Onchocerciasis, also known as river blindness, is a parasitic infection caused by the worm Onchocerca volvulus. It is spread through the bites of infected blackflies of the species Simulium. This neglected tropical disease mostly affects people in Sub-Saharan Africa and parts of Latin America, especially in rural and remote locations with little access to healthcare and resources. Onchocerca volvulus' life cycle begins when an infected blackfly bites a human host, sending microscopic larvae known as microfilariae into the skin. These larvae develop into adult worms that can survive in nodules under the skin and deep connective tissues for up to 15 years. The female worms expel millions of microfilariae, which spread throughout the body and cause a variety of illnesses. Onchocerciasis is distinguished by extreme itching, particularly on the skin where the adult worms live. Repeated infections can cause skin changes such as thickening, depigmentation, and the growth of nodules over time. The transfer of microfilariae to the eyes, however, has the most damaging effect. These parasites can inflame and destroy the eye tissues, resulting in vision impairment and, in severe cases, irreversible blindness. Because it frequently happens in communities living near rivers where blackflies spawn, it is known as "river blindness." Controlling the blackfly population through vector control programs that include insecticide spraying and environmental management are the primary preventative approaches. Furthermore, mass drug administration initiatives utilizing a medicine known as ivermectin have been critical in disease control. Ivermectin eliminates the microfilariae that circulate in the body, limiting transmission and avoiding disease progression. However, it does not kill adult worms, necessitating long-term and consistent treatment to stop transmission and relieve symptoms. Beyond physical health, onchocerciasis has an economic and social impact on communities because to its impacts on production and ability to care for oneself. Global health organizations, governments, and non-governmental organizations have worked to lower the disease's prevalence, but obstacles remain in reaching rural people and maintaining long-term control initiatives. In order to eliminate onchocerciasis as a public health problem, continued commitment to control measures and research for new therapies is critical.
