229,000,000 people in 2019. In 2019, 409,000 people died from the disease transmitted by mosquitoes in 87 countries.High costs and a lack of infrastructure make it difficult to control and treat malaria in rural areas and developing countries. Although rapid diagnostic tests (RDTs for malaria) are not able to detect the early stages of the disease and can produce false positive or negative results, they can be used to diagnose the condition. They cannot also determine the severity of an infection.Associate Professor Liu Quan from NTU's School of Chemical and Biomedical Engineering led the study. He said that the kit was able to detect the presence of malaria even when there are very few parasites, particularly in the early stages of disease. It can also quantify parasite counts in each test, which allows doctors to track their patients' progress with fighting the disease."We hope that this will help with malaria elimination and control. Our test had one goal: to decrease the dependence on laboratory equipment for malaria detection. This is an important step towards diagnosing malaria in the field. Our goal was to find a tool that could be easily produced and accurate enough for quick screening.Dr Clement Yuen (Research Fellow at NTU's School of Chemical and Biomedical Engineering), holding a prototype of the rapid-malaria test kit. He was part the team of scientists that created the kit, led by Assoc Prof Liu Quan. Credit: NTU SingaporeLaurent Renia (Director of the Respiratory and Infectious Diseases Programme, NTU's Lee Kong Chian School of Medicine), who wasn't part of the study, assessed the test and said that the NTU test kit would fill the gap in the detection of malaria. It is sensitive, accurate, quick, and inexpensive. The test kit could be used by malaria specialists who are working remotely, or those without access to laboratory equipment, as it is easy to use and can be carried out without any training.In May, the study was published in Sensors and Actuators B. Chemical. NTU's team filed a patent application to protect their technology on top of an existing patent they had obtained in 2017.The key to the test's success is digested bloodThe current international standard for diagnosing malaria parasites in blood is still microscopic examination. This requires expertise and microscopes, which are often not readily available in rural areas or in countries with malaria-endemic populations.Researchers could be less dependent on expensive laboratory equipment by using the made-in-NTU kit. It would only need a sample of blood and water to function (see Image 1). The kit detects hemozoin, which is a byproduct of the malaria parasites' digestion of blood, and it provides a unique indicator of disease.To force the parasites out of red blood cells, mix ten microlitres (which is less than one drop) of patient's blood with water.The test kit contains a pump that draws in blood to make it contact with chemical patches. This causes hemazoin light up. A detector known as a Raman spectrumrometer detects the flashes of light and determines if there is an infection.The researchers infected human blood with malaria parasites to validate the accuracy and reliability of the test kit. This test can detect early stage parasites at levels of 125 parasites in a microlitre of blood. This is higher than the current rapid diagnostic tests.According to the researchers, each test would be approximately US$1 per device. This would allow for low-cost field testing at large scales.The team is looking for an industry partner and will conduct more trials on the malaria test kit in order to improve its functionality and sensitivity.Continue reading Magnetic attraction: A breakthrough test for malariaClement Yuen and colleagues, Towards malaria diagnosis based surface-enhanced Raman scattered with on-chip sample prep and near-analyte nucleote synthesis, Sensors & Actuators B : Chemical (2021). Clement Yuen and colleagues, Towards malaria diagnosis based upon surface-enhanced Raman scattered with on-chip sample prep and near-analyte synthesis. (2021). DOI: 10.1016/j.snb.2021.130162