Activities of evaluation, planification and transfer unit

ONCHOCERCIASIS CONTROL PROGRAMME IN WEST AFRICA Expert Advisory Committee Seventeenth session Ouagadougou. 10-14 June 1996 Briefing session, 8 June 1996 OCP/EACl7/Briefing paper no.4 ORIGINAL: FRENCH ACTTVITIES OF EVALUATION, PLANIFICATION AND TRANSFER UNIT I. Epidemiological evaluation activities : 1. Epidemiolo&il:al monitoring in sentinel villages of the orieinal area ln 199511996, 70 sentinel villages were evaluated in the seven countries of the original area Results were overall satisfactory in the seven countries except: - In Burkina Faso, in the Bougouriba basin where a 3% awlual rate of onchocercal infection incidence was observed in November 1995, confirming a recrudescence of onchocerciasis in the village of Zoulo and other neighbouring villages. A detailed epidemiological mapping of the basin is under way. Further investigations relating to entomology, sociology and population growttr will be made in order to better assess the epidemiological situation and understand this first case of onchocerciasis recrudescence. Appropriate action will be taken for ivermectin distribution. - In Ghana, in the White Volta basin where prevalence rates of 4.9 and 6.3% were observed. - In Benin, on the Oti-Pendjari where prevalence rates ranging from 1.7 to 24.1% were observed, particularly in villages evaluated for the first time. Further evaluations will be undertaken in order to better assess the epidemiological situation around these villages (Ghana and Benin). - In Togo, in the Oti basin where more than 50% of positive persons were migrants who had stayed in the OCP southern extension zone and who came back to resettle in their respective villages in the National Park now reopened to villagers. 2. Epidemiological evaluation and decision to stop larviciding The Kankelaba basin, in Mali, was evaluated this year with a view to assess the impact of vector control in this basin where ivermectin distribution is also carried out. The first results are generally good. However, because of ivermectin distribution, further epidemiological evaluation will be undertaken in the basin, next year, to enable decision to be made. 3. Epidemiological evaluation in the extension zones under ivermectin treatment and larviciding The monitoring of a cohorte of non infected persons in l2l villages will enable to determine the impact of the control activities on onchocerciasis incidence in the population. The first results reported from two villages in the Milo basin in Guinea which were evaluated in December 1995 show a nul incidence rated after eight years of combined ivermectin distribution and vector control. Epidemioloeical evaluation in Sierra leone With the situation now safe again, epidemiological evaluations have resumed in the kaba, Mongo, Seli and Bagbe basins in Sierra Leone, 22 months after a temporary suspension of ivermectin -2- distribution. The table below shows the results in two villages, in May 1994 before treatment suspension and in March-April 1996. Villages Prevalence May 94 Prevalence March-April 96 Kamoia Momora-Badala Yirafilaia Yiraia Tuba Serdoya 49,0% 41,7% 4l,l% 41,5% 52,3% 56,4% 6l,l% 68,3% 4. Epidemiological evaluation in villages in basins under ivermectin treatment alone An evaluation of the impact of ivermectin distribution after five years of operation was carried out in the Rio Geba basin in Guinea Bissau in June 1995 and in Guinea in the Koulountou-Koliba basin in July 1995. The results were excellent with a nul incidence rate. In the Koulountou basin prevalence ranges from8.6% to 44.6% as compared to 48.2% and 62.7Vo observed in 1988/1990; in Rio Geba basin it ranges from 0.0% to 3.2% as compared to 16. l% to 23.5% (1990). 5. Ophthalmological evaluation In order to monitor the impact of ivermectin distribution on ocular morbidity, ophthalmological evaluations were undertaken in Guinea. Within the original area, some villages which have longitudinal ophthalmological data available were also evaluated six years after the cessation of vector control. The results were overall excellent. Details will be provided during the briefing session. II. Ivermectin distribution Ivermectin distribution was continuing. However, emphasis was put on training with a view to implementing the community-based ivermectin treatment. Around two million people will have received ivermectin treatment through all the existing modes (mobile team, community-based, and passive). III. Evaluation of ivennectin distribution programmes in COte d'Ivoire, Benin, Togo and Ghana The evaluation conducted from 17 March to 27 Aprll1996 in C6te d'Ivoire, Benin, Togo and Ghana was in line with the recommendation to pursue the evaluation of ivermectin distribution prograrnmes in all the other Participating Countries after the one carried out in 1995 in Guinea, Mali and Senegal. The evaluation was to pay special attention to individuals treated in the villages; the villages treated in the basins; the management; and the preparation for the decentralization of treatment prograrnmes in the countries. This year the evaluation team included an Oncho National Coordinator from another country. A total of 130 villages were evaluated and 3420 persons interrogated in C6te d'Ivoire, Benin, Togo and Ghana. Generally, the coverage was 67.2%, though in Benin and Togo it was below the level (65%) recommended by OCP. Overall 26.1% of the individuals were not treated; orly 29.4% wenr through the whole cycle treatment. Absence during the distribution period was the main reason (54%) of non- treatment. Acceptability and tolerability of ivermectin were good (85%). Adverse effects, mainly itching (8.6%), did not require any treatment. Only 2.6% of individuals refused to be treated. In all -3- a the treated villages, the populations expressed their willingness to continue the treatment. Mobile treatrnent seemed to be the preferred method for most of the village chiefs (73.2%). Yery few volunteers were trained in ivermectin distribution. Inadequacy was noted at IEC level; in the organization of the treatment in the villages; and in the peripheral health workers' involvement in ivermectin distribution. In conclusion, efforts should be made to ensure a better geographical coverage of the villages in the treated areas, and to intensify IEC by a good demonstration in the field with a view to setting up a community-based treatrnent under the health staff supervision. IV. Diagnosis of Onchocerciasis Following a review of the different techniques for diagnosis onchocerciasis during a meeting held in Geneva on 12 and 13 February 1996, and in order to have available a field operational diagnostic test, it w:rs recommended: that research on the DEC patch test be intensified in the different geographical zones of the Prograrnme with a view to validating this test and; that studies on immunodiagnostic test and PCR be continued. Some of the first results will be presented during the briefing session. V. Epidemiological modelting Simulations were carried out in order to account for the epidemiological patterns observed in the Kulpawn, Bui and Gambia basins, as well as in certain basins in Sierra Leone using the ONCHOSIM epidemiological model. With respect to these basins, the following questions will be raised and tentative answers provided during the briefing session using the results from the simulations: could ivermectin replace larviciding in those basins which have been under vector control for several years without much success? e.g. Bui and Kulpawn. In the zones where endemicity level is low (less than 20%) and the intensity of the infection (before vector control operations) as measured by the CMFL is about 30 mf/s, could interruption of transmission in those basins be conjectured on the basis of ivermectin distribution alone? Example of the Gambia in Senegal and certain basins of northern Sierra kone. vI. National workshops for developing an implementation for commrrnity-based distribution of ivermectin and decentralization of epidemiological surveillance See the report on workshops. VII. Training and refresher courses OCP is continuing to grant scholarships for training with continued emphasis on epidemiology and public health in training centres in the Africa Region. Fourteen new scholarships were granted since March 1995. Thus, from 1974 to 9 May 1996, the total number of nationals from participating Countries who were beneficiaries of OCP training grants in various fields amounts to 447. All the countries are organizing onthe-job training in the epidemiological surveillance of target diseases at the district level, using among others the problem-solving modules designed by WHO/AFRO and PASE methodology. District level health workers were identihed and trained in epidemiological evaluation techniques in four countries (Mali, Benin, Togo and Ghana). OCP has trained 37 members of the national teams in the analysis and interpretation of onchocerciasis epidemiological surveillance data. (