Interruption of the transmission of Onchocerca volvulus in the Kashoya-Kitomi focus, western Uganda by long-term ivermectin treatment and elimination of the vector Simulium neavei by larviciding.

Uganda is the only country in sub-Saharan Africa whose onchocerciasis elimination programme extensively uses vector control and biannual treatment with ivermectin. The purpose of this study was to assess the impact of combined strategies on interrupting onchocerciasis transmission in the Kashoya-Kitomi focus. Mass Drug Administration annually (13 years) followed by biannual treatments (6 years) and ground larviciding (36 cycles in 3 years) with temephos (Abate®, EC500) against Simulium neavei were conducted. Routine fly catches were conducted for over seven years in six catching sites and freshwater crabs Potamonautes aloysiisabaudiae were examined for immature stages of Simulium neavei. Epidemiological assessments by skin snip were performed in 2004 and 2013. Collection of dry blood spots (DBS) from children <10 years for IgG4 antibodies analysis were done in 2010 and 2013. Treatment coverage with ivermectin improved with introduction of biannual treatment strategy. Microfilaria prevalence reduced from 85% in 1991 to 62% in 2004; and to only 0.5% in 2013. Crab infestation reduced from 59% in 2007 to 0% in 2013 following ground larviciding. Comparison of total fly catches before and after ground larviciding revealed a drop from 5334 flies in 2007 to 0 flies in 2009. Serological assays conducted among 1,362 children in 2010 revealed 11 positive cases (0.8%; 95% CI: 0.4%-1.2%). However, assessment conducted on 3246 children in 2013 revealed five positives, giving point prevalence of 0.15%; 95% CI: 0.02%-0.28%. Four of the five children subjected to O-150 PCR proved negative. The data show that transmission of onchocerciasis has been interrupted based on national and WHO Guidelines of 2012 and 2016, respectively.

Onchocerciasis control in the Democratic Republic of Congo (DRC): challenges in a post-war environment.

OBJECTIVE: To evaluate onchocerciasis control activities in the Democratic Republic of Congo (DRC) in the first 12 years of community-directed treatment with ivermectin (CDTI). METHODS: Data from the National Programme for Onchocerciasis (NPO) provided by the National Onchocerciasis Task Force (NOTF) through the annual reports of the 21 CDTI projects for the years 2001-2012 were reviewed retrospectively. A hypothetical-inputs-process-outputs-outcomes table was constructed. RESULTS: Community-directed treatment with ivermectin expanded from 1968 communities in 2001 to 39 100 communities by 2012 while the number of community-directed distributors (CDD) and health workers (HW) multiplied. By 2012, there were ratios of 1 CDD per 262 persons and 1 HW per 2318 persons at risk. More than 80% of the funding came from the fiduciary funds of the African Programme for Onchocerciasis Control. The cost of treatment per person treated fell from US$ 1.1 in 2001 to US$ 0.1 in 2012. The therapeutic coverage increased from 2.7% (2001) to 74.2% (2012); the geographical coverage, from 4.7% (2001) to 93.9% (2012). Geographical coverage fell in 2005 due to deaths in loiasis co-endemic areas, and the therapeutic coverage fell in 2008 due to insecurity. CONCLUSIONS: Challenges to CDTI in DRC have been serious adverse reactions to ivermectin in loiasis co-endemic areas and political conflict. Targets for personnel or therapeutic and geographical coverages were not met. Longer term funding and renewed efforts are required to achieve control and elimination of onchocerciasis in DRC.

The disappearance of onchocerciasis from the Itwara focus, western Uganda after elimination of the vector Simulium neavei and 19 years of annual ivermectin treatments.

The Itwara onchocerciasis focus is located around the Itwara forest reserve in western Uganda. In 1991, annual treatments with ivermectin started in the focus. They were supplemented in 1995 by the control of the vector Simulium neavei, which was subsequently eliminated from the focus. The impact of the two interventions on the disease was assessed in 2010 by nodule palpations, examinations of skin snips by microscopy and PCR, and Ov16 recombinant ELISA. There was no evidence of any microfilaria in 688 skin snips and only 2 (0.06%) of 3316 children examined for IgG4 were slightly above the arbitrary cut off of 40. A follow up of the same children 21 months later in 2012 confirmed that both were negative for diagnostic antigen Ov-16, skin snip microscopy and PCR. Based on the World Health Organization (WHO) elimination criteria of 2001 and the Uganda onchocerciasis certification guidelines, it was concluded that the disease has disappeared from the Itwara focus after 19 years of ivermectin treatments and the elimination of the vector around 2001. Ivermectin treatments were recommended to be halted.

Factors affecting the attrition of community-directed distributors of ivermectin, in an onchocerciasis-control programme in the Imo and Abia states of south-eastern Nigeria.

In areas of Nigeria where onchocerciasis is endemic, community-directed distributors (CDD) distribute ivermectin annually, as part of the effort to control the disease. Unfortunately, it has been reported that at least 35% of the distributors who have been trained in Nigeria are unwilling to participate further as CDD. The selection and training of new CDD, to replace those unwilling to continue, leads to annual expense that the national onchocerciasis-programme is finding difficult to meet, given other programme priorities and the limited resources. If the reported levels of attrition are true, they seriously threaten the sustainability of community-directed treatment with ivermectin (CDTI) in Nigeria. In 2002, interviews were held with 101 people who had been trained as CDD, including those who had stopped serving their communities, from 12 communities in south-eastern Nigeria that had high rates of CDD attrition. The results showed that, although the overall reported CDD attrition was 40.6%, the actual rate was only 10.9%. The CDD who had ceased participating in the annual rounds of ivermectin blamed a lack of incentives (65.9%), the demands of other employment (14.6%), the long distances involved in the house-to-house distribution (12.2%) or marital duties (7.3%). Analysis of the data obtained from all the interviewed CDD showed that inadequate supplies of ivermectin (P<0.01), lack of supervision (P<0.05) and a lack of monetary incentives (P<0.001) led to significant increases in attrition. Conversely, CDD retention was significantly enhanced when the distributors were selected by their community members (P<0.001), supervised (P<0.001), supplied with adequate ivermectin tablets (P<0.05), involved in educating their community members (P<0.05), and/or involved in other health programmes (P<0.001). Although CDD who were involved in other health programmes were relatively unlikely to cease participating in the distributions, they were more likely to take longer than 14 days to complete ivermectin distribution than other CDD, who only distributed ivermectin. Data obtained in interviews with present and past CDD appear vital for informing, directing, protecting and enhancing the performance of CDTI programmes, in Nigeria and elsewhere.

Community-directed interventions strategy enhances efficient and effective integration of health care delivery and development activities in rural disadvantaged communities of Uganda.

The community-directed interventions (CDI) strategy achieved a desired coverage of the ultimate treatment goal (UTG) of at least 90% with ivermectin distribution for onchocerciasis control, and filled the gap between the health care services and the communities. However, it was not clear how its primary actors--the community-directed health workers (CDHW) and community-directed health supervisors (CDHS)--would perform if they were given more responsibilities for other health and development activities within their communities. A total of 429 of 636 (67.5%) of the CDHWs who were involved in other health and development activities performed better than those who were involved only in ivermectin distribution, with a drop-out rate of 2.3%. A total of 467 of 864 (54.1%) of CDHSs who were involved in other health and development activities also maintained the desired level of performance. They facilitated updating of household registers (P<0.05), trained and supervised CDHWs, and educated community members about onchocerciasis control (P<0.001). Their drop-out rate was 2.6%. The study showed that the majority of those who dropped out had not been selected by their community members. Therefore, CDI strategy promoted integration of health and development activities with a high potential for sustainability.

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.

Implementing community-directed treatment with ivermectin for the control of onchocerciasis in Uganda (1997-2000): an evaluation.

Over the period 1997-2000, an evaluation was made, in 10 districts of Uganda, of the onchocerciasis-control programme based on community-directed treatment with ivermectin (CDTI). This programme is supported by the Ministry of Health, the African Progamme for Onchocerciasis Control (APOC) and The Carter Center Global 2000 River Blindness Programme. The data analysed came from: (1) monthly and annual reports; (2) annual interviews, in randomly-selected communities in selected districts, with heads of household, community leaders and ivermectin distributors; (3) participatory evaluation meetings (PEM); (4) participant observation studies; and (5) key informants. The percentage of treated communities in the 10 study districts achieving satisfactory treatment coverage [i.e. > or = 90% of the annual treatment objective (ATO)] rose from 46.0 in 1997 to 86.8 in 2000. This improvement was largely attributable to the adoption of collective CDTI decision-making by community members, avoidance of paving monetary incentives to the ivermectin distributors, and the satisfaction with the programme of those who had been treated. Coverage improved as the numbers of community members who were involved in choosing the method of distribution and in selecting their own community-directed health workers (CDHW) increased. Health education was also critical in improving individual members' involvement in decision-making, and in mobilizing other community members to take part in CDTI. Involvement of kinship groups, as well as educated community members as supervisors of CDHW, also helped to increase coverage. In a regression model, satisfaction with the programme was revealed as a significant predictor of the achievement of the target coverage (P<0.001). Cost per person, as an indicator for sustainability, varied with the size of the population under treatment, from at least U.S. $0.40 when the district ATO was <15,000 people, to U.S. $0.26 with an ATO of 15,000-40,000 and less than U.S. $0.10 when the district ATO exceeded 40,000 people. These results cast doubt on the validity of the current APOC indicator for sustainability, of a cost of no more than U.S. $0.20/person for all CDTI projects, whatever the size of the population to be treated. Although some women were involved in decision-making, their current involvement as supervisors or CDHW was minimal. Most of the present data were obtained through monitoring and operational-research activities that have been carried out, in an integrated fashion, within the Ugandan CDTI programme since its launch. It is recommended that assessment, monitoring and evaluation be widely used within all CDTI efforts. Operational research should remain focused and appropriate and directly involve the personnel who are executing the programme.

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 health (CDH) workers enhance the performance and sustainability of CDH programmes: experience from ivermectin distribution in Uganda.

The performance and 'drop-out' rates of ivermectin (Mectizan) distributors in the Ugandan programme for community-directed treatment with ivermectin (CDTI) were investigated and related to the manner in which the distributors were recruited. Distributors, from randomly selected communities endemic for onchocerciasis in seven of the 10 affected districts, were interviewed. Questionnaires were initially completed for 296 communities (in which ivermectin had been distributed in 1998 but not in 1999) and then extended to another 310 communities (in which ivermectin had been distributed in both study years). Discussions were also held with some other community members, in participatory evaluation meetings (PEM) in 14 communities from four districts. Despite the CDTI being labelled as 'community-directed', the first round of interviews and questionnaires revealed that there were in fact three categories of distributors: 322 (69.4%) of those questioned had been selected by community members and were therefore truly community-directed health workers (CDHW) but 101 (22%) were community-based health workers appointed by the leaders of the local council (CBHW-LC) and 41 (9%) were self-appointed volunteers (CBHW-SA). During 1999, only the CDHW received good community support; they still helped to mobilise and educate their community members and advocate CDTI, and 98% of them agreed that they would distribute ivermectin during the following year. In contrast, many of the CBHW-LC were neither supported nor appreciated by the community members. Presumably in consequence, many of the CBHW-LC did not help to mobilise or educate their community members in 1999, nor did they advocate CDTI. Almost all (95%) of the CBHW-LC said that they would not be available to distribute in the following year, and were therefore regarded as total 'drop-outs' from the CDTI. The CBHW-SA were better supported by community members than were the CBHW-LC, they did more to advocate the CDTI, and 93% reported that they would distribute ivermectin during the following year. The 'drop-out' rates for 1999 were < 2% for the CDHW, 7% for the CBHW-SA, and 95% for the CBHW-LC. The results also indicated that the CBHW-SA were not as reliable as the CDHW. Similar results were obtained from the second round of questionnaires, in which 224 (73%) of the interviewees were CDHW, 57 (18%) were CBHW-LC and 28 (9%) were CBHW-SA. The results of the PEM showed that the CDHW, who mainly came from the same kinship groups as the people who selected them, were likely to achieve higher ivermectin coverage within a week than the other categories of distributors. It is clear that, for the optimum performance and sustainability of the CDTI, the distributors used should be CDHW selected by their own community members.

Rapid epidemiological mapping of onchocerciasis in areas of Uganda where Simulium neavei sl is the vector.

OBJECTIVE: To test whether Rapid Epidemiological Mapping of Onchocerciasis (REMO) was suitable for mapping of onchocerciasis in foci where S. neavei sl is the primary vector. DESIGN: Topographical maps of scale 1:250,000 were used in demarcating regions into ecotopographic divisions and zones in order to identify potential onchocerciasis endemic areas. SETTING: The study was conducted in Kabarole and Nebbi districts. High-risk communities were selected 30 km from each other, and closest to rivers where vector breeding appeared likely. Secondary and additional communities were selected 10 km and 20 km away from high-risk communities, respectively. SUBJECTS OR PARTICIPANTS: Communities were mobilised for nodule palpation. A sample of thirty males aged at least 20 years, from each community that had lived in the area for at least ten years, were randomly selected and examined. INTERVENTIONS: Individuals positive for at least one nodule were expressed in terms of Nodule Prevalence Rates (NPR) which were used to map the distribution of onchocerciasis. MAIN OUTCOME MEASURES: Coefficient of variation (CV) of Nodule Prevalence Rates between high risk secondary communities. RESULTS: In Kabarole district, the results indicated a low coefficient of variation (CV) of 75 in NPR between high risk and secondary communities while in Nebbi district, higher CV of 187.4 was attained. The less varied NPR implies that communities in Kabarole were almost equally exposed to onchocerciasis while highly varied situation in Nebbi indicated decreasing NPR with increasing distance from high-risk communities. CONCLUSION: REMO is applicable in areas where S. neavei sl is the primary vector, for identification and mapping communities requiring mass treatment with ivermectin.

PIP: This study was undertaken to test whether rapid epidemiological mapping of onchocerciasis (REMO) was suitable for mapping of onchocerciasis in foci where Simulium neavei sl is the primary vector. Topographical maps of scale 1:250,000 were used in demarcating regions into ecotopographic divisions and zones in order to identify potential onchocerciasis endemic areas in Kabarole and Nebbi districts in Uganda. High-risk communities were selected 30 km from each other, while secondary and additional communities were selected 10 km and 20 km away from high-risk communities, respectively. A sample of 30 males aged at least 20 years from each community, who had lived in the area for at least 10 years, were randomly selected and examined. In the Kabarole district, results showed a low coefficient of variation (CV) of 75 in nodule prevalence rates (NPRs) between high-risk and secondary communities; a higher CV of 187.4 was seen in Nebbi district. The less varied NPRs imply that communities in Kabarole were almost equally exposed to onchocerciasis, while the highly varied situation in Nebbi indicated declining NPRs with increasing distance from high-risk communities. In conclusion, REMO is applicable in areas where S. neavei sl is the primary vector for the identification and mapping out of communities requiring mass treatment with ivermectin.

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.

Community-directed, ivermectin-treatment programmes for onchocerciasis control in Uganda: the selection and validation of indicators for monitoring sustainability at the district level.

The selection and validation of indicators for predicting and monitoring sustainment in community-directed, ivermectin-treatment programmes (CDITP) at the community level in the Kabale, Kisoro and Rukungiri districts of Uganda have already been reported. The aim of the present study was to select and validate similar indicators at the district level, in the same districts over the same 4-year period. Three dependent-variable scales of programme sustainability (PS), PS1, PS2 and PS3, were compared by district. As at the community level, Rukungiri district clearly performed better than Kabale or Kisoro. Cost variables compiled at the district level and the ratios of numbers of community-based distributors (CBD) to community members were used as input variables in regression and correlation models, with PS1, PS2, and PS3 as outcome variables. In the regression model, cost of training CBD was found to be statistically significant (P = 0.0186). This variable also scored 100% on a scale for programme-indicator sensitivity and hence was selected as a helpful indicator. In the correlation model, cost of health education of community members had a weak relationship with PS1 (P = 0.0662). Cost of training CBD had a significant negative correlation with PS2 (P = 0.0186), indicating that reducing the cost of training would facilitate sustainability. PS3 showed weak negative correlations with cost of health education of community members (P = 0.0586) and cost/person treated in the district (P = 0.0584). Sustainment of CDITP might be better, therefore, if the costs per person could be reduced. As correlation relationships may not be linear, however, they were not considered particularly useful in the selection of helpful indicators.

The selection and validation of indicators for monitoring progress towards self-sustainment in community-directed, ivermectin-treatment programmes for onchocerciasis control in Uganda.

A retrospective analysis was made of quantitative data on coverage obtained over 4 years of annual ivermectin treatment of the eligible populations (approximately 56,000 individuals) of 71 communities with endemic onchocerciasis in the Kabale, Kisoro and Rukungiri districts of Uganda. The objective was to formulate methods for defining sustainability in community-directed, ivermectin-treatment programmes (CDITP). Three dependent-variable scales of programme sustainability (PS), PS1, PS2, and PS3, were tested for statistical significance by analysis of variance. The inhabitants of a random sample of 230 households drawn from 23 communities [each containing one community leader and one community-based distributor (CBD)] were then invited to answer a questionnaire covering seven independent variables. These variables were analysed in regression and correlation models, with the PS scales as dependent variables. In the regression model, only one variable, selection of CBD by community members (P = 0.038), which scored 100% on the scale of programme-indicator sensitivity, passed as a useful indicator for predicting the sustainability and monitoring the sustainment of CDITP at the community level. The same variable was also selected in the correlation model (P = 0.028). Although two other variables--involvement of CBD in other primary-health-care activities (P = 0.0594) and provision of incentives for the CBD (P = 0.0558)--showed weak negative associations with sustainability in the correlation model, they did not exhibit a linear relationship with it and cannot therefore be used as valid indicators for predicting sustainability or monitoring sustainment.

PIP: This article investigates indicators for monitoring progress towards self-sustainment in community-directed ivermectin-treatment programs (CDITP) in Uganda. This retrospective analysis was made of quantitative data on coverage obtained over 4 years of annual ivermectin treatment of the eligible populations of 71 communities with endemic onchocerciasis in the Kabale, Kisoro and Rukungiri districts of Uganda. Three dependent-variable scales of program sustainability (PS), namely PS1, PS2, and PS3, were tested for statistical significance by analysis of variance. Samples included a random selection of 230 households drawn from 23 communities. Analysis of variance revealed that on each of the three PS scales mean scores differed between districts (P = 0.0001 for each). In the regression model, only selection of community-based distributor passed as a useful indicator for predicting and monitoring the sustainability of CDITP at the community level. The same variable was also selected in the correlation model (P = 0.028).