Smart phones are transforming the way that people communicate throughout the world. Now scientists are using them in an innovative way to help diagnose intestinal worm infections in school children living in rural Tanzania.
The scientists have developed an inexpensive microscope using a glass lens costing $8 USD, a strip of double-sided tape, and a cheap flashlight – altering an iPhone 4s into a device that can detect intestinal worm infections; parasites that infect two billion people and result in malnutrition.
Isaac Bogoch, MD, an infectious disease specialist at Toronto General Hospital and the study’s lead author explained:
“There’s been a lot of tinkering in the lab with mobile phone microscopes, but this is the first time the technology has been used in the field to diagnose intestinal parasites.”
The scientists’ findings were published in the American Journal of Tropical Medicine and Hygiene, and evaluated 199 stool samples of children using their unique device.
Along with a standard light microscope the researchers examined the samples with the cell phone microscopes and a regular laboratory slide. The kids participating in the trial on Pemba Island, Tanzania, were undergoing different treatments for eliminating intestinal worms.
Scientists first covered the slide in cellophane, then used the double-sided tape to attach it to the camera, lit it from underneath with the flashlight and finally took a picture.
The iPhone microscope was found to be not as sensitive as a light microscope, however, the scientists believe that with some changes it will come close. Bogoch commented, “We think cell phone microscopes could soon become a valuable diagnostic tool in poor, remote regions where intestinal worms are a serious health problem, particularly in children.”
The cell phone microscope sensitivity was dependent on the type of worm and the strength of the infection.
For example, the cellphone found 81 percent of infections of giant roundworm (A. lumbricoides) and 54 percent of roundworm infections (T. trichiura ). But, it only detected 14 percent of all hookworm infections; the researchers say that this is due to the much smaller number of eggs present than with the other parasites.
“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 said.
Worms that infect the intestines, such as roundworms and hookworms – or soil-transmitted helminths – harm nearly two billion people worldwide. In isolated, poor regions of developing nations rates of this disease are particularly high and can result in chronic malnutrition and anemia in kids.
Bogoch and his team aimed to find an alternative tool by taping a 3 millimeter ball lens to the camera of Bogoch’s Apple iPhone 4S – one he already owned. However, the researchers noted that any phone that has a camera with a zoom option could work effectively. Ball lenses are normally used in the telecommunications field in couplings for optical fiber cable. They are inexpensive – generally $8 to $10 USD.
Instead of an electric light, they used a small flashlight that just needs a single battery for many hours of operation. The entire set-up can be developed for $15 USD, in addition to the cost of the phone, and can be assembled in five minutes.
The authors believe that the “mobile phone microscope would likely be of clinical use when it is sensitive enough to detect 80 percent of infections,” and note that even now there are new developments underway to improve the current cell phone microscopes.
Bogoch said, “I’m confident that in the near future we will see cell phone microscopes widely used in low-resource settings. They’re easy to make, portable, and today, you can find mobile phones with cameras even in some of the most remote regions in the world.”
The cell microscope can be used for treating and diagnosing people with worm infections as well as observing the prevalence of disease amongst the broader population.
One example could be when administering drug treatment to large populations. Cell phone microscopes could serve as cheap and effective tools to calculate the effectiveness of these mass drug administration campaigns.
David H. Walker, MD, president of the American Society of Tropical Medicine and Hygiene said:
“I have nothing but praise for the ingenuity of scientists using all available tools to solve pressing health problems in some of the poorest parts of the world. This study is an illustration of how a modest investment in tropical disease research can help reap enormous health benefits for children.”
Written by Kelly Fitzgerald