The case for vaccine development in the strategy to eradicate river blindness (onchocerciasis) from Africa.

Onchocerciasis or river blindness is a neglected parasitic disease causing severe dermatitis and visual impairment, predominantly in Africa. Historically, onchocerciasis control targeted vector breeding sites, but the current strategy relies on mass administration of a single drug, ivermectin. As programmatic goals shift from reducing public health impact to active elimination, sole reliance on ivermectin is threatened by contraindications in areas coendemic for loiasis, an inability to break transmission in some foci, and the emergence of drug resistance. Here, we argue that prophylactic and therapeutic vaccines would accelerate elimination efforts and safeguard the enormous strides made in onchocerciasis control. These vaccines could be based on one or more of three lead candidates identified by a newly formed transatlantic partnership, The Onchocerciasis Vaccine for Africa Initiative.

River Blindness Program

It brings information about the program of river blindness and also presents information about the disease, such as transmission, distribution, impacts, treatment and control.

Sir Nicholas Harold Lloyd Ridley: 10 July 1906 - 25 May 2001.

Sir Harold Ridley invented and refined the modern miracle of replacing lenses obscured by cataracts with plastic optical lenses, thus rendering a complete cataract cure. This operation, broadly termed the cataract-intraocular lens (IOL) operation, has since brought sight to many millions of people throughout the world, and continues to improve the quality of life of more than 10 million patients worldwide each year. Ridley not only launched this powerful and irreversible forward movement in the field of ophthalmology and the visual sciences, but through it he also helped give birth to the exciting and new field of artificial biodevice implantation as well as transplantation techniques now applied to many other organs and tissues of the body. He has therefore been credited with healing to create the relatively new specialty of biomedical engineering. Few of the millions of patients worldwide who now enjoy the benefits of the modern cataract - IOL operation are aware of the origin of this innovation. Indeed, few eye care professionals - even ophthalmic surgeons who implant them almost daily - are aware of the origin of the IOL - an invention that, as Harold himself liked to say, 'cured aphakia'. (The word aphakia comes from teh Greek, meaning absence of lens, the situation that occurs when a cataractous lens is surgically removed.)

Nematode infections of the eye: toxocariasis, onchocerciasis, diffuse unilateral subacute neuroretinitis, and cysticercosis.

Nematode infections of the eye are common in different parts of the world, but some are usually encountered only in developing nations, such as onchocerciasis and cysticercosis. Ocular toxocariasis is a well-known cause of unilateral ocular disease affecting mainly children and young adults, and is usually caused by T canis. Prevention of ocular toxocariasis is based on such measures as appropriate health care for dogs and cats, including regular anthelmintic treatments, preventing contamination of the environment with feces, and promoting responsible pet ownership [1,49-51]. Onchocerciasis is caused by infection with the filarial parasite O volvulus, and occurs in endemic areas along rivers and streams. In hyperendemic areas almost every person is infected and about half of the population is eventually blinded by onchocerciasis. Because of this, elimination of host-vector contact is very important. DUSN is caused by a motile nematode and is found in the Southeastern and Midwestern United States and in many parts of the world. In Brazil, DUSN is becoming an important cause of posterior uveitis in children and young healthy adults. The destruction of the worm during the early stages of the disease can prevent progression of the visual loss. It is important to remain aware of this entity, not only in areas where it has been described, but also in regions not yet identified as being endemic [52]. Cysticercosis is caused by the encystment of the larvae of the tapeworm T solium, and usually results from ingesting eggs from food, water, or other material contaminated with human feces. Surgical removal of the cyst is usually indicated when possible.

Oncocercosis

La oncocercosis es una filariasis producida por Onchocerca volvulus y transmitida por un insecto díptero del género Simulium. El parásito adulto, de varios centímetros de longitud, afecta a la población de diversos países africanos y americanos, en donde esta enfermedad es endémica. La clínica viene definida por la presencia de nódulos en la piel, lesiones dérmicas y lesiones oculares, que pueden producir ceguera, la complicación más grave. El diagnóstico se fundamenta en la clínica y en las pruebas serológicas, y se confirma al observar las filarias adultas en los nódulos extirpados o las microfilarias en las biopsias cutáneas. El tratamiento se realiza, preferentemente, con ivermectina por vía oral y dosis única (AU)

The socio-economic aspects of human onchocerciasis in Africa: present appraisal.

The pattern of socio-economic liability that has emerged due to human onchocerciasis in Africa has been particularly damaging. Due to debilitation and blindness, the sufferer is unable to maintain for long any type of productive activity. As a cause of permanent disability through blindness or serious visual impairment, it withdraws the affected individuals' potential supply of labour years of activity requiring vision. The desertation of many river valleys in the savannah zone that are agriculturally fertile have been attributed mainly to the effects of this disease. This has by definition, meant that emigrants impose demands upon other territories that are often agriculturally less fertile consequently resulting to constant population maladjustment. As a cause of death, infection removes individual's supply of labour years in the future. The social life obtainable in these areas is better imagined than seen. It is a common trend seeing chains of blind adults being led to markets or within cities by children with good vision-constituting destitutes. The distressing skin features give patients prematurely aged appearance and together with dreadful malformation due to sclerosing lymphadenitid, infected individuals show shyness towards free social interactions; even sexual life is greatly affected if not completely hindered. The present economic benefit analysis of control projects, limitations and needs for future studies are disoussed.