Pierre Richet (1904-1983), fighting onchocerciasis and totalitarism.

While Eugène Jamot's name is associated with the combat against sleeping sickness, Pierre Richet is permanently linked to the battle against river blindness, which he first reported in 1936 in two neighboring households in Garango (Burkina Faso). Onchocerciasis remained a continuous interest, through his last article "The OCCGE and Onchocerciasis", written in 1983. Nonetheless over the course of these five decades, Richet's trajectory was far from that of a specialist dedicating his life to a single disease. After a decade essentially spent fighting trypanosomiasis, came a decade of war in which the specialist in endemism joined the Free French Army and put his organizational know-how at General Lerclerc's disposal, from Morocco to Indochina, via Germany. On his return to Africa in 1953, he extended the principle of mobile teams to the other major endemic diseases accessible to treatment and to vaccines. Richet organized first the combat against leprosy and launched vaccination programs. In 1955, he returned to the battle against onchocerciasis and deployed the first large-scale insecticide program in Chad. The intermediate term failure of this prototype fermented his scientific, interdisciplinary, and organizational thought, which flourished at Bobo-Dioulasso. At the dawn of the independence of French-speaking African countries, and against the political tides of the time, he obtained in 1960 the creation of a supranational organization, the OCCGE, common to 8 countries of West Africa, and he headed it for a decade. Drawing lessons from the past and in the absence of effective pharmaceutical treatment, Richet the physician played the entomological card with one hand, with technical support from Orstom (IRD); this detailed work enabled the development of a strategy. With the other hand, he played the multilateral card, which led in 1974 to the launching of the extraordinary Onchocerciasis Control Program (OCP). If it is Jamot who awakened Africa, Richet is the person who restored its view but also millions of hectares of cultivable land.

[Towards the elimination of onchocerciasis at the global scale: history, challenges and future prospects].

The total number of patients with onchocerciasis on the African continent was estimated in 2008 at 25720000. The control strategy for onchocerciasis has dramatically changed during the last 30 years, resulting in a decrease of patients. Vector control was mainly used until around 1990. Since then, the strategy has been transferred to "Mass Drug Administration using Ivermectin". An "Integrated Approach" for several endemic diseases has become a popular control strategy since 2005. Several tasks remain for eliminating onchocerciais: improvement of the population coverage of drug distribution, construction of monitoring systems to inspect the emergence of drug resistance, invention of anti-macrofilarial drugs to replace anti-microfilarial drugs, and reinforcement of the health authorities in African countries. The possible elimination of onchocerciasis also depends on the continued political commitment to the program by the Ministry of Health. If the ongoing control program keeps producing results at the current pace, the elimination of onchocerciasis could be achieved in the near future.

The onchocerciasis chronicle: from the beginning to the end?

The year 2012 marks the 25th anniversary of the donation of ivermectin to fight onchocerciasis and the projected date for elimination of transmission of the disease in the Americas. This review looks at the history of onchocerciasis, from its discovery through to 2025, by which time it is projected that the disease will have been eliminated as a public health problem, except in a handful of sub-Saharan countries, where it should be well on the way towards elimination.

The discovery of the vector of Robles disease.

The origin and transmission of African filariasis has long remained enigmatic. Between 1915 and 1917, the pathogenic role of Onchocerca volvulus and its transmission by insects of the genus Simulium, had been established in Guatemala by Rodolfo Robles who took opportunity of a series of discoveries to formulate his hypothesis on the origin of Latin Americna Onchocerchiasis. The present paper gives an historical account of the steps and the context having led to the formulation of the aetiological hypothesis and the relevant vector identification.

Satoshi Omura: in pursuit of nature's bounty.

Professor Satoshi Omura has spent over 40 years searching for bioactive compounds in naturally occurring microorganisms, discovering more than 330 biomedically and commercially significant compounds in the process. The discovery, development and delivery of the drug ivermectin has pioneered the way for subsequent partnerships between the public and private sectors, as well as international collaborations and drug donation programmes. It has involved a variety of ground-breaking steps, providing a curative drug that will help rid Africa and the world of at least one of the most devastating of all human diseases, onchocerciasis. It has also improved the health of pets and livestock around the globe, and encouraged development of a community-based delivery mechanism that could herald a revolution in public health care in Africa.

[Overseas disease: comparative studies of onchocerciasis in Latin America and Africa]. / Doença de além-mar: estudos comparativos da oncocercose na América Latina e Africa.

Round worm is a parasite, Onchocera, and is transmitted by a black fly, simulidae; it can cause blindness. Originally from the African continent, where it is widespread, in Latin America it was first discovered in Guatemala in 1917; later instances were recorded in Mexico, Venezuela, Colombia and Brazil. The establishment of this disease in the Americas has intrigued scientists since then and today it is an open question. The multidisciplinary project described in this research note aims to investigate historical aspects of the arrival and spread of the disease in Latin America and, to make comparative studies of the history of the disease on both continents. The increasing importance of the disease has meant greater value being attributed to collections of simuliídeo, whose Brazilian species were first studied by Adolpho Lutz at the beginning of the 20th century.

Doença de além-mar: estudos comparativos da oncocercose na América Latina e Africa / Overseas disease: comparative studies of onchocerciasis in Latin America and Africa

Objetiva investigar os aspectos históricos da introduçäo e disseminaçäo da oncocercose na América Latina, e realizar estudos comparativos sobre a história da doença nos dois continentes. A importância que adquiriu acarretou a revalorizaçäo das coleçöes de simuliídeos, cujas espécies brasileiras começaram a ser estudadas por Adolpho Lutz no início do século XX. (AU)

Coleçäo de simuliídeos (Diptera - Simuliidae) de Adolpho Lutz, sua história e importância / Adolpho Lutz`s collection of black flies (Diptera - Simuliidae), its history and importance

Apresenta as espécies de simuliídeos que pertencem à coleçäo de Adolpho Lutz depositadas no Laboratório de Simuliídeos e Oncocercose do Departamento de Entomologia do Instituto Oswaldo Cruz (IOC). Pioneiro no estudo desses dípteros, Lutz descreveu cerca de 25 espécies de diferentes localidades do Brasil. Vetor da oncocercose, os simuliídeos tiveram sua importância médico-sanitária reconhecida em fins da década de 1920. (AU)

Human onchocerciasis in Brazil: an overview

The article reports on the history of the disease`s discovery, its distribution, and incrimination of vector simuliid species. The literature that has been generated on the parasite, its vectors, and control of the disease is critically analyzed as well as the organization of epidemiological surveys and the control program developed by the Brazilian government and an international agency. Suggestions for future work are made. (AU)

Models for the population biology and control of human onchocerciasis.

The absence of animal models in which to reproduce successfully the complete life cycle of Onchocerca volvulus has hindered progress towards unravelling the processes involved in the regulation of parasite abundance in the vertebrate host. Mathematical frameworks have been developed to explore the consequences of such processes in determining parasite population dynamics and the effect on these of control interventions. Post-control predictions are strongly influenced by the assumptions concerning the reproductive life span of the adult female worm (the longest-lived parasite stage) and the distribution of its survival times, and this notion is important to all frameworks. Here, we review the development of models concerning onchocerciasis and discuss the various approaches that have been used, presenting a deterministic framework with parameter values estimated from the Mexican onchocerciasis control programme. This model is used to evaluate interventions combining the removal of adult worms (nodulectomy) and the microfilaricidal and possibly sterilizing effect of ivermectin.

[Introduction of onchocerciasis in Central America: the role of the French expeditionary corps to Mexico (1861-1867)]. / L'introduction de l'onchocercose en Amérique centrale: le rôle du corps expéditionnaire français au Mexique (1861-1867).

Close relationships between American and African strains (from savanna) of onchocerciasis have been confirmed by biochemical analysis. It is admitted that the parasite could have been introduced by slave trade. But in Mexico, Torroela supported the hypothesis that onchocerciasis was introduced by Nubian soldiers of the French troops between 1861 and 1867. Some of the 600 soldiers of the Egyptian bataillon, included in the French expeditionnary corps, could have been onchocerciasis carriers. But these troops caserned in Vera Cruz remained in the littoral plain and have not been in contact with the Oxoaca focus of onchocerciasis. It is very unlikely that they can have been at the origin of the disease focus.

[Coffee tree cultivation and the social history of onchocerciasis in Soconusco, Chiapas state, Mexico]. / Cafeticultura e historia social de la oncocercosis en el Soconusco, estado de Chiapas, México.

Due to the social and ecological changes that have taken place in the region of Soconusco, Chiapas, Mexico, the coffee tree growth economy (established in the latter part of the last century) has been an important factor in the transmission of onchocerciasis. The optimum ecological conditions for the growth of the coffee tree coincide with those of the disease's growth rate vector; the mobilization of migrant workers for the cultivation and gathering of coffee beans, plus changes in the natural environment, are elements which explain the disease's distribution in the different regions. The origin of the disease in Chiapas may be due to the migration of coffee plantation workers from Guatemala in search of land in which to settle. Social changes occurring after the Agrarian Distribution (land distributions that occurred in 1918 and 1940) caused an intensification and modernization in the areas of cultivation which in turn caused a decline in the disease's growth rate vector. This, together with standard of living improvements and control measures against the disease, explain why the problem in these regions has decreased considerably. The use of ivermectin as a new therapy paves the way for better disease control in the future. Nevertheless, in the smaller locations occupied by middle and poor class farmers, where coffee bean cultivation is just commencing and still in a rudimentary form, onchocerciasis and other diseases continue to present serious health problems.