RESUMEN
Schistosomiasis control in sub-Saharan Africa is enacted primarily through preventive chemotherapy. Predictive models can play an important role in filling knowledge gaps in the distribution of the disease and help guide the allocation of limited resources. Previous modeling approaches have used localized cross-sectional survey data and environmental data typically collected at a discrete point in time. In this analysis, 8 years (2008-2015) of monthly schistosomiasis cases reported into Ghana's national surveillance system were used to assess temporal and spatial relationships between disease rates and three remotely sensed environmental variables: land surface temperature (LST), normalized difference vegetation index (NDVI), and accumulated precipitation (AP). Furthermore, the analysis was stratified by three major and nine minor climate zones, defined using a new climate classification method. Results showed a downward trend in reported disease rates (~ 1% per month) for all climate zones. Seasonality was present in the north with two peaks (March and September), and in the middle of the country with a single peak (July). Lowest disease rates were observed in December/January across climate zones. Seasonal patterns in the environmental variables and their associations with reported schistosomiasis infection rates varied across climate zones. Precipitation consistently demonstrated a positive association with disease outcome, with a 1-cm increase in rainfall contributing a 0.3-1.6% increase in monthly reported schistosomiasis infection rates. Generally, surveillance of neglected tropical diseases (NTDs) in low-income countries continues to suffer from data quality issues. However, with systematic improvements, our approach demonstrates a way for health departments to use routine surveillance data in combination with publicly available remote sensing data to analyze disease patterns with wide geographic coverage and varying levels of spatial and temporal aggregation.
Asunto(s)
Clima , Monitoreo del Ambiente/estadística & datos numéricos , Tecnología de Sensores Remotos , Esquistosomiasis/epidemiología , Monitoreo Epidemiológico , Ghana/epidemiología , Humanos , Desarrollo de la Planta , Esquistosomiasis/prevención & control , Estaciones del Año , Tiempo (Meteorología)RESUMEN
OBJECTIVE: Mass drug administration (MDA) for the control of lymphatic filariasis (LF), in Ghana, started in the year 2000. While this had great success in many implementation units, there remain areas with persistent transmission, after more than 10 years of treatment. A closer examination of the parasite populations could help understand the reasons for persistent infections and formulate appropriate strategies to control LF in these areas of persistent transmission. MATERIALS AND METHODS: In a longitudinal study, we assessed the prevalence of microfilaraemia (mf) in two communities with 12 years of MDA in Ghana. In baseline surveys 6 months after the National MDA in 2014, 370 consenting individuals were tested for antigenaemia using immunochromatographic test (ICT) cards and had their mf count determined through night blood surveys. 48 ICT positives, of whom, 17 were positive for mf, were treated with 400 µg/kg ivermectin + 400 mg albendazole and subsequently followed for parasitological assessment at 3-month intervals for 1 year. This overlapped with the National MDA in 2015. RESULTS: There was a 68% parasite clearance 3 months after treatment. The pre-treatment mf count differed significantly from the post-treatment mf counts at 3 months (P = 0.0023), 6 months (P = 0.0051), 9 months (P = 0.0113) and 12 months (P = 0.0008). CONCLUSION: In these settings with persistent LF transmission, twice-yearly treatment may help accelerate LF elimination. Further large-scale evaluations are required to ascertain these findings.
Asunto(s)
Albendazol/uso terapéutico , Filariasis Linfática/parasitología , Filaricidas/uso terapéutico , Filarioidea/crecimiento & desarrollo , Ivermectina/uso terapéutico , Adolescente , Adulto , Anciano , Albendazol/farmacología , Animales , Antígenos Helmínticos/sangre , Niño , Filariasis Linfática/sangre , Filariasis Linfática/epidemiología , Filariasis Linfática/prevención & control , Femenino , Filaricidas/farmacología , Filarioidea/efectos de los fármacos , Ghana/epidemiología , Programas de Gobierno , Humanos , Ivermectina/farmacología , Estudios Longitudinales , Masculino , Microfilarias/efectos de los fármacos , Microfilarias/crecimiento & desarrollo , Persona de Mediana Edad , Prevalencia , Adulto JovenRESUMEN
BACKGROUND: Several African countries have adopted a biannual ivermectin distribution strategy in some foci to control and eliminate onchocerciasis. In 2010, the Ghana Health Service started biannual distribution to combat transmission hotspots and suboptimal responses to treatment. We assessed the epidemiological impact of the first 3 years of this strategy and quantified responses to ivermectin over 2 consecutive rounds of treatment in 10 sentinel communities. METHODS: We evaluated Onchocerca volvulus community microfilarial intensity and prevalence in persons aged ≥20 years before the first, second, and fifth (or sixth) biannual treatment rounds using skin snip data from 956 participants. We used longitudinal regression modeling to estimate rates of microfilarial repopulation of the skin in a cohort of 217 participants who were followed up over the first 2 rounds of biannual treatment. RESULTS: Biannual treatment has had a positive impact, with substantial reductions in infection intensity after 4 or 5 rounds in most communities. We identified 3 communities-all having been previously recognized as responding suboptimally to ivermectin-with statistically significantly high microfilarial repopulation rates. We did not find any clear association between microfilarial repopulation rate and the number of years of prior intervention, coverage, or the community level of infection. CONCLUSIONS: The strategy of biannual ivermectin treatment in Ghana has reduced O. volvulus microfilarial intensity and prevalence, but suboptimal responses to treatment remain evident in a number of previously and consistently implicated communities. Whether increasing the frequency of treatment will be sufficient to meet the World Health Organization's 2020 elimination goals remains uncertain.
Asunto(s)
Antiparasitarios/administración & dosificación , Antiparasitarios/uso terapéutico , Ivermectina/administración & dosificación , Ivermectina/uso terapéutico , Oncocercosis Ocular , Adulto , Estudios de Cohortes , Ghana/epidemiología , Humanos , Masculino , Oncocercosis Ocular/tratamiento farmacológico , Oncocercosis Ocular/epidemiología , Oncocercosis Ocular/parasitología , Carga de Parásitos , Prevalencia , Piel/parasitología , Resultado del Tratamiento , Adulto JovenRESUMEN
OBJECTIVES: Situational analysis of lymphatic filariasis (LF) morbidity and its management in Ahanta West, Ghana, to identify potential barrier to healthcare for LF patients. METHODS: Lymphoedema and hydrocoele patients were identified by community health workers from a subset of villages, and were interviewed and participated in focus group discussions to determine their attitudes and practices towards managing their morbidity, and their perceived barriers to accessing care. Local health professionals were also interviewed to obtain their views on the availability of morbidity management services in the district. RESULTS: Sixty-two patients (34 lymphoedema and 28 hydrocoeles) and 13 local health professionals were included in the study. Lymphoedema patients predominantly self-managed their conditions, which included washing with soap and water (61.8%), and exercising the affected area (52.9%). Almost 65% of patients had sought medical assistance at some stage, but support was generally limited to receiving tablets (91%). Local health professionals reported rarely seeing lymphoedema patients, citing stigma and lack of provisions to assist patients as a reason for this. Almost half of hydrocoele patients (44%) chose not to seek medical assistance despite the negative impact it had on their lives. Whilst surgery itself is free with national health insurance, 63% those who had not sought treatment stated that indirect costs of surgery (travel costs, loss of earnings, etc.) were the most prohibitive factor to seeking treatment. CONCLUSIONS: The information obtained from this study should now be used to guide future morbidity strategies in building a stronger relationship between the local health services and LF patients, to ultimately improve patients' physical, psychological and economic wellbeing.
Asunto(s)
Manejo de la Enfermedad , Filariasis Linfática/terapia , Accesibilidad a los Servicios de Salud , Servicios de Salud , Aceptación de la Atención de Salud , Autocuidado , Costos y Análisis de Costo , Filariasis Linfática/complicaciones , Femenino , Grupos Focales , Ghana , Gastos en Salud , Personal de Salud , Humanos , Linfedema/etiología , Linfedema/terapia , Masculino , Morbilidad , Hidrocele Testicular/etiología , Hidrocele Testicular/terapiaRESUMEN
BACKGROUND: Lymphoedema and hydrocoele are the two most common clinical manifestations of lymphatic filariasis (LF). In order to effectively target morbidity management strategies, more information is rapidly needed on morbidity burden across all endemic countries. The purpose of this study was to develop and test an SMS tool (MeasureSMS) which enables trained community-based health workers to report basic information on all cases they identified. METHODS: The tool was trialled in Chikwawa district, Malawi and Ahanta West district, Ghana in 2014. Salaried health surveillance assistants (HSAs) identified and reported cases in Malawi whereas volunteer community health workers (CHWs) were used in Ghana. Health workers were trained in recognising lymphoedema and hydrocoeles and submitting individual case data using MeasureSMS, after which they undertook a LF morbidity survey. After the reporting period, a random sample of reported cases was visited by a physician to verify the health workers' diagnoses. The proportion of correctly diagnosed cases i.e. the positive predictive value (PPV) was then calculated. RESULTS: HSAs in Malawi successfully reported 256 unique cases by SMS from 107 communities (166 hydrocoele, 88 lymphoedema, 2 with both), resulting in an estimated adult prevalence of 17.7 per 10,000 and 33.0 per 10,000 for lymphoedema and hydrocoele respectively. In Ghana, despite being less experienced in using SMS, CHWs successfully reported 360 unique cases by SMS from 33 communities (169 hydrocoele, 185 lymphoedema, 6 with both), resulting in an estimated adult prevalence of 76.9 per 10,000 and 70.5 per 10,000 adults for lymphoedema and hydrocoele respectively. The verification exercise resulted in a PPV for lymphoedema and hydrocoele diagnosis of 90 % (n = 42, 95 % CI 76.5 - 96.9) and 92 % (n = 49, 95 % CI 79.5 - 97.4) in Malawi and 94 % (n = 34, 95 % CI 78.9 %-99.0 %) and 47 % (n = 59, 35.1 %-61.7 %) in Ghana, indicating that non-invasive methods for diagnosing hydrocoeles needed to be further emphasised. CONCLUSIONS: The study concludes that given the appropriate education and tools, community-based health workers are exceptionally well-placed to participate in quantifying LF morbidity burden, and other NTDs with observable symptoms. This concept has the potential to enable national programmes to more effectively monitor their community impact in an efficient, timely and cost-effective way.
Asunto(s)
Filariasis Linfática/epidemiología , Telemedicina , Adolescente , Adulto , Anciano , Agentes Comunitarios de Salud/psicología , Filariasis Linfática/patología , Femenino , Ghana/epidemiología , Humanos , Malaui/epidemiología , Masculino , Persona de Mediana Edad , Morbilidad , Prevalencia , Índice de Severidad de la Enfermedad , Programas Informáticos , Encuestas y Cuestionarios , Adulto JovenRESUMEN
BACKGROUND: Recently, there has been a shift in onchocerciasis control policy, changing from prevention of morbidity toward elimination of infection. Switching from annual to biannual ivermectin distribution may accelerate progress toward the elimination goals. However, the settings where this strategy would be cost effective in Africa have not been described. METHODS: An onchocerciasis transmission framework (EpiOncho) was coupled to a disease model in order to explore the impact on disability-adjusted life years averted, program cost, and program duration of biannual ivermectin treatment in different epidemiological and programmatic scenarios in African savannah. RESULTS: While biannual treatment yields only small additional health gains, its benefit is pronounced in the context of the elimination goals, shortening the time frames for and increasing the feasibility of reaching the proposed operational thresholds for stopping treatment. In settings with high precontrol endemicity (and/or poor coverage and compliance), it may not be possible to reach such thresholds even within 50 years of annual ivermectin, requiring adoption of biannual treatment. Our projections highlight the crucial role played by coverage and compliance in achieving the elimination goals. CONCLUSIONS: Biannual ivermectin treatment improves the chances of reaching the 2020/2025 elimination goals, potentially generating programmatic cost savings in settings with high precontrol endemicity. However, its benefit and cost are highly sensitive to levels of systematic noncompliance and, in many settings, it will lead to an increase in costs. Furthermore, it may not always be feasible to implement biannual treatment, particularly in hard-to-reach populations. This highlights the continued need for a macrofilaricide.
Asunto(s)
Antihelmínticos/economía , Antihelmínticos/uso terapéutico , Costos de la Atención en Salud , Ivermectina/economía , Ivermectina/uso terapéutico , Oncocercosis/epidemiología , Oncocercosis/prevención & control , África/epidemiología , Erradicación de la Enfermedad , Humanos , Enfermedades Desatendidas/tratamiento farmacológico , Enfermedades Desatendidas/epidemiología , Enfermedades Desatendidas/prevención & control , Oncocercosis/tratamiento farmacológicoRESUMEN
BACKGROUND: Schistosomiasis and soil-transmitted helminth infections are among the neglected tropical diseases (NTDs) affecting primarily marginalized communities in low- and middle-income countries. Surveillance data for NTDs are typically sparse, and hence, geospatial predictive modeling based on remotely sensed (RS) environmental data is widely used to characterize disease transmission and treatment needs. However, as large-scale preventive chemotherapy has become a widespread practice, resulting in reduced prevalence and intensity of infection, the validity and relevance of these models should be re-assessed. METHODOLOGY: We employed two nationally representative school-based prevalence surveys of Schistosoma haematobium and hookworm infections from Ghana conducted before (2008) and after (2015) the introduction of large-scale preventive chemotherapy. We derived environmental variables from fine-resolution RS data (Landsat 8) and examined a variable distance radius (1-5 km) for aggregating these variables around point-prevalence locations in a non-parametric random forest modeling approach. We used partial dependence and individual conditional expectation plots to improve interpretability of results. PRINCIPAL FINDINGS: The average school-level S. haematobium prevalence decreased from 23.8% to 3.6% and that of hookworm from 8.6% to 3.1% between 2008 and 2015. However, hotspots of high-prevalence locations persisted for both infections. The models with environmental data extracted from a buffer radius of 2-3 km around the school location where prevalence was measured had the best performance. Model performance (according to the R2 value) was already low and declined further from approximately 0.4 in 2008 to 0.1 in 2015 for S. haematobium and from approximately 0.3 to 0.2 for hookworm. According to the 2008 models, land surface temperature (LST), modified normalized difference water index, elevation, slope, and streams variables were associated with S. haematobium prevalence. LST, slope, and improved water coverage were associated with hookworm prevalence. Associations with the environment in 2015 could not be evaluated due to low model performance. CONCLUSIONS/SIGNIFICANCE: Our study showed that in the era of preventive chemotherapy, associations between S. haematobium and hookworm infections and the environment weakened, and thus predictive power of environmental models declined. In light of these observations, it is timely to develop new cost-effective passive surveillance methods for NTDs as an alternative to costly surveys, and to focus on persisting hotspots of infection with additional interventions to reduce reinfection. We further question the broad application of RS-based modeling for environmental diseases for which large-scale pharmaceutical interventions are in place.
Asunto(s)
Infecciones por Uncinaria , Esquistosomiasis , Animales , Ancylostomatoidea , Prevalencia , Ghana/epidemiología , Esquistosomiasis/epidemiología , Esquistosomiasis/prevención & control , Infecciones por Uncinaria/epidemiología , Infecciones por Uncinaria/prevención & control , Heces , AguaRESUMEN
INTRODUCTION: Delivering preventive chemotherapy through mass drug administration (MDA) is a central approach in controlling or eliminating several neglected tropical diseases (NTDs). Treatment coverage, a primary indicator of MDA performance, can be measured through routinely reported programmatic data or population-based coverage evaluation surveys. Reported coverage is often the easiest and least expensive way to estimate coverage; however, it is prone to inaccuracies due to errors in data compilation and imprecise denominators, and in some cases measures treatments offered as opposed to treatments swallowed. OBJECTIVE: Analyses presented here aimed to understand (1) how often coverage calculated using routinely reported data and survey data would lead programme managers to make the same programmatic decisions; (2) the magnitude and direction of the difference between these two estimates, and (3) whether there is meaningful variation by region, age group or country. METHODS: We analysed and compared reported and surveyed treatment coverage data from 214 MDAs implemented between 2008 and 2017 in 15 countries in Africa, Asia and the Caribbean. Routinely reported treatment coverage was compiled using data reported by national NTD programmes to donors, either directly or via NTD implementing partners, following the implementation of a district-level MDA campaign; coverage was calculated by dividing the number of individuals treated by a population value, which is typically based on national census projections and occasionally community registers. Surveyed treatment coverage came from post-MDA community-based coverage evaluation surveys, which were conducted as per standardised WHO recommended methodology. RESULTS: Coverage estimates using routine reporting and surveys gave the same result in terms of whether the minimum coverage threshold was reached in 72% of the MDAs surveyed in the Africa region and in 52% in the Asia region. The reported coverage value was within ±10 percentage points of the surveyed coverage value in 58/124 of the surveyed MDAs in the Africa region and 19/77 in the Asia region. Concordance between routinely reported and surveyed coverage estimates was 64% for the total population and 72% for school-age children. The study data showed variation across countries in the number of surveys conducted as well as the frequency with which there was concordance between the two coverage estimates. CONCLUSIONS: Programme managers must grapple with making decisions based on imperfect information, balancing needs for accuracy with cost and available capacity. The study shows that for many of the MDAs surveyed, based on the concordance with respect to reaching the minimum coverage thresholds, the routinely reported data were accurate enough to make programmatic decisions. Where coverage surveys do show a need to improve accuracy of routinely reported results, NTD programme managers should use various tools and approaches to strengthen data quality in order to use data for decision-making to achieve NTD control and elimination goals.
Asunto(s)
Filariasis Linfática , Administración Masiva de Medicamentos , Niño , Humanos , Filariasis Linfática/tratamiento farmacológico , Filariasis Linfática/epidemiología , Filariasis Linfática/prevención & control , Encuestas y Cuestionarios , África , Enfermedades Desatendidas/epidemiologíaRESUMEN
BACKGROUND: The control of onchocerciasis in Ghana started in 1974 under the auspices of the Onchocerciasis Control Programme (OCP). Between 1974 and 2002, a combination of approaches including vector control, mobile community ivermectin treatment, and community-directed treatment with ivermectin (CDTI) were employed. From 1997, CDTI became the main control strategy employed by the Ghana OCP (GOCP). This review was undertaken to assess the impact of the control interventions on onchocerciasis in Ghana between 1974 and 2016, since which time the focus has changed from control to elimination. METHODS: In this paper, we review programme data from 1974 to 2016 to assess the impact of control activities on prevalence indicators of onchocerciasis. This review includes an evaluation of CDTI implementation, microfilaria (Mf) prevalence assessments and rapid epidemiological mapping of onchocerciasis results. RESULTS: This review indicates that the control of onchocerciasis in Ghana has been very successful, with a significant decrease in the prevalence of infection from 69.13% [95% confidence interval) CI 60.24-78.01] in 1975 to 0.72% (95% CI 0.19-1.26) in 2015. Similarly, the mean community Mf load decreased from 14.48 MF/skin snip in 1975 to 0.07 MF/skin snip (95% CI 0.00-0.19) in 2015. Between 1997 and 2016, the therapeutic coverage increased from 58.50 to 83.80%, with nearly 100 million ivermectin tablets distributed. CONCLUSIONS: Despite the significant reduction in the prevalence of onchocerciasis in Ghana, there are still communities with MF prevalence above 1%. As the focus of the GOCP has changed from the control of onchocerciasis to its elimination, both guidance and financial support are required to ensure that the latter goal is met.
Asunto(s)
Control de Enfermedades Transmisibles/métodos , Oncocercosis/epidemiología , Oncocercosis/prevención & control , Animales , Control de Enfermedades Transmisibles/organización & administración , Control de Enfermedades Transmisibles/normas , Ghana/epidemiología , Humanos , Ivermectina/uso terapéutico , Onchocerca volvulus/efectos de los fármacos , Oncocercosis/tratamiento farmacológico , PrevalenciaRESUMEN
Background: The achievement of neglected tropical diseases (NTDs) program goals depends on numerous factors, including the ability of national programs to use high-quality, timely data to inform their decision-making and program delivery. This paper presents a use case analysis of the routine data used by national NTD programs targeting lymphatic filariasis, onchocerciasis, schistosomiasis, soil-transmitted helminthiasis, and trachoma. Methods: The use cases were developed through a combination of secondary and primary research focused on both global trends and deep dives into Burkina Faso, Ethiopia, and Tanzania. Results were refined through a stakeholder convening and the final eight use cases were determined through iteration and prioritization with stakeholders. Results: Eight use cases were developed: improve treatment register data quality, strengthen supervision of drug distributors during mass drug administration (MDA), generate accurate community-level population data for MDAs, create and manage an accurate inventory of drugs, meet district coverage targets during MDA campaigns, feedback and performance to sub-district teams, feedback on performance to sub-national teams, and national-level program use of data for evaluation and decision making. Each use case identifies key actors and their data-related needs and critical challenges, defines the current and desired state, and articulates the profile of a solution (digital and non-digital) needed to complete the use case. Conclusion: The systematic strengthening of data use for decision-making in NTD programs is key for reaching the 2030 Roadmap goals. Integrated together, the presented use cases, when translated into action using appropriate and innovative solutions, can help to ensure that accurate and timely data are present at every step of a program and empower countries to use these data to make program decisions.
RESUMEN
BACKGROUND: Lymphatic filariasis (LF) is endemic in Ghana, and the country has implemented the GPELF strategy since 2000 with significant progress made in the control of the disease. However, after several years of mass drug administration (MDA) implementation, there is persistent transmission in 17 of the 98 endemic districts in the country. Current approaches to surveillance are clearly unable to target untreated individuals and new strategies are required to address the endgame challenges to enhance LF elimination as a public health problem in endemic countries. Community registers are used during MDAs to enumerate community members, their age, gender, house numbers, and records of their participation in MDAs. These MDA registers represent an untapped opportunity to identify and characterize non-compliance and inform appropriate programmatic actions. In this study, we analyzed the data presented in the registers to assess the coverage and individuals' compliance in MDA. METHODS: The information in the MDA registers were assessed to verify the reported coverages obtained from the district. The community registers were obtained from the district health offices and the data from each individual record was entered into a database. A simple questionnaire was used to cross-check the participation of study participants in the 2017 MDA. The questionnaire solicited data on: participation in the 2017 MDA, reasons for not taking part in the MDA, adverse events experienced, what was done for the adverse events, and willingness to participate in subsequent MDAs. RESULTS: We found that 40.1% of the population in the registers missed at least one MDA in 3 years (2016-2018) and the majority of them were between 10-30 years of age. The results of the questionnaire assessment indicated that 13.8% of the respondents did not receive treatment in 2017 for various reasons, the most prominent among them being "absence/travel" (37.1%). Data in the registers were used to verify the treatment coverage for the years 2017 and 2018, and reviewed against the reported coverage obtained from the district. Significant differences between the reported and verified coverages were only observed in four communities. However, the assessment also revealed that the reported coverage was only accurate in 33.3% of cases. CONCLUSIONS: The MDA registers allow for the identification of eligible individuals who were not reached during any MDA round. Thus, the MDA registers could be utilized at the community and programme levels to identify missing and untreated individuals, appropriately address their non-compliance to MDA, and thereby improve MDA coverage in each implementation unit and monitor the progress towards elimination of LF. The challenges observed through the review of the registers also offer opportunities to improve the training given to the community drug distributors.
Asunto(s)
Erradicación de la Enfermedad/organización & administración , Transmisión de Enfermedad Infecciosa/prevención & control , Filariasis Linfática/epidemiología , Filariasis Linfática/prevención & control , Enfermedades Endémicas , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Utilización de Medicamentos/estadística & datos numéricos , Femenino , Filaricidas/uso terapéutico , Ghana/epidemiología , Humanos , Lactante , Masculino , Administración Masiva de Medicamentos , Cumplimiento de la Medicación , Persona de Mediana Edad , Sistema de Registros/estadística & datos numéricos , Adulto JovenRESUMEN
OBJECTIVES: The study assessed associations between Schistosoma haematobium infection (presence of parasite eggs in urine or hematuria) and self-reported metrics (macrohematuria, fetching surface water, or swimming) to evaluate their performance as proxies of infection in presence of regular preventive chemotherapy. It also examined community water characteristics (safe water access, surface water access, and groundwater quality) to provide context for schistosomiasis transmission in different types of communities and propose interventions. METHODS: Logistic regression was used to assess the associations between the various measured and self-reported metrics in a sample of 897 primary school children in 30 rural Ghanaian communities. Logistic regression was also used to assess associations between community water characteristics, self-reported water-related behaviors and S. haematobium infection. Communities were subsequently categorized as candidates for three types of interventions: provision of additional safe water sources, provision of groundwater treatment, and health education about water-related disease risk, depending on their water profile. RESULTS: Microhematuria presence measured with a reagent strip was a good proxy of eggs in urine at individual (Kendall's τb = 0.88, p < 0.001) and at school-aggregated (Spearman's rs = 0.96, p < 0.001) levels. Self-reported macrohematuria and swimming were significantly associated (p < 0.05) with egg presence, but self-reported fetching was not. Of the community water characteristics, greater surface water access and presence of groundwater quality problems were significantly associated with increased likelihood of fetching, swimming, and S. haematobium infection. Access to improved water sources did not exhibit an association with any of these outcomes. CONCLUSIONS: The study illustrates that in presence of regular school-based treatment with praziquantel, microhematuria assessed via reagent strips remains an adequate proxy for S. haematobium infection in primary schoolchildren. Community water profiles, in combination with self-reported water-related behaviors, can help elucidate reasons for some endemic communities continuing to experience ongoing transmission and tailor interventions to these local contexts to achieve sustainable control.
Asunto(s)
Schistosoma haematobium , Esquistosomiasis Urinaria/diagnóstico , Esquistosomiasis Urinaria/epidemiología , Esquistosomiasis Urinaria/transmisión , Animales , Niño , Femenino , Ghana/epidemiología , Hematuria/epidemiología , Humanos , Modelos Logísticos , Masculino , Tiras Reactivas , Factores de Riesgo , Población Rural , Esquistosomiasis Urinaria/orina , Instituciones Académicas , Natación , Agua/parasitologíaRESUMEN
BACKGROUND: Despite the progress achieved in scaling-up mass drug administration (MDA) for lymphatic filariasis (LF) in Ghana, communities with persistent LF still exist even after 10 years of community treatment. To understand the reasons for persistence, we conducted a study to assess the status of disease elimination and understand the adherence to interventions including MDA and insecticide treated nets. METHODOLOGY AND PRINCIPAL FINDINGS: We conducted a parasitological and epidemiological cross-sectional study in adults from eight villages still under MDA in the Northern Region savannah and the coastal Western Region of the country. Prevalence of filarial antigen ranged 0 to 32.4% and in five villages the prevalence of night blood microfilaria (mf) was above 1%, ranging from 0 to 5.7%. Median mf density was 67 mf/ml (range: 10-3,560). LF antigen positivity was positively associated with male sex but negatively associated with participating in MDA the previous year. Male sex was also associated with a decreased probability of participating in MDA. A stochastic model (TRANSFIL) was used to assess the expected microfilaria prevalence under different MDA coverage scenarios using historical data on one community in the Western Region. In this example, the model simulations suggested that the slow decline in mf prevalence is what we would expect given high baseline prevalence and a high correlation between MDA adherence from year to year, despite high MDA coverage. CONCLUSIONS: There is a need for an integrated quantitative and qualitative research approach to identify the variations in prevalence, associated risk factors and intervention coverage and use levels between and within regions and districts. Such knowledge will help target resources and enhance surveillance to the communities most at risk and to reach the 2020 LF elimination goals in Ghana.
Asunto(s)
Filariasis Linfática , Filaricidas/uso terapéutico , Administración Masiva de Medicamentos , Albendazol/uso terapéutico , Animales , Anopheles/parasitología , Antígenos Helmínticos/sangre , Brugia Malayi/efectos de los fármacos , Niño , Preescolar , Estudios Transversales , Dietilcarbamazina/uso terapéutico , Filariasis Linfática/tratamiento farmacológico , Filariasis Linfática/epidemiología , Filariasis Linfática/transmisión , Femenino , Ghana/epidemiología , Humanos , Ivermectina/uso terapéutico , Masculino , Microfilarias/efectos de los fármacos , Microfilarias/aislamiento & purificación , Carga de Parásitos , Factores de Riesgo , Población Rural , Wuchereria bancrofti/efectos de los fármacosRESUMEN
BACKGROUND: Ghana started its national programme to eliminate lymphatic filariasis (LF) in 2000, with mass drug administration (MDA) with ivermectin and albendazole as main strategy. We review the progress towards elimination that was made by 2016 for all endemic districts of Ghana and analyze microfilaria (mf) prevalence from sentinel and spot-check sites in endemic districts. METHODS: We reviewed district level data on the history of MDA and outcomes of transmission assessment surveys (TAS). We further collated and analyzed mf prevalence data from sentinel and spot-check sites. RESULTS: MDA was initiated in 2001-2006 in all 98 endemic districts; by the end of 2016, 81 had stopped MDA after passing TAS and after an average of 11 rounds of treatment (range 8-14 rounds). The median reported coverage for the communities was 77-80%. Mf prevalence survey data were available for 430 communities from 78/98 endemic districts. Baseline mf prevalence data were available for 53 communities, with an average mf prevalence of 8.7% (0-45.7%). Repeated measurements were available for 78 communities, showing a steep decrease in mean mf prevalence in the first few years of MDA, followed by a gradual further decline. In the 2013 and 2014 surveys, 7 and 10 communities respectively were identified with mf prevalence still above 1% (maximum 5.6%). Fifteen of the communities above threshold are all within districts where MDA was still ongoing by 2016. CONCLUSIONS: The MDA programme of the Ghana Health Services has reduced mf prevalence in sentinel sites below the 1% threshold in 81/98 endemic districts in Ghana, yet 15 communities within 13 districts (MDA ongoing by 2016) had higher prevalence than this threshold during the surveys in 2013 and 2014. These districts may need to intensify interventions to achieve the WHO 2020 target.
Asunto(s)
Erradicación de la Enfermedad/métodos , Filariasis Linfática/tratamiento farmacológico , Filariasis Linfática/epidemiología , Albendazol/uso terapéutico , Animales , Niño , Preescolar , Filariasis Linfática/diagnóstico , Filariasis Linfática/prevención & control , Enfermedades Endémicas , Femenino , Ghana/epidemiología , Investigación sobre Servicios de Salud , Humanos , Ivermectina/uso terapéutico , Masculino , Administración Masiva de Medicamentos/métodos , Microfilarias/patogenicidad , Prevalencia , Encuestas y Cuestionarios , Organización Mundial de la SaludRESUMEN
The World Health Organization's (WHO) 2015-2020 Global Strategy on water, sanitation, and hygiene (WASH) and neglected tropical diseases (NTDs) encourages integration, whilst maintaining existing structured NTD investments, and acceleration towards Sustainable Development Goal (SDG) targets. Accordingly, SDG-associated and WASH-NTD indicators have been developed, commencing important intersectoral dialogue, alongside opportunities for future disease-specific refinements. The rationale for soil-transmitted helminthiasis (STH)- and schistosomiasis-specific WASH considerations, and a traffic-light figure, are presented here to indicate where current international definitions may, or may not, suffice. Certain unique aspects in control dynamics and parasitic lifecycles, however, necessitate additional implementation research with more appropriate measurement indicators developed to record programmatic interventions and to define strategic priorities more effectively.
Asunto(s)
Erradicación de la Enfermedad/métodos , Helmintiasis/prevención & control , Higiene/normas , Saneamiento/normas , Esquistosomiasis/prevención & control , Agua/parasitología , Erradicación de la Enfermedad/normas , Erradicación de la Enfermedad/tendencias , Helmintiasis/transmisión , Humanos , Saneamiento/tendencias , Esquistosomiasis/transmisión , Suelo/parasitología , Organización Mundial de la SaludRESUMEN
BACKGROUND: Schistosomiasis is a water-related neglected tropical disease. In many endemic low- and middle-income countries, insufficient surveillance and reporting lead to poor characterization of the demographic and geographic distribution of schistosomiasis cases. Hence, modeling is relied upon to predict areas of high transmission and to inform control strategies. We hypothesized that utilizing remotely sensed (RS) environmental data in combination with water, sanitation, and hygiene (WASH) variables could improve on the current predictive modeling approaches. METHODOLOGY: Schistosoma haematobium prevalence data, collected from 73 rural Ghanaian schools, were used in a random forest model to investigate the predictive capacity of 15 environmental variables derived from RS data (Landsat 8, Sentinel-2, and Global Digital Elevation Model) with fine spatial resolution (10-30 m). Five methods of variable extraction were tested to determine the spatial linkage between school-based prevalence and the environmental conditions of potential transmission sites, including applying the models to known human water contact locations. Lastly, measures of local water access and groundwater quality were incorporated into RS-based models to assess the relative importance of environmental and WASH variables. PRINCIPAL FINDINGS: Predictive models based on environmental characterization of specific locations where people contact surface water bodies offered some improvement as compared to the traditional approach based on environmental characterization of locations where prevalence is measured. A water index (MNDWI) and topographic variables (elevation and slope) were important environmental risk factors, while overall, groundwater iron concentration predominated in the combined model that included WASH variables. CONCLUSIONS/SIGNIFICANCE: The study helps to understand localized drivers of schistosomiasis transmission. Specifically, unsatisfactory water quality in boreholes perpetuates reliance on surface water bodies, indirectly increasing schistosomiasis risk and resulting in rapid reinfection (up to 40% prevalence six months following preventive chemotherapy). Considering WASH-related risk factors in schistosomiasis prediction can help shift the focus of control strategies from treating symptoms to reducing exposure.
Asunto(s)
Modelos Estadísticos , Schistosoma haematobium/aislamiento & purificación , Esquistosomiasis Urinaria/epidemiología , Animales , Niño , Estudios Transversales , Femenino , Geografía , Ghana/epidemiología , Humanos , Higiene , Masculino , Prevalencia , Tecnología de Sensores Remotos , Saneamiento , Esquistosomiasis Urinaria/parasitología , Instituciones Académicas , Agua , Calidad del AguaRESUMEN
The African Programme for Onchocerciasis Control (APOC), which focused on annual mass treatment with ivermectin, was launched in 1995 and was replaced by the Expanded Special Project for Neglected Tropical Diseases (ESPEN) by the end of 2015. In Ghana, the Community Directed Treatment with Ivermectin (CDTI) was introduced in 1999. After a decade, biannual reinforcement was introduced during which the Ghana Health Service (GHS) recorded coverage rates through routine data collection. Transmission studies conducted in the Upper Denkyira East Municipal (UDEM) of the forest zone of Ghana in 2002 and 2006 had shown that annual treatments with ivermectin had hardly any effect on the transmission of Onchocerca volvulus by the vector Simulium sanctipauli. In order to establish whether or not this was due to an insufficient compliance to the CDTI programme, an additional questionnaire survey was carried out in 2013 following those conducted in 2002 and 2006. The repeat transmission survey conducted in 2013 in the same area revealed that the vector S. sanctipauli had apparently disappeared from the rivers Ofin and Pra due to gold mining activities. In 2006 and 2013, we conducted surveys using structured questionnaires to address issues related to compliance and to compare results on the effectiveness of CDTI. A total of 692 individuals from 7 villages and 447 individuals from 9 villages were interviewed in 2006 and 2013 respectively. Questions asked included whether or not they had taken the ivermectin and reasons for not doing so when that was the case. Results were compared with the previous investigations conducted in 2002. Whereas official reported coverage rates ranged from 59 to 85% in 2006 and from 88 to 97% in 2013, compliance rates decreased from 36% in 2006 to 21% in 2013. Factors affecting compliance included fear of unpleasant side effects (pruritus and oedema), which decreased from 36% to 21% for the same period. Lack of awareness of CDTI sharply increased from 12% to 46% for the same period. Participants believed that treatments were no longer necessary due to the absence of vectors observed in 2013. There seems to be a considerable difference between coverage and compliance rates in the study communities. The difference can be attributed to the performance of the Community-Directed Distributors (CDDs) and the absence of the vector population observed in 2013. Discussions with CDDs suggested that factors that led to non-compliance were mostly side effects, unawareness of the disease by immigrants and lack of financial motivation for the CDDs. Also included was the fact that they needed to complete distribution of the drugs in the entire village, covering all households within just one week irrespective of the size of the catchment area. This, they thought was too much work for a short period of time. We propose to intensify the training of CDDs by the national Neglected Tropical Diseases Programme (NTDP) and to include the Community-based Health and Planning Services (CHPS) concept into onchocerciasis control efforts for awareness creation while the vector population and the transmission should be further monitored. The population should be made aware that the side effects they experienced from previous treatments or had heard about had reduced significantly. They also should be in the known that vector flies may return and so the risk of transmission remains.
Asunto(s)
Antiparasitarios/uso terapéutico , Ivermectina/uso terapéutico , Onchocerca volvulus/efectos de los fármacos , Oncocercosis/prevención & control , Adulto , Animales , Femenino , Bosques , Ghana/epidemiología , Humanos , Insectos Vectores , Masculino , Persona de Mediana Edad , Oncocercosis/transmisión , Simuliidae/parasitología , Encuestas y CuestionariosRESUMEN
Lymphatic filariasis in Africa is caused by the parasite Wuchereria bancrofti and remains a major cause of morbidity and disability in 74 countries globally. A key strategy of the Global Programme for the Elimination of Lymphatic Filariasis, which has a target elimination date of 2020, is the treatment of entire endemic communities through mass drug administration of albendazole in combination with either ivermectin or diethylcarbamazine. Although the strategy of mass drug administration in combination with other interventions, such as vector control, has led to elimination of the infection and its transmission in many rural communities, urban areas in west Africa present specific challenges to achieving the 2020 targets. In this Personal View, we examine these challenges and the relevance of mass drug administration in urban areas, exploring the rationale for a reassessment of policy in these settings. The community-based mass treatment approach is best suited to rural areas, is challenging and costly in urban areas, and cannot easily achieve the 65% consistent coverage required for elimination of transmission. In our view, the implementation of mass drug administration might not be essential to interrupt transmission of lymphatic filariasis in urban areas in west Africa. Evidence shows that transmission levels are low and that effective mass drug distribution is difficult to implement, with assessments suggesting that specific control measures against filariasis in such dynamic settings is not an effective use of limited resources. Instead, we recommend that individuals who have clinical disease or who test positive for W bancrofti infection in surveillance activities should be offered antifilarial drugs through a passive surveillance approach, as well as morbidity management for their needs. We also recommend that more precise studies are done, so that mass drug administration in urban areas is considered if sustainable transmission is found to be ongoing. Otherwise, the limited resources should be directed towards other elements of the lymphatic filariasis programme.
Asunto(s)
Antihelmínticos/administración & dosificación , Antihelmínticos/uso terapéutico , Filariasis Linfática/prevención & control , Política de Salud/economía , Administración Masiva de Medicamentos/economía , Población Urbana , África Occidental/epidemiología , Filariasis Linfática/tratamiento farmacológico , Filariasis Linfática/economía , HumanosRESUMEN
(1) Background: Current international policy for schistosomiasis and soil-transmitted helminthiasis (STH) control emphasises mass administration of deworming drugs in school-based programmes. However, this approach is insufficient to control the transmission of these diseases, and their burden in non-school cohorts is recognised, albeit under-researched. This research will investigate the feasibility and acceptability of expanding access to praziquantel (PZQ) against schistosomiasis, and albendazole (ALB) against STH, to communities in selected transmission settings in Ghana. (2) Methods: A three-site longitudinal study will be implemented to investigate the effectiveness of expanding treatment strategies for PZQ and ALB to community members. In the context of community mass drug administration (to preschool children, school non-attending children, and adults, including pregnant women), the intervention will be assessed in a random sample of community members, at baseline with follow-up at 6, 12, and 18 months. In each community, 658 participants will be enrolled, and 314 followed up at each time point. The primary outcome measure is the prevalence of infection of Schistosoma haematobium and/or S. mansoni at study endpoint, as assessed by longitudinal surveys. Secondary outcomes are to quantify the infection of schistosomiasis and STH infections in non-treated cohorts, reductions in prevalence of STH, and intensity of schistosomiasis and STH, and treatment coverage. Nested within this study will be qualitative, cost-benefit, and cost-effectiveness evaluations that will explore accessibility, feasibility, and economic impact of expanded treatment from different complementary perspectives. (3) Discussion: Using a multidisciplinary approach, this study will generate evidence for improved availability, acceptability, affordability, and accessibility to deworming drugs against schistosomiasis and STH to individuals and communities in Ghana. This is likely to have considerable research, programmatic, and political value to contribute evidence for national programme policy development within Ghana, and, more broadly, World Health Organization policy development.
RESUMEN
Ghana has been implementing mass drug administration (MDA) of ivermectin and albendazole for the elimination of lymphatic filariasis (LF) since the year 2000, as part of the Global Programme to Eliminate Lymphatic Filariasis (GPELF). It was estimated that 5â»6 years of treatment would be sufficient to eliminate the disease. Tremendous progress has been made over the years, and treatment has stopped in many disease endemic districts. However, despite the successful implementation of MDA, there are districts with persistent transmission. In this study we assessed the epidemiology of LF in three adjoining districts that have received at least 16 years of MDA. The assessments were undertaken one year after the last MDA. 1234 adults and 182 children below the age of 10 years were assessed. The overall prevalence of circulating filarial antigen in the study participants was 8.3% (95% CI: 6.9â»9.9), with an estimated microfilaria prevalence of 1.2%. The microfilarial intensity in positive individuals ranged from 1 to 57 microfilariae/mL of blood. Higher antigen prevalence was detected in males (13.0%; 95% CI: 10.3â»16.2) compared to females (5.5%; 95% CI: 4.1â»7.2). The presence of infection was also highest in individuals involved in outdoor commercial activities, with the risks of infection being four- to five-fold higher among farmers, fishermen, drivers and artisans, compared to all other occupations. Using bednets or participating in MDA did not significantly influence the risk of infection. No children below the age of 10 years were found with infection. Detection of Wb123 antibodies for current infections indicated a prevalence of 14.4% (95% CI: 8.1â»23.0) in antigen-positive individuals above 10 years of age. No antibodies were detected in children 10 years or below. Assessment of infection within the An. gambiae vectors of LF indicated an infection rate of 0.9% (95% CI: 0.3â»2.1) and infectivity rate of 0.5% (95% CI: 0.1â»1.6). These results indicate low-level transmission within the districts, and suggest that it will require targeted interventions in order to eliminate the infection.