Onchocerciasis in Yemen: moving forward towards an elimination program.

The onchocerciasis focus in Yemen has been known for many years as an endemic area with unique characteristics, notably the atypical and most severe form of onchodermatitis, known as sowda or reactive onchodermatitis (ROD). The national effort to control the disease began in 1992 as an individual case treatment program by administering ivermectin to those presenting with ROD. The challenging geography of the endemic area and the current political and military unrest both underscore a need for special approaches when attempting to eliminate onchocerciasis from this country.

Absence of an association between Plasmodium falciparum infection and post-ivermectin Loa-related non-neurologic serious adverse events.

Although ivermectin treatment can induce serious adverse events (SAEs) in individuals harboring high Loa loa microfilaremia (mf), not all patients with high mf levels develop such reactions, suggesting that cofactors may be involved. A study was conducted in Cameroon to investigate the possible role of Plasmodium coinfection at the time of ivermectin treatment in the development of SAEs. Before their first ivermectin treatment, thick smears were obtained from 4,175 individuals to determine the burden of Plasmodium sp.

A controlled trial to assess the effect of quinine, chloroquine, amodiaquine, and artesunate on Loa loa microfilaremia.

Onchocerciasis control is currently based on mass ivermectin treatment. Unfortunately, this drug can induce serious adverse events (SAEs) in persons with high levels of Loa loa microfilaremia (> 30,000 microfilaria/mL). A means of preventing SAEs would be to treat at risk populations with a drug that would progressively reduce the microfilarial loads before administering ivermectin.

Loa loa microfilarial periodicity in ivermectin-treated patients: comparison between those developing and those free of serious adverse events.

The main risk factor of post-ivermectin serious adverse events (SAEs) is the presence of a high Loa loa microfilaremia. However, the majority of patients with such high loads do not develop SAEs, suggesting that co-factors may be involved. An infection with simian Loa parasites, whose microfilariae show a nocturnal periodicity, might be such a co-factor.

The Mectizan Donation Program (MDP).

The launch of the Mectizan Donation Program (MDP) in 1987, by Merck & Co., Inc., created a number of new opportunities for onchocerciasis control.

Operational lessons from 20 years of the Mectizan Donation Program for the control of onchocerciasis.

The donation of ivermectin (Mectizan, Merck & Co., Inc.) to control onchocerciasis (river blindness) was established in 1987 and has since gradually expanded to provide for >570 million treatments cumulatively over the past 20 years.

Encephalopathy after ivermectin treatment in a patient infected with Loa loa and Plasmodium spp.

Despite over 350 million people being safely treated with ivermectin, there have been rare cases of death post-treatment; these events are most often associated with high Loa loa microfilaremia. This first autopsy description of an encephalopathy case following the administration of ivermectin involves a 45-year-old male who became comatose 3 days after treatment. He slowly deteriorated over 5 weeks and died at 54 days after the anthelminthic treatment, probably as a result of a secondary skin or pulmonary infection exacerbated by malnutrition.

Health care at the end of the road: opportunities from 20 years of partnership in onchocerciasis control.

The unprecedented decision of Merck & Co., Inc., to donate ivermectin through the Mectizan(R) Donation Program, has catalysed an exemplary partnership, to distribute the drug to the communities at risk of onchocerciasis, and empower them to take charge of the drug distribution themselves.

Randomized, controlled, double-blind trial with ivermectin on Loa loa microfilaraemia: efficacy of a low dose (approximately 25 microg/kg) versus current standard dose (150 microg/kg).

Neurological serious adverse events (SAEs) following ivermectin treatment may occur in individuals harbouring high Loa loa microfilarial densities and are of major concern in the context of mass ivermectin distributions organized in Africa for onchocerciasis and lymphatic filariasis control. As those SAEs are induced by the rapid and massive microfilaricidal effect of a standard dose of ivermectin (150 microg/kg), we performed a randomized, controlled, double-blind trial to determine whether ivermectin given as: (a) a single low dose of 1.5mg (i.

Towards the elimination of onchocerciasis.

Human onchocerciasis is a severely disabling filarial disease that is endemic in 28 African countries, six Latin American countries and Yemen. The disease causes a high burden of blindness and visual loss, along with itching and other severe dermal manifestations. It constitutes a significant obstacle to socio-economic development in highly endemic riverine areas, where the Simulium blackflies that act as vectors breed.

The Mectizan Donation Program - highlights from 2005.

Through the Mectizan Donation Program, Merck & Co., Inc. has donated Mectizan (ivermectin, MSD) for the treatment of onchocerciasis worldwide since 1987.

A simplified cataract grading system.

A simplified method for grading the presence and severity of different cataract types is needed for field use in assessment of the magnitude of the cataract problem. A cataract grading system was developed by a panel of experts with the objective of making available a simple system for use with a slit lamp to allow for the reliable grading of the most common forms of cataract by relatively inexperienced observers. Three levels, reflecting progressive severity, for grading of nuclear, cortical and posterior subcapsular (PSC) cataract were included in the classification; three standard photos were used for grading nuclear cataract.

The global impact of eye injuries.

Using data compiled from the ophthalmic literature and WHO's Blindness Data Bank, the available information on eye injuries from an epidemiological and public health perspective has been extensively reviewed. This collection of data has allowed an analysis of risk factors, incidence, prevalence, and impact of eye injuries in terms of visual outcome. However, most of the estimates are based on information from More Developed Countries (MDCs).

[Progress in the control of world blindness and future perspectives].

Worldwide, there are approximately 180 million severely visually impaired people, of whom some 45 million are blind. Cataract remains the major cause of blindness, especially in the less developed countries. Substantial improvements have been achieved in the control of blinding diseases, mainly in respect of onchocerciasis and xerophthalmia.

Prevention of blindness--WHO's mission for vision.

Changes in the world order and in technology during the last half-century have revolutionized approaches to blindness prevention and sight restoration. Although the possibilities have improved and increased immeasurably, unnecessary blindness will remain common, especially among the poor, unless a concerted international effort is made to prevent it.

[World Health Organization alliance for the elimination of trachoma].

Although trachoma has either decreased or disappeared in many Third World countries through socio economic development during the past forty years, it remains a major problem among the poorest communities, which is often ignored by decision-makers when setting priorities. Fortunately, recent developments will allow to overcome many of the past obstacles and to offer new opportunities for trachoma control programmes. WHO aware of this new favourable context for trachoma control has taken the leadership in mobilizing and coordinating trachoma control efforts through the creation of a WHO Alliance for the Global Elimination of Trachoma.

The WHO programme for the prevention of deafness and hearing impairment.

The WHO Programme for the Prevention of Deafness and hearing Impairment (PDH) was established in 1987 to deal with causes of avoidable hearing loss, particularly in developing countries. The Programme is developing its strategies on the basis of essential ear care as part of primary health care, and the collection of epidemiologically sound data on ear disease and hearing impairment. A uniform Ear Examination Form is being finalized, for use in field surveys.