The Weathervane

摘要

A revolutionary method of diagnosis for malaria is pending, one that would reveal the disease long before symptoms appear. Transmitted by the anopheles mosquito, malaria infects some 207 million people worldwide. Scientists reporting in Nature Medicine found in their study they could harness magnetic sensors to diagnose the parasite in 5 minutes with better accuracy than routine microscopy. Current methods require a few drops of blood on a dipstick to get an answer in 15 minutes, but miss 17% of cases. Microscopy is more accurate, but requires training, equipment and time. In this study researchers detected parasites in blood as low as 1/5th the levels perceptible with microscopes. The device relies on the inherent magnetism in the iron-containing hemoglobin in red blood cells. The parasites invade the rbc, gorge on the hemoglobin and convert it into hemozoin that boosts rbc magnetization. The red cell reveals the parasite, according to co-author Weng Kung Peng of the Singapore MIT Alliance for Research and Technology. The diagnostic device, inspired by nuclear magnetic resonance machines, could fit in a shoebox. “With malaria, a few days can be the difference between life and death,” said co-author Peter Preiser at the Nanyang Technological University in Singapore. “If confirmed in humans, this technique could detect disease roughly two to four days earlier.”