Programmatic factors associated with the limited impact of Community-Directed Treatment with Ivermectin to control Onchocerciasis in three drainage basins of South West Cameroon

Introduction

The CDTI model is known to have enhanced community participation in planning and resource mobilization toward the control of onchocerciasis. These effects were expected to translate into better individual acceptance of the intervention and hence high Treatment Coverage, leading to a sustainable community-led strategy and reduction in the disease burden. A survey revealed that after 10–12 rounds of treatment, prevalence of onchocerciasis was still high in three drainage basins of South West Cameroon and transmission was going on.

Methods

We designed a three (3)-year retrospective (2012, 2013 and 2014), descriptive cross-sectional study to explore the roles of operational challenges in the failure of CDTI to control the disease as expected. We administered 83 semi-structured questionnaires and conducted 12 in-depth interviews with Chiefs of Bureau Health, Chiefs of Centers, CDDs and Community Heads. Descriptive statistics was used to explore indicators of performance which were supported with views from in-depth interviews.

Results

We found that community participation was weak; communities were not deciding time and mode of distributions. Only 6 (15.0%) of 40 Community Drug Distributors reported they were selected at general community meetings as required. The health service was not able to meet and discuss Community-Directed Treatment with Ivermectin activities with individual communities partly due to transportation challenges; this was mostly done through letters. Funding was reported to be inadequate and not timely. Funds were not available to conduct Community-Self Monitoring after the 2014 Mass Drug Administration. There was inadequate health staff at the frontline health facility levels, and some Chiefs of Center reported that Community-Directed Treatment with Ivermectin work was too much for them. The mean operational Community Drug Distributor-population ratio was 1 Community Drug Distributor per 317 populations (range: 194–464, expected is 1:250). Community Drug Distributor attrition rate was 14% (2012), 11% (2013) and 12% (2014) of total Community Drug Distributors trained in the region. Lack of incentive for Community Drug Distributor was primary reason for Community Drug Distributor attrition. Number of Community Drug Distributors trained together by health area ranged from 14 to 127 (mean ± SD = 51 ±32) with duration of training ranging from 4–7 hours (mean ± SD = 5.05 ± 1.09). The trainings were conducted at the health centers. Community Drug Distributors always conducted census during the past three distributions (Mean ± SD = 2.85 ± 0.58). Community-Self Monitoring was facing challenge. Several of the community heads, Chiefs of Bureau Health and Chiefs of Center agreed that Community-Self Monitoring was not being carried out effectively due to lack of incentives for monitors in the communities.

Conclusion

Inadequate human resource, funding issues and transportation challenges during distribution periods reduced the ability of the health service to thoroughly sensitize communities and supervise CDTI activities. This resulted in weak community understanding, acceptance and participation in the process. CDTI in our study area did not achieve sustainable community-led campaign and this may have led to the reduced impact on Onchocerciasis.

River blindness is caused by a very tiny, thread-like worm. The disease is better controlled when affected communities are included in the planning and carrying out of distribution of Ivermectin used to treat the disease. For a community to be able to prevent people from getting this disease, members must take Ivermectin once or twice a year, continuously for about 20 years. Hence, the organization in charge of controlling river blindness (African Programme for Onchocerciasis Control–APOC) decided that when a control programme is started in a community, the community must be involved and assisted to take full charge of the programme so that within 12 years the community can sustain the distribution of Ivermectin for as long as necessary. This community directed strategy prevented river blindness in many communities. However, after 10–12 years of implementation, studies found that river blindness largely persists in communities in three drainage basins in South West Region of Cameroon. This paper discussed the operational challenges that the programme may have faced in these areas.

Towards elimination of lymphatic filariasis: social mobilization issues and challenges in mass drug administration with anti-filarial drugs in Tamil Nadu, South India

India is a signatory to World Health Assembly resolution for elimination of lymphatic filariasis (LF) and National Health Policy has set the goal of LF elimination by 2015. Annual mass drug administration (MDA) is ongoing in endemic districts since 1996-97. Compliance rate is a crucial factor in achieving elimination and was assessed in three districts of Tamil Nadu for 10th and 11th treatment rounds (TRs). An in-depth study assessed the impact of social mobilization by drug distributors (DDs) in two areas from each of the three districts. Overall coverage and compliance for assessed TRs were 76.3 and 67.7% which is below the optimum level to achieve LF elimination. Modifiable determinants continue to be the reason for non-consumption even in the 11th TR and 20.8% were systematic non-compliers. In 76.4% of the cases, DDs failed to adhere to three mandatory visits as per the guidelines. Number of visits by DDs in relation to low and high MDA coverage areas showed a significant relationship (P ≤ 0.000). MDA is limited to drug distribution alone and efforts by DDs in preparing the community were inadequate. Probable means to meet the challenges in preparation of the community is discussed.

The rapid monitoring of ivermectin treatment: will school-based surveys provide the answer?

The data on ivermectin-treatment coverage recorded in household surveys sometimes conflict with those recorded in school-based surveys or in the relevant treatment registers maintained by community-directed distributors (CDD). An attempt has now been made, in two sites in Nigeria (Enugu and Kaduna states) and one in Sudan (Abu Hamad province), to determine how well these three sets of data are correlated (and to explore the effectiveness of several alternative channels for the delivery of treatment-monitoring forms to schools). Using a cross-sectional approach, data were collected from primary schools, households and treatment registers. Calculation of Pearson's correlation coefficients (r) indicated that, overall, the data from the household surveys were very similar to those collected using the school-based strategy (r=0.66; P<0.0001) or from the treatment registers of the CDD (r=0.86; P<0.0001). The information recorded in the CDD registers also closely matched that recorded in the school-based surveys (r=0.67; P<0.0001). These encouraging results for the pooled data masked some inter-site differences. The correlation between the household-survey and treatment-register data was, for example, only good in Enugu (r=0.89; P<0.001), and was too weak to be statistically significant in Abu Hamad or Kaduna. Although the results of the school-based survey in Kaduna also did not closely correlate with those of the corresponding household survey (r=0.10; P=0.71), the household survey at this site was probably not conducted as well as those at the two other sites. In general, it appears that school-based surveys are an effective means of monitoring community coverage with ivermectin, rapidly, accurately and at relatively low cost. It is therefore recommended that school-based methods of monitoring of coverage are adopted by programme managers.

Strengthening of mass drug administration implementation is required to eliminate lymphatic filariasis from India: an evaluation study

BACKGROUND & OBJECTIVES

The mass drug administration (MDA) is one of the strategies to eliminate lymphatic filariasis in India. Eleven districts are endemic for the disease in Madhya Pradesh state of India, which conduct MDA activities annually. A mid-term evaluation was conducted with the objectives to review the progress of the single dose of di-ethyl-carbamazine (DEC) administration, and to understand the functioning of the programme to recommend mid-term amendments.

METHODS

A qualitative cross-sectional study was conducted in three endemic districts of Madhya Pradesh between July and October 2007. The teams of faculty members from medical college visited the study districts and collected data by desk review, indepth interviews, on site observations, and from the community.

RESULTS

The filaria units in these districts were understaffed. There were no night clinics in two out of the three districts. The sufficient number of trainings for MDA were conducted without any mechanism for quality assurance. There was erratic and inadequate supply of DEC tablets, leading to the postponement of MDA activity, twice. The evaluated coverage with DEC tablets was much lower than that reported by the district officials. The tablet intake was not ensured by the distributors and the compliance rate was in the range of 60-70%. The IEC activities were conducted in limited areas, and there were prevailing myths and misconceptions, contributing to low compliance rate. There was no proper recording of the data on filariasis with gross mismatch at district headquarters and peripheral health facilities. A proportion of community members developed side effects following DEC tablet intake and had to visit private health facilities for treatment.

INTERPRETATION & CONCLUSION

This evaluation study noted that MDA is restricted to tablet distribution only and the major issues of implementation in compliance, health education, side effect and morbidity management, and the logistics were not being given due attention. The implementation should be strengthened immediately in the MDA programme in India to achieve the goal of LF elimination by 2015.

Ivermectin and onchocerciasis: is it all solved?

The donation of ivermectin by Merck and Co. Inc. has led to one of the most effective private-public partnerships controlling a disease of major public health importance particularly in Africa. The up scaling of ivermectin distribution during the last 15 years has been remarkable with almost 40 million people treated in 2003, many already on their regular annual dose. The tools that have been developed particularly by the APOC programme have been instrumental in this increase. However, ivermectin is a microfilaricide and does not kill the adult worms. Distribution will be needed for at least 25 years and latest estimates indicate that 90 million people need annual treatment if onchocerciasis is to be eliminated as a public health problem. In spite of this incredible progress it is difficult to see how the programme will be sustained, especially after the closure of APOC in 2010. A macrofilaricide destroying adult worms and safe for mass distribution would solve the problem of onchocerciasis.

A rapid method to assess the coverage of the mass drug administration of diethylcarbamazine in the program to eliminate lymphatic filariasis in India

A rapid method to assess the coverage of mass drug administration (MDA) in the program to eliminate lymphatic filariasis needs to be developed for monitoring and evaluation of the program. This study attempted to develop and test a method of rapid assessment of coverage by using the existing resources of the program. This is based on the data obtained from the randomly selected health workers and drug distributors involved in the drug distribution process and the data of a household coverage survey of the program. The MDA coverage rate obtained through the evaluation survey was highly correlated with the rates obtained from health workers and drug distributors as a rapid assessment. Thus, MDA coverages assessed through health workers and drug distributors can give a good coverage estimate. The involvement of the existing human resources of the program in this rapid method of assessing MDA coverage was cost-effective.

The delivery of ivermectin (Mectizan)

Over a comparatively short period of time, the development and distribution of ivermectin (Mectizan) has radically altered the consequences of infection with Onchocerca volvulus. To achieve this required the fostering of many partnerships and the development of new tools and methods. The long-term commitment of Merck, the World Bank and other sponsors, as well as governments and non-governmental organizations, has been crucial. Yet the enthusiasm with which communities have taken up the delivery of ivermectin among themselves is perhaps the greatest reason for the success of this programme. The present challenge is sustaining the methods that have brought success so far, and making them part of health services and disease control programmes in some of the world's most impoverished and unstable areas. A major part of this challenge is continuing the commitment to controlling onchocerciasis as memory of the disease is fading, and while the hope of elimination or eradication for most endemic countries remains distant.

Impact of ivermectin on illness and disability associated with onchocerciasis

The Onchocerciasis Control Program (OCP), one of the most successful vertical disease control programs in the history of public health, came to an end in 2003 with devolvement of responsibilities for control program activities passed to the countries affected. Fortunately, 15 years ago the Mectizan Distribution Program (MDP) was founded to provide a complementary approach to controlling the disabling consequences of this parasitic infection. With over 250 million doses of ivermectin distributed over the past 15 years, the MDP is well on its way to both solidifying the progress made by the OCP and extending program reach well beyond the boundaries of the OCP. Through the extensive clinical testing protocols implemented in a variety of countries in Aftica, ivermectin has been proven to be a safe and highly effective treatment for onchocerciasis. Regular distribution to populations living in endemic areas has demonstrated significant reductions in blinding ocular complications, transmission, and disability caused by onchocercal skin disease. As yet undocumented, are the likely significant impact regular population dosing with ivermectin has on intestinal helminth infections, lymphatic filariasis, and human scabies infection. While there are significant barriers to continued program success, focussed attention on expanding and improving community-directed ivermectin distribution is likely to lead to further progress against this resilient infection.

Economic evaluation of Mectizan distribution

The distribution of ivermectin has dramatically altered the nature of onchocerciasis control. Existing economic analyses of ivermectin distribution programmes show that these programmes have a highly beneficial impact. Most analyses have estimated the economic benefits in terms of increased labour productivity as a result of reductions in blindness, and in terms of additional land-availability because of a reduced transmission of the parasite. Economic evaluations of the Onchocerciasis Control Program (OPC) in West Africa have calculated a net present value - equivalent discounted benefits minus discounted costs - of $485 million for the programme over a 39-year period, using a conservative 10% rate to discount future health and productivity gains. The net present value for the African Program for Onchocerciasis Control (APOC) is calculated at 88 million US dollars over a 21-year time period, also using a 10% discount rate. Cost-effectiveness analyses of ivermectin distribution have found a cost of 14-30 US dollars per disability-adjusted life-year prevented - estimates comparable with other priority disease control programmes. However, the economic success of ivermectin distribution is sensitive to the fact that the drug itself has been donated free of charge. The market value of Merck's donations to the APOC for just 1 year considerably outweighs the benefits calculated for both the OPC and the APOC over the life of these projects. Pending the development of an effective macrofilaricide, the distribution of ivermectin will remain a public health priority into the foreseeable future.

Mectizan Donation Program: evaluation of a public-private partnership

The Mectizan Donation Program (MDP) has been perceived as a highly effective public health programme, and as a possible model for addressing future problems in international health. This evaluation examines how the MDP partnership has been functioning from the perspectives of partner organizations. The results of a survey of 25 partners show that the perceived benefits far outweigh the problems, and that the direct costs to the organizations have been minimal. The partnership is rated highly on many aspects of governance and management, with relatively few problems identified. A factor analysis demonstrated that a wide range of factors have influenced the partners' perceptions. The benefits with the largest weights appear to be those related to external perceptions of the organization, and those indicating that the organization feels that its opinions will matter and lead to action in the partnership. The biggest factors influencing the positive perceptions on the governance and management of the MDP partnership appear to be the involvement of senior leaders from different organizations, and being able to agree on priorities. The MDP has been able to involve a large and heterogeneous number of partner organizations through relatively informal mechanisms that rely on goodwill and reciprocity. The survey results show how there was a strong alignment of the MDP with the interests of the various partners, and that a manageable number of problems were addressed and services provided. While having long-term goals, the MDP and the onchocerciasis control programmes have been effective at demonstrating the effectiveness of the approach through regular, professional, and outcome-oriented evaluations. Although the MDP is considered to be central to concerns of national officials, this feature is not rated as high as public perceptions, the internal characteristics of the partnership, or its accomplishments. Similarly, the need to secure resources is not viewed as a major determinant of the partnership's success, perhaps because resources were readily available through Merck and the partner organizations and programmes. These findings, along with the strategic and operational success of the MDP confirm the view that this type of public-private partnership should be pursued vigorously in other areas of public health. Other potential partnerships would do well to examine the characteristics of the MDP partnership, with careful attention to the features of its governance and the management, including a strong alignment of interests with partners, balancing a long-term vision with clarity of roles and intensive management of coordination, and professional and results-oriented accountability.

A multi-centre study of community-directed ivermectin distributors' (CDDs') involvement in other healthcare and development programme activities in Cameroon, Togo, Sudan, Nigeria and Uganda

A multi-centre study to determine whether community-directed distributors (CDDs) are capable of carrying out additional healthcare and developmental activities in their communities was carried out in Cameroon, Nigeria, Sudan, Uganda and Togo to ascertain the potential effects of their involvement on the implementation of community-directed treatment with ivermectin (CDTI). Both quantitative and qualitative methods were used to collect data from households, community-directed distributors, community leaders, and health workers. The results showed no major decrease in the CDDs' performance in CDTI: on the contrary, the involvement of CDDs in other health and development activities motivated them to perform their CDTI functions better. However, the results did not show any significant increase in therapeutic coverage of ivermectin distribution. The expansion of the CDDs' experience to include additional healthcare and development related activities would be of interest to onchocerciasis control programmes--it will strengthen CDTI sustainability through greater integration.

Using ivermectin-treatment coverage among schoolchildren monitored by schoolteachers as a proxy of population coverage in areas of Uganda where onchocerciasis is endemic

In the control of onchocerciasis using mass treatment with ivermectin, coverage needs to be monitored regularly so that communities with poor or insufficient coverage can be identified and timely and appropriate interventions then instituted. The aim of the present study was to assess whether ivermectin-treatment coverage in schoolchildren, as monitored by schoolteachers, could be used as a proxy of population coverage. Although the coverages estimated in schoolchildren were found to be significantly correlated with estimates based on household surveys (P=0.01), there was poor correlation between either school and household-survey coverage and the values recorded in community registers. Although the community-register figures are the ones which the district health services normally use to report treatment coverage, they may be unreliable. Ivermectin-treatment coverage in schoolchildren monitored by schoolteachers could give a good and more accurate approximation of total population coverage. Further, large-scale studies, that take into consideration the cost-effectiveness of the various methods available to validate reported treatment coverage, are recommended.

The Carter Center's assistance to river blindness control programs: establishing treatment objectives and goals for monitoring ivermectin delivery systems on two continents

Periodic mass treatment with ivermectin in endemic communities prevents eye and dermal disease due to onchocerciasis. As part of an international global partnership to control onchocerciasis, The Carter Center's Global 2000 River Blindness Program (GRBP) assists the ministries of health in ten countries to distribute ivermectin (Mectizan, donated by Merck & Co.). The GRBP priorities are to maximize ivermectin treatment coverage and related health education and training efforts, and to monitor progress through regular reporting of ivermectin treatments measured against annual treatment objectives and ultimate treatment goals (e.g., full coverage, which is defined as reaching all persons residing in at risk villages who are eligible for treatment). Since the GRBP began in 1996, more than 21.2 million ivermectin treatment encounters have been reported by assisted programs. In 1999, more than 6.6 million eligible persons at risk for onchocerciasis received treatment, which represented 96% of the 1999 annual treatment objective of 6.9 million, and 78% of the ultimate treatment goal in assisted areas.

Involvement of women in community-directed treatment with ivermectin for the control of onchocerciasis in Rukungiri district, Uganda: a knowledge, attitude and practice study

A study of knowledge, attitudes and practice was carried out in the Rukungiri district of Uganda, in order to investigate the involvement of women in community-directed treatment with ivermectin (CDTI), for the control of onchocerciasis. The data analysed came from interviews with 260 adult women (one from each of 260 randomly-selected households in 20 onchocerciasis-endemic communities), community informants, and participatory evaluation meetings (PEM) in eight communities. The women who had been treated with ivermectin in 1999 generally had more knowledge of the benefits of taking ivermectin, were more likely to have attended the relevant health-education sessions and were more involved in community decisions on the method of ivermectin distribution than the women who had not received ivermectin in that year. There were fewer female community-directed health workers (CDHW) than male CDHW in the communities investigated. The reasons for not attending health-education sessions, not participating in community meetings concerning the CDTI, and the reluctance of some women to serve as CDHW were investigated. The most common reasons given were domestic chores, a reluctance to express their views in meetings outside their own kinship group, suspicions that other women might take advantage of them, and a lack of interest. Most of the women interviewed (as well as other community members) felt that there were relatively few women CDHW. The women attributed this to a lack of interaction and trust amongst themselves, which resulted in more men than women being selected as CDHW. The rest of the community members were not against women working as CDHW. It is recommended that communities be encouraged to select women to serve as CDHW in the CDTI, and that the performances of male and female CDHW be compared.

Community-directed treatment: the way forward to eliminating lymphatic filariasis as a public-health problem in Ghana

The elimination of lymphatic filariasis as a public-health problem is currently dependent on the delivery of annual drug treatments to at least 80% of the eligible members of endemic populations for at least 5 years. However, for various reasons, this goal may not be achievable by the health systems of most endemic countries in sub-Saharan Africa, particularly if treatment is not community-directed. In Ghana, community-directed ivermectin treatment involving the regular public-health services at the implementation level (ComDT/HS) has recently been compared with mass-treatment in which only the health services participated (HST). Health staff and the target communities appreciated the ComDT/HS approach more than the HST approach and were more willing to participate in the community-directed scheme. The treatment coverage achieved by ComDT/HS (74.5%) was not only much higher than that of HST (43.5%) but also probably adequate for filariasis elimination. HST coverage was particularly poor in villages located > 5 km from a health facility, but distance from such a facility had no significant effect on treatment coverage in the ComDT/HS arm. As virtually all the subjects who received drugs swallowed them, compliance with treatment was not a problem. The ComDT/HS approach is therefore recommended, especially for areas where access to health facilities is poor and the health workers are over-stretched. The implications of these findings for the global programme for filariasis elimination are discussed.

In rural Ugandan communities the traditional kinship/clan system is vital to the success and sustainment of the African Programme for Onchocerciasis Control

In rural Ugandan communities where onchocerciasis is meso- or hyper-endemic, control of the disease is now being carried out using a strategy of community-directed programmes for the annual distribution of ivermectin to all persons eligible to take the drug. For these programmes to achieve their annual target coverage of at least 90% of the population eligible to take ivermectin, and to continue to sustain themselves for 10-15 years or more, even after external donor funding ceases, it has been found essential to replace the initial community-based strategy, imposed from outside, by a community-directed strategy developed by the community members themselves. Furthermore, it is essential for success that full use be made of the traditional social system, which is very strong in all rural communities in Uganda. This system is based on patrilineal kinships and clans, governed by traditional law, and in it women pay an important role. If this system is ignored or by-passed by government health personnel or by the sponsors and promoters of the programme, the communities are likely to fail to reach their targets. When rural communities increase in size and complexity, following development and the arrival of migrant families, they become semi-urbanized. The kinship/clan system is then weakened, community-directed drug distribution is much more difficult to organize, and coverage targets are not often achieved. This effect is of minor importance in a rural disease, such as onchocerciasis, but is likely to be of greater significance in the control of diseases, such as tuberculosis and lymphatic filariasis, which thrive in urban environments.

Controlling onchocerciasis by community-directed, ivermectin-treatment programmes in Uganda: why do some communities succeed and others fail?

In Uganda, human onchocerciasis is controlled by annual, mass, community-directed, ivermectin-treatment programmes (CDITP) in all endemic communities where the prevalence of the disease is > or = 30%. This is a practical, long-term and cost-effective strategy. In some communities, this system succeeds in providing treatment at the desired level of coverage (i.e. 90% of the annual treatment objective, which is itself equivalent to all those individuals eligible to take ivermectin). Other communities, however, fail to reach this target. The aim of the present study was to determine the factors that were significantly associated with success or failure in achieving this target. The data analysed were answers to a questionnaire completed by 10 household heads randomly selected from each of 64 randomly selected endemic communities (of which 36 succeeded and 28 failed to reach their coverage target) in the four districts of Kabale, Moyo, Nebbi and Rukungiri. Among the programme-related factors investigated, success was associated, at a statistical level of significance (P < or = 0.05), with involvement of community members in: (1) decisions about the execution of the programme; (2) attendance at health-education sessions; (3) selection of the community-based distributors (CDB); and (4) rewarding CBD in kind. In general, the involvement of community members in the planning and execution of a CDITP (and the resultant sense of pride in community ownership) was more likely to produce successful results than when external health workers or even community leaders or local councils took responsibility.

Community financing of local ivermectin distribution in Nigeria: potential payment and cost-recovery outlook

The preferred payment mechanism in a community financing scheme for local ivermectin distribution was elicited from randomly selected household heads from three communities in Nigeria using interviewer-administered structured questionnaires. The majority of the respondents in the three communities were prepared to pay for local ivermectin distribution. Additionally, the average amounts the respondents were prepared to pay per person treated ($0.28, $0.30 and $0.38 in Nike, Achi and Toro, respectively) were all more than the $0.20 ceiling recommended by the partners of the African Programme on Onchocerciasis Control (APOC). Thus, the cost-recovery outlook is bright in these communities. However, the preferred payment modality varied. Fee-for-service was the predominant payment modality in the Achi and Nike communities, while the Toro community preferred pre-payment. This study demonstrates that many communities have different payment preferences for endemic disease control efforts. This knowledge will help in developing acceptable and sustainable schemes. The imposition of unacceptable payment mechanisms will lead to an unwillingness to pay.

Cost of mass annual single dose diethylcarbamazine distribution for the large scale control of lymphatic filariasis

Economic analysis of the revised strategy to control lymphatic filariasis with mass annual single dose diethylcarbamazine (DEC) at 6 mg/kg body weight launched in one of the districts of Tamil Nadu in 1996 was carried out. This exploratory study, proposed for five years in 13 districts under 7 states on a pilot scale through the Department of Public Health is an additional input of the existing National Filaria Control Programme in India. A retrospective costing exercise was undertaken systematically from the provider's perspective following the completion of the first round of drug distribution. The major activities and cost components were identified and itemized cost menu was prepared to estimate the direct (financial) and indirect (opportunity) cost related to the implementation of the Programme. The total financial cost of this Programme to cover 22.7 lakh population in the district was Rs. 22.05 lakhs. The opportunity cost of labour and capital investment was calculated to be Rs. 7.98 lakhs. The total per capita cost was Rs. 1.32, with Rs. 0.97 and Rs. 0.35 as financial and opportunity cost respectively. Based on these estimates, the implementation cost of the Programme at Primary Health Centre (PHC) level was calculated and projected for five years. The additional financial cost for the existing health care system is estimated to be Rs. 27,800 per PHC every year. DEC tablets (50 mg) was the major cost component and sensitivity analysis showed that the cost of the Programme could be minimized by 20 per cent by switching over to 100 mg tablets. The analysis indicates that this Programme is a low-cost option and the results are discussed in view of its operational feasibility and epidemiological impact.

The community-directed, ivermectin-treatment programme for onchocerciasis control in Uganda--an evaluative study (1993-1997)

The first 5 years of a community-directed, ivermectin-treatment programme, to control onchocerciasis in 1805 endemic communities in 10 districts in Uganda, are evaluated. Each year, the desired treatment coverage of the population eligible to take invermectin (90%) was achieved in 42.6%-51% of the 1713 communities for which complete data were available; 67%-74.8% achieved 80% coverage. The annual cost per person treated with ivermectin (ACPTI) was much higher in the districts with small populations to be treated (< 15,000) than in those with large populations (> 40,000) (U.S.$0.40 v. U.S.$0.10 or less). The community members' acceptance of the programme was related to their attendance at health-education sessions (P = 0.009), and their participation in the mobilisation of other community members increased greatly when they were allowed to take part in the selection of the community-based distributors (CBD) and the choice of treatment sites. The overall target ratio of one CBD/71 families was attained by 1997. However, the failure of some trained CBD to participate in the treatment exercise prevented some communities achieving 90% treatment coverage. Providing CBD with cash incentives or externally derived incentives 'in kind' proved counter-productive whereas locally generated incentives 'in kind' were simply regarded as the normal obligations of the community. District health staff successfully integrated the programme with their other health commitments, but the involvement of CBD in other programmes proved detrimental to their performance. Other constraints identified were rebel insurgency in some areas, and abnormally heavy rains in hilly areas with poor roads.

A method to determine the coverage of ivermectin distribution in onchocerciasis-control programmes

Onchocerciasis is a human filarial infection responsible for an estimated 750,000 blind and severely visually disabled people. In some African countries, this disease represents the main cause of blindness, with considerable socio-economic impact on the affected communities. Since the introduction of ivermectin as a microfilaricidal agent, there is hope that visual loss from onchocerciasis can be eliminated through community-based ivermectin-distribution programmes. The African Programme for Onchocerciasis Control (APOC) has now been initiated, by the World Health Organization and World Bank, to distribute ivermectin in 19 African countries where onchocerciasis is endemic. Estimates of ivermectin coverage in distribution programmes for onchocerciasis control have so far been based on the number of treatments given, in any one year, to a target population. There is a need for a standardized method to evaluate, measure and monitor coverage over time. In April 1996, a cluster random-sampling method was used to calculate coverage with ivermectin in an urban population of 30,000 people in the Central African Republic. The method was adapted from that used to determine coverage by the WHO Expanded Programme on Immunization. It proved to be inexpensive and easy to perform, requiring only local equipment and personnel. The method used and results obtained in Bossangoa and the potential use of the technique in other distribution programmes are discussed.

Onchocerciasis control in Uganda

In 1990 a community-based programme of onchocerciasis control, involving the use of ivermectin, was introduced in Uganda. The problems confronting it are discussed and suggestions are made for making it sustainable.

Problems and perspectives of managing an onchocerciasis control programme: a case study from Plateau state, Nigeria

The onchocerciasis control programme in Plateau state (now Plateau and Nasarawa states), Nigeria, was one of the pioneering Mectizan-distribution projects in Nigeria. Although initiated under the River Blindness Foundation (RBF) in 1991, in collaboration with the Ministry of Health, it was absorbed into the Carter Center's Global 2000 River Blindness Programme (GRBP) in 1996. The objectives of the programme were to support the delivery of Mectizan (ivermectin, MSD) to at least 80% of those living in communities where onchocerciasis was highly endemic, within the first 3 years of the project's inception, and to maintain this coverage for a period of 10-15 years. The programme has so far been successful, and much of this success is attributed to problem identification and problem-solving through continuous review and evaluation of programme activities, and implementation of strategies, when required, to ensure those programme objectives are met. The implementation steps of the programme, and some of the managerial problems identified during the course of the effort, are reviewed. The challenge now is to learn how to transform this functional, programme-designed and programme-directed effort into the new community-directed treatment being promoted by the African Programme for Onchocerciasis Control. The new challenges of the transition require middle-level managers and implementors with effective, efficient and indeed state-of-the-art management skills.

Control of onchocerciasis: challenges for the future

The control of onchocerciasis has grown over the last two decades to attain global dimensions. This rapid growth poses challenges that are technical and managerial in nature. Appropriate control measures have to be applied to eliminate the disease as a worldwide, public-health problem and prevent the problem recurring. Novel tools and innovative approaches, both for control and surveillance activities, will have to be developed. The health systems of the affected countries need not only to be directly involved in control activities but also to direct operations and have adequate resources to run them successfully.

Mectizan delivery systems and cost recovery in the Central African Republic

The Central African Republic (CAR) has a serious onchocerciasis problem. The disease is endemic in three quarters of the country and there is considerable onchocercal blindness in the north-west. The low population density and extreme poverty (the CAR being one of the 20 poorest countries in the world) combine to make mass treatment with Mectizan (ivermectin, MSD) a challenge. Although planned, primary health care (PHC) is not widely developed in the country. Mectizan distribution was carried out in 1993-1994 by mobile teams in order to address the most urgent need, particularly in the north-west. Since then, the strategy has been one of community involvement, using village health workers, chosen by their own communities, to do the treatment. The system has been a stimulus to the development of PHC in some areas, as the co-ordinators of the Mectizan programme are often the only health personnel to visit every village. The long distances between health centres, with a mean of 45 km, are likely to be an obstacle to the population collecting their own Mectizan, within the self-treatment system otherwise in place. Operational research is planned to examine ways in which the population can contribute to cost recovery without there being a reduction in treatment coverage.

Changes in the use profile of Mectizan: 1987-1997

The usually conservative approach of Merck & Co. to drug development became even more so in the Mectizan (ivermectin, MSD) programme because of adverse experiences following 'extra-label' use in Collie dogs and the discovery of a low threshold for acute neurotoxicity in CF-1 mice. Although a very cautious approach and rapid development programme ensued, Merck remained conservative and excluded children under the age of 5 years, pregnant women, and mother who were nursing children under the age of 3 months from treatment. A subsequent, more relaxed set of standards was based on vast human clinical experience, inadvertent use in hundreds of pregnant women without ill-effect, and new laboratory information indicating that the presence of a protective blood-brain barrier protein component (P-glycoprotein) helped to stop Mectizan from crossing the placenta and from crossing the blood-brain barrier in most animal species, including humans. This has allowed more groups to be included in Mectizan treatments: pregnant women living in areas where the risk of loss of sight because of onchocerciasis is very high; and women who are nursing children as young as 1 week of age. Mass distribution of the drug continues to be largely under community control and the likelihood of serious adverse experiences related to finding a human population with unusually low levels of P-glycoprotein (or no P-glycoprotein) seems remote.

Delivery systems and cost recovery in Mectizan treatment for onchocerciasis

The efficiency of on-going delivery systems and cost recovery in Mectizan (ivermectin, MSD) treatment for onchocerciasis are reviewed. The search is on for an effective system of Mectizan delivery, involving drug procurement, delivery from port to districts and distribution to eligible persons, which can be sustained by the endemic countries for many years. The mechanisms for procuring and clearing the drug at the ports, and the drug's integration into the existing delivery systems of each national health service, need to be improved. Although large-scale treatments by mobile teams or community-based methods evidently achieve high and satisfactory rates of coverage, they also incur high recurrent costs which have to be covered by external partners and are not sustainable by national health services. Cost-sharing is considered an important factor in a sustainable delivery system and community-directed treatment, in which the community shares the cost and ownership of local distribution and is empowered to design and implement it, is likely to be more cost-effective and sustainable.

Mectizan as a stimulus for development of novel partnerships: the international organization's perspective

Following the free donation of Mectizan (ivermectin, MSD) by Merck & Co. in 1987, early efforts to mass distribute the drug came from non-governmental development organizations (NGDO), which had already established projects in Africa and Latin America by 1989. In the beginning, these projects were NGDO-specific and fairly independent from one another. Subsequently, the need to co-ordinate all attempts at Mectizan distribution led to the creation of the Onchocerciasis Eradication Programme of the Americas (OEPA), in 1991, and the NGDO Co-ordination Group for Ivermectin Distribution, in 1992. The latter was to become the 'prime mover' in Mectizan-distribution programmes, particularly in areas of Africa not monitored by the Onchocerciasis Control Programme in West Africa (OCP), until the advent of the African Programme for Onchocerciasis Control (APOC) in 1995. Once the co-ordination group had been established and its co-ordinator appointed, the Mectizan-distribution programme expanded rapidly, reaching 7 million people by 1995. However, the limited resources of the co-ordination group and the need to achieve a better co-ordinated and more comprehensive control of onchocerciasis ultimately led to the creation of the APOC in 1995. The international co-operation behind the APOC has inaugurated a unique type of global partnership, in which the success of the programme lies not with a single player, but with close working relationships and collaboration between many partners: donors; governments of endemic countries; NGDO; international organizations; and private institutions. This is a complex process, the success of which cannot be guaranteed. However, if it can be made to succeed, it will serve as a model to be used to address other serious and intractable development or health problems.

The Mectizan Donation Programme--a 10-year report

In the 10 years since 1987 when Merck & Co. announced a plan to donate its safe and effective microfilaricide, Mectizan (ivermectin, MSD), to treat onchocerciasis wherever and for as long as needed, more than 96 million treatments have been enabled in community-based treatment programmes in all 34 countries, in Africa, the Middle East, and Latin America, where the disease is endemic. It is expected that donations enabling some 33 million treatments will be approved in 1997. Since the beginning of the donation programme, it is estimated that some 19-20 million people have received at least one dose of the drug and that many have received their sixth, seventh, eighth, or even ninth annual dose.