Children suffering from intestinal worms can now be diagnosed using a mobile phone microscope that is significantly cheaper than conventional methods, which are prohibitively expensive for many people.
The microscope costs around US$15 and runs off the phone’s battery, whereas a conventional light microscope costs US$200 and requires electricity in most countries.
To build the microscope, scientists transformed an iPhone 4S mobile phone into a microscope by temporarily mounting a 3-millimetre ball lens to the camera, using double-sided tape to hold it firmly. A US$8 ball lens was positioned in a small hole punctured in the middle of the double-sided tape.
They then placed the mobile phone microscope on top of the slide, which was illuminated from below by a small flashlight. Images were viewed on the mobile phone screen, and magnification of up to 60 times was enabled using the digital zoom function.
Scientists from Canada, Switzerland, Tanzania and United States, used the microscope to evaluate stool samples from almost 200 children in Pemba, Tanzania, alongside conventional light microscope to measure the efficacy of different intestinal worm treatments.
A study published in the American Journal of Tropical Medicine and Hygiene reports that the accuracy of the mobile phone microscope varies depending on the worm type and infection intensity. The microscope was found to detect 69.4 per cent of helminth eggs, 81 per cent of giant roundworm infections and 14 per cent of all hookworm infections.
“It is 70 per cent accurate but we think it can be up to 90 per cent,” says Isaac Bogoch, an infectious disease specialist at Toronto General Hospital, Canada, and the study’s lead author. The study reports that the microscope will only be of clinical standard when it is sensitive enough to detect 80 per cent of infections.
“It was quite successful at detecting moderate to heavy infections but not very good at detecting mild infections where there might be only a few eggs in the sample,” Bogoch adds.
However, the researchers are confident the technology could be a valuable and popular tool for regions where intestinal worm infestation is widespread, due to it being easy to make, portable and cheap.