Recently, the Premium Times, a Nigerian news source, reported on a potential health crisis facing up to 50 million Nigerian citizens: onchocerciasis, or river blindness. Onchocerciasis is considered a “neglected tropical disease” (NTD), conditions that are typically present in areas where residents may not have access to fresh water or adequate waste disposal. While the country does have a strategy to address this disease, Michael Igbe, the Program Manager for the Federal Ministry of Health’s National Onchocerciasis Elimination Program, suggests that there are still numerous roadblocks inhibiting the program from being successful.

Igbe’s Concerns

During his discussion, Igbe shared the struggles of addressing neglected tropical diseases. According to the Research Center for Neglected Diseases of Poverty, NTDs are:

a group of infectious, mainly chronic, debilitating and often stigmatizing diseases that primarily afflict the poorest of the poor, living in remote rural and deprived urban settings of tropical and sub-tropical countries. The most common NTDs include ascariasis, trichuriasis, and hookworm infection (600-800 million cases), schistosomiasis, lymphatic filariasis and onchocerciasis (>300 millions), and trachoma (100-200 million), food-borne trematodiases including opisthorchiasis (50 million), and leishmaniasis and Chagas disease (20-40 million).

In Nigeria, the Community Directed Treatment with Ivermectin (CDTI) program was put into place for treating patients with onchocerciasis. However, Igbe discusses that logistical issues, funding problems, and government insecurity all played a role in the difficulty of implementation. With so many people now at risk of harm, addressing and fixing these problems will be crucial to combatting the spread of onchocerciasis and other NTDs.

Onchocerciasis

Also known as river blindness, onchocerciasis is a NTD caused by a parasitic worm called Onchocerca volvulus. The parasitic worms are carried around by blackflies. Then, when a blackfly bites a human, it deposits Onchocerca volvulus larvae into the bitten site. Next, the larvae mature inside of the human, causing a host of physical issues. It is possible to be bitten more than once, with disease severity increasing with each bite. Interestingly, it is female blackflies that pass along the larvae. Once the worms are mature, they can live for up to 10-15 years and produce additional larvae. Treatments, like ivermectin, are needed to kill the larvae. Only then will symptoms stop.

In 2017, an estimated 20.9 million people had onchocerciasis, with a majority of cases localized to Africa. However, this disease is also common in South America and Yemen. Symptoms typically appear within 12-18 months of being bitten, and include:

• Pruritus (extreme itching)
• Eye lesions
• Skin rashes or bumps under the skin
• Thin and brittle skin
• Light sensitivity
• Cataracts
• Visual impairment and eventual blindness

Learn more about onchocerciasis.