By Greg Porter
In 1944, a young British military doctor – Harold Ridley – set out to make a statement to the medical world. A small man with a round face and circular glasses, Harold spent 18 months stationed in Ghana, where he traveled to remote areas investigating river blindness (also known as onchocerciasis), a disease little known to the international scientific community at the time.
Harold set forth his argument that while the international community was focussing on trachoma, there was another disease, all-consuming of the eyes, which may affect up to 1 million people, and so far had gained no interest from the medical community.
“If every ophthalmic surgeon (eye surgeon) were asked to record a vote for worst infection of infestation of the eye, there is little doubt that trachoma would head the list,” Ridley declares in his opening sentence of this now infamous report. He goes on to argue, “Though onchocerciasis is widely endemic in the major part of the British Colonial empire, it has excited only the barest interest amongst British ophthalmologists.”
After detailing the life cycle of river blindness that causes severe itching and irreversible blindness, Ridley optimistically declares that science shall overcome this parasite, “it is inconceivable that, in the end, science will be defeated by a filaria”.
The hubris of scientific thinking during the early 20th century did not foresee the complexities of an actual disease elimination program. But now, 80 years later, after fly control campaigns, medicinal breakthroughs, and hundreds of thousands of people working together, Niger is on the cusp of becoming the first country in Africa to achieve WHO verification of river blindness elimination. Science, perseverance and compassion have won out.
Watch a two part series examining how Niger came to this point
“You look at all the years that onchocerciasis control has been going on in Africa and you aren’t seeing success. Sometimes It was a bit disheartening and it looked like you weren’t doing enough,” admits Dr. Daniel Boakye in the END Fund’s new short film about Niger’s road to elimination.
Daniel, a senior technical advisor at the END Fund, has been working to eliminate river blindness for more than 50 years, and has seen each stage of the process. In the 1970s, Niger made its first attempts at mapping the disease, finding that 70 percent of the population was living with the parasite. While not everyone with the parasite would go blind, the findings meant that a large portion of the population was at risk of losing their sight or would experience unrelenting, chronic itching.
With no known treatment, the Onchocerciasis Control Program had to turn to ‘vector control’, which meant trying to kill the flies that carry the disease from one human to another. The program would regularly spray the rivers with larvicide, which led to a rapid reduction in the spread of the disease.
In 1987, the pharmaceutical company Merck decided to donate a new drug found to be effective for river blindness – ivermectin – now the standard treatment against the disease. It continues to donate the medicine to other countries today.
“Ivermectin gave a lot of hope to the country,” says Dr. Salissou Adamou Batchiri, Niger’s national coordinator for lymphatic filiariasis and onchocerciasis. “The use of helicopters (for larvicide treatments)… are very expensive. We had to find an alternative strategy…We have to think about extending it to the whole of Africa, because the disease was rampant throughout Africa.”
The combination of medicine and vector control in Niger reduced the prevalence down to 0.02% by 2002. The economic and health benefits from such a radical reduction were already being felt. A recent report concluded that the success of the program added $2.3 billion USD to Niger’s economy. Since there was a reduction in blindness, people who would have had to leave the workforce to care for a family member could continue working, adding nearly 18 billion working hours, boosting GDP.
When Daniel traveled with a team to document Niger’s success, the benefits were evident. They wanted the perspective of someone who had gone blind from the disease. However, by the 2020s, finding anyone blinded by the disease was a difficult task. The team finally found Nassar Banga, the only blind person in his village. His experience served as a stark reminder of the necessity to ensure this disease does not bounce back.
“I am the only one in my village to become blind,” Nassar told us, “Since going blind I cannot go anywhere, I cannot travel. I am always just sitting in the same place. My life has been nothing but suffering.”
In the early 2000s, Niger’s government needed to continue treating people. In 2012, it cost nearly $3 million USD. Although costly, without verifying the elimination of the disease, the risk of resurgence was too high.
As evidence mounted that Niger had successfully eliminated transmission of river blindness, the task moved into the next stage: scientifically proving it.
However, there was no facility that could process all of the samples needed to prove the elimination. After building a facility and training staff, the country was finally able to collect samples and test children. After testing 16,000 children, they found a stunning zero cases of infection.
“Imagine already in the 16,000 children from five to nine years old, no infection was found,” Dr. Salissou recounts.
“I felt proud for those who were living on the ground and still afraid. Because those who have lived with the disease until now, as soon as they have a red pimple or as soon as they get bitten by an insect, they think that it’s the disease that’s there. I am proud to go back and tell them, ‘You can sleep well today. There is no longer the infected fly that can give you onchocerciasis. Onchocerciasis blindness is over.’”
Niger has officially submitted its dossier to the WHO for verification of onchocerciasis elimination. This elimination will mark a significant milestone in plan to eliminate neglected tropical disease set by the WHO’s NTD 2030 Roadmap. Niger will act as a blueprint for more countries in the region to achieve elimination and ensure that generations can live without the fear of river blindness.
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