ABSTRACT
Over the past decade, considerable progress has been made in the control, elimination, and eradication of neglected tropical diseases (NTDs). Despite these advances, most NTD programs have recently experienced important setbacks; for example, NTD interventions were some of the most frequently and severely impacted by service disruptions due to the coronavirus disease 2019 (COVID-19) pandemic. Mathematical modeling can help inform selection of interventions to meet the targets set out in the NTD road map 2021-2030, and such studies should prioritize questions that are relevant for decision-makers, especially those designing, implementing, and evaluating national and subnational programs. In September 2022, the World Health Organization hosted a stakeholder meeting to identify such priority modeling questions across a range of NTDs and to consider how modeling could inform local decision making. Here, we summarize the outputs of the meeting, highlight common themes in the questions being asked, and discuss how quantitative modeling can support programmatic decisions that may accelerate progress towards the 2030 targets.
Subject(s)
COVID-19 , Neglected Diseases , Tropical Medicine , Neglected Diseases/prevention & control , Humans , COVID-19/epidemiology , COVID-19/prevention & control , Models, Theoretical , World Health Organization , SARS-CoV-2 , Decision Making , Global HealthABSTRACT
The objective of this manuscript is to provide selective examples of the work of the Pan American Health Organization/World Health Organization (PAHO/WHO) Collaborating Centre for Research and Training in Parasite Epidemiology and Control which contribute to the WHO goal of eliminating neglected tropical diseases by 2030. This PAHO/WHO CC specifically aligns its activities with the Sustainable Development Goals and with the goals outlined in the WHO Road Map for Neglected Tropical Diseases 2021-2030. Its role is to contribute to advancing global action on NTDs, primarily through policy development and knowledge translation. Three important projects have recently been completed: 1. Finalizing the Monitoring and Evaluation Framework for the NTD Road Map (published May 2021; this PAHO/WHO CC was a member of the working group); 2. Developing new guidelines for the preventive chemotherapy of Taenia solium taeniasis (published September 2021; this PAHO/WHO CC was co-Chair; and 3. Formulating a policy brief on deworming for adolescent girls and women of reproductive age (published January 2022; this PAHO/WHO CC is co-lead). These projects are the result of the integration of expertise and experience from multiple partners, including from PAHO and WHO (where both organizations provided key leadership), this PAHO/WHO CC, government ministries, civil society organizations and universities, among others. In conclusion, this PAHO/WHO CC contributes timely guidance to country-led evidence-informed public health policy, to cost-effective program implementation and to the identification of priority research topics - all focused, ultimately, on eliminating NTD-attributable morbidity by 2030.
El objetivo de este artículo es proporcionar ejemplos seleccionados de la labor del centro colaborador de investigación y capacitación en epidemiología y control de parásitos de la Organización Panamericana de la Salud/Organización Mundial de la Salud (OPS/OMS), que contribuye al objetivo de la OMS de eliminar las enfermedades tropicales desatendidas para el 2030. Este centro colaborador de la OPS/OMS alinea sus actividades específicamente con los Objetivos de Desarrollo Sostenible y con los objetivos descritos en la Hoja de ruta sobre enfermedades tropicales desatendidas 2021-2030 de la OMS. Su función es contribuir al avance de las medidas mundiales sobre las enfermedades tropicales desatendidas, principalmente mediante la elaboración de políticas y la traducción de conocimiento. Recientemente se han completado tres proyectos importantes: 1) finalización del marco de seguimiento y evaluación de la Hoja de ruta sobre enfermedades tropicales desatendidas (publicado en mayo del 2021; este centro colaborador de la OPS/OMS formó parte del grupo de trabajo); 2) elaboración de nuevas directrices para la quimioterapia preventiva de la teniasis por Taenia solium (publicado en septiembre del 2021; este centro colaborador fue copresidente); y 3) formulación de un informe de políticas sobre la desparasitación de las adolescentes y las mujeres en edad reproductiva (publicado en enero del 2022; este centro colaborador fue coautor). Estos proyectos son el resultado de la integración del conocimiento y la experiencia de múltiples asociados, como la OPS y la OMS (ambas organizaciones ofrecieron un liderazgo clave), este centro colaborador de la OPS/OMS, así como varios ministerios gubernamentales, organizaciones de la sociedad civil y universidades, entre otros. En conclusión, este centro colaborador de la OPS/OMS ofrece orientaciones oportunas para las políticas de salud pública basadas en la evidencia lideradas por los países, la ejecución de programas costo-efectivos y la determinación de los temas de investigación prioritarios, todo ello destinado, en última instancia, a eliminar la morbilidad atribuible a las enfermedades tropicales desatendidas para el 2030.
O objetivo deste manuscrito é fornecer exemplos seletivos do trabalho do Centro Colaborador de Pesquisa e Treinamento em Epidemiologia e Controle de Parasitos da Organização Pan-Americana da Saúde/Organização Mundial da Saúde (OPAS/OMS) que contribuem para a meta da OMS de eliminar até 2030 as doenças tropicais negligenciadas. Este CC da OPAS/OMS alinha especificamente suas atividades com os Objetivos de Desenvolvimento Sustentável e com as metas delineadas no Roteiro da OMS para Doenças Tropicais Negligenciadas 2021-2030. Seu papel é contribuir para o avanço da ação global contra doenças tropicais negligenciadas, principalmente por meio do desenvolvimento de políticas e da tradução de conhecimentos. Três importantes projetos foram concluídos recentemente: 1. Finalização da Estrutura de Monitoramento e Avaliação do Roteiro para as DTN (publicada em maio de 2021 este CC da OPAS/OMS foi membro do grupo de trabalho); 2. Desenvolvimento de novas diretrizes para a quimioprofilaxia da teníase por Taenia solium (publicado em setembro de 2021 este CC da OPAS/OMS foi copresidente); e 3. Formulação de orientação para políticas de desparasitação para adolescentes e mulheres em idade reprodutiva (publicado em janeiro de 2022 este CC da OPAS/OMS foi cogestor). Esses projetos são o resultado da integração de conhecimentos e experiência de múltiplos parceiros, incluindo a OPAS e a OMS (onde ambas as organizações forneceram liderança essencial), este CC da OPAS/OMS, ministérios governamentais, organizações da sociedade civil e universidades, entre outros. Em suma, este CC da OPAS/OMS contribui com orientações oportunas para uma política de saúde pública liderada pelos países e informada com base em evidências, para a implementação de programas com boa relação custo-benefício e para a identificação de tópicos prioritários de pesquisa todos focados, em última análise, na eliminação da morbidade atribuível às DTN até 2030.
ABSTRACT
Maps of the geographical variation in prevalence play an important role in large-scale programs for the control of neglected tropical diseases. Precontrol mapping is needed to establish the appropriate control intervention in each area of the country in question. Mapping is also needed postintervention to measure the success of control efforts. In the absence of comprehensive disease registries, mapping efforts can be informed by 2 kinds of data: empirical estimates of local prevalence obtained by testing individuals from a sample of communities within the geographical region of interest, and digital images of environmental factors that are predictive of local prevalence. In this article, we focus on the design and analysis of impact surveys, that is, prevalence surveys that are conducted postintervention with the aim of informing decisions on what further intervention, if any, is needed to achieve elimination of the disease as a public health problem. We show that geospatial statistical methods enable prevalence surveys to be designed and analyzed as efficiently as possible so as to make best use of hard-won field data. We use 3 case studies based on data from soil-transmitted helminth impact surveys in Kenya, Sierra Leone, and Zimbabwe to compare the predictive performance of model-based geostatistics with methods described in current World Health Organization (WHO) guidelines. In all 3 cases, we find that model-based geostatistics substantially outperforms the current WHO guidelines, delivering improved precision for reduced field-sampling effort. We argue from experience that similar improvements will hold for prevalence mapping of other neglected tropical diseases.
Subject(s)
Helminthiasis , Helminths , Animals , Humans , Kenya , Neglected Diseases , Prevalence , Sierra Leone , Soil , ZimbabweABSTRACT
The Kubic FLOTAC microscope (KFM) is a compact, low-cost, versatile and portable digital microscope designed to analyse fecal specimens prepared with Mini-FLOTAC or FLOTAC, in both field and laboratory settings. In this paper, we present the characteristics of the KFM along with its first validation for fecal egg count (FEC) of gastrointestinal nematodes (GINs) in cattle. For this latter purpose, a study was performed on 30 fecal samples from cattle experimentally infected by GINs to compare the performance of Mini-FLOTAC either using a traditional optical microscope (OM) or the KFM. The results of the comparison showed a substantial agreement (concordance correlation coefficient = 0.999), with a very low discrepancy (−0.425 ± 7.370) between the two microscopes. Moreover, the KFM captured images comparable with the view provided by the traditional OM. Therefore, the combination of sensitive, accurate, precise and standardized FEC techniques, as the Mini-FLOTAC, with a reliable automated system, will permit the real-time observation and quantification of parasitic structures, thanks also to artificial intelligence software, that is under development. For these reasons, the KFM is a promising tool for an accurate and efficient FEC to improve parasite diagnosis and to assist new generations of operators in veterinary and public health.
Subject(s)
Cattle Diseases/diagnosis , Feces/parasitology , Microscopy/instrumentation , Microscopy/methods , Nematode Infections/veterinary , Parasite Egg Count/instrumentation , Animals , Cattle , Cattle Diseases/parasitology , Imaging, Three-Dimensional/veterinary , Nematode Infections/diagnosis , Nematode Infections/parasitology , Statistics, NonparametricABSTRACT
The World Health Organization recommends deworming to reduce soil-transmitted helminth (STH)-attributable morbidity in women of reproductive age, including pregnant and lactating women, to reduce blood loss, iron deficiency anaemia and nutrient malabsorption. This study assessed the impact of maternal postpartum deworming with albendazole approximately 1 day after delivery on infant milk intake among a subset of 216 randomly selected mother-infant pairs recruited into a large trial in Peru. Infant milk intake was measured using the deuterium-oxide method at 1- and 6-month postpartum. Maternal STH infection was measured at 6-month postpartum. At 1-month postpartum, mean intake was 756 ± 16 and 774 ± 18 mL day-1 in the albendazole and placebo groups, respectively (mean difference: -18 mL day-1 ; 95% CI: -65, 30). At 6-month postpartum, mean intake was 903 ± 16 and 908 ± 18 mL day-1 in the albendazole and placebo groups, respectively (mean difference: -5 mL day-1 ; 95% CI: -52, 43). There was no statistically significant difference in milk intake between groups at either time point. At 6-month postpartum, mothers infected with Trichuris trichiura had infants with higher milk intakes (adjusted mean difference: 70 mL day-1 ; 95% CI: 20, 120) compared with uninfected mothers. However, there was no statistically significant difference in infant milk intake between mothers who had moderate-and-heavy intensity infection compared with the comparison group (mothers with no and light intensity infection). A lower prevalence and intensity of infection, and inclusion of uninfected mothers in both arms of the trial, resulting in effect dilution, may explain the null findings.
Subject(s)
Helminthiasis , Lactation , Female , Helminthiasis/epidemiology , Humans , Infant , Milk, Human , Mothers , Postpartum Period , PregnancyABSTRACT
OBJECTIVE: Preventive chemotherapy is the WHO-recommended control method for soil-transmitted helminthiases. In the Bolivian Chaco, 6-monthly single-dose mebendazole delivery to school-age children achieved a dramatic decrease in soil-transmitted helminthiases prevalence between 1987 and 2013. Consequently, in September 2016, preventive chemotherapy delivery was interrupted in nine rural communities. In compliance with WHO recommendations, we intensified surveillance to monitor soil-transmitted helminthiases prevalence and detect potential changes that would require interventions. METHODS: We conducted two cross-sectional parasitology surveys 12 months apart (September 2016-2017) among school-age children living in the communities where preventive chemotherapy delivery had been halted. Study design, methods of sampling and sample analysis technique (direct microscopy, Kato-Katz technique) followed WHO recommendations, aiming to obtain data representative of the Bolivian Chaco ecological zone. RESULTS: We collected 426 samples in 2016 and 520 in 2017. Soil-transmitted helminthiasis prevalence was unremarkable: 0.7% (95% CI 0-1.5%) in 2016 and 0.8% (0-1.5%) in 2017. Conversely, the prevalence of tapeworms (13% in 2016, 12% in 2017) and intestinal protozoan infections (81% in 2016 and 75% in 2017) continued to be high. CONCLUSIONS: Our findings support the role of preventive chemotherapy in reducing soil-transmitted helminthiases transmission, as otherwise poor hygienic and health conditions persist in the Bolivian Chaco. A national survey, involving areas from all the ecological zones of Bolivia, is now warranted.
Subject(s)
Anthelmintics/therapeutic use , Helminthiasis/prevention & control , Mebendazole/therapeutic use , Bolivia/epidemiology , Chemoprevention/methods , Child , Cross-Sectional Studies , Female , Helminthiasis/epidemiology , Humans , Male , Prevalence , Program Evaluation , Rural Population/statistics & numerical data , Soil/parasitologySubject(s)
Communicable Diseases , Gastroenterology , Gynecology , Schistosomiasis , Tropical Medicine , Urology , Female , Pregnancy , Humans , Child , Colposcopy , Global Health , Consensus , Endoscopy, Gastrointestinal , Schistosomiasis/diagnosis , Schistosomiasis/drug therapy , Schistosomiasis/epidemiology , Primary Health Care , Italy/epidemiologyABSTRACT
OBJECTIVES: The prevalence of Strongyloides stercoralis infections is grossly underestimated because infections go mostly undetected, although they can persist for a lifetime due to the auto-infective cycle. In the Bolivian Chaco, the prevalence of soil-transmitted nematodes dropped dramatically in the past 25 years, but the mebendazole used for preventive chemotherapy has no effect on S. stercoralis. Meanwhile, the prevalence of intestinal protozoan infections remains unchanged. We compared S. stercoralis seroprevalence in rural communities of the Bolivian Chaco from 1987 to 2013. METHODS: Sera collected during two previous serosurveys, conducted in the Chaco region in 1987 and 2013, were tested for S. stercoralis using a commercial assay (Bordier-ELISA, Bordier Affinity Products, Switzerland). RESULTS: Overall, 355 sera were analysed, 122 from the 1987 survey and 233 from the 2013 survey. Seropositivity for S. stercoralis was significantly more prevalent in 1987 (19/122, 16% in 1987 vs. 15/233, 6% in 2013, P = 0.006), accounted for by a drop from 17% to 3% in people under 26 years of age. Multivariate analysis showed a significant association between seropositivity for S. stercoralis and age in the 2013 population (OR 1.03 for each one-year increase, 95%CI 1.00-1.05, P = 0.04), but none in 1987. CONCLUSIONS: The significant reduction in S. stercoralis seroprevalence in Bolivian Chaco cannot be explained by preventive chemotherapy or improved social-sanitary conditions. As the drop is seen in younger generations, it is consistent with little transmission occurring. However, the risk of transmission still exists, as prevalence is persistently high in older individuals, who present a potential reservoir due to the lifelong nature of S. stercoralis infections.
Subject(s)
Intestinal Diseases, Parasitic/epidemiology , Rural Population , Strongyloides stercoralis/growth & development , Strongyloidiasis/epidemiology , Adolescent , Adult , Age Factors , Aged , Animals , Bolivia/epidemiology , Child , Child, Preschool , Female , Humans , Infant , Intestinal Diseases, Parasitic/transmission , Male , Middle Aged , Multivariate Analysis , Odds Ratio , Prevalence , Seroepidemiologic Studies , Soil/parasitology , Strongyloidiasis/transmission , Young AdultABSTRACT
Objectives: To evaluate the performance of a questionnaire in assessing the pregnancy status of women of reproductive age during preventive chemotherapy interventions. Methods: A questionnaire (20 questions) was administered to 1217 women of reproductive age (≥18 years) from Ilemela and Buchosa districts, northwestern Tanzania. A single urine sample was collected from each of them and tested using a rapid pregnancy test for presence of pregnant. Results: Overall, 10.8% (132/1217) of the women reported to be pregnant at the specific question in the questionnaire. The rapid pregnancy test identified 15.1% (184/1217) of the women to be pregnant. In total, 86.4% (114/132) of the women who reported to be pregnant during the interview were confirmed to be pregnant using the rapid pregnant test. The question on pregnancy demonstrated an overall sensitivity of 62% and specificity of 98.3%. Conclusions: The questionnaire performance was not completely satisfactory; however, it managed to identify pregnant women in the first trimester. The question on the last date of the start of the menstrual period yield the highest sensitivity and appeared to be the key one used in combination with other questions. Further validation of these results in other countries with different cultures are recommended to fully evaluate the performance of this method.
ABSTRACT
The World Health Organization has started a process to issue guidelines for the control of strongyloidiasis. The guidelines might recommend to implement preventive chemotherapy (PC) at community level (i.e. to all individuals above 5 years of age), over a defined prevalence threshold. We previously estimated the number of school-age children (SAC) who would need PC. Here we estimate the number of people above 15 years of age who might be included in PC for strongyloidiasis. Based on previous Strongyloides prevalence estimates and on countries' age distribution, we retrieved the number of adults in need of PC. We then subtracted the number of people already involved in ivermectin mass distribution for the elimination of onchocerciasis and lymphatic filariasis and people living in countries where Loa loa is endemic. The number of adults to be involved in PC was estimated at 905.4 (95% confidence interval (CI): 520.6-1177.2), 660.2 (95% CI: 512.7-1214.9), and 512.1 (95% CI: 276-719.4) million people, when the strongyloidiasis prevalence threshold for implementing PC was set to 10%, 15% and 20%, respectively. Estimates at country level are also provided.These estimates might help endemic countries wishing to implement PC for strongyloidiasis to allocate resources to include adults in addition to SAC in control programmes. This article is part of the Theo Murphy meeting issue 'Strongyloides: omics to worm-free populations'.
Subject(s)
Elephantiasis, Filarial , Onchocerciasis , Strongyloidiasis , Child , Adult , Humans , Ivermectin/therapeutic use , Strongyloidiasis/drug therapy , Strongyloidiasis/epidemiology , Strongyloidiasis/prevention & control , Onchocerciasis/drug therapy , Onchocerciasis/epidemiology , Elephantiasis, Filarial/drug therapy , Elephantiasis, Filarial/epidemiology , Elephantiasis, Filarial/prevention & control , PrevalenceABSTRACT
Fascioliasis, only foodborne trematodiasis of worldwide distribution, is caused by Fasciola hepatica and F. gigantica, liver flukes transmitted by freshwater snails. Southern and southeastern Asia is an emerging hot spot of F. gigantica, despite its hitherto less involvement in human infection. In Vietnam, increasing cases have been reported since 1995, whereas only sixteen throughout 1800-1994. A database was created to include epidemiological data of fascioliasis patients from the 63 Vietnam provinces throughout 1995-2019. Case profiles were based on serology, symptoms, eosinophilia, imaging techniques, stool egg finding, and post-specific-treatment recovery. Radio broadcasting about symptoms and costless diagnosis/treatment led patients to hospitals after symptom onset. Yearly case numbers were modelled and spatio-temporally analyzed. Missing data and confounders were assessed. The countrywide spread has no precedent. It started in the central coast, including 53,109 patients, mostly adults and females. Seasonality, linked to vegetable consumption, peaks in June, although the intensity of this peak differs according to relief/climatic zones. Incidence data and logistic regression curves are obtained for the first time in human fascioliasis. Fasciolid hybrids accompanying the spreading F. gigantica flukes, and climate change assessed by risk index correlations, are both ruled out as outbreak causes. Human-guided movements of livestock from an original area prove to be the way used by fasciolids and lymnaeid vectors to expand geographically. Radix viridis, a highly efficient transmitting and colonizing vector, played a decisive role in the spread. The use of irrigated crop fields, widely inhabited by R. viridis, for livestock grazing facilitated the transmission and spread of the disease. General physician awareness and diagnostic capacity improvement proved the successful impact of such knowledge transfer in facilitating and increasing patient infection detection. Information, education and communication to the public by radio broadcasting demonstrated to be very helpful. Fasciola gigantica is able to cause epidemic and endemic situations similar to F. hepatica. The magnitude of the human outbreak in Vietnam is a health wake-up call for southern and southeastern countries of Asia which present the highest human population densities with increasing food demands, uncontrolled livestock inter-country exchange, foreign import practices, and monsoon's increasing climate change impact.
ABSTRACT
Strongyloidiasis is a soil-transmitted helminthiasis that is estimated to affect 300-600 million people across Asia, Africa, South and central America, and the Pacific. This neglected parasitic disease is most known for its ability to persist as a lifelong infection due to autoinfection and its risk of hyperinfection and disseminated disease during immunosuppression, which has a more than 60% case fatality. Despite the large global burden of strongyloidiasis, there have been no large-scale public health programmes or WHO guidelines directed towards its control and elimination. However, over the past decade, key scientific and policy changes along with requests from endemic countries have led to WHO incorporating strongyloidiasis into its 2021-30 roadmap and public health targets for control and elimination of neglected tropical diseases. In 2024, WHO published its first guideline on public health control of strongyloidiasis with a single recommendation: in endemic settings with a Strongyloides stercoralis infection prevalence of 5% or higher (measured either with Baermann or agar plate culture from stool specimens), WHO conditionally recommends mass drug administration with single-dose ivermectin (200 µg/kg; oral therapy) in all age groups from 5 years and older to reduce strongyloidiasis. This Review, written by the 2023-24 strongyloidiasis guidelines development group along with WHO colleagues and international experts, presents a summary of the recently published WHO guideline recommendation for strongyloidiasis, and the supporting evidence, considerations for public health implementation, and future research needs.
ABSTRACT
OBJECTIVE: Schistosomiasis is known to occur in preschool-aged children, but achieving accurate dosing of praziquantel in its current form is challenging. While waiting for a paediatric formulation, there is a need to develop a means for using the available products to treat this age group. Current 600-mg tablets are differently scored to give units of 150 mg (a quarter of a tablet) or 300 mg (half a tablet). METHODS: We examined several dosing schemes to dose accurately (40-60 mg/kg) children aged 3-72 months (weight range 4-25 kg, based on available weight-for-age growth references from sub-Saharan Africa and Brazil, n = 106,230). RESULTS: Adequate dosing can be achieved with formulations that can be split into four 150 mg quarters for children weighing 5 kg or more, and with tablets than can be split into two 300 mg halves for children weighing 10 kg or more. Giving ½ tablet for 5-7 kg; ¾ tablet for 8-10 kg; 1 tablet for 11-15 kg; 1 ½ tablet for 16-21 kg; and two tablets for 22-25 kg will have 100% of subjects correctly dosed within the target 40-60 mg/kg range. CONCLUSIONS: Formulations that can be divided into four parts (to give 150 mg increments) are preferred for children weighing less than 11 kg; the same dosing can be applied with 600 mf praziquantel formulations that can be divided into four quarters or two halves from 11 kg body weight.
Subject(s)
Anthelmintics/administration & dosage , Praziquantel/administration & dosage , Schistosomiasis/drug therapy , Africa South of the Sahara , Anthelmintics/therapeutic use , Body Weight/physiology , Brazil , Child , Child, Preschool , Dose-Response Relationship, Drug , Female , Humans , Infant , Male , Praziquantel/therapeutic use , Treatment OutcomeABSTRACT
After a baseline survey in 2003 which showed an overall parasitological prevalence of soil-transmitted helminths of 69.7% in school children (prevalence of ascariasis 48.5%, prevalence of trichuriasis 57.5% and prevalence of hookworm infection 6.5), a national deworming programme was established. After 7 years of implementation, it had resulted in a significant reduction of STH prevalence (prevalence of any STH 21%, prevalence of ascariasis 5.8%, prevalence of trichuriasis 18.6% and prevalence of hookworm infection 0.3%) as well as a reduction of the infections of moderate-heavy intensity from 18.5% at baseline to less than 7%. The results are encouraging and a reduction of the frequency of deworming can be envisaged in two of four ecological areas of Myanmar.
Subject(s)
Helminthiasis/prevention & control , Intestinal Diseases/prevention & control , Nematode Infections/prevention & control , Program Evaluation/statistics & numerical data , Albendazole/therapeutic use , Anemia/blood , Anemia/epidemiology , Anthelmintics/therapeutic use , Child , Child, Preschool , Feces/parasitology , Government Programs/economics , Government Programs/organization & administration , Helminthiasis/epidemiology , Helminthiasis/transmission , Hemoglobins/analysis , Humans , Intestinal Diseases/epidemiology , Intestinal Diseases, Parasitic , Myanmar/epidemiology , Nematode Infections/epidemiology , Nematode Infections/transmission , Parasite Egg Count , Prevalence , Rural Population , Schools/statistics & numerical data , Soil/parasitologyABSTRACT
The WHO tablet pole was developed in 2001 to facilitate the distribution of praziquantel in large-scale treatment campaigns for the control of schistosomiasis. Although a number of field studies have confirmed the accuracy of the tool in normal individuals, some studies have demonstrated that overweight and obese individuals are underdosed. This article proposes an adjustment in the number of praziquantel tablets for treatment of individuals who are overweight or obese according to their body mass index. We demonstrate that by adding an extra tablet of praziquantel to that indicated by the WHO tablet pole, the tool provides the appropriate number of tablets for treatment of overweight and obese individuals. We also propose a pictogram be included in the instructions for use of the WHO tablet pole.
Subject(s)
Anthelmintics , Praziquantel , Humans , Praziquantel/therapeutic use , Overweight/drug therapy , Body Height , Obesity/drug therapy , Tablets , World Health Organization , Anthelmintics/therapeutic useABSTRACT
BACKGROUND: Establishment of efficient control programs for strongyloidiasis, the infection by Strongyloides stercoralis, is among the World Health Organization (WHO) targets for 2030. Ivermectin is a drug of choice for strongyloidiasis, but its weight-based administration can be unfeasible in remote areas. We evaluated a WHO tablet pole for administration of ivermectin in school-age children living in remote villages in Ecuador. METHODS: Children were enrolled in 16 villages in Esmeraldas Province of Ecuador, between July 2021 and June 2022. The pole identified four height intervals corresponding to ivermectin doses going from one to four tablets. For each child, we calculated the dose (µg/kg) administered with both weight-based and pole-based administration. Results were classified as follows: optimal dose, acceptable, overdose, underdose. Agreement between the two methods for estimating the number of tablets was assessed with Cohen's kappa coefficient. Estimations were reported with 95% confidence intervals (CIs). RESULTS: Total of 778 children (47.3% female) were enrolled, with median age of 9.59 years (interquartile range: 7.42â11.22). Optimal dose was achieved for a higher proportion of children when assessed with weight (37.9%) than with pole (25.7%). Underdose and overdose were more frequent with the pole (8.3% and 19.2% children, respectively) than with the weight-based (3.7% and 6.0%, respectively) administration. Agreement between weight-based and pole-based administration was moderate: 0.56 (95% CI 0.51, 0.61). The two methods indicated the same number of tablets in 71.6% (95% CI 0.684, 0.748) cases. CONCLUSIONS: In our setting, the tablet pole could be a valid alternative. The tool needs further evaluation in different populations.
Subject(s)
Anthelmintics , Strongyloides stercoralis , Strongyloidiasis , Child , Animals , Female , Humans , Male , Ivermectin/therapeutic use , Strongyloidiasis/drug therapy , Strongyloidiasis/epidemiology , Anthelmintics/therapeutic use , Ecuador/epidemiologyABSTRACT
Kenya is among the countries endemic for soil-transmitted helminthiasis (STH) with over 66 subcounties and over 6 million individuals being at-risk of infection. Currently, the country is implementing mass drug administration (MDA) to all the at-risk groups as the mainstay control strategy. This study aimed to develop and analyze an optimal control (OC) model, from a transmission interruption model, to obtain an optimal control strategy from a mix of three strategies evaluated. The study used the Pontryagin's maximum principle to solve, numerically, the OC model. The analysis results clearly demonstrated that water and sanitation when implemented together with the MDA programme offer the best chances of eliminating these tenacious and damaging parasites. Thus, we advocate for optimal implementation of the combined mix of the two interventions in order to achieve STH elimination in Kenya, and globally, in a short implementation period of less than eight years.
ABSTRACT
Madagascar is one of the countries with the highest burden of schistosomiasis worldwide. The release from the WHO of the new 2021-2030 neglected tropical disease (NTD) roadmap alongside with the schistosomiasis guidelines sets the ambitious goal of eliminating schistosomiasis as a public health problem worldwide. In Madagascar, implementation barriers exist. This paper has the objective of identifying strengths, weaknesses, opportunities and threats in order to build on their basis practices and policies that can help the country to align with the international global health agenda and reach the ambitious goal set by the WHO.
Subject(s)
Schistosomiasis , Humans , Madagascar/epidemiology , Schistosomiasis/epidemiology , Schistosomiasis/prevention & control , Public Health , Global Health , World Health OrganizationABSTRACT
The World Health Organization (WHO) announced in 2021 a commitment to develop a comprehensive framework for integrated action on the prevention, diagnosis, and management of anemia and to establish an Anaemia Action Alliance to support the implementation of the framework. WHO commissioned four background papers to provide reflections about the most pressing issues to be addressed for accelerating reductions in the prevalence of anemia. Here, we provide a complete vision of the framework.