The African Programme for Onchocerciasis Control: impact on onchocercal skin disease.

OBJECTIVES: To assess the long-term impact of the African Programme for Onchocerciasis Control on itching and onchocercal skin disease (OSD). METHODS: Seven study sites in Cameroon, Sudan, Nigeria and Uganda participated. Two cross-sectional surveys were conducted of communities meso- and hyper-endemic for onchocerciasis before and after 5 or 6 years of community-directed treatment with ivermectin (CDTI). Individuals were asked about any general health symptoms including itching and underwent full cutaneous examinations. Onchocercal skin lesions were documented according to a standard classification. RESULTS: Five thousand one hundred and ninety three people were examined in phase I and 5,180 people in phase II. The presence of onchocercal nodules was a strongly significant (P < 0·001) risk factor for all forms of onchocercal skin disease: APOD (OR 1·66); CPOD (OR 2·84); LOD (OR 2·68); reactive skin lesions (OR 2·38) and depigmentation (OR 3·36). The effect of community-directed treatment with ivermectin was profound. At phase II, there were significant (P < 0·001) reductions in the odds of itching (OR 0·32), APOD (OR 0·28); CPOD (OR 0·34); reactive skin lesions (OR 0·33); depigmentation (OR 0·31) and nodules (OR 0·37). Reduction in the odds of LOD was also significant (OR 0.54, P < 0.03). CONCLUSIONS: This first multi-country report of the long-term impact of CDTI reveals a substantial reduction in itching and OSD. APOC operations are having a major effect in improving skin health in poor rural populations in Africa.

Bacteriological quality of weaning food and drinking water given to children of market women in Nigeria: implications for control of diarrhoea.

Bacteriological quality of weaning food and drinking water given to 2 groups of children aged < or = years was evaluated by estimating bacterial cell count. One group consisted of those taken to market and the other of those left at home in the care of older siblings or house-helps. Bacterial counts (geometric mean) ranged from 5.02 +/- 1.82 to 8.70 +/- 1.0 log10 cfu per g or mL of food, and from 1.15 +/- 1.67 to 6.53 +/- 0.81 log10 cfu per g or 100 mL of water. Analysis of variance showed no significant difference in counts between types of food and between meals (breakfast and lunch). Bacterial contamination increased significantly with storage time, and was, in all circumstances except the water samples, significantly higher in foods given to children left at home. Reheated leftover foods also had significantly higher bacterial load than the freshly-cooked food. Coliform count varied significantly with source of drinking water. Poor hygiene standard (inferred from bacterial contamination) was generally observed among mothers weaning < or = 2-year-old children, while they were engaged in trading activities in the market, thus exposing their children to high risk of diarrhoea. Hygiene was significantly poorer in weaning of children left at home in the care of older siblings or house-helps. This implies that, in spite of their trading activities in the market, mothers still take better care of their babies than the older siblings or house-helps who may be inexperienced. These mothers may need education on childcare and food hygiene to suit to their trading activities, for example, during their monthly meetings. There is also a need to establish ORT (oral rehydration therapy) corners in the markets as part of the municipal services. This can be used not only for efficient and quick management of diarrhoea in the market but also for reinforcing hygiene education.

The elimination of the vector Simulium neavei from the Itwara onchocerciasis focus in Uganda by ground larviciding.

The Itwara focus of onchocerciasis covers an area of approximately 600 km(2) in western Uganda about 20 km north of Fort Portal. The vector is Simulium neavei, whose larvae and pupae live in a phoretic association on freshwater crabs. The phoretic host in the Itwara focus is the crab Potamonautes aloysiisabaudiae. Before any onchocerciasis control, ATPs were estimated to reach between 4500 and 6500 infective larvae per person per year. S. neavei was found to be a very efficient vector with 40% of parous flies harbouring developing larvae of Onchocerca volvulus. After 4 years of community-based distribution of ivermectin transmission was still considerable and in 1995 monthly treatment of streams with the larvicide temephos commenced in the first of three sub-foci, and was gradually extended to the whole focus. Biting S. neavei disappeared from the first sub-focus (Itwara main) in June 1996, and the last infested crab was caught in November 1996. In the second sub-focus (Siisa) treatment commenced towards the end of 1995, and the last biting fly was caught in March 1997, but a deterioration in the security situation interrupted the programme (after only three treatments in the third sub-focus). Monthly treatments restarted in the second and third sub-foci (Aswa) in September 1998, and when the situation was reassessed in 2003 no biting flies were found anywhere, and the flies had not reinvaded the first sub-focus, but infected crabs were found in the second and third sub-foci. The last treatments were carried out in April-June 2003, and since then no infested crabs have been found. In summary, no S. neavei-infested crabs have been found anywhere in the focus since June 2003 and the vector is considered eliminated from that date. However, transmission had already been halted since February 2001, when the last biting flies had been collected. The parasite reservoir should die out in the human population by 2016.

The elimination of the onchocerciasis vector from the island of Bioko as a result of larviciding by the WHO African Programme for Onchocerciasis Control.

The island of Bioko is part of the Republic of Equatorial Guinea and is the only island in the World to have endemic onchocerciasis. The disease is hyperendemic and shows a forest-type epidemiology with low levels of blindness and high levels of skin disease, and the whole population of 68,000 is estimated to be at risk. Control of onchocerciasis began in 1990 using ivermectin and this yielded significant clinical benefits but transmission was not interrupted. Feasibility and preparatory studies carried out between 1995 and 2002 confirmed the probable isolation of the vector on the island, the high vectorial efficiency of the Bioko form of Simulium yahense, the seasonality of river flow, blackfly breeding and biting densities, and the distribution of the vector breeding sites. It was proposed that larviciding should be carried out from January to April, when most of the island's rivers were dry or too low to support Simulium damnosum s.l., and that most rivers would not need to be treated above 500 m altitude because they were too small to support the breeding of S. damnosum s.l. Larviciding (with temephos) would need to be carried out by helicopter (because of problems of access by land), supplemented by ground-based delivery. Insecticide susceptibility trials showed that the Bioko form was highly susceptible to temephos, and insecticide carry was tested in the rivers by assessing the length of river in which S. damnosum s.l. larvae were killed below a temephos dosing point. Regular fly catching points were established in 1999 to provide pre-control biting densities, and to act as monitoring points for control efforts. An environmental impact assessment concluded that the proposed control programme could be expected to do little damage, and a large-scale larviciding trial using ground-based applications of temephos (Abate 20EC) throughout the northern (accessible) part of the island was carried out for five weeks from 12 February 2001. Following this, a first attempt to eliminate the vectors was conducted using helicopter and ground-based applications of temephos from February to May 2003, but this was not successful because some vector populations persisted and subsequently spread throughout the island. A second attempt from January to May 2005 aimed to treat all flowing watercourses and greatly increased the number of treatment points. This led to the successful elimination of the vector. The last biting S. damnosum s.l. was caught in March 2005 and none have been found since then for more than 3 years.

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.

The effect of two child-care practices of market women on diarrhoea prevalence, feeding patterns and nutritional status of children aged 0-24 months.

A cross-sectional comparative study was conducted in seven markets in Enugu and Nsukka, Nigeria, to evaluate the child-care practices, occurrence of diarrhoea, feeding patterns and nutritional status among 506 and 157 children aged 0-24 months taken to the market (CTTM) by their mothers and those left at home (CLAH) respectively. A lack of a caretaker at home was the most common reason for taking children to the market. The majority (92%) of the caretakers at home were young (< 20 years). There was no difference in the occurrence of diarrhoea in the last month between the CTTM (39%) and the CLAH (41%) groups (p > 0.05). However, there were differences in reported diarrhoea episodes between children aged 0-6 months and higher age classes (chi 2 = 20.0; p = 0.003). Very few children (0.8%) were exclusively breastfed. More CTTM (58%) were still being breastfed than the 42% of CLAH (OR = 1.87; 95% C.I. = 1.27-2.37; p < 0.001). Children cared for at home had a slightly better but nonsignificant (p > 0.05) anthropometric status as characterised by weight-for-age and height-for-age. There was no relationship between feeding patterns and diarrhoea.

PIP: A cross-sectional comparative study was conducted in 7 markets in Enugu and Nsukka, Nigeria, to evaluate child care practices, the occurrence of diarrhea, feeding patterns, and nutritional status among 506 children aged 0-24 months taken to the market (CTTM) by their mothers and 157 similarly aged children left at home (CLAH). 49% of CTTM were infants, compared to only 35% of CLAH. Lack of a caretaker at home was the most common reason why mothers took their children to the market. 92% of caretakers at home were under 20 years old. 39% and 41% of children in the CTTM and CLAH groups, respectively, had diarrhea during the previous month. Differences were reported in the number of diarrhea episodes between children aged 0-6 months and older children. 0.8% of children were exclusively breast-fed, with 58% and 42% of children in the CTTM and CLAH groups, respectively, still being breast-fed. Children cared for at home had a slightly better but nonsignificant anthropometric status as characterized by weight-for-age and height-for-age. No relationship was observed between feeding patterns and diarrhea.

The achievements and challenges of the African Programme for Onchocerciasis Control (APOC).

The main strategy of APOC, of community-directed treatment with ivermectin (CDTI), has enabled the programme to reach, empower and bring relief to remote and under-served, onchocerciasis-endemic communities. With CDTI, geographical and therapeutic coverages have increased substantially, in most areas, to the levels required to eliminate onchocerciasis as a public-health problem. Over 20 million people received treatment in 2000. APOC has also made effective use of the combination of the rapid epidemiological mapping of onchocerciasis (REMO) and geographical information systems (GIS), to provide information on the geographical distribution and prevalence of the disease. This has led to improvements in the identification of CDTI-priority areas, and in the estimates of the numbers of people to be treated. A unique public-private-sector partnership has been at the heart of APOC's relative success. Through efficient capacity-building, the programme's operations have positively influenced and strengthened the health services of participating countries. These laudable achievements notwithstanding, APOC faces many challenges during the second phase of its operations, when the full impact of the programme is expected to be felt. Notable among these challenges are the sustainability of CDTI, the strategy's effective integration into the healthcare system, and the full exploitation of its potential as an entry point for other health programmes. The channels created for CDTI, could, for example, help efforts to eliminate lymphatic filariasis (which will feature on the agenda of many participating countries during APOC's Phase 2). However, these other programmes need to be executed without compromising the onchocerciasis-control programme itself. Success in meeting these challenges will depend on the continued, wholehearted commitment of all the partners involved, particularly that of the governments of the participating countries.

Rapid epidemiological mapping of onchocerciasis (REMO): its application by the African Programme for Onchocerciasis Control (APOC).

One of the fundamental challenges that the African Programme for Onchocerciasis Control (APOC) has had to face is how to identify the endemic communities where its mass ivermectin-treatment operations are to be carried out in conformity with its stated objective of targetting the most highly endemic, affected and at-risk populations. This it has done by adopting a technique, known as the rapid epidemiological mapping of onchocerciasis (REMO), that provides data on the distribution and prevalence of onchocerciasis. Integration of the REMO data into a geographical information system (GIS) enables delineation of zones of various levels of endemicity, and this is an important step in the planning process for onchocerciasis control. Zones are included in (or excluded from) the APOC-funded programme of community-directed treatment with ivermectin (CDTI), depending on whether or not their levels of onchocercal endemicity reach the threshold set by APOC. This review describes the application of the REMO/GIS technique by APOC in its operations, and identifies the remaining related challenges.

The challenges of community-directed treatment with ivermectin (CDTI) within the African Programme for Onchocerciasis Control (APOC).

The principal strategy adopted by the African Programme for Onchocerciasis Control (APOC), for the control of onchocerciasis in the 19 countries of Africa that now fall within the programme's remit, is that of community-directed treatment with ivermectin (CDTI). Halfway through its 12-year mandate, APOC has gathered enough information on the main challenges to guide its activities in Phase 2. An analysis of reports and other documents, emanating from consultants, scientists, monitors and national and project-level implementers, indicates that there are three broad categories of challenge: managerial; technical; and socio-political. Under these three categories, this review identifies the most pertinent concerns that APOC must address, during Phase 2, to enhance the prospects of establishing sustainable systems for ivermectin distribution. The major challenges include: (1) maintaining timely drug-collection mechanisms; (2) integrating CDTI with existing primary-healthcare services; (3) strengthening local health infrastructure; (4) achieving and maintaining an optimal treatment coverage; (5) establishing and up-scaling community self-monitoring; (6) designing and implementing operations research locally; (7) ensuring the adequacy of community-directed distributors; (8) increasing the involvement of local non-govemmental develop organizations in the programme; (9) achieving financial sustainability; (10) implementing equitable cost-recovery systems; and (11) engaging in effective advocacy. The implications of the challenges and suggestions about how they are being (or could be) addressed are also highlighted in this brief review, which should be of value to other programmes and agencies that may be contemplating the adoption of this unique strategy.

Gender issues in the community-directed treatment with ivermectin (CDTI) of the African Programme for Onchocerciasis Control (APOC).

This paper reviews the issues relating to compliance and participation among the men and women of three countries within the remit of the African Programme for the Control of Onchocerciasis (APOC): Cameroon, Nigeria and Tanzania. Project-monitoring data from 109 focus-group discussions, 6069 household-survey respondents and 89 interviews with ivermectin distributors were analysed to gain an insight into the attitudes and behaviours of men and women in relation to ivermectin treatment and their participation in the programme. Although there are no statistically significant gender differences in coverages for ivermectin treatment, culturally prescribed gender relationships influence the ways in which men and women express and experience treatment-related behaviours. Gender roles also affect participation in the programme. Decision-making in communities on the selection of distributors tends to follow socio-cultural hierarchies based upon patriarchy and gerontocracy. Relatively few ivermectin distributors (21%) are women. Although they receive less support than their male counterparts, the female distributors are just as willing to continue ivermectin distribution in the community, and they perform as well or better than men in this regard. The terms 'community-directed', 'community participation' and even 'compliance' obfuscate important gender differences that are inherent in the implementation of onchocerciasis control. Development of strategies that recognize these gender differences will have important implications for long-term adherence to treatment and for the overall quality and sustainability of the programme.

Monitoring community-directed treatment programmes for sustainability: lessons from the African Programme for Onchocerciasis Control (APOC).

Community-directed treatment is a relatively new strategy that was adopted in 1997 by the African Programme for Onchocerciasis Control (APOC), for large-scale distribution of ivermectin (Mectizan). Participatory monitoring of 39 of the control projects based on community-directed treatment with ivermectin (CDTI) was undertaken from 1998-2000, with a focus on process implementation of the strategy and the predictors of sustainability. Data from 14,925 household interviews in 2314 villages, 183 complete treatment records, 382 focus-group discussions, and the results of interviews with 669 community leaders, 757 trained community-directed drug distributors (CDD) and 146 health personnel (in 26 projects in four countries) were analysed. The data show that CDD dispensed ivermectin to 65.4% of the total population (71.2% of the eligible population), with no significant gender differences in coverage (P > 0.05). Treatment coverage ranged from 60.2% of the eligible subjects in Cameroon to 76.9% in Uganda. There was no significant relationship between the provision of incentives to CDD and treatment coverage (P > 0.05). The frequency of treatment refusal was highest in Cameroon (29.2%). Although most (72.1%) of the communities investigated selected their CDD on the basis of a community decision at a village meeting, only 37.9% chose their distribution period in the same way. There is clearly a need to improve communication strategies, to address the issues of absentees and refusals, to emphasise community ownership and to de-emphasise incentives for CDD. The investigation of the 'predictor indicators' of sustainability should enable APOC to understand the determinants of project performance and to initiate any appropriate changes in the programme.

APOC's strategy of community-directed treatment with ivermectin (CDTI) and its potential for providing additional health services to the poorest populations. African Programme for Onchocerciasis Control.

Since its inauguration in 1995, the African Programme for Onchocerciasis Control (APOC) has made significant progress towards achieving its main objective: to establish sustainable community-directed treatment with ivermectin (CDTI) in onchocerciasis-endemic areas outside of the remit of the Onchocerciasis Control Programme in West Africa (OCP). In the year 2000, the programme, in partnership with governments, non-governmental organizations and the endemic communities themselves, succeeded in treating 20,298,138 individuals in 49,654 communities in 63 projects in 14 countries. Besides the distribution of ivermectin, the programme has strengthened primary healthcare (PHC) through capacity-building, mobilization of resources and empowerment of communities. The community-directed-treatment approach is a model that can be adopted in developing other community-based health programmes. The approach has also made it possible to bring to the poor some measure of intervention in some other healthcare programmes, such as those for malaria control, eye care, maternal and child health, nutrition and immunization. CDTI presents, at all stages of its implementation, a unique window of opportunity for promoting the functional integration of healthcare activities. For this to be done successfully and in a co-ordinated manner, adequate funding of CDTI within PHC is as important as an effective sensitization of the relevant policy-makers, healthworkers and communities on the value of integration (accompanied by appropriate training at all levels). Evaluation of the experiences in integration of health services, particularly at community level, is crucial to the success of the integration.