WHO/APOC impact assessment of onchocerciasis in Bushenyi (south west Uganda): Ophthalmological report

II WHO/APOC IMPACT ASSESSMENT OF ONCHOCERCISIS IN BUSHENYI(sourH-wEST UGANDA) OPHTHALMOLO GICAL REPORT Dr BANLA Meba (ophthalmologist) Dr MAGIMBI Christopher (ophthalmologist) March - April 2004 By I I Background Information The Onchocerciasis Control Programme(OcP) has been carrying out vector control in I I West African Countries since it's creation in 1974 and is on the verge of eliminating the disease in these countries through vector control. More than 35 million persons have been prevented from being infected by onchocerciasis while over 500 000 others have escaped from becoming blind. Ten million children born at the Programme face no risk of contracting the disease. More than 25 million hectares of fertile land has been recovered for farming by communities. Onchocerciasis still affects over 17.5 million persons,85% (15 million persons) of whom lives outside the OCP zone. As a result, affected communities suffer not only from disabling ill health but also from its consequence of socio economical loss. It is with this realm that African program for Onchocerciasis control (APOC) launched it's Programme in 1995 GC using the community directed treatment with Ivermectin (CDTI) in l9 countries. The baseline data for Uganda had been collected five years ago in 1999 in the same site The current study on the impact assessment of Onchocerciasis was carried out in Bushenyi district which is located some 300 km in the South - West of Uganda. As in 1999, a group of experts in the field coming from different institutions looked for ocular, dermatological, epidemiological and socio-economical impact of the Disease. Introduction The period of this assessment was from 10tr March to 2"d April 2004. Activities began in Kampala by meetings between national team and external team members, preparing materials for the field work and waiting for the team leader who had some travel problems. Four teams who had undertaken this assessment are; socio-demographic, dermatological, ophthalmological and entomological team. Each team constituted of one external and one local expert, all specially trained for the study. Obiectives General Objective To evaluate the ocular impact of onchocerciasis control after the phase I of CDTI in Busnenyi's area (South - West Uganda). Specific Objectives o To collect data which permits to determine the change in prevalence of onchocercal eye lesions in this area. o To determine the prevalence of onchocercal eye lesions, visual field defects and blindness in this area Workins vnothesis Regular ivermictin treatment will prevent the development or delay progression of onchocercal eye lesions and blindness, and may regress early stages of ocular lesions. 2 Methodoloev The study site is in Bushenyi district, which is located 300 km south west of Uganda. From the sample of l9l9 persons selected by social scientists, these include children from five years and above were to have dermatological evaluation. Eye examination was performed for those persons aged l0 years and above who went through dermatological evaluation; a total of 415 individuals were examined. Ophthalmological examinations were carried out as follows: o An ophthalmic nurse performed visual acuity measurement at 6 Mt using standard Snellen's chart and Pin Hole. o Visual field test using the Wu-Jones computerized visual field test (CVFT) were performed by two trained personals. . Eye examination, using the questionnaire for detailed Anterior and posterior segment lesions were performed by one external ophthalmologist and one local ophthalmologist come from Kampala; they are especially trained for the study. Anterior segment was examined using a slit lamp bio-microscope following subject's head bended down between his knee for at least 2 minutes. Corneal oncho lesions and dead microfilaries, microfilaria in the aqueous, iridocyclitis and others anterior segments lesions were looked for. Posterior Segment examination after dilatation of the pupils by a mydriatic cocktail eye drops were performed using direct and/or indirect ophthalmoscope. All persons have their intra ocular pressure (IOP) measured with goldman's applanation tonometer. Some anterior or posterior segment onchocerciasis related lesions have been photographed with the Topcon's fundus camera. Duration of data collection, examination and analysis: Data collection activity was done over a period of fourteen days.a a Two secretaries did data entry; data cleaning and analysis was done by an epidemiologist (National coordinator) using SPSS. J aResults A total of 415 individuals underwent ocular examination for any onchocerciasis related lesions. Out of which 176 (42.4%) were males and239 (57.6%) were females, with sex ratio of 1.38 F / I M. The mean age of the study population was 31.65%. Out of 415 individuals 0.48% had dead microfilariae in the cornea; 1.46 had microfilariae in the anterior chamber of the study population (table l). The load of microfilariae in the anterior chamber of the study population was low, ranging 1-10 per eye with the exception of one case who had more than 10 Microfilaria in the aqueous humor. Anterior segment lesions mainly fewpunctuate keratitis in 3 cases (0.72%), and sclerosing keratitis in l1 cases (2.65%) of the study population were observed. Four cases (0.96%) of iridocyclitis were observed (table 2). Similarly posterior segment lesions were observed in 18 (4.46%) of the study groups (able 3). Majority of these had an early chorioretinal lesion that includes mottling of retinal pigment epithelium (RPE). Among these individuals examined, 14 (3.37%) were blind (table 3) Conclusion This study has shown that the prevalence of onchocerciasis related eye lesions and its visual morbidity is low. Hence, the ocular findings of the study area fit the characteristic feature of forest onchocerciasis with more cases of previous oncho lesions. Remarks Population examination : o Subjects were irregular to the place we choused for examining and we changed the place in the same site for the last tree days. This was due to the activities of the rainy season with them having to work their fields first. o At the end of our activity 50 villagers who had eye pains and were not in the sample had been examined and when possible treated. This involved rapid eye screening evaluation for the potential blinding problems of cataract, trachoma and glaucoma. Subjects were advised to get treatment at the nearby ophthalmic hospital. Results: o As for the previous prevalences in 1999, ocular oncho lesions were low and were generally non active. . Ocular microfilaries were seen in more people than in 1999, but with a non significant difference; this small difference could be due to persons of the sample who were absent at the first assessment. This indicates that the CDTI members have to take more care on the treatment in this site. o None of subjects had an advanced segment anterior lesion Limitations: o Ophthalmological team began their field work three days later than the other teams. This was due to the late arrival of the slit lamp from WHO Addis Ababa. o The recurrent rains interrupted the regular coming of the subjects. 4 IAnnex Table I Microfilaries and oncho lesions in the population examined Table II Oncho lesion in the anterior segment Age groups (years) Population With MF in the cornea (%\ With MF in the anterior chamber (o/o\ With Oncho- lesion Ant. & Post. segments (o/"1 Blindness Oncho Non-oncho 10-14 r25 1 1 t5 -24 75 2 1 25 -34 59 1 1 J 35-44 43 I J 45-54 35 I 5 2 55-04 35 I 4 1 4 65+ 35 2 7 I 5 Total 415 2 (0.48) 6 (1.461 2s (6.02) 4(0.96) r0(2.41\ Age groups (years) Population With Puctate Keratitis (7o) With Sclerosing Keratitis (%) With Iridocyclitis (%\ 10-14 125 1 t5 -24 75 25 -34 59 1 35-44 43 1 2 45-54 35 2 1 55-64 35 I 4 65+ 35 3 2 Total 4t5 3 (0.72) 11 (2.6s) 4 (0.e6) 5 aAble III Oncho lesion in the SE With oncholesion Posterior segment (7o) With intraretinal deposite (%)Age groups (years) Population t0-14 123 t5 -24 74 2 57 I25 -34 241 235-44 31 5 245-54 31 5 455-64 28 J J65+ 18 (4.67) 11 (2.86)Total 385 6 ?