Intestinal parasites are transmitted through contact with infected feces, which can lodge in the soil and spread though poor sanitation.

The study was published this week in the American Journal of Tropical Medicine and Hygiene. It was conducted by scientists from the United States, Switzerland, Tanzania and Canada.

First time in the field

This is not the first time scientists have converted a smartphone into a microscope, but past experiments have been limited to the lab, Bogoch said.

Two years ago, scientists at the University of California, Davis improvised a microscope using an iPhone.

They inserted a small ball lens into a rubber sheet, which they taped over the smartphone's camera.

At the time, researchers said they planned to validate the device for use in the field.