Samenvatting
The goal of the African Programme for Onchocerciasis Control (APOC) is to eliminate Onchocerciasis as a disease of public Health significance and an important constraint to socio-economic development in the 19 none OCP (Onchocerciasis Control Project) countries covered through Community-Directed Treatment with Ivermectin, CDTI. In 1998, impact assessment studies were carried out in Morogoro, Tanzania during which baseline ophthalmological parameters were established. The hypothesis being tested is that CDTI will prevent or delay progression of onchocercal eye lesions and blindness. A total of 425 subjects aged 10 years or more from 14 villages within Bwakira district of Morogoro region in Tanzania were examined for Snellen visual acuity, ocular microfilaria, lens opacities, uveitis and posterior segment disease especially chorioretinitis and optic nerve disease. Motion Sensitivity Screening Test (MSST) was carried out as well. Microfilaria was present in the anterior chamber of nearly half (49.2%) of all subjects examined. Prevalence of blindness was extremely high at 15.2%. Onchocercal lesions were responsible for blindness in 41.5% of these, followed by cataracts (27.7%), glaucoma (10.8%) and trachoma (6.2%). The main pathway to onchocercal blindness in this population was anterior uveitis with or without secondary cataracts. There is an urgent need to get CDTI underway and institute other horizontal primary eye care measures, especially cataract backlog reduction, in order to reduce the excessive burden of avoidable blindness in this community.
Keywords: Baseline, ophthamological, APOC, onchocerciasis, impact, Tanzania
Résumé
Le but du programme Africain pour le controle de l’onchocércose(PACO) est d’élliminer l’onchocércose comme une maladie de santé publique significantive et une contrainte au developement socio économique dans 19 pays couvert par le traitement a l’ivermectin en CD1. En 1989 les études d’évaluation de l’impact étaient faite a Morogoro, Tanzanie ou les paramétres ophthalmologiques étaient établies. L’hypothese testée que le CD1 previendra ou retardera la progression des lésions onchocercales des yeux et l’aveugleté. Un total de 925 individus agés d’au plus 10 ans de 14 villages dans le district de Bwakira, Morogoro, Tanzanie étaient examinés pour l’acuité visuelle, microfilaire occulaire, opacités des lentilles uvete et désordre du fragment posterieur speciallement chorioretinité et du nerf optique. Le test de depistage de sensibilité du mouvement était aussi faite. Le microfilaire était present dans la chambre antérieure chez presque la moitié des sujets(49.2%) examinés. Le taux d’aveugleté était extremement élevée de 15.2% avec les lésions onchocercales responsable de l’aveugeté etait de 41.5%, suivi par le catarract de 27.7%, glaucome 10.8%, et trachome(6.2%).le chemin principal de l’aveugleuté onchocercale dans la population était uvete antérieure avec ou sans catarract secondaire.Il y a un besion urgent au CD1 et d’instituer d’autres mesures des soins ophthalmologiques primaires speciallement la réduction du catarract, afin de réduire la ménace excessive de l’aveugleté dans cette communaute.
Correspondence: Dr. O.E. Babalola, Rachel Eye Centre, P.O. Box 4108, Garki, Abuja, Nigeria. E-mail: bablo57@gmail.com
Referenties
Abiose A. Onchocercal eye disease and the impact of mectizan treatment. Annals of Tropical Medicine and Parasitology.1998; 92 (1) S11-S22
Abiose A, Murdoch I, Babalola O, Cousens S, and Liman I. Distribution and aetiology of blindness and visual impairment in mesoendemic onchocercal communities, Kaduna State, Nigeria. British Journal of Ophthamol, 1994; 78 (1): 8-13.
APOC Impact Assessment Data Analysis Workshop, September 6-17, 1999. Ouagadougou, Burkina Faso. Report N°2, page 3.
Boatin BA, Hougard JM, Alley ES, Akpoboua L K, Yameogo L, Dembele N, Seketeli A, Dadzie KY. The impact of mectizan on the transmission of onchocerciasis: Annals of Tropical Medicine and Parasitology. 1998; 92 (1) S47-S60.
Wegesa P. Onchocerciasis 1. Epidemiological Surveys: The discovery of two new foci of onchocerciasis in Tanzania. Annual report of the East African Institute of Malaria and other vector-borne diseases-January to December 1968: Pg 34-36 (Amani, Tanzania)
Abaru DE and Van Dam HE. Onchocerciasis clinical survey: In the annual report of the East African Institute of Malaria and other Vector Borne diseases: January 1972-December 1973; Pp 81-100 (Amani, Tanzania).
TDR/AFR/RP/95.1 (Applied Field Research Report no 1): The importance of onchocercal skin disease: A report of a multi=country study by the Pan-African study group on onchocercal skin disease. WHO 1995. Pages 3-45.
Raybould J.N. and White G.B. The distribution, bionomics and control of onchocerciasis vectors (Diptera: Simuliidae) in the Eastern Africa and the Yemen. Tropical Medicine and Parasitology 1979; 30: 505-547.
Dunbar RW. Correlation of breeding sites and anthropophilia in East Africa to infer which species of S. Damnosum complex may be vectors of onchocerciasis. In annual report of the East Africa Institute of Malaria and other vector –borne diseases: January 1974- December 1975, pg 50-59. Amani, Tanzania.
Maegga BT and Cupp EW. Chromosomal diagnostic criteria for some members of the Simulium damnosum complex in East Africa. Tropical Medicine and Parasitology 1993; 44: 165-171.
Wu J.X. , Jones B R, Cassels-Brown A, Murdoch I, Adeniyi F, Alexander N, Minassian D and Abiose A. Preliminary report on the use of laptop computer perimetry with a motion sensitivity screening test to detect optic nerve disease in onchocercal communities of rural Nigeria. Proceedings of the Xth international Perimetry Society meeting, Kyoto, Japan. Published in Perimetry update 1992/1993, pp 323-329.