Landmarks in discovery and treatment
1875 O’Neill discovered microfilariae in skin biopsies in West Africans with a skin condition called “craw-craw”
1891/1893 Manson reported on a new species Onchocerca volvulus referring to the personal communication by Leuckart, who had received two nodules from Ghana from a German doctor.
1903 Theobald decribed Simulium damnosum from a collection of dead insects received from the in Uganda operating sleeping-sickness-committee.
1907 In Hamburg Fülleborn found the way of infection in another filariosis.
1909 Hoffmann and Halberstädter demonstrated histologically the presence of microfilariae in the skin (but science ignored it).
1913 Fülleborn improves the method of dyeing microfilariae for differential diagnostics.
1913 Ouzilleau found an unusual Elefantiasis in the Mbomou-Uéle Region which was thought to be linked to onchocerciasis, but even today no one had been able to find proof.
1916 Robles discovered Onchocerca infection in Guatemala.
1917 Robles postulated on epidemiological grounds that Simulium flies may be the vector of Onchocerca in Guatemala, and suggested a relationship between this infection and eye disease
1920 In Africa Montpellier and Lacroix once more drew attention to the presence of microfilaria volvulus in the skin and related this infection to dermatitis (Gale filarienne), just like O’Neill had done earlier on confirming the location of microfilariae in the skin.
1923 Fülleborn observed onchocerciasis from Mexico in a German child in Hamburg.
1926 In Africa Blacklock described the development of microfilaria volvulus into infective larvae in Simulium damnosum.
1928 Ochoterena demonstrated histologically the presence of microfilariae in the eye and optic nerve.
1930 Torroella observed microfilariae in the cornea and anterior chamber with a slit lamp.
1930 Hoffmann showed that species of Simulium were the vectors in Central America
1931 Hissette emphasized the ocular manifestations of onchocerciasis in Africa.
1932 Hissette described the scared retina through onchocerciasis.
1935 Bryant provided a first painting of this scared fundus.
1936 Van den Berghe discovered free living adult worms in autopsies of two humans.
1941 Amongst 57 species of flies in Africa and a similar number of flies in the Americas there were only two insects which were carriers of O. volvulus in Africa: S. damnosum and S. neavei. In the Americas there were three vectors: S. mooseri (=callidum), S. ochraceum, S. avidum.
1945 Ridley’s monograph had the effect of arousing interest in ocular onchocerciasis.
1947 Van Hoof and his colleagues showed that suramin killed adult worms but various workers found this drug to be very toxic.
1948 Mazzotti and Hewitt reported that skin microfilarial density decreased after treatment with diethylcarbamazine, although adult worms were not killed.
1948 Mazzotti suggested that the precipitation of a rash by diethylcarbamazine could be used as a diagnostic method (Mazzotti test, now out of use).
1949 Garnham and McMahon eradicated flies from a limited focus in Kenya by applying DDT to streams.
1954 Kershaw and his colleagues found that eye changes and blindness correlate with the numerical distribution of microfilariae of Onchocerca volvulus in the skin, especially of the head.
1957 Fawdry found the “black leg” or “sowda” in Yemen, a hyperimmune response caused by onchocerciasis.
1958 In Bonjongo, Cameroons, Choyce confirmed that the scared fundus would be identical with the chorioidal sclerosis described by Sorsby in 1939.
1963 No evidence was found that vitamin A deficiency causes chorioretinitis in onchocerciasis (Woodruff et al.).
1963 Budden found differences between forest onchocerciasis and onchocerciasis of the savannah.
1975 The Onchocerciasis Control Programme (OCP) started in West-Africa with the eradication of Simuliidae using pesticides; it was finished in 2002.
1982 Aziz and his colleagues indicated that ivermectin greatly reduced the density of skin microfilariae.
1990 Bandi and his colleagues described the appearance of Wolbachia or Rickettsiales endosymbionts in several worms.
1994 The African Programme for Onchocerciasis Control (APOC) started with village health workers administering the annual treatments with Ivermectin in Africa (Community Directed Treatment with Ivermectin = CDTI).
2000 Wolbachia is an excellent target for doxycycline that reduces the pathogenesis of filarial infections, especially onchocerciasis (Hoerauf et al.); this offered a novel approach to chemotherapy and control of filarial infections.
2002 Saint André and her colleagues showed that Wolbachia play a major role in the pathogenesis of ocular onchocerciasis in the human host.
2010 CDTI has been reduced or stopped in many countries in Africa, but two conflict areas have been left: The Central African Republic and the Democratic Republic of the Congo (formerly Zaire/Belgian Congo).