A new mobile iPhone application developed by UC Berkeley undergraduates is promising to overcome a roadblock in the treatment of river blindness in rural African communities.

River blindness is caused by the parasitic worm onchocerca volvulus, which is transmitted to humans by blackfly bites. River blindness has a high incidence rate near fast-flowing streams in tropical climates, with 99% of cases occurring in Africa, and 1% in Latin America and Yemen, where experts speculate the fly migrated with the slave trade centuries ago. The disease is termed “river blindness” due to the effect the parasite’s larvae (microfilariae) have on their human host: if left untreated, the microfilariae migrate to the skin and eye, where human immune response is somewhat limited. The microfilariae can lacerate the cornea, over which scar tissue forms to eventually cause permanent blindness.

As the second leading cause of infectious blindness, river blindness has a devastating impact on local communities, often forcing migration from fertile land. Local communities face a trade-off between productivity and susceptibility. The World Health Organization estimated that in the 1970s, river blindness cost communities $30 million in potential economic opportunities.

While somewhat correlated with geographic location, the relatively high incidence of river blindness in Sub-Saharan Africa is a result of poor health infrastructure in rural agricultural areas that cannot provide thorough prevention and treatment programs. Many blackfly bites are in fact needed to cause infection, indicating that diligent community interventions can curb parasitic transmission. By partnering with pharmaceutical giant Merck to distribute the drug Mectizan (which kills the parasite’s larvae), the Carter Center spearheaded a successful campaign to eliminate river blindness in Colombia, and is currently working in Ecuador, Brazil, Venezuela, Uganda, Sudan, Ethiopia and Nigeria.

However, treatment and prevention campaigns were suspended in some communities after ivermectin (the generic label for Mectizan) was found to harm patients who were also infected with another parasite, commonly known as Loa loa, or African eye worm. Similar to the onchocerca volvulus, Loa loa is transmitted via deerflies found in the rainforests of West and Central Africa and can also cause blindness. Ivermectin administered in patients with high Loa loa levels (exceeding 30,000 per milliliter of blood) can potentially lead to severe or fatal brain damage.

In order to quantify the prevalence of Loa loa parasites in a patient and determine their eligibility for ivermectin treatment, laboratory technicians traditionally counted them manually in blood samples—a technique not conducive to use in the field or in mass treatment campaigns, such as those led by the Carter Center. By drastically improving the efficiency and accessibility of Loa loa screening, however, the new iPhone app CellScope Loa, promises to increase the reach of river blindness treatment and prevention programs.

Born from an optics class project in 2006 by a group of undergraduate students at UC Berkeley, the mobile phone application was first developed by UC Berkeley’s Fletcher Lab in 2009. A $400,000 project to expand its global health application was later funded by the Bill & Melinda Gates Foundation, UC Berkeley Blum Center for Developing Economies, USAID, and the National Institute of Allergy and Infectious Disease (NIAID). Thomas Nutman, the head of clinical parasitology at the National Institutes of Health and a bioengineering professor at UC Berkeley, led the team of UC Berkeley engineers at the Fletcher Lab to design CellScope Loa.

CellScope Loa is breaking ground in the field of mobile imaging technology because it uniquely combines hardware and software to provide point-of-care testing. The hardware—a 3D printed plastic base, microcontrollers, gears, circuitry LED lights and a USB port—captures images of the sample, while an algorithmic software analyzes the “wiggling movements” observed to determine the prevalence of the parasite. CellScope Loa is more accurate than laboratory testing, which was more vulnerable to human error. The entire testing process also takes about three minutes: one minute to obtain a blood sample via finger prick, and two minutes for the microscope to analyze the sample using motion testing.

Their initial testing of 33 patients in Cameroon yielded zero false negatives and two false positives; Fletcher and Nutman are taking 15 devices back to Cameroon this summer to test 40,000 more patients. If successful, CellScope Loa would mark a significant stride in mobile health technology, which is shifting the approach—and increasing the impact—of public health initiatives. Although its applicability is somewhat limited to motion-sensing tests (versus tests for antibodies that diagnose other infectious diseases, such as hepatitis B), CellScope Loa can also be used to guide ivermectin treatment of lymphatic filariasis, or elephantiasis, and may have future applications in tuberculosis and malaria testing.

Jacqueline Fedida

Sources: Bloomberg News, The Carter Center, Science of Translational Medicine, UC Berkeley, Washington Post
Photo: Bloomberg

Taking Steps to Eliminate River Blindness
The Carter Center in Atlanta is working to make the eradication of river blindness a worldwide goal for the World Health Organization (WHO), as the WHO determines which diseases will appear on the world health agendas.

River blindness is caused by a parasite that is spread through the bites of black flies. The flies breed in and near fast flowing rivers, which is where the disease gets its name. The larvae of the parasite causes skin irritation, itching and a range of eye diseases, including blindness in the worst cases.

People in 36 countries are at risk for contracting river blindness. About 99% of the 17.7 million cases of larvae infection are from Africa. Nigeria is the most endemic country in Africa, with reportedly half of the world’s cases.

That is why Nigerian businessman Sir Emeka Offor gave the Carter Center $10 million to aid to eliminate river blindness in his home country. This is on top of the quarter million he donated several years back. This is a huge turning point in dealing with the disease.

The Carter Center has been working with the Nigerian Health Ministry for twenty years. The program uses community-based health education and administers the only drug that can treat river blindness, Mectizan. In fact, the company that makes Mectizan made a commitment to donate the drug until every case of river blindness is solved. The donation from Sir Offor means that the Carter Center can reach more people, especially those in difficult areas to reach. Coverage will increase, meaning that the Carter Center will be closer to reaching their goal of eliminating river blindness by 2020. In 2014, 7 million Nigerians were treated.

The Carter Center has already been successful in Latin America. Colombia was the first country to be declared free of river blindness in 2013, with Ecuador following  in 2014. Both Guatemala and Mexico are currently going through the verification process to be declared river blindness-free by the WHO. The only areas left to treat are hard-to-reach areas of the Amazon in Venezuela and Brazil.

If the Carter Center can prove with this latest donation that their program is successful in the most plagued country, Nigeria, on top of their success in Latin America, then the WHO will be more likely to join the movement and target river blindness as a disease to fight.

– Katherine Hewitt

Sources: AP News, Carter Center 1, Carter Center 2, Inside Philanthropy
Photo: GHIF

tropical diseases
Neglected tropical diseases
are diseases that are either bacterial or parasitic and infect around one in six people around the world. Over half of a billion children are infected with these diseases.

These diseases are considered “neglected” because they do not receive very much attention or funding from governments or medical communities around the world.

These diseases tend to be especially widespread in areas with high levels of poverty, bad sanitation and poor access to health care. These diseases tend to especially affect women and children.

While they are grouped together, neglected tropical diseases can be very different from one another. Some kill quickly while others will infect for years or simply harm, but not kill, their victims. Some are parasitic, caused by parasites, and spread through mosquitoes, snails or flies. Others are bacterial and are spread through water or soil.

Treatments for these diseases also vary. Some have cheap treatments available (although this could potentially lead to drug resistance), others have no treatment or a very expensive or difficult treatment.

According to the World Health Organization there are 17 neglected tropical diseases. Here is a brief description of the seven most common neglected tropical diseases. These seven diseases account for 90 percent of global cases of neglected tropical diseases.

1. Ascariasis (roundworm) is the infection of the small intestine that is caused by a roundworm. The eggs of the roundworm are often ingested and the eggs then hatch in the person’s intestine. They then reach the lungs through the bloodstream. The worms can grow to be longer than 30 centimeters. Roundworm causes about 60,000 deaths each year.

2. Trichuriasis (whipworm) is spread and moves through the body like roundworm. Around the world about 700 million people are infected with whipworm.

3. Schistosomiasis (snail fever) is caused by parasitic worms. A person can become infected by coming in direct contact with contaminated fresh water. Over 200 million are infected with snail fever around the world.

4. Lymphatic filariasis (elephantiasis) is transmitted through mosquitoes and damages the lymphatic system causing painful, visible disfigurations. More than 120 million are infected around the world.

5. Trachoma is an infection of bacteria in the eye, causing the yield to turn inwards, eventually resulting in blindness. Six million people are blind due to trachoma.

6. Onchocerciasis (river blindness) is a parasitic disease caused by flies that carry larval worms that grow to cause blindness, lesions and loss of pigmentation in the skin.

7. Hookworm is spread and moves through the body like whipworm and roundworm. Around 600 million people throughout the world are infected with hookworm.

Although neglected tropical diseases affect millions, they are relatively inexpensive to treat: for around 50 cents a year, one person could be treated and protected for all of the seven most common neglected diseases.

– Lily Tyson

Sources: Reuters, Global Network, CDC, WHO
Photo: EndTheNeglect