In Africa, the spread of parasitic worms known as Loa loa is seriously hindering the efforts of health care workers to cure particular, rampant diseases. Though there are drugs available to treat both river blindness and lymphatic filariasis, if they are administered to a patient who also happens to also be infected with Loa loa the consequences can be lethal. This is complicated further by the inherent difficulties in screening for the worms, but a newly developed mobile phone microscope needing only a drop of blood to automatically detect the parasite promises to make things a whole lot simpler.

For years, a team of researchers at the University of California Berkeley has been refining the CellScope, a mobile phone attachment that repurposes the device as a clinical-grade microscope. The team even recently branched out and launched a commercial product called Oto Home, a cell phone attachment that enables parents to perform ear exams on their children at home.

The group's latest offering is dubbed CellScope Loa. It comprises a 3D-printed plastic base fitted out with LED lights, microcontrollers, gears and a USB port. Sliding a smartphone into the base and loading it with a single drop of blood, users can conduct an analysis of the sample in around two minutes.

Over Bluetooth, the purpose-built app communicates with the base, running the sample in front of the phone's camera and creating a video. An algorithm then processes the footage, searching for the wriggling worms in action and displaying the total count on screen.

"We previously showed that mobile phones can be used for microscopy, but this is the first device that combines the imaging technology with hardware and software automation to create a complete diagnostic solution," says Daniel Fletcher, professor of bioengineering at UC Berkeley who pioneered the CellScope. "The video CellScope provides accurate, fast results that enable health workers to make potentially life-saving treatment decisions in the field."

The difference could come in an improved ability of health care workers to determine appropriate courses of action when dealing with patients. River blindness spreads throughout populations through the bites of blackflies, and according to the World Health Organization caused blindness in around 50 percent of males in West African communities. Lymphatic filariasis is spread by mosquitos and causes massive swelling in different parts of the body and a disease known as elephantiasis. Both are highly endemic in parts of Africa.

An antiparasitic drug called ivermectin is effective in treating these conditions, though not if patients happen to be infected with Loa loa worms. If levels of Loa loa are high in the patient, the ivermectin can cause severe or even fatal brain damage. What makes CellScope Loa promising is the ability for those on the ground to scan for these worms without needing to lug samples back to the lab. Current detection methods involve a blood smear and lab technicians manually counting the worms under a typical microscope.

The team has carried out a pilot study with CellScope Loa in Cameroon, where workers are trying to tackle river blindness and lymphatic filariasis. It was found that it was able to detect the parasitic worms with accuracy equal to conventional methods.