While the United States is struggling with chronic diseases like diabetes and heart disease, Sub-Sahara Africa is trying to eliminate neglected tropical diseases like river blindness. Also known as onchocerciasis, river blindness is both preventable and treatable as long as it is caught early. Sightsavers, a UK based non-profit, provides humanitarian aid to these regions to uplift communities and provide public health solutions for a treatable problem.
The tiny worms (Onchocerca volvulus) that cause river blindness, hitch a ride inside a Simulium black fly, a “vampire bug” commonly found in high numbers near fast flowing tropical rivers. An up-close, electron microscope scan of the mouth parts of these flies is enough to make anyone who has ever been bitten by a biting insect cringe. When black flies bite humans, they first forcefully spread the skin thin with their jaw as this makes it easier to pierce. They then use their razor sharp proboscis to penetrate down to the subcutaneous layer of the skin to draw a pool of blood. Then, as they siphon the blood, the nematode larvae that cause River Blindness are deposited into the deeper layers of skin and the bloodstream through their saliva.
One bite from a Simulium black fly is all it takes to develop River Blindness, a devastating disease if untreated. Symptoms start out as severe itching, as the larvae grow into adult nematodes. Unfortunately, the adults then multiply more rapidly than fruit flies. In fact, a female Onchocerca nematode can produce more than a thousand larvae daily! It is also common for hands and limbs to swell and for the skin to become blotchy and depigmented. As the Onchocerca larvae migrate to the eye and become embedded there, they cause eye problems and blindness in three primary ways:
1. Damage To the Cornea
The cornea is the clear protective layer on the outside of the eye. If it becomes scared by the nematodes, eye sight will be impaired and the person could go legally blind if the scarring is severe. The only way to fix this is a cornea transplant.
2. Damage to the Middle Eye
The middle part of the eye contains a drainage system. If too much pressure is exerted in this section of the eye, a person may develop glaucoma. Surgery can sometimes help by relieving some of the fluid pressure.
3. Damage to the Retina
The retina is the layer in the back of the eye that captures light signals and passes these along to the brain for interpretation via the optic nerve. Damage to the retina can cause permanent irreversible blindness.
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The spread of River Blindness affects Sub-Saharan African villages in many ways. If parents contract the disease, they often can no longer work to feed their family. Children have to drop out of school to do the work and care for their parents. Those afflicted by River Blindness are often ostracized as well. In many spots along the rivers where villages once thrived, the outbreak of river blindness is so severe, entire villages have been forced to move.
Sub-Saharan Africa is currently home to more than billion people, most of whom are impoverished, and the majority make a living through subsistence farming. Unlike western populations, where people concentrate in industrialized cities because that’s where work is available, Sub-Saharan Africans mostly live in small villages with few hospitals and little to no medical care. More importantly, their subsistence farms and homes must be located near rivers where the soil is more fertile for farming and where they can fish.
So, rivers and the surrounding river valleys become the heartbeat of life in these Sub-Saharan African villages. When the threat of River Blindness forces the subsistence farmers, who have little to begin with, away from these life giving river areas, it drives them even deeper into poverty! An outbreak of River Blindness can force communities into areas where it is nearly impossible to support individuals and families. Sometimes these situations become so dire starvation may become a factor.
Sightsavers is a charity that has been working hard to reduce River Blindness in Sub-Saharan Africa. They have now set as their mission to completely eradicate River Blindness and other neglected tropical diseases that are preventable and treatable if the proper medication is available and people are educated about the disease. Sightsavers’ volunteers and staff are driven by the fact that River Blindness has already been eradicated in other parts of the world, including Ecuador and Mexico.
One of the main ways Sightsavers is reducing, and hopefully eliminating, River Blindness is by administering a medicine called Mectizan. This comes in tablet form and is a potent anti-parasitic agent developed by Merck. Mectizan kills the nematode that causes the disease. This helps ease symptoms like severe itching, reduce the effect of the disease, and in some cases, cures the disease if it is caught early enough. Reducing the parasites in affected people also helps to stop the spread of the disease as black flies go from human to human.
In some cases, Sightsavers has been instrumental in surgically removing the skin and muscle nodules containing the adult nematodes that can continue to live and produce larvae for up to fifteen years. Since River Blindness is caused by such a endurant parasite, people must take the medication twice a year for many years. So, a public health operation dedicated to these types of diseases must have a long term life- as the Sightsavers program has been. Sightsavers has also been instrumental in glaucoma surgeries and in cornea transplants but the bulk of their work is centered around distributing the Mectizan, which has become a medical miracle in Sub-Saharan Africa and other tropical places with this disease.
Sightsavers has many partners so these medical miracles are truly a collaborative effort. Bill and Melinda Gates have made large donations from their foundation. Merck Sharpe & Dohme provide the Mectizan medication for free. Citizens from the UK had their Sightsavers donations matched by their government through the Department for International Development’s Aid Match program.
Sightsavers also trains volunteers in risk Sub-Saharan African villages to help distribute the medication and educate members of their own village. This happens during the months of April and October. The volunteers use a “dose pole” to measure the height of the villagers to determine how many tablets they should take. These poles are often decorated with bright colors and patterns and has become a symbol of this medicinal miracle. The kids especially like to get their height measured by the dose pole and take the medicine.
Everyone who receives the humanitarian aid from Sightsavers and their partners benefits from the opportunity to live health lives. The older people who have been affected by the disease try to help teach the kids in their village why they need to take the medicine, breaking down public health barriers and changing village culture. The local DJs send out radio broadcasts about the program in multiple languages to keep everyone informed, especially any new residents in the area who may not know about the disease and why it’s so important that everyone is protected. For the program to work, they need need cooperation from entire villages and a coordinated team effort to start eradicating River Blindness entirely.
The Sightsavers’ program for River Blindness is already being called a medical miracle, and a triumph human success story. Sightsavers is determined to keep the program going for as long as it takes to be completely eradicate the disease and uplift communities in need.
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