Figure 1 - uploaded by Patricia Nkem Okorie
Content may be subject to copyright.
Map of Nigeria and its geopolitical zones. North Central - Benue, FCT, Kogi, Kwara, Nasarawa, Niger, Plateau. North East - Adamawa, Bauchi, Borno, Gombe, Taraba, Yobe. North West - Kaduna, Katsina, Kano, Kebbi, Sokoto, Jigawa,, Zamfara. South East - Abia, Anambra, Ebonyi, Enugu, Imo. South - Akwa-Ibom, Bayelsa, Cross-River, Delta, Edo, Rivers. South West - Ekiti, Lagos, Osun, Ondo, Ogun, Oyo. Note: Elevation data based on ETOPO2 global 2-minute gridded resolution from National Oceanic and Atmospheric Administration (NOAA) available from ESRI Redland, CA. doi:10.1371/journal.pntd.0002416.g001 

Map of Nigeria and its geopolitical zones. North Central - Benue, FCT, Kogi, Kwara, Nasarawa, Niger, Plateau. North East - Adamawa, Bauchi, Borno, Gombe, Taraba, Yobe. North West - Kaduna, Katsina, Kano, Kebbi, Sokoto, Jigawa,, Zamfara. South East - Abia, Anambra, Ebonyi, Enugu, Imo. South - Akwa-Ibom, Bayelsa, Cross-River, Delta, Edo, Rivers. South West - Ekiti, Lagos, Osun, Ondo, Ogun, Oyo. Note: Elevation data based on ETOPO2 global 2-minute gridded resolution from National Oceanic and Atmospheric Administration (NOAA) available from ESRI Redland, CA. doi:10.1371/journal.pntd.0002416.g001 

Source publication
Article
Full-text available
Nigeria has a significant burden of lymphatic filariasis (LF) caused by the parasite Wuchereria bancrofti. A major concern to the expansion of the LF elimination programme is the risk of serious adverse events (SAEs) associated with the use of ivermectin in areas co-endemic with Loa filariasis. To better understand this, as well as other factors th...

Context in source publication

Context 1
... distribution of the filarial parasite Loa in Africa [7] is also a major impediment due to the risk of severe adverse events (SAEs) in co-infected individuals when treated with ivermectin [8] [9]. These constraints pose significant problems for the national LF programmes and GPELF with the potential to severely hinder the 2020 goal of LF elimination globally. To begin to address these complexities, a number of specific objectives and strategies have been developed. First, the GPELF strategic plan aims to achieve full geographical coverage with MDA by 2016, targeting the countries with the highest burden, including Nigeria [1]. Second, the use of integrated vector management (IVM) [10] is advocated in malaria co-endemic areas where both diseases are transmitted by Anopheles mosquitoes [11]. Finally, a provisional strategy for interrupting LF transmission in loiasis endemic countries recently developed recommends albendazole (400 mg) twice yearly in combination with vector control in all co-endemic areas [12]. Finally, mapping LF and L. loa at the lowest possible administra- tive unit is also considered important to identify small areas that can be treated for LF using the most appropriate regimes to reduce the risk of SAEs, which is considered to be highest when L. loa microfilaremia (mf) prevalence is $ 20%. The coordinated effort of global disease control programmes is becoming increasingly important as many operate in the same countries and distribute interventions that have multiple benefits [13]–[16]. GPELF is likely to benefit from the activities of the Global Malaria Programme, including the recent scale up of insecticide treated/long-lasting insecticidal mosquito nets (ITNs/ LLINs) and indoor residual spraying (IRS) [11]. These interventions have also been shown to impact LF transmission in a range of ecological settings [17], thus more synergy between the programmes in Africa could optimize resources and increase the impact on both diseases [15]–[18]. In countries such as Nigeria where malaria and LF are co-endemic and both transmitted by Anopheles mosquitoes [19] [20], the use of ITNs has shown to be effective at reducing LF transmission in L. loa co-endemic areas [21]. ITNs have also been successfully integrated with MDA activities in Central Nigeria with report of an increase in ITN ownership and retention [22] [23]. However, to take advantage of these programmatic links, more data on LF vectors is critical as there are many gaps in our knowledge as highlighted in the Anopheles database recently compiled for Nigeria [19]. Integrating activities and combining resources across the various NTD programmes will also have many advantages [13] [24]. For example, the African Programme for Onchocerciasis Control (APOC) has developed a sustainable community-directed treatment with ivermectin (CDTi) for the parasitic disease caused by the filarial worm Onchocerca volvulus , [25]–[27]. The CDTi approach has been successful in reaching millions of people across high transmission areas of onchocerciasis in Africa, and has also been used to distribute other health interventions including LF treatment and bed nets for malaria control [26]. Moreover, the maps of CDTi priority areas highlight the potential geographical overlap of onchocerciasis with LF, and it is likely that the wide and frequent use of ivermectin has reduced transmission in co-endemic areas [28]–[31]. However, the extent of this impact is yet to be determined at a large scale and needs to be quantified so that benefits from this and future NTD control programmes can be better understood and fully exploited [5] [32]–[34]. These issues are particularly relevant for Nigeria, given the large population at risk of W. bancrofti infection [3]–[5]. The National Lymphatic Filariasis Elimination Programme (NLFEP) is yet to complete LF mapping [3] [35] and will need significant financial and technical support to scale up MDA activities across this large, populous country. The aim of this paper, therefore, is to use the Micro-stratification Overlap Mapping (MOM) approach [24] to review and synthesize the current knowledge of the distribution of W. bancrofti in Nigeria, and factors that will impact on the control and elimination of LF such as loiasis co-endemicity, onchocerciasis control programmes, and malaria bed net distributions. This information is a prerequisite for effective planning and will help to optimize the future LF MDA implementation strategy to ensure safety, maximum cost effectiveness as well as impact. Nigeria is a Federal Republic comprising 36 States and its Federal Capital Territory, Abuja [35] [36]. The states are grouped into six geopolitical zones, the North Central (NC), North East (NE), North West (NW), South West (SW), South East (SE) and South (SS). Nigeria covers an area of approximately 923,768 sq. km, and has a large low plateau intersected by two major rivers, the Niger and Benue, in the central region of the country (Figure 1). It shares borders with Benin in the west, Chad and Cameroon in the east, and Niger in the north. Its coast in the south lies on the Gulf of Guinea on the Atlantic Ocean and Lagos, the former capital, is an important port city. Nigeria is Africa’s most populous country with the total population estimated to be 160 million in 2012, with approximately 50% living in urban areas. To review and synthesize the current knowledge of the human distribution of LF in Nigeria, a systematic search for data in peer- reviewed published literature and national reports was carried out. The search was conducted using PubMed, JSTOR, Google, SCOPUS and other online scientific and historical databases. References were also obtained from the references listed within articles, and then from the references within those articles. Studies and reports with data on the prevalence of i) LF infection as circulating filarial antigen (CFA) from using immunochromatographic tests (ICTs), antibodies by ELISAs, and microfilaria (Mf) from blood slides, and ii) disease cases (hydrocele, lymphodema) [2] [37] were identified and collated into a database. Information on the location/collection site (village, local government area (LGA) and State), and time period (month, year), was also collected for mapping and descriptive analyses. Specific information on whether MDA for LF had been administered prior to the LF prevalence measure was recorded and considered in the analysis. The range of methods used to detect LF in the different studies was recorded, as well as information on the mosquito species, which was cross-checked with the Nigerian Anopheles database [19]. The locations of the community or collection site were geo- referenced using the latitude and longitude coordinates obtained from references directly or by cross-checking the names with data from the GEOnet Names Server, Directory of Cities and Towns in the World databases [38] [39]. The coordinates of the midpoint of the LGA was used as a proxy for the locations that could not be allocated exact latitude and longitude coordinates. This is considered to be a limitation of the review and restricts any accurate detailed mapping. It is also acknowledged that LF prevalence distribution has a degree of bias as the data are based on the locations selected by the investigators in the original study, and does not take sampling methodologies between studies into account, which may affect the outcome. In addition, selected data from the Federal Ministry of Health (FMoH) collected during LF mapping activities were collated and included in the database. The LF data available for this study were based on Mf prevalence rates collected in selected LGA sentinel sites during baseline surveys in 31 LGAs across 18 States of Nigeria. The WHO standard protocol was used to collect blood samples at night and examined for the presence of Mf. The coordinates of the midpoint of each LGA was used to map the LF prevalence. A national LF endemicity map by LGA was also available from the FMoH, which provided an overall CFA prevalence based on ICT survey in each State carried out between 2000 and 2010. Specific LGA data is not publicly available and not included in this database, however, the State-level information on the number of LGAs surveyed, prevalence range and year of survey is available in the recently published Master Plan for NTDs [35]. All the relevant information was entered into an Excel worksheet and data analysis was performed using Stata software (version 12, StataCorp, Texas, USA). All data were mapped using the geographical information systems (GIS) software ArcGIS 10.0 (ESRI, Redlands, CA) to produce maps of LF prevalence distributions, and to examine the geographical overlaps with loiasis-endemic areas, and the different intervention distributions. To examine the potential extent of LF and L. loa co-endemicity, the recent map of the predicted loiasis prevalence produced from a Rapid Assessment Procedure of Loiasis (RAPLOA) based on eye worm history carried out between 2004 and 2010 across Africa, including Nigeria [7], was imported into ArcGIS. Three levels of predicted loiasis prevalence were digitised (i.e. outlined, shaded) based on the defined distribution boundaries, which included low , 20%, medium 20–40% and high . 40% prevalence areas; the latter is equivalent to mf prevalence of . 20%. The different levels of loiasis prevalence and the overlap with LF prevalence distributions were highlighted to help identify potential low risk (i.e. loiasis , 20%) and medium to high risk (i.e loiasis . 20%) SAE areas. Onchocerciasis control programmes. To examine the distribution of ivermectin and its association with LF and loiasis endemicity, the CDTi map produced from REMO surveys carried out in 2004 and 2005 [31] was imported into ArcGIS. The CDTi priority (i.e. ivermectin treatment) areas were digitized, and the overlap with LF and loiasis distributions highlighted. It is acknowledged ...

Similar publications

Article
Full-text available
Background: Loiasis is a parasitic infection endemic in the African rain forest caused by the filarial nematode Loa loa. Loiasis can be co-endemic with onchocerciasis and/or lymphatic filariasis. Ivermectin, the drug used in the control of these diseases, can induce serious adverse reactions in patients with high L loa microfilaraemia (LLM). A dru...
Article
Full-text available
Background: Onchocerciasis and lymphatic filariasis (LF) are major filarial infections targeted for elimination in most endemic sub-Saharan Africa (SSA) countries by 2020/2025. The current control strategies are built upon community-directed mass administration of ivermectin (CDTI) for onchocerciasis, and ivermectin plus albendazole for LF, with e...
Article
Full-text available
Lymphatic filariasis, onchocerciasis and loiasis are widespread neglected tropical diseases causing serious public health problems and impacting the socio-economic climate in endemic communities. More than 100 million people currently suffer from filarial infections but disease-related symptoms and infection-induced immune mechanisms are still ambi...
Article
Full-text available
The filarial parasite Loa loa, the causative agent of loiasis, is endemic in Central and Western Africa infecting 3-13 million people. L. loa has been associated with fatal encephalopathic reactions in high Loa-infected individuals receiving ivermectin during mass drug administration programs for the control of onchocerciasis and lymphatic filarias...
Article
Full-text available
Abstract The Millennium Development Goals (MDGs) made a marked transformation for neglected and vulnerable communities in the developing countries from the start, but infectious diseases of poverty (IDoPs) continue to inflict a disproportionate global public health burden with associated consequences, thereby contributing to the vicious cycle of po...

Citations

... The LF caused by the parasite Wuchereria bancrofti is largely prevalent in sub-Saharan Africa and is one of the leading causes of long-term disability in the World [14]. As reported by Okorie and colleagues in 2013, Nigeria has a high burden of lymphatic filariasis (LF) caused by the parasite W. bancrofti [15]. Nigeria was reported in 2016 to have the third highest national burden of LF with estimated 114 million individual at risk of the infection. ...
... Nigeria in 2013 as reported by Okorie et al., [6], is ranked as the third most endemic country in the world after India and Indonesia for LF considering that over 98% of Nigeria 774 ...
Article
Full-text available
National lymphatic filariasis elimination programme (NLFEP) of Federal Ministry of Health sets to provide status of LF in the country before 2020. Borno State, situated in the North East political zone of Nigeria with an estimated population of 4.1million had been enmeshed in insurgency for over a decade. Following an initial mapping between 2008 and 2016 in 16 LGAs out of 27 LGAs, it became imperative that the status of LF in the remaining 11 LGAs of Borno State be ascertained in order to have complete data for planning and policy. Using stratified sampling method, eleven communities were selected from the 11 LGAs namely: Abadam, Ngala, Guzamala, Ngazai, Gubio, Mafa, Jere, Biu, Bayo, Askirin/Uba, and Kwayar Kusar. Blood samples were obtained from consented 990 participants and filarial test strip (FTS) were employed to determine their LF status between November 2017 and February 2018. Of the 990 consented participants only 15 (1.5%) were positive for lymphatic filariasis. Ten cases of hydrocele in men were observed in 4 communities namely Bunari (3), Peta (3), Zaramiramga (2) and Uba (2). Considering the number of positive cases by FTS and hydrocele, result showed that hydrocele accounted for 66.7% of the total positive cases within the positive communities. It is advised that the State health workers should continue to properly educate communities on health programmes including LF preventive measures. Also both Federal Ministry of Health and State Ministry of Health sensitize health partners to start LF treatment and morbidity management in all positive communities to fast track elimination of LF.
... There are over one billion people with at least an NTD (including more than 500 million children) and 500,000 deaths yearly (9). In Africa, 34 countries are endemic to lymphatic filariasis, with Nigeria bearing the highest burden of the disease, with a risk population of 80 to 120 million people (10,11). Nigeria also contributes the highest burden of 29 million cases of schistosomiasis among sub-Saharan African (SSA) countries (12), as well as the highest number (38 million) of hookworm infestation, Ascaris (55 million), and trichuria (34 million) in the region (11)(12)(13). ...
Article
Full-text available
Background: Getting evidence from Health Policy and Systems Research (HPSR) into policy and practice for effective control of neglected tropical diseases (NTDs) is essential for providing better service delivery because evidence-informed decision-making improves the effectiveness of a health system and health outcomes. The paper provides new knowledge on the policy-/decision-makers’ level of knowledge, capacity to use, and how evidence from HPSR has been used in decision-making for the control of endemic tropical diseases (ETDs), especially the NTDs and malaria in Nigeria. Methods: A cross-sectional qualitative study of decision-makers was undertaken in Anambra and Enugu states, southeast Nigeria. Data was collected through in-depth interviews (n=22) of purposively selected decision-makers to assess how HPSR evidence is translated into policy and practice for controlling ETDs. The respondents were selected based on their job description, roles, and involvement in the control of ETDs. Data were analyzed using the thematic content approach. Results: There is a considerable level of knowledge on HPSR and its relationship with evidence-informed policy- and decision-making towards control of ETDs and health system strengthening. Organizational capacity to use HPSR evidence in decision�making was found to be weak due to various reasons such as no embedded structure for translating research evidence to policy and practice, lack of decision-making autonomy by individuals, and politically driven decisions. Few respondents have either ever used or are currently using HPRS evidence for developing/reviewing and implementing strategies for ETDs programs. Majority of the respondents reported that their main source of evidence was routine data from health information management system, which they found useful due to its representativeness and completeness. Mainenabler for using HPSR evidence for decision-making is existing collaborations between researchers and policy-/decision-makers. Conclusion: There is a high level of awareness about evidence from HPSR and the usefulness of such evidence in decision-making. However, this awareness does not translate to optimal use of evidence for decision-making due to weak organizational capacity and other constraints. There is the need to invest in capacity-building activities to develop a critical mass of users of evidence (policy-/decision-makers) to facilitate enhanced uptake of high-quality evidence into policy decisions for better control of ETDs.
... Ogun State is one of the thirty-six states in Nigeria [21] located in the south-western region of the country [22]. It is bordered to the West by Republic of Benin, which makes it an access route to the expansive markets of the Economic Community of West African State (ECOWAS). ...
... We expected the prevalence of stunting in Ogun State to be lower than the average of Nigeria [35], considering that Ogun State is in the Southwestern region of Nigeria [22], which is more affluent. Also, Ogun State started a school feeding programme for children in January 2017 [54]. ...
Article
Full-text available
Background: Nigeria has the second-highest prevalence of stunting in children under five in the world. Stunting can have long-term effects on development, performance, and productivity, and it is, therefore, important to assess who is most at risk so that interventions can be better targeted. The study aimed at assessing the prevalence of stunting in under age five children in Ogun State, Nigeria, and its relationship with age, sex, maternal education, household income, and residence type. Methods: We used cross-sectional secondary data from the 2018 Nigeria Demographic and Health Survey to assess the prevalence of stunting and establish if and how stunting is related to the children’s age, sex, household income, maternal education, and type of residence. We included data on age, sex, height/length, maternal education, household income, and type of place of residence of 274 children, aged 0-59 months. Stunting was calculated using the online version of the World Health Organization (WHO) Anthro Survey Analyser. Data were analyzed using Statistical Package for Social Sciences (v.25). Results: The prevalence of stunting was 23%. Stunting was significantly associated with age (p=0.001). The odds of stunting were significantly highest in children aged 36-47 months (OR 22.61, 95%CI: 2.81, 181.93) relative to other age groups. Stunting was not significantly associated with sex (p=0.079), maternal education (p=0.079), household income (p=0.183) or type of place of residence (p=0.299). Conclusions: Whilst the prevalence of stunting in children aged under five in Ogun State is lower than the average prevalence of stunting in Nigeria, it is still medium according to WHO classification. Intensive nutrition interventions should be targeted to children aged 3-5 years to reduce the stunting prevalence.
... Several authors suggested that montmorillonite is commonly found but at low concentrations in soil,sediment load of natural waters, and in airborne dust. [2,72] reported that kaolinite is the most abundant clay mineral found in clay in Ogun, Edo and Delta State, Nigeria as shown in Table 3. From their study, one could conclude that kaolin clay is a major clay found within the area they studied any clay that consist mainly of kaolinite with presence of other mineral is referred to as ball clay. Although, [73] were of the view that Kaolin clay in most situation is found associated with some mineral impurities such as quartz, hematite, montmorillonite, mica, illite, ilmenite, feldspar, zircon, graphite, bauxite, rutile, titaniferrous, silliminate, halloysite, attapulgite and carbonaceous materials, which might impair their industrial use. ...
... Several authors suggested that montmorillonite is commonly found but at low concentrations in soil,sediment load of natural waters, and in airborne dust. [2,72] reported that kaolinite is the most abundant clay mineral found in clay in Ogun, Edo and Delta State, Nigeria as shown in Table 3. From their study, one could conclude that kaolin clay is a major clay found within the area they studied any clay that consist mainly of kaolinite with presence of other mineral is referred to as ball clay. Although, [73] were of the view that Kaolin clay in most situation is found associated with some mineral impurities such as quartz, hematite, montmorillonite, mica, illite, ilmenite, feldspar, zircon, graphite, bauxite, rutile, titaniferrous, silliminate, halloysite, attapulgite and carbonaceous materials, which might impair their industrial use. ...
Article
Full-text available
This paper reviews the mineralogical and chemical characteristics of clays found in southern part of Nigeria, with a view to determine its usability. The usability of clays, depends on its chemical and mineralogical charactertics, the end product of clay after it is been processed is also based on it’s charactertics. From reviewed literature, it was observed that sampled clay within the study area were analyzed using the XRD, XRF and ICPMS method. Further findings also revealed that the dominant clay minerals within the study area include montmorillonite, illite, and kaolinite. On the other hand, it was observed that non-clay minerals such as feldspar, quartz, dickite and many others were found with clay as revealed by several scholars. While chemical charactertics of clay consists mainly of Al2O3, K2O, CaO and SiO2, with other major oxides such as P2O5, MgO, Fe2O3, TiO2, MnO and Na2O. Some trace elements such Be, Ba, Sc, Sr, Zr, V and Y were reported to be present in clays deposit found in selected part of Ogun state. From reviewed articles, it was observed that mineralogical and chemical charactertics of clay make it suitable for pharmaceutical, textile, cosmetic and polymer industries, but considered to be fairly suitable for oil and gas industry.
... Prevalence of Wuchereria bancrofti found in this study was lower than the reports of previous studies in Nigeria because Okorie et al., [21] in 2013 found the prevalence of, Lymphatic Filariasis in Nigeria and reported that the mean prevalence of circulating filarial antigen (CFA) was 14.0% (in 134 locations), and by microfilaria (Mf) was 8.2% (in 162 locations). Okorie et al., [21] concluded that Nigeria has the highest burden of lymphatic filariasis (LF)/elephantiasis caused by Wuchereria bancrofti which is transmitted by mosquitoes; Mu`awiyya et al., [22] carried out a sero-prevalence of Lymphatic Filariasis in Six Communities of Talata Mafara Local Government Area, Zamfara State, Nigeria and found an overall sero-prevalence of 37.8%. ...
... Prevalence of Wuchereria bancrofti found in this study was lower than the reports of previous studies in Nigeria because Okorie et al., [21] in 2013 found the prevalence of, Lymphatic Filariasis in Nigeria and reported that the mean prevalence of circulating filarial antigen (CFA) was 14.0% (in 134 locations), and by microfilaria (Mf) was 8.2% (in 162 locations). Okorie et al., [21] concluded that Nigeria has the highest burden of lymphatic filariasis (LF)/elephantiasis caused by Wuchereria bancrofti which is transmitted by mosquitoes; Mu`awiyya et al., [22] carried out a sero-prevalence of Lymphatic Filariasis in Six Communities of Talata Mafara Local Government Area, Zamfara State, Nigeria and found an overall sero-prevalence of 37.8%. with highest prevalence of 43.3% in farmers than other occupational groups and Adekunle et al., [23] reported that 27%(291) out of 1,090 blood specimens examined were positive for infection with W. bancrofti in Ose Local Government Area, Ondo State, Nigeria. ...
Article
Full-text available
Study Background: Plasmodium spp., (Protozoan) and Wuchereria bancrofti (Nematode) are transmitted by mosquitos to cause insect borne diseases known as malaria and Lymphatic filariasis/Elephantiasis. Apart from the social implication of these parasitic infections the infections can also elicit immune responses. Aim and Objective: This work was therefore designed to determine the pattern of mosquito borne parasitic infection in the night blood samples of patients with elevated TNF-α of > 5.0 pg/ml. Materials and Methods: Seventy (70; aged 31 – 76 years; Male- 35; Female-35) volunteers with plasma TNFα of 5.8 ±0.7 pg/including age-matched control participants ( n= 50 ; TNFα of 2.2 ± 0.3 pg/ml). All participants were negative to Acid Fast Bacilli, ant-HCV, HBsAg and HIV tests were recruited for the study. Night blood samples and sputum samples were obtained from the participants. Blood sample was used for determination of TNFα, HIVp24ag-Ab, anti-HCV, HBsAg by ELISA and identification of Plasmodium and Wuchereria by Geimsha thick blood film staining while sputum samples were used for the demonstration of Acid Fast Bacilli by Ziehl Neelsen staining. Results: The results showed a frequency of Plasmodium spp., in individuals with plasma TNF-α of 5.8 ±0.7 pg/ml as 31.4%(22) as against a frequency of 18%(9) in subjects with plasma TNF-α of 2.2 ± 0.3 pg/ml.. The results also showed a frequency of 5.71%(4) and2%(1) Wuchereria bancrofti in subjects with plasma TNF-α of 5.8 ±0.7 pg/ml and TNF-α of 2.2 ± 0.3 pg/ml. respectively. The overall frequency of parasitic infection obtained in both test and control subjects include: 33.3% (40)Plasmodium spp., and 4.2%(5) Wuchereria bancrofti.The overall results from both test and control subjects also showed a gender distribution of 20%(24) and 13.3%(16) Plasmodium spp.,in female and males respectively while a distribution of 1.7%(2) and 2.5%(3) Wuchereria bancrofti in females and males respectively. Conclusion: This work revealed increase in the frequency of Plasmodium spp. and Wuchereria bancrofti infections with increase in plasma TNF-α while the overall frequency of parasitic infection obtained in both test and control subjects was found to be 33.3% (40)Plasmodium spp., and 4.2%(5) Wuchereria bancrofti with possible variations in regional and gender distributions. Mosquito borne parasitic infection of Plasmodium spp., was found to be more prevalent in patients with elevated TNF-α of> 5.0 pg/ml.
... Evidence from research shows that, in 2013, 34 African countries were endemic to lymphatic filariasis, and Nigeria had the highest burden, with 80 to 120 million people at risk [7,8]. In 2015, Nigeria contributed the highest burden (29 million) of schistosomiasis in SSA [9]. ...
Article
Full-text available
Background: Endemic tropical diseases (ETDs) constitute a significant health burden in resource-poor countries. Weak integration of research evidence into policy and practice poses a major challenge to the control of ETDs. This study was undertaken to explore barriers to the use of research evidence in decision-making for controlling ETDs. It also highlights potential strategies for addressing these barriers, including the gaps in research generation and utilisation in the context of endemic disease control. Methods: Information on barriers and solutions to integrating research evidence into decision-making for controlling ETDs in Anambra State, Nigeria, was collected from 68 participants (producers and users of evidence) during structured discussions in a workshop. Participants were purposively selected and allocated to groups based on their current involvement in endemic disease control and expertise. Discussions were facilitated with a topic guide and detailed notes were taken by an appointed recorder. Outputs from the discussions were synthesised and analysed manually. Results: Cross-cutting barriers include a weak research linkage between producers and users of evidence and weak capacity to undertake health policy and systems research (HPSR). Producers of evidence were purported to conceptualise and frame their research questions based on their academic interests and funders' focus without recourse to the decision-makers. Conversely, poor demand for research evidence was reported among users of evidence. Another user barrier identified was moribund research units of the Department of Planning Research and Statistics within the State Ministry of Health. Potential solutions for addressing these barriers include creation of knowledge networks and partnerships between producers and users of evidence, institutionalisation of sustainable capacity-building of both parties in HPSR and revival of State research units. Conclusions: Evidence-informed decision-making for controlling ETDs is limited by constraints in the interactions of some factors between the users (supply side) and producers (demand side) of evidence. These constraints could be solved through stronger research collaborations, institutionalisation of HPSR, and frameworks for getting research into policy and practice.
... Mf prevalence declines much more quickly due to the stronger microfilaricidal effects of treatment. In addition, in Nigeria, where there are vast areas co-endemic for both LF and onchocerciasis [49], and of which MDA for onchcocerciasis, using ivermectin, pre-dates the survey data used in this study. Although this study models the baseline prevalence of LF, it does not account for the therapeutic effects of onchocerciasis treatment in LF co-endemic areas [50]. ...
Article
Full-text available
Introduction The baseline endemicity profile of lymphatic filariasis (LF) is a key benchmark for planning control programmes, monitoring their impact on transmission and assessing the feasibility of achieving elimination. Presented in this work is the modelled serological and parasitological prevalence of LF prior to the scale-up of mass drug administration (MDA) in Nigeria using a machine learning based approach. Methods LF prevalence data generated by the Nigeria Lymphatic Filariasis Control Programme during country-wide mapping surveys conducted between 2000 and 2013 were used to build the models. The dataset comprised of 1103 community-level surveys based on the detection of filarial antigenemia using rapid immunochromatographic card tests (ICT) and 184 prevalence surveys testing for the presence of microfilaria (Mf) in blood. Using a suite of climate and environmental continuous gridded variables and compiled site-level prevalence data, a quantile regression forest (QRF) model was fitted for both antigenemia and microfilaraemia LF prevalence. Model predictions were projected across a continuous 5 × 5 km gridded map of Nigeria. The number of individuals potentially infected by LF prior to MDA interventions was subsequently estimated. Results Maps presented predict a heterogeneous distribution of LF antigenemia and microfilaraemia in Nigeria. The North-Central, North-West, and South-East regions displayed the highest predicted LF seroprevalence, whereas predicted Mf prevalence was highest in the southern regions. Overall, 8.7 million and 3.3 million infections were predicted for ICT and Mf, respectively. Conclusions QRF is a machine learning-based algorithm capable of handling high-dimensional data and fitting complex relationships between response and predictor variables. Our models provide a benchmark through which the progress of ongoing LF control efforts can be monitored.
... Mf, Ag and or disease surveys were used to map areas requiring MDA. [79][80][81][82] In Rwanda, mapping showed that there was only one Ag positive case in all five districts that were surveyed and this helped in declaring that LF was not a public health problem and therefore MDA was deferred thereby saving money and other humane efforts. 63 In the countries of the African region, starting with rapid assessment procedures (Ag survey and key informant interviews on LF symptoms) for delimiting areas endemic for LF, the progress made on mapping of LF has been tremendous. ...
... In Nigeria, a similar approach using historical data helped in producing a series of maps to assist in maximizing existing interventions, cost effective usage of resources as the LF elimination programme scaled up. 81 Countries such as Ghana, Uganda and India used the historical data (Mf, Ag), for predicting LF prevalence in the uncertain and un-surveyed areas using geo-statistical models 67,69,[90][91][92][93] and showed the heterogeneous distribution of LF for the respective countries, indicating the possibility on the risk of occurrence of LF even in the probably non-endemic areas. Three studies from India used Mf prevalence to identify districts for MDA. ...
Article
Full-text available
Lymphatic filariasis (LF) is targeted for elimination by the year 2020. The Global Programme for Elimination of LF (GPELF) aims to achieve elimination by interrupting transmission through annual mass drug administration (MDA) of albendazole with ivermectin or diethylcarbamazine. The program has successfully eliminated the disease in 11 of the 72 endemic countries, putting in enormous efforts on systematic planning and implementation of the strategy. Mapping areas endemic for LF is a pre-requisite for implementing MDA, monitoring and evaluation are the components of programme implementation. This review was undertaken to assess how the mapping and impact monitoring activities have evolved to become more robust over the years and steered the LF elimination programme towards its goal. The findings showed that the WHO recommended mapping strategy aided 17 countries to delimit, plan and implement MDA in only those areas endemic for LF thereby saving resources. Availability of serological tools for detecting infection in humans (antigen/antibody assays) and molecular xenomonitoring (MX) in vectors greatly facilitated programme monitoring and evaluation in endemic countries. Results of this review are discussed on how these existing mapping and monitoring procedures can be used for re-mapping of unsurveyed and uncertain areas to ensure there is no resurgence during post-MDA surveillance. Further the appropriateness of the tests (Microfilaria (Mf)/antigenemia (Ag)/antibody(Ab) surveys in humans or MX of vectors for infection) used currently for post-MDA surveillance and their role in the development of a monitoring and evaluation strategy for the recently WHO recommended triple drug regimen in MDA for accelerated LF elimination are discussed.