Onchocerciasis also known as river blindness is one of the Neglected Tropical Diseases (NTDs) plaguing many worldwide.
This is most especially found in Tropical areas with its effects ranging from its adverse impact on deteriorating the health of its victims as well as negatively affecting the health sector and the economy.
According to the World Health Organisation (WHO), river blindness occurs mainly in tropical areas and more than 99% of infected persons live in 31 countries in Sub-Saharan Africa which includes Nigeria.
The Exemplars News Agency noted that Onochocerciasis is a debilitating disease that has stolen the eyesight of an estimated 120, 000 Nigerians.
Onchocerciasis is a disease that is caused by a parasitic filarial nematode worm (Onchocera volvulus) which is then transmitted by the bites of black flies (Simulium damnosum) which breed in fast-flowing rivers hence the name River Blindness.
The Tropical Disease is being spread by repeated bites from black flies common in those who live in remote African villages; mainly tropical areas.
The larvae of the parasite which can take up to 12-18 months for its development into mature adult worms in the human body can migrate into the eye and cause blindness. It can even spread into other organs in the body leading to its damage.
Research shows that about 90 million people are at risk of contracting the disease, and 17.6 million are infected including 326,000 people who have gone blind in 34 countries of the world. In Africa, it is a record of over 96 percent of all global cases.
According to the Centers for Disease Control and Prevention (CDC), worldwide Onchocerciasis is second only to trachoma as an infectious cause of blindness.
The National Library of Medicine revealed a provisional estimation of about 7 to 10 million Nigerians are infected with Onchocera volvulus and approximately 40 million are at risk of the disease.
Symptoms of the debilitating disease on infected persons may include; severe itching and various skin changes and disfigurement. Some infected persons can develop eye lesions which can lead to visual impairment and permanent blindness.
It can also cause permanent skin damage and blindness when it is left untreated for a long time, this can increase mortality rate.
Abel Eigege, Program Director for The Carter Centre in Nigeria for the past 25 years, elaborated on the prevalence of the disease; “It was a daunting challenge that had plagued our forefathers for generations”.
The National Coordinator, Neglected Tropical Disease, Federal Ministry of Health, Prof. Fatai Oyediran, noted that among all NTDs, Nigeria has the highest burden of Onchocerciasis globally.
“Onchocerciasis is transmitted through repeated bites of this infected black fly and over 50 million Nigerians and about 40, 000 communities in 32 states and FCT are at risk.
“Onchocerciasis remains the second most common cause of infective blindness after glaucoma. Nigeria has the highest burden of Onchocerciasis in the world,” he explained.
There has also been a misconception of River blindness and Yellow fever. However, the latter is different.
Yellow Fever is a hemorrhagic condition transmitted mainly by mosquitoes (mainly Aedes and Haemogogus). Unlike Onchocerciasis, Yellow Fever does not thrive in tropical areas but rather in jungle-like areas.
Symptoms of yellow fever include; high fever, damaged cells, liver, and kidneys. Others include albuminuria, hemorrhage, bleeding, vomiting, dizziness, headache, and jaundice which gives the shin and white sides of the eaters a yellow color.
However, one difference between yellow fever and river blindness is that despite the yellow patches on the eyes of patients suffering from yellow fever, it doesn’t affect their sight.
In the case of river blindness, if left untreated for a while, it spreads into the eyes causing blindness which would then require eye surgery such as glaucoma surgery or cataract surgery which would be needed to restore vision.
Researchers and medical experts, just as the Centre For Disease Control and Prevention (CDC) think that there seems to be no vaccine or recommended drug available to prevent the disfiguring disease hence, some people do not have access to them.
Furthermore, studies from the National Library of Medicine of the US National Institute of Health (NIH) show a positive association between subclinical onchocerciasis and glaucoma. Onchocerciasis infection, even in the absence of ocular onchocerciasis, is a potential risk factor for the development of glaucoma. Furthermore, patients with advanced ocular changes from onchocerciasis have an increased prevalence of glaucoma.
However, the World Health Organization (WHO) recommends that infected patients treat Onchocerciasis with ivermectin at least once yearly for 10 to 15 years.
WHO also advised that one of the most effective ways of battling the disease is by adopting preventive measures which suggested avoiding being bitten by infected black flies on exposed skin, wearing long sleeve shirts and pants (wearing permethrin-treated clothing) as well as keeping the environment clean and healthy so that there are no breeding places for parasitic black fly to thrive.
Medical experts are also urging members of the general public to raise alarm if strange symptoms are seen and infected persons should also seek medical attention with no hesitations so that the disease can be eradicated from our society.
