Source: Chioma Obinna

…Transmission interrupted in 10 states, but challenges persist

Despite decades of sustained effort and significant progress, over 43 million Nigerians remain at risk of river blindness (onchocerciasis), a parasitic disease that remains a leading cause of preventable blindness in Africa.

This development comes as the Federal Government, in collaboration with the Nigerian Institute of Medical Research (NIMR), announced that transmission of the disease has been interrupted in at least 10 states, including Kaduna, Nasarawa, Anambra, and Abia.

Children Under 10 Now Targeted for Final Surveillance

At NIMR’s monthly media briefing in Lagos, Dr. Babatunde Adewale, Director of Research and a leading public health parasitologist, explained that children under the age of 10 in endemic communities are now being targeted for blood sampling.

“If these children test negative for the parasite using Ov-16 antigen tests, it means transmission has likely been halted,” he said.

This testing phase is a key step in confirming whether the parasite is still being passed on by blackflies, the primary carriers of onchocerciasis.

Decades of Progress Through Ivermectin Distribution

Nigeria began fighting river blindness in the 1990s through mass drug administration (MDA) of Ivermectin, a treatment that kills the larvae of the parasite and reduces disease transmission.

The country adopted the community-directed treatment with Ivermectin (CDTI) approach, empowering locals to manage distribution themselves. This model has been credited with high coverage and sustained engagement.

“We are no longer just controlling the disease. Elimination is now within reach,” said Dr. Adewale. “By 2030, we hope Nigeria will be declared free of onchocerciasis.”

Scientific Criteria for Elimination

According to Dr. Adewale, over 37 million Nigerians have received treatment so far. For transmission to be declared interrupted, samples tested must show positivity rates below 0.1%.

Elimination involves a three-phase strategy:

1. Phase One – Interrupt transmission through treatment.
2. Phase Two – Post-treatment surveillance for 3–5 years.
3. Phase Three – WHO verification and declaration of elimination.

River Blindness and Rural Livelihoods

The disease, caused by the Onchocerca volvulus parasite, disproportionately affects rural communities, which are often dependent on agriculture and fishing.

“These communities are the backbone of our food system,” said Dr. Adewale. “Protecting their health is key to Nigeria’s food security.”

Challenges: Insecurity and Health Literacy

Despite the progress, challenges remain. Insecurity in some regions has made it difficult for health workers to access certain communities. Only Lagos and Rivers States remain officially non-endemic.

Dr. Kazeem Osuolale, a Senior Research Fellow at NIMR, emphasized the need for stronger community engagement and economic empowerment to ensure compliance and lasting results.

“Health interventions must be people-centered. People are more likely to participate when they are economically stable,” he said.

Mr. Adeniyi Adeneye, another NIMR research fellow, stressed the importance of health literacy:

“Without public understanding of disease causes and prevention, even the most expensive innovations may fail.”

The Road Ahead

With over 10 states having already halted transmission and others making strong progress, Nigeria is closer than ever to eliminating river blindness. The remaining work lies in surveillance, sustained community engagement, and reaching the hardest-to-access areas.