Eliminating onchocerciasis within the Meme River Basin of Cameroon: A social-ecological approach to understanding everyday realities and health systems.

BACKGROUND: Onchocerciasis affects some of the world's most marginalized people, perpetuating poverty and inequalities. Mass Drug Administration (MDA) with Ivermectin has taken place within the Meme River basin region in Cameroon for over 15 years. Despite this, onchocerciasis is still prevalent in the region due to existing and emerging contextual challenges. Using a social-ecological approach we explore the everyday realities of communities, highlighting the challenges and potential solutions that could support Neglected Tropical Disease (NTD) programmes when transitioning from control to elimination of onchocerciasis in this highly endemic area and other similar communities. METHODOLOGY/PRINCIPAL FINDING: In-depth interviews (71) with community members and Community Drug Distributors (CDDs) were conducted to understand current knowledge, attitudes, and behaviours in relation to transmission, prevention and treatment of onchocerciasis. Through application of the social-ecological model, four key themes were identified: 1. Contextual factors on health promotion interventions (Onchocerciasis history and understanding of the disease, prevention and mitigation strategies and MDA experience); 2. Social determinants (poverty and livelihoods, economic and social impacts on CDD volunteers and stigma); 3. Environmental determinants (exposure, housing, occupation and poverty); and 4. health seeking pathways and decision making for treatment (access, cost and preferable treatment routes). We discuss these core and cross cutting themes (gender differences and community participation/ownership) in relation to intersectoral collaboration, gender equity and health systems support, making recommendations for NTD programmes within the context of integrated and interdisciplinary approaches. These include the need for; intersectional and gender analysis at the local level, addressing environmental dimensions of onchocerciasis through integrated and regular health promotion, vector control strategies and access to safe water sources; reflection and action that embeds responses to social and economic barriers to MDA; integrated case detection and management that is responsive to onchocerciasis symptoms and related stigma and a fair and just support network for CDDs. CONCLUSION/SIGNIFICANCE: NTD programmes need to respond to diverse community circumstances and behaviours. Communities are not a homogeneous risk group and treating them in this way will delay elimination. A deeper understanding of individual needs and their capacity to seek prevention and treatment must be considered if onchocerciasis is to be eliminated and the remaining impacts managed.

Implementation of test-and-treat with doxycycline and temephos ground larviciding as alternative strategies for accelerating onchocerciasis elimination in an area of loiasis co-endemicity: the COUNTDOWN consortium multi-disciplinary study protocol.

BACKGROUND: Onchocerciasis is a priority neglected tropical disease targeted for elimination by 2025. The standard strategy to combat onchocerciasis is annual Community-Directed Treatment with ivermectin (CDTi). Yet, high prevalence rates and transmission persist following > 12 rounds in South-West Cameroon. Challenges include programme coverage, adherence to, and acceptability of ivermectin in an area of Loa loa co-endemicity. Loiasis patients harbouring heavy infections are at risk of potentially fatal serious adverse events following CDTi. Alternative strategies are therefore needed to achieve onchocerciasis elimination where CDTi effectiveness is suboptimal. METHODS/DESIGN: We designed an implementation study to evaluate integrating World Health Organisation-endorsed alternative strategies for the elimination of onchocerciasis, namely test-and-treat with the macrofilaricide, doxycycline (TTd), and ground larviciding for suppression of blackfly vectors with the organophosphate temephos. A community-based controlled before-after intervention study will be conducted among > 2000 participants in 20 intervention (Meme River Basin) and 10 control (Indian River Basin) communities. The primary outcome measure is O. volvulus prevalence at follow-up 18-months post-treatment. The study involves four inter-disciplinary components: parasitology, entomology, applied social sciences and health economics. Onchocerciasis skin infection will be diagnosed by skin biopsy and Loa loa infection will be diagnosed by parasitological examination of finger-prick blood samples. A simultaneous clinical skin disease assessment will be made. Eligible skin-snip-positive individuals will be offered directly-observed treatment for 5 weeks with 100 mg/day doxycycline. Transmission assessments of onchocerciasis in the communities will be collected post-human landing catch of the local biting blackfly vector prior to ground larviciding with temephos every week (0.3 l/m3) until biting rate falls below 5/person/day. Qualitative research, including in-depth interviews and focus-group discussions will be used to assess acceptability and feasibility of the implemented alternative strategies among intervention recipients and providers. Health economics will assess the cost-effectiveness of the implemented interventions. CONCLUSIONS: Using a multidisciplinary approach, we aim to assess the effectiveness of TTd, alone or in combination with ground larviciding, following a single intervention round and scrutinise the acceptability and feasibility of implementing at scale in similar hotspots of onchocerciasis infection, to accelerate onchocerciasis elimination.

Implementation research: new imperatives and opportunities in global health.

Implementation research is important in global health because it addresses the challenges of the know-do gap in real-world settings and the practicalities of achieving national and global health goals. Implementation research is an integrated concept that links research and practice to accelerate the development and delivery of public health approaches. Implementation research involves the creation and application of knowledge to improve the implementation of health policies, programmes, and practices. This type of research uses multiple disciplines and methods and emphasises partnerships between community members, implementers, researchers, and policy makers. Implementation research focuses on practical approaches to improve implementation and to enhance equity, efficiency, scale-up, and sustainability, and ultimately to improve people's health. There is growing interest in the principles of implementation research and a range of perspectives on its purposes and appropriate methods. However, limited efforts have been made to systematically document and review learning from the practice of implementation research across different countries and technical areas. Drawing on an expert review process, this Health Policy paper presents purposively selected case studies to illustrate the essential characteristics of implementation research and its application in low-income and middle-income countries. The case studies are organised into four categories related to the purposes of using implementation research, including improving people's health, informing policy design and implementation, strengthening health service delivery, and empowering communities and beneficiaries. Each of the case studies addresses implementation problems, involves partnerships to co-create solutions, uses tacit knowledge and research, and is based on a shared commitment towards improving health outcomes. The case studies reveal the complex adaptive nature of health systems, emphasise the importance of understanding context, and highlight the role of multidisciplinary, rigorous, and adaptive processes that allow for course correction to ensure interventions have an impact. This Health Policy paper is part of a call to action to increase the use of implementation research in global health, build the field of implementation research inclusive of research utilisation efforts, and accelerate efforts to bridge the gap between research, policy, and practice to improve health outcomes.

Study of lymphoedema of non-filarial origin in the northwest region of Cameroon: spatial distribution, profiling of cases and socio-economic aspects of podoconiosis.

Background: Although podoconiosis is endemic in Cameroon, little is known about its epidemiology and spatial distribution. Methods: This cross-sectional, population-based study enrolled all adults (≥15 y) residing in the districts of the northwest region of Cameroon for 10 or more years. Participants were interviewed and had a physical examination. The study outcomes were prevalence estimates of lymphoedema and podoconiosis. House-to-house screening was conducted by Community Health Implementers (CHIs). CHIs registered all individuals with lymphoedema and collected additional individual and household-related information. A panel of experts re-examined and validated all lymphoedema cases registered by CHIs. Results: Of the 439 781 individuals registered, 214 195 were adults (≥15 y old) and had lived in the districts of the region for more than 10 y. A total of 2143 lymphoedema cases were identified by CHIs, giving a prevalence of lymphoedema of 1.0% (2143/214 195; 95% CI, 0.96-1.04). After review by experts, podoconiosis prevalence in the study area was 0.48% (1049/214 195; 95% CI, 0.46-0.52). The prevalence of podoconiosis varied by health district, from 0.16% in Oku to 1.92% in Bafut (p<0.05). A total of 374 patients were recruited by stratified random sampling from the validated CHIs' register to assess the clinical features and socio-economic aspects of the disease. Patients reportedly were said to have first noticed swelling at an average age of 41.9±19.1 (range: 6-90 y). Most patients (86.1%; 315/366) complained of their legs suddenly becoming hot, red and painful. The majority (96.5%; 361/374) of the interviewees said they had worn shoes occasionally at some point in their life. The reported mean age at first shoe wearing was 14.2±10.1 (±SD,range 1-77 y). A high proportion (82.8%; 309/374) of the participants wore shoes at the time of interview. Of those wearing shoes, only 21.7% (67/309) were wearing protective shoes. Conclusion: This study provides an insight into the geographical distribution and epidemiology of podoconiosis in the North West region of Cameroon, yet management is limited. Evidence-informed targeted interventions are needed to manage people with lymphoedema.

A Comparative Analysis of Economic Cost of Podoconiosis and Leprosy on Affected Households in the Northwest Region of Cameroon.

Leprosy and podoconiosis (podo) are neglected tropical diseases that cause severe disfigurement and disability, and may lead to catastrophic health expenditure and hinder economic development of affected persons and households. This study compared economic costs of both diseases on affected households with unaffected neighboring households in the Northwest Region (N.W.R.) of Cameroon. A matched comparative cross-sectional design was used enrolling 170 households (43 podo case households, 41 podo control households, 43 leprosy case households, and 43 leprosy control households) from three health districts in the N.W.R. Direct treatment costs for podo averaged 142 United State dollar (USD), compared with zero for leprosy (P < 0.001). This was also reflected in the proportion of annual household income consumed (0.4 versus 0.0, respectively, P < 0.001). Both diseases caused considerable reductions in working days (leprosy 115 versus podo 135 days. P for comparison < 0.001). The average household income was considerably lower in podo-affected households than unaffected households (410 versus 913 USD, P = 0.01), whereas income of leprosy-affected households was comparable to unaffected households (329 versus 399 USD, P = 0.23). Both leprosy and podo cause financial burdens on affected households, but those on podo-affected families are much greater. These burdens occur through direct treatment costs and reduced ability to work. Improved access to public health interventions for podo including prevention, morbidity management and disability prevention are likely to result in economic returns to affected families. In Cameroon, one approach to this would be through subsidized health insurance for these economically vulnerable households.

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.

Ivermectin treatment of Loa loa hyper-microfilaraemic baboons (Papio anubis): Assessment of microfilarial load reduction, haematological and biochemical parameters and histopathological changes following treatment.

BACKGROUND: Individuals with high intensity of Loa loa are at risk of developing serious adverse events (SAEs) post treatment with ivermectin. These SAEs have remained unclear and a programmatic impediment to the advancement of community directed treatment with ivermectin. The pathogenesis of these SAEs following ivermectin has never been investigated experimentally. The Loa/baboon (Papio anubis) model can be used to investigate the pathogenesis of Loa-associated encephalopathy following ivermectin treatment in humans. METHODS: 12 baboons with microfilarial loads > 8,000mf/mL of blood were randomised into four groups: Group 1 (control group receiving no drug), Group 2 receiving ivermectin (IVM) alone, Group 3 receiving ivermectin plus aspirin (IVM + ASA), and Group 4 receiving ivermectin plus prednisone (IVM + PSE). Blood samples collected before treatment and at Day 5, 7 or 10 post treatment, were analysed for parasitological, hematological and biochemical parameters using standard techniques. Clinical monitoring of animals for side effects took place every 6 hours post treatment until autopsy. At autopsy free fluids and a large number of standard organs were collected, examined and tissues fixed in 10% buffered formalin and processed for standard haematoxylin-eosin staining and specific immunocytochemical staining. RESULTS: Mf counts dropped significantly (p<0.05) in all animals following ivermectin treatment with reductions as high as (89.9%) recorded; while no significant drop was observed in the control animals. Apart from haemoglobin (Hb) levels which recorded a significant (p = 0.028) drop post treatment, all other haematological and biochemical parameters did not show any significant changes (p>0.05). All animals became withdrawn 48 hours after IVM administration. All treated animals recorded clinical manifestations including rashes, itching, diarrhoea, conjunctival haemorrhages, lymph node enlargement, pinkish ears, swollen face and restlessness; one animal died 5 hours after IVM administration. Macroscopic changes in post-mortem tissues observed comprised haemorrhages in the brain, lungs, heart, which seen in all groups given ivermectin but not in the untreated animals. Microscopically, the major cellular changes seen, which were present in all the ivermectin treated animals included microfilariae in varying degrees of degeneration in small vessels. These were frequently associated with fibrin deposition, endothelial changes including damage to the integrity of the blood vessel and the presence of extravascular erythrocytes (haemorrhages). There was an increased presence of eosinophils and other chronic inflammatory types in certain tissues and organs, often in large numbers and associated with microfilarial destruction. Highly vascularized organs like the brain, heart, lungs and kidneys were observed to have more microfilariae in tissue sections. The number of mf seen in the brain and kidneys of animals administered IVM alone tripled that of control animals. Co-administration of IVM + PSE caused a greater increase in mf in the brain and kidneys while the reverse was noticed with the co-administration of IVM + ASA. CONCLUSIONS: The treatment of Loa hyper-microfilaraemic individuals with ivermectin produces a clinical spectrum that parallels that seen in Loa hyper-microfilaraemic humans treated with ivermectin. The utilization of this experimental model can contribute to the improved management of the adverse responses in humans.

Detecting and staging podoconiosis cases in North West Cameroon: positive predictive value of clinical screening of patients by community health workers and researchers.

BACKGROUND: The suitability of using clinical assessment to identify patients with podoconiosis in endemic communities has previously been demonstrated. In this study, we explored the feasibility and accuracy of using Community Health Implementers (CHIs) for the large scale clinical screening of the population for podoconiosis in North-west Cameroon. METHODS: Before a regional podoconiosis mapping, 193 CHIs and 50 health personnel selected from 6 health districts were trained in the clinical diagnosis of the disease. After training, CHIs undertook community screening for podoconiosis patients under health personnel supervision. Identified cases were later re-examined by a research team with experience in the clinical identification of podoconiosis. RESULTS: Cases were identified by CHIs with an overall positive predictive value (PPV) of 48.5% [34.1-70%]. They were more accurate in detecting advanced stages of the disease compared to early stages; OR 2.07, 95% CI = 1.15-3.73, p = 0.015 for all advanced stages). Accuracy of detecting cases showed statistically significant differences among health districts (χ2 = 25.30, p = 0.0001). CONCLUSION: Podoconiosis being a stigmatized disease, the use of CHIs who are familiar to the community appears appropriate for identifying cases through clinical diagnosis. However, to improve their effectiveness and accuracy, more training, supervision and support are required. More emphasis must be given in identifying early clinical stages and in health districts with relatively lower PPVs.

Assessment of the usage and effectiveness of intermittent preventive treatment and insecticide-treated nets on the indicators of malaria among pregnant women attending antenatal care in the Buea Health District, Cameroon.

BACKGROUND: Malaria in pregnancy is an immense public health problem with at least 50 million pregnant women living in malaria endemic areas. To prevent malaria and its complications in pregnancy the World Health Organization recommends the use of intermittent preventive treatment sulfadoxine-pyrimethamine (IPTp-SP), the use of insecticide-treated nets (ITNs), and effective case management. In most malaria endemic countries in Africa, 40% of pregnant women sleep under ITNs. In Cameroon, about 90% of pregnant women receive the first dose of SP, while 64% take the complete dose. Following the 2011 mass-campaign of free distribution of ITNs coupled with routine ANC distribution of ITN and adoption of IPTp in Cameroon, little has been done to assess the effectiveness of both interventions outside of Yaoundé, the capital city. This study sought to assess the usage and effectiveness of IPTp-SP and ITNs on malaria in pregnancy. METHODS: The research was a cross-sectional hospital-based study that included 410 pregnant women attending antenatal clinics in the Buea Health District. Capillary blood samples were collected to check malaria parasite by microscopy and haemoglobin levels by microhaematocrit technique. RESULTS: A prevalence of 13.4 and 41.7% was detected for malaria and anaemia, respectively. The Overall coverage of ITN was 32.4% while that of ITPp was 63.2%. Malaria prevalence was least (7.2%) amongst women using both IPTp-SP and ITN while those with no intervention had the highest malaria prevalence of 18.6% (χ2 = 6.188; P = 0.103). Of the women with malaria, 12.73% were using ITN and had taken at least one dose of SP, 38.18% had taken at least one dose IPTp only, 10.91% were using only ITN and 38.18% were not using any preventive measure. There was a difference in anaemia status within the different intervention groups (χ2 = 8.673; P = 0.034). Pregnant women using both interventions were less associated to malaria (OR = 0.341, 95% CI = 0.138-0.841) compared to those using only one control method. CONCLUSION: Repeated doses of SP in combination with ITN use are effective in reducing malaria parasitaemia and improving haemoglobin level of pregnant women.

Understanding of research, genetics and genetic research in a rapid ethical assessment in north west Cameroon.

BACKGROUND: There is limited assessment of whether research participants in low-income settings are afforded a full understanding of the meaning of medical research. There may also be particular issues with the understanding of genetic research. We used a rapid ethical assessment methodology to explore perceptions surrounding the meaning of research, genetics and genetic research in north west Cameroon. METHODS: Eleven focus group discussions (including 107 adults) and 72 in-depth interviews were conducted with various stakeholders in two health districts in north west Cameroon between February and April 2012. RESULTS: Most participants appreciated the role of research in generating knowledge and identified a difference between research and healthcare but gave varied explanations as to this difference. Most participants' understanding of genetics was limited to concepts of hereditary, with potential benefits limited to the level of the individual or family. Explanations based on supernatural beliefs were identified as a special issue but participants tended not to identify any other special risks with genetic research. CONCLUSION: We demonstrated a variable level of understanding of research, genetics and genetic research, with implications for those carrying out genetic research in this and other low resource settings. Our study highlights the utility of rapid ethical assessment prior to complex or sensitive research.

Perceptions of consent, permission structures and approaches to the community: a rapid ethical assessment performed in North West Cameroon.

BACKGROUND: Understanding local contextual factors is important when conducting international collaborative studies in low-income country settings. Rapid ethical assessment (a brief qualitative intervention designed to map the ethical terrain of a research setting prior to recruitment of participants), has been used in a range of research-naïve settings. We used rapid ethical assessment to explore ethical issues and challenges associated with approaching communities and gaining informed consent in North West Cameroon. METHODS: This qualitative study was carried out in two health districts in the North West Region of Cameroon between February and April 2012. Eleven focus group discussions (with a total of 107 participants) were carried out among adult community members, while 72 in-depth interviews included health workers, non-government organisation staff and local community leaders. Data were collected in English and pidgin, translated where necessary into English, transcribed and coded following themes. RESULTS: Many community members had some understanding of informed consent, probably through exposure to agricultural research in the past. Participants described a centralised permission-giving structure in their communities, though there was evidence of some subversion of these structures by the educated young and by women. Several acceptable routes for approaching the communities were outlined, all including the health centre and the Fon (traditional leader). The importance of time spent in sensitizing the community and explaining information was stressed. CONCLUSIONS: Respondents held relatively sophisticated understanding of consent and were able to outline the structures of permission-giving in the community. Although the structures are unique to these communities, the role of certain trusted groups is common to several other communities in Kenya and Ethiopia explored using similar techniques. The information gained through Rapid Ethical Assessment will form an important guide for future studies in North West Cameroon.

Validation of the rapid assessment procedure for loiasis (RAPLOA) in the Democratic Republic of Congo.

BACKGROUND: A simple method called RAPLOA, to rapidly assess what proportion of people in a community are infected with L. loa and hence which communities are at high risk of severe adverse reactions following ivermectin treatment, was developed in Cameroon and Nigeria. The method needed further validation in other geographical and cultural contexts before its application in all endemic countries. The present study was designed to validate RAPLOA in two regions in the North East and South West of the Democratic Republic of Congo. METHODS: In each study region, villages were selected from different bio-ecological zones in order to cover a wide range of loiasis endemicity. In each selected community, 80 people above the age of 15 years were interviewed for a history of eye worm (migration of adult L. loa under the conjunctiva of the eye) and parasitologically examined for the presence and intensity of L. loa infection. In total, 8100 individuals from 99 villages were enrolled into the study. RESULTS: The results confirmed the findings of the original RAPLOA study: i) the eye worm phenomenon was well-known in all endemic areas, ii) there was a clear relationship between the prevalence of eye worm history and the prevalence and intensity of L. loa microfilaraemia, and iii) using a threshold of 40%, the prevalence of eye worm history was a sensitive and specific indicator of high-risk communities. CONCLUSION: Following this successful validation, RAPLOA was recommended for the assessment of loiasis endemicity in areas targeted for ivermectin treatment by lymphatic filariasis and onchocerciasis control programmes.

Intention to continue with ivermectin treatment for onchocerciasis control after eight years of annual distribution in Cameroon, Nigeria, and Uganda.

This study identified the socio-demographic correlates of intention to comply with ivermectin treatment, from a structured interview of 2,306 persons aged 10 years and above, grouped into high and low compliers, who took ivermectin 6-8 times and 0-2 times respectively. Simple descriptive statistics were employed in characterizing the respondents into high and low compliers, while some socio-demographic and key perceptual factors were employed in regression models constructed to explain levels of compliance among the respondents. Demographic and perceptual factors associated with intention to comply with prolonged treatment with ivermectin were identified. Intention to comply was higher among married persons (91.8%, p < 0.001); local populations (89.8%, p < 0.001); and those with history of complying with treatment (98.2%, p < 0.001). Perception of onchocerciasis and effectiveness of ivermectin influenced intention to continue. The perceptual factors that drive the intention to comply should inform plans for health education at the project and village levels.

The geographic distribution of Loa loa in Africa: results of large-scale implementation of the Rapid Assessment Procedure for Loiasis (RAPLOA).

BACKGROUND: Loiasis is a major obstacle to ivermectin treatment for onchocerciasis control and lymphatic filariasis elimination in central Africa. In communities with a high level of loiasis endemicity, there is a significant risk of severe adverse reactions to ivermectin treatment. Information on the geographic distribution of loiasis in Africa is urgently needed but available information is limited. The African Programme for Onchocerciasis Control (APOC) undertook large scale mapping of loiasis in 11 potentially endemic countries using a rapid assessment procedure for loiasis (RAPLOA) that uses a simple questionnaire on the history of eye worm. METHODOLOGY/PRINCIPAL FINDINGS: RAPLOA surveys were done in a spatial sample of 4798 villages covering an area of 2500×3000 km centred on the heartland of loiasis in Africa. The surveys showed high risk levels of loiasis in 10 countries where an estimated 14.4 million people live in high risk areas. There was a strong spatial correlation among RAPLOA data, and kriging was used to produce spatially smoothed contour maps of the interpolated prevalence of eye worm and the predictive probability that the prevalence exceeds 40%. CONCLUSION/SIGNIFICANCE: The contour map of eye worm prevalence provides the first global map of loiasis based on actual survey data. It shows a clear distribution with two zones of hyper endemicity, large areas that are free of loiasis and several borderline or intermediate zones. The surveys detected several previously unknown hyperendemic foci, clarified the distribution of loiasis in the Central African Republic and large parts of the Republic of Congo and the Democratic Republic of Congo for which hardly any information was available, and confirmed known loiasis foci. The new maps of the prevalence of eye worm and the probability that the prevalence exceeds the risk threshold of 40% provide critical information for ivermectin treatment programs among millions of people in Africa.

Feasibility of measuring compliance to annual ivermectin treatment in the African Programme for Onchocerciasis Control.

The African Programme for Onchocerciasis Control (APOC) sponsors annual distribution of ivermectin to control onchocerciasis. Ivermectin should be taken annually by 65% of community members for a number of years to eliminate the disease as a public health problem. While many community coverage surveys have been undertaken during project monitoring, individual compliance could not be studied until several annual rounds of distribution had occurred. This paper reports on the efforts to determine whether adequate records could be found to enable a compliance study. A step-down process from project to district to community level was used to identify project sites where continuous ivermectin distribution up through 2004 had occurred. The first step consisted of selecting 17 of 25 projects by APOC. The second step determined adequacy of districts where distribution had occurred on a regular annual basis. Among 121 districts 58.6% undertook distribution in all 7 years. A total 852 villages were visited and community level records were found in all but three. Records showed that distribution had occurred for a minimum of five consecutive times in 429 villages, and ultimately 10 projects. While the feasibility study found an adequate number of villages to study compliance, the large number of projects, districts and villages that did not qualify for the follow-on compliance study should lead National Onchocerciasis Control Programme managers to strengthen the overall coverage and consistency of their efforts.

Combined Utilisation of Rapid Assessment Procedures for Loiasis (RAPLOA) and Onchocerciasis (REA) in Rain forest Villages of Cameroon.

BACKGROUND: Individuals with high microfilarial loads of Loa loa are at increased risk of neurologic serious adverse (SAE) events following ivermectin treatment against onchocerciasis. RAPLOA (Rapid Assessment Procedure for loiasis), a newly developed rapid assessment procedure for loiasis that relates the prevalence of key clinical manifestation of loiasis (history of eye worm) to the level of endemicity of the infection (prevalence of high intensity), is a very useful tool to identify areas at potential risk of L. loa post ivermectin treatment encephalopathy. In a perspective of treatment decision making in areas of co-endemicity of loiasis/onchocerciasis, it would be advantageous (both in time and cost savings) for national onchocerciasis control programmes to use RAPLOA and the Rapid epidemiologic assessment for onchocerciasis (REA), in combination in given surveys. Since each of the two rapid assessment tools have their own specificities, the workability of combining the two methods needed to be tested. METHODS: We worked in 10 communities of a forest area presumed co-endemic for loiasis and onchocerciasis in the North-West Province of Cameroon where the mass-treatment with ivermectin had not been carried out. A four-step approach was used and comprised: (i) generating data on the prevalence and intensity of loiasis and onchocerciasis in an area where such information is scarce; (ii) testing the relationship between the L. loa microfilaraemia prevalence and the RAPLOA prevalence, (iii) testing the relationship between the O. volvulus microfiladermia prevalence and the REA prevalence, (iv) testing the workability of combining RAPLOA/REA by study teams in which a single individual can perform the interview for RAPLOA and the nodule palpation for REA. RESULTS: The microfilaraemia prevalence of loiasis in communities ranged from 3.6% to 14.3%. 6 (0.61%) individuals had L. loa microfilarial loads above 8000 mf/ml but none of them attained 30,000 mf/ml, the threshold value above which the risk of developing neurologic SAE after ivermectin treatment is very high. None of the communities surveyed had RAPLOA prevalence above 40%. All the communities had microfiladermia prevalence above 60%. The microfiladermia results could be confirmed by the rapid epidemiologic method (nodule palpation), with all the 10 communities having REA prevalence above 20%. For the first time, this study has demonstrated that the two rapid assessment procedures for loiasis and onchocerciasis can be carried out simultaneously by a survey team, in which a single individual can administer the questionnaire for RAPLOA and perform the nodule palpation for REA. CONCLUSION: This study has: (i) Revealed that the Momo valley of the North West province of Cameroon is hyperendemic for onchocerciasis, but is of lower level of endemicity for L. loa. (ii) Confirmed the previous relationships established between RAPLOA and the L. loa microfilaraemia prevalence in one hand and between the REA and the O. volvulus microfiladermia prevalence in another hand (iii) Shown that RAPLOA and REA could be used simultaneously for the evaluation of loiasis and onchocerciasis endemicity in areas targeted by the African Programme for onchocerciasis Control for community-directed treatment with ivermectin (CDTI).