Smart phone video microscope for detecting parasites

Nature : Smart phones may become useful medical tools in Central Africa, where many people live in remote locations far from medical facilities. One major diagnostic problem involves several deadly blood-borne parasites. Two parasitic nematodes, Onchocerca volvulus and Wuchereria bancrofti, can be readily treated with a drug called ivermectin. However, if a third parasitic nematode, Loa loa, is also present, ivermectin can cause life-threatening side effects. Now Daniel Fletcher of the University of California, Berkeley, and his colleagues have developed a smart phone–based microscope for detecting the presence of L. loa. Unlike other smart phone microscopes, the new device does not require conventional sample preparation and staining. Rather, a blood sample from a finger prick is collected in a small glass capillary, which is loaded into the device, and an app magnifies it and takes video. Then an algorithm looks for movements in the fluid that match those of L. loa. By being able to quickly and efficiently exclude patients with L. loa, medical professionals will be able to safely administer ivermectin to those infected with the other parasites. The device could also be modified to diagnose other parasitic infections, says Fletcher.