{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,20]],"date-time":"2026-07-20T10:38:18Z","timestamp":1784543898204,"version":"3.55.0"},"reference-count":110,"publisher":"The Royal Society","issue":"1384","license":[{"start":{"date-parts":[[1999,4,29]],"date-time":"1999-04-29T00:00:00Z","timestamp":925344000000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/royalsociety.org\/journals\/ethics-policies\/data-sharing-mining\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Phil. Trans. R. Soc. Lond. B"],"published-print":{"date-parts":[[1999,4,29]]},"abstract":"<jats:p>\n                    Human onchocerciasis (river blindness) is the filarial infection caused by\n                    <jats:italic>Onchocerca volvulus<\/jats:italic>\n                    and transmitted among people through the bites of the\n                    <jats:italic>Simulium<\/jats:italic>\n                    vector. Some 86 million people around the world are at risk of acquiring the nematode, with 18 million people infected and 600 000 visually impaired, half of them partially or totally blind. 99% of cases occur in tropical Africa; scattered foci exist in Latin America. Until recently control programmes, in operation since 1975, have consisted of antivectorial measures. With the introduction of ivermectin in 1988, safe and effective chemotherapy is now available. With the original Onchocerciasis Control Programme of West Africa coming to an end, both the new African Programme for Onchocerciasis Control and the Onchocerciasis Elimination Programme for the Americas, rely heavily on ivermectin self\u2013sustained mass delivery. In consequence, the need for understanding the processes regulating parasite abundance in human and simuliid populations is of utmost importance. We present a simple mathematical framework built around recent analyses of exposure\u2013 and density\u2013dependent processes operating, respectively, within the human and vector hosts. An expression for the basic reproductive ratio,\n                    <jats:italic>R<\/jats:italic>\n                    <jats:sub>0<\/jats:sub>\n                    , is derived and related to the minimum vector density required for parasite persistence in localities of West Africa in general and northern Cameroon in particular. Model outputs suggest that constraints acting against parasite establishment in both humans and vectors are necessary to reproduce field observations, but those in humans may not fully protect against reinfection. Analyses of host age\u2013profiles of infection prevalence, intensity, and aggregation for increasing levels of endemicity and intensity of transmission in the Vina valley of northern Cameroon are in agreement with these results and discussed in light of novel work on onchocerciasis immunology.\n                  <\/jats:p>","DOI":"10.1098\/rstb.1999.0433","type":"journal-article","created":{"date-parts":[[2002,7,26]],"date-time":"2002-07-26T19:55:21Z","timestamp":1027713321000},"page":"809-826","source":"Crossref","is-referenced-by-count":94,"title":["Population biology of human onchocerciasis"],"prefix":"10.1098","volume":"354","author":[{"given":"Mar\u00eda-Gloria","family":"Bas\u00e1\u00f1ez","sequence":"first","affiliation":[{"name":"WellcomeTrust Centre for Epidemiology of Infectious Disease, Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK ()"},{"name":"Centro Amaz\u00f3nico para Investigaci\u00f3n y Control de EnfermedadesTropicales, Apdo. Postal 59, Puerto Ayacucho 7101, Estado Amazonas, Venezuela"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Michel","family":"Boussinesq","sequence":"additional","affiliation":[{"name":"ORSTOM, CS no. 5, 213 rue La Fayette, 75480 Paris, Cedex 10, France"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"175","published-online":{"date-parts":[[1999,4,29]]},"reference":[{"key":"p_4","first-page":"60","article-title":"Studies on nodules and adult Onchocerca volvulus during a nodulectomy trial in hyperendemic villages in Liberia and Upper Volta. I. Palpable and impalpable onchocercomata.Tropenmed","volume":"34","author":"Albiez E. J.","year":"1983","journal-title":"Parasitol."},{"key":"p_5","unstructured":"Albiez E. J. B\u00cfttner D. W. & Schulz-Key H. 1984 Studies on nodules and adult Onchocerca volvulus during a nodulectomy trial in hyperendemic villages in Liberia and Upper Volta. II. 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