Predictive Value of Microfilariae-Based Stop-MDA Thresholds After Triple Drug Therapy With IDA Against Lymphatic Filariasis in Treatment-Naive Indian Settings.

Mass drug administration (MDA) of antifilarial drugs is the main strategy for the elimination of lymphatic filariasis (LF). Recent clinical trials indicated that the triple-drug therapy with ivermectin, diethylcarbamazine, and albendazole (IDA) is much more effective against LF than the widely used two-drug combinations (albendazole plus either ivermectin or diethylcarbamazine). For IDA-based MDA, the stop-MDA decision is made based on microfilariae (mf) prevalence in adults. In this study, we assess how the probability of eventually reaching elimination of transmission depends on the critical threshold used in transmission assessment surveys (TAS-es) to define whether transmission was successfully suppressed and triple-drug MDA can be stopped. This analysis focuses on treatment-naive Indian settings. We do this for a range of epidemiological and programmatic contexts, using the established LYMFASIM model for transmission and control of LF. Based on our simulations, a single TAS, one year after the last MDA round, provides limited predictive value of having achieved suppressed transmission, while a higher MDA coverage increases elimination probability, thus leading to a higher predictive value. Every additional TAS, conditional on previous TAS-es being passed with the same threshold, further improves the predictive value for low values of stop-MDA thresholds. An mf prevalence threshold of 0.5% corresponding to TAS-3 results in ≥95% predictive value even when the MDA coverage is relatively low.

Reducing the Antigen Prevalence Target Threshold for Stopping and Restarting Mass Drug Administration for Lymphatic Filariasis Elimination: A Model-Based Cost-effectiveness Simulation in Tanzania, India and Haiti.

BACKGROUND: The Global Programme to Eliminate Lymphatic Filariasis (GPELF) aims to reduce and maintain infection levels through mass drug administration (MDA), but there is evidence of ongoing transmission after MDA in areas where Culex mosquitoes are the main transmission vector, suggesting that a more stringent criterion is required for MDA decision making in these settings. METHODS: We use a transmission model to investigate how a lower prevalence threshold (<1% antigenemia [Ag] prevalence compared with <2% Ag prevalence) for MDA decision making would affect the probability of local elimination, health outcomes, the number of MDA rounds, including restarts, and program costs associated with MDA and surveys across different scenarios. To determine the cost-effectiveness of switching to a lower threshold, we simulated 65% and 80% MDA coverage of the total population for different willingness to pay per disability-adjusted life-year averted for India ($446.07), Tanzania ($389.83), and Haiti ($219.84). RESULTS: Our results suggest that with a lower Ag threshold, there is a small proportion of simulations where extra rounds are required to reach the target, but this also reduces the need to restart MDA later in the program. For 80% coverage, the lower threshold is cost-effective across all baseline prevalences for India, Tanzania, and Haiti. For 65% MDA coverage, the lower threshold is not cost-effective due to additional MDA rounds, although it increases the probability of local elimination. Valuing the benefits of elimination to align with the GPELF goals, we find that a willingness to pay per capita government expenditure of approximately $1000-$4000 for 1% increase in the probability of local elimination would be required to make a lower threshold cost-effective. CONCLUSIONS: Lower Ag thresholds for stopping MDAs generally mean a higher probability of local elimination, reducing long-term costs and health impacts. However, they may also lead to an increased number of MDA rounds required to reach the lower threshold and, therefore, increased short-term costs. Collectively, our analyses highlight that lower target Ag thresholds have the potential to assist programs in achieving lymphatic filariasis goals.

An Ensemble Framework for Projecting the Impact of Lymphatic Filariasis Interventions Across Sub-Saharan Africa at a Fine Spatial Scale.

BACKGROUND: Lymphatic filariasis (LF) is a neglected tropical disease targeted for elimination as a public health problem by 2030. Although mass treatments have led to huge reductions in LF prevalence, some countries or regions may find it difficult to achieve elimination by 2030 owing to various factors, including local differences in transmission. Subnational projections of intervention impact are a useful tool in understanding these dynamics, but correctly characterizing their uncertainty is challenging. METHODS: We developed a computationally feasible framework for providing subnational projections for LF across 44 sub-Saharan African countries using ensemble models, guided by historical control data, to allow assessment of the role of subnational heterogeneities in global goal achievement. Projected scenarios include ongoing annual treatment from 2018 to 2030, enhanced coverage, and biannual treatment. RESULTS: Our projections suggest that progress is likely to continue well. However, highly endemic locations currently deploying strategies with the lower World Health Organization recommended coverage (65%) and frequency (annual) are expected to have slow decreases in prevalence. Increasing intervention frequency or coverage can accelerate progress by up to 5 or 6 years, respectively. CONCLUSIONS: While projections based on baseline data have limitations, our methodological advancements provide assessments of potential bottlenecks for the global goals for LF arising from subnational heterogeneities. In particular, areas with high baseline prevalence may face challenges in achieving the 2030 goals, extending the "tail" of interventions. Enhancing intervention frequency and/or coverage will accelerate progress. Our approach facilitates preimplementation assessments of the impact of local interventions and is applicable to other regions and neglected tropical diseases.

Subnational Projections of Lymphatic Filariasis Elimination Targets in Ethiopia to Support National Level Policy.

BACKGROUND: Lymphatic filariasis (LF) is a debilitating, poverty-promoting, neglected tropical disease (NTD) targeted for worldwide elimination as a public health problem (EPHP) by 2030. Evaluating progress towards this target for national programmes is challenging, due to differences in disease transmission and interventions at the subnational level. Mathematical models can help address these challenges by capturing spatial heterogeneities and evaluating progress towards LF elimination and how different interventions could be leveraged to achieve elimination by 2030. METHODS: Here we used a novel approach to combine historical geo-spatial disease prevalence maps of LF in Ethiopia with 3 contemporary disease transmission models to project trends in infection under different intervention scenarios at subnational level. RESULTS: Our findings show that local context, particularly the coverage of interventions, is an important determinant for the success of control and elimination programmes. Furthermore, although current strategies seem sufficient to achieve LF elimination by 2030, some areas may benefit from the implementation of alternative strategies, such as using enhanced coverage or increased frequency, to accelerate progress towards the 2030 targets. CONCLUSIONS: The combination of geospatial disease prevalence maps of LF with transmission models and intervention histories enables the projection of trends in infection at the subnational level under different control scenarios in Ethiopia. This approach, which adapts transmission models to local settings, may be useful to inform the design of optimal interventions at the subnational level in other LF endemic regions.

How Does the Proportion of Never Treatment Influence the Success of Mass Drug Administration Programs for the Elimination of Lymphatic Filariasis?

BACKGROUND: Mass drug administration (MDA) is the cornerstone for the elimination of lymphatic filariasis (LF). The proportion of the population that is never treated (NT) is a crucial determinant of whether this goal is achieved within reasonable time frames. METHODS: Using 2 individual-based stochastic LF transmission models, we assess the maximum permissible level of NT for which the 1% microfilaremia (mf) prevalence threshold can be achieved (with 90% probability) within 10 years under different scenarios of annual MDA coverage, drug combination and transmission setting. RESULTS: For Anopheles-transmission settings, we find that treating 80% of the eligible population annually with ivermectin + albendazole (IA) can achieve the 1% mf prevalence threshold within 10 years of annual treatment when baseline mf prevalence is 10%, as long as NT <10%. Higher proportions of NT are acceptable when more efficacious treatment regimens are used. For Culex-transmission settings with a low (5%) baseline mf prevalence and diethylcarbamazine + albendazole (DA) or ivermectin + diethylcarbamazine + albendazole (IDA) treatment, elimination can be reached if treatment coverage among eligibles is 80% or higher. For 10% baseline mf prevalence, the target can be achieved when the annual coverage is 80% and NT ≤15%. Higher infection prevalence or levels of NT would make achieving the target more difficult. CONCLUSIONS: The proportion of people never treated in MDA programmes for LF can strongly influence the achievement of elimination and the impact of NT is greater in high transmission areas. This study provides a starting point for further development of criteria for the evaluation of NT.

The effectiveness of albendazole against hookworm infections and the impact of bi-annual treatment on anaemia and body mass index of school children in the Kpandai district of northern Ghana.

The impact of the Global Programme to Eliminate Lymphatic Filariasis (GPELF) (initiated in 2000 in Ghana and ran for 12 years) in mitigating soil-transmitted helminth (STH) infections in LF-endemic areas is unknown. During a 1-year hiatus which ensued between 2011 and 2012, a longitudinal study was conducted to determine GPELF effect on hookworm infections in selected communities involved in the programme since its inception, while measuring the effectiveness of biannual ALB treatments on schoolchildren living in such communities. A total of 399 school children aged 3 to 18 years were randomly selected from four communities in the Kpandai district of northern Ghana. Each presented a single stool sample at baseline, 21 days post-treatment, at the 3rd and 6th months, 21 days post-second intervention (i.e. following sample collection and treatment with ALB in the 6th month), and in the ninth month of the study period. Haemoglobin (hb) levels were also measured at all time points using finger prick blood samples and a URIT digital test kit. Each participant submitting a sample, was treated with a single-dose ALB (400mg) at baseline and in the sixth month. Stool samples were processed by preparing duplicate Kato-Katz slides per sample, and examined by microscopy. The Body Mass Index-for-age z-scores (BAZ) of participants were assessed following the determination of BMIs at each time point by measuring their height and weight with a stadiometer and weighing scale. Overall hookworm prevalences were 25.68% (95% CI = 20.51-31.75) at baseline, 11.18% (95% CI = 7.87-15.41) 21 days post-treatment, 11.78% (95% CI = 8.38-16.11) and 6.95% (95% CI = 4.41-10.43) in the 3rd and 6th months, 0.91% (95% CI = 0.19-2.65) 21 days post-second intervention, and 8.46% (95% CI = 5.62-12.23) in the ninth month. Observed overall faecal egg count reduction rates (ERRs) were 94.21% (95% CI = 81.50%- 100.00%) 21 days after baseline treatment, 97.70% (95% CI = 85.08-100.00) and 96.95% (95% CI = 84.18%- 100.00%) in the 3rd and 6th months, 99.98% (95% CI = 86.42%- 100.00%) 21 days post-second intervention, and 17.18% (95% CI = 14.07%- 20.67%) in the 9th month. Respective cure rates (CRs) were 62.35% (95% CI = 46.71-81.56%), 85.88% (95% CI = 67.32-100.00%), 87.06% (95% CI = 68.36%- 100.00%), 98.82% (95% CI = 78.83%- 100.00%), and 36.36% (95% CI = 9.91%- 93.11%). Additionally, increases in the percent frequency of 'normal hb' (p < 0.01) were observed across the study time points, whilst 'normal BAZ' cases remained high (from 94.87% to 98.87%) throughout the study period. These findings primarily indicate satisfactory effectiveness of ALB which may be maintainable in mass drug administration programmes by the modification of treatment strategies from annual to bi-annual regimes. This could minimize the likelihood of emerging poorly-responding hookworm phenotypes in Ghana. Additionally, a positive impact of bi-annual treatment on participant anaemia status is herein indicated with particular regard to the school children in our cohort.

Impact assessment of onchocerciasis through lymphatic filariasis transmission assessment surveys using Ov-16 rapid diagnostic tests in Sierra Leone.

BACKGROUND: Onchocerciasis is endemic in 14 of Sierra Leone's 16 districts with high prevalence (47-88.5%) according to skin snips at baseline. After 11 rounds of mass treatment with ivermectin with good coverage, an impact assessment was conducted in 2017 to assess the progress towards eliminating onchocerciasis in the country. METHODS: A cluster survey was conducted, either integrated with lymphatic filariasis (LF) transmission assessment survey (TAS) or standalone with the LF TAS sampling strategy in 12 (now 14) endemic districts. Finger prick blood samples of randomly selected children in Grades 1-4 were tested in the field using SD Bioline Onchocerciasis IgG4 rapid tests. RESULTS: In total, 17,402 children aged 4-19 years in 177 schools were tested, and data from 17,364 children aged 4-14 years (14,230 children aged 5-9 years) were analyzed. Three hundred forty-six children were confirmed positive for Ov-16 IgG4 antibodies, a prevalence of 2.0% (95% CI 1.8-2.2%) in children aged 4-14 years with prevalence increasing with age. Prevalence in boys (2.4%; 95% CI 2.1-2.7%) was higher than in girls (1.6%; 95% CI 1.4-1.9%). There was a trend of continued reduction from baseline to 2010. Using data from children aged 5-9 years, overall prevalence was 1.7% (95% CI 1.5-1.9%). The site prevalence ranged from 0 to 33.3% (median prevalence = 0.0%): < 2% in 127 schools, 2 to < 5% in 34 schools and ≥ 5% in 16 schools. There was a significant difference in average prevalence between districts. Using spatial analysis, the Ov-16 IgG4 antibody prevalence was predicted to be < 2% in coastal areas and in large parts of Koinadugu, Bombali and Tonkolili Districts, while high prevalence (> 5%) was predicted in some focal areas, centered in Karene, Kailahun and Moyamba/Tonkolili. CONCLUSIONS: Low Ov-16 IgG4 antibody prevalence was shown in most areas across Sierra Leone. In particular, low seroprevalence in children aged 5-9 years suggests that the infection was reduced to a low level after 11 rounds of treatment intervention. Sierra Leone has made major progress towards elimination of onchocerciasis. However, attention must be paid to those high prevalence focal areas.

A dynamic game of lymphatic filariasis prevention by voluntary use of insecticide treated nets.

Lymphatic filariasis (LF) has been targeted for elimination as a public health concern by 2030 with a goal to keep the prevalence of LF infections under the 1% threshold. While mass drug administration (MDA) is a primary strategy recommended by WHO, the use of insecticide treated nets (ITN) plays a crucial role as an alternative strategy when MDA cannot be used. In this paper, we use imitation dynamics to incorporate human behavior and voluntary use of ITN into the compartmental epidemiological model of LF transmission. We find the equilibrium states of the dynamics and the ITN usage as it depends on epidemiological parameters and the cost of ITNs. We investigate the conditions under which the voluntary use of ITNs can keep the LF prevalence under the 1% threshold. We found that when the cost of using the ITNs is about 105 smaller than the perceived cost of LF, then the voluntary use of ITNs will eliminate LF as a public health concern. Furthermore, when the ITNs are given away for free, our model predicts that over 80% of the population will use them which would eliminate LF completely in regions where Anopheles are the primary vectors.

An evaluation of mental health integration in the neglected tropical diseases program in Zamfara, North-west Nigeria.

BACKGROUND: Mental health and neglected tropical diseases (NTDs) are critical in healthcare systems, especially in low- and middle-income countries. Several policies are planned or designed by health stakeholders to address the mental health needs of people affected by NTDs. Still, the impact of such policies seems to be of no consequence. METHODS: The GAD-7 and PHQ-9 tools were used to determine the rate of depression and anxiety, respectively, among people affected by skin NTDs (leprosy and lymphatic filariasis [LF]) in Zamfara State, North-west Nigeria. The study also evaluated the barriers to the uptake of mental health services for people affected by skin NTDs in the state. We assessed 48 people affected by NTDs (leprosy, 32; lymphatic filariasis, 16) along with a corresponding 48 people who served as controls in the study. Qualitative interviews were carried out with the participants to elicit the barriers to mental health services for people affected by NTDs. Additionally, 48 selected healthcare workers from the state were assessed for their skills and capacity to offer mental health services. RESULTS: We found anxiety disorder present in 100% of the people living with LF and in 62% of the people living with leprosy. Depression was also found in 56% and 75% of the people living with leprosy and LF, respectively. An assessment of the barriers to the uptake of mental health services reveals that most people with NTDs are constrained by a lack of money to visit hospitals, the fear of stigmatisation and discrimination and long distances to health centres. Regarding the healthcare workers, the skills and capacity to offer mental health services were very low. CONCLUSIONS: We conclude that for mental health services to be integrated into the community health system for people with NTDs, there should be a concerted effort by all stakeholders and the intervention should be context specific instead of generalised. CONTEXTE: La santé mentale et les maladies tropicales négligées (MTN) sont des problématiques centrales dans la santé, en particulier dans les pays à revenu faible ou intermédiaire. Plusieurs politiques sont conçues par les acteurs de la santé publique pour répondre aux besoins de soins en santé mentale pour les personnes touchées par les MTN. Pourtant, le bilan reste mitigé quant à l'efficacité de ces soins. MÉTHODES: Les outils GAD-7 et PHQ-9 ont été utilisés pour déterminer le taux de dépression et d'anxiété chez les personnes atteintes de MTN cutanées (lèpre et filariose lymphatique) dans l'État de Zamfara, au nord-ouest du Nigeria. L'étude a également évalué les obstacles à l'utilisation des services de santé mentale pour les personnes atteintes de MTN cutanées dans l'État. Nous avons évalué 48 personnes atteintes de MTN (lèpre : 32, filariose lymphatique : 16) ainsi que 48 personnes correspondantes qui ont servi de témoins dans l'étude. Des entretiens qualitatifs ont été menés avec les participants afin d'identifier les obstacles aux services de santé mentale pour les personnes atteintes de MTN. En outre, 48 professionnels de la santé sélectionnés dans l'État ont été évalués pour déterminer leurs compétences et leur capacité à offrir des services de santé mentale. RÉSULTATS: Nous avons trouvé des troubles anxieux chez 100% des personnes atteintes de filariose lymphatique et chez 62% des personnes atteintes de lèpre. La dépression touche 56% et 75% des personnes vivant avec la lèpre et la filariose lymphatique respectivement. Une évaluation des obstacles à l'utilisation des services de santé mentale révèle que la plupart des personnes atteintes de MTN sont limitées par le manque d'argent pour se rendre à l'hôpital, la peur de la stigmatisation et de la discrimination, et les longues distances à parcourir pour se rendre dans les centres de santé. Les compétences et les capacités des professionnels de la santé à offrir des services de santé mentale sont très faibles. CONCLUSION: L'efficacité d'un protocole de soins pour les patients atteints de MTN (traitant la pathologie physique et d'éventuelles pathologies psychiatriques associées) nécessite une intégration des services de santé mentale dans le système de santé communautaire. ANTECEDENTES: La salud mental y las enfermedades tropicales desatendidas (ETDs), son fundamentales en los sistemas sanitarios, especialmente en los países de renta baja y media. Las partes interesadas en la sanidad planean o diseñan varias políticas para abordar las necesidades de salud mental de las personas afectadas por ETDs. Sin embargo, el impacto de dichas políticas parece ser nulo. MÉTODOS: Se utilizaron las herramientas GAD-7 y PHQ-9 para determinar la tasa de depresión y ansiedad, respectivamente, entre las personas afectadas por ETDs cutáneas (lepra y filariasis linfática) en el Estado de Zamfara, al noroeste de Nigeria. El estudio también evaluó las barreras para la aceptación de los servicios de salud mental por parte de las personas afectadas por ETDs cutáneas en el Estado. Se evaluó a 48 personas afectadas por ETDs (lepra: 32; filariasis linfática: 16) y a otras 48 que sirvieron de control en el estudio. Se llevaron a cabo entrevistas cualitativas con los participantes para determinar las barreras a los servicios de salud mental para las personas afectadas por ETDs. Además, se evaluaron las habilidades y la capacidad para ofrecer servicios de salud mental de 48 profesionales sanitarios del Estado. RESULTADOS: Encontramos trastorno de ansiedad presente en el 100% de las personas que vivían con filariasis linfática y en el 62% de las personas que vivían con lepra. También se encontró depresión en el 56% y el 75% de las personas que vivían con lepra y filariasis linfática respectivamente. Una evaluación de los obstáculos para la utilización de los servicios de salud mental revela que la mayoría de las personas con ETDs se ven limitadas por la falta de dinero para acudir a los hospitales, el miedo a la estigmatización, la discriminación y las largas distancias hasta los centros sanitarios. Por parte del personal sanitario, los conocimientos y la capacidad para ofrecer servicios de salud mental eran muy escasos. CONCLUSIONES: Para que los servicios de salud mental para personas con ETD se integren en el sistema sanitario comunitario, debe haber una concertación entre todas las partes interesadas y la intervención debe ser específica para cada contexto en lugar de generalizada.

Lessons from integrating mental health as part of lymphatic filariasis morbidity management and disability prevention services in Jigawa State, Nigeria.

Lymphatic filariasis (LF) is a neglected tropical disease affecting >120 million people worldwide. LF has debilitating effects on humans and leads to morbidity and sometimes irreversible disability. A significant proportion of persons affected by LF morbidity also suffer from ill health, such as depression, anxiety, pain, stigma and social isolation due to disfigurement, as well as loss of mobility, livelihood and income. Mental health is often overlooked as a component of morbidity management and disability prevention (MMDP) services, despite the high prevalence of depression and anxiety among people affected by LF. To address this gap, Christian Blind Mission (CBM) piloted a comprehensive approach providing morbidity management and disability prevention by integrating mental health as part of the MMDP care package. The participatory evaluation of the project reviewed the project documents and a review meeting, small group discussions and in-depth interviews with project stakeholders. Findings suggest that project training and service delivery targets were exceeded in most cases. In addition, the disability and gender disaggregated data highlights the interplay of gender and disability in accessing care and the existence of unmet mental health needs. The financial cost of transportation to utilise referrals or access other MMDP services, such as replenishing treatment supplies, was a major constraint in accessing services for LF morbidity patients and low levels of awareness, fear of hydrocoele surgery and social stigmatisation were reported. The project outcomes demonstrate the feasibility and effectiveness of integrating mental health as part of a comprehensive MMDP package of care. Integration strategies should target training of MMDP providers in basic mental health skills, screening for mental health issues and the provision of mental health services and other MMDP services within the same facilities. Integration is an important step towards comprehensive care for people affected by LF and other NTD morbidities and disabilities.

The national distribution of lymphatic filariasis cases in Malawi using patient mapping and geostatistical modelling.

BACKGROUND: In 2020 the World Health Organization (WHO) declared that Malawi had successfully eliminated lymphatic filariasis (LF) as a public health problem. Understanding clinical case distributions at a national and sub-national level is important, so essential care packages can be provided to individuals living with LF symptoms. This study aimed to develop a national database and map of LF clinical cases across Malawi using geostatistical modelling approaches, programme-identified clinical cases, antigenaemia prevalence and climate information. METHODOLOGY: LF clinical cases identified through programme house-to-house surveys across 90 sub-district administrative boundaries (Traditional Authority (TA)) and antigenaemia prevalence from 57 sampled villages in Malawi were used in a two-step geostatistical modelling process to predict LF clinical cases across all TAs of the country. First, we modelled antigenaemia prevalence in relation to climate covariates to predict nationwide antigenaemia prevalence. Second, we modelled clinical cases for unmapped TAs based on our antigenaemia prevalence spatial estimates. PRINCIPLE FINDINGS: The models estimated 20,938 (95% CrI 18,091 to 24,071) clinical cases in unmapped TAs (70.3%) in addition to the 8,856 (29.7%), programme-identified cases in mapped TAs. In total, the overall national number of LF clinical cases was estimated to be 29,794 (95% CrI 26,957 to 32,927). The antigenaemia prevalence and clinical case mapping and modelling found the highest burden of disease in Chikwawa and Nsanje districts in the Southern Region and Karonga district in the Northern Region of the country. CONCLUSIONS: The models presented in this study have facilitated the development of the first national LF clinical case database and map in Malawi, the first endemic country in sub-Saharan Africa. It highlights the value of using existing LF antigenaemia prevalence and clinical case data together with modelling approaches to produce estimates that may be used for the WHO dossier requirements, to help target limited resources and implement long-term health strategies.

Heterogeneity in elimination efforts could increase the risk of resurgence of lymphatic filariasis in Madagascar.

BACKGROUND: Progress in lymphatic filariasis (LF) elimination is spatially heterogeneous in many endemic countries, which may lead to resurgence in areas that have achieved elimination. Understanding the drivers and consequences of such heterogeneity could help inform strategies to reach global LF elimination goals by 2030. This study assesses whether differences in age-specific compliance with mass drug administration (MDA) could explain LF prevalence patterns in southeastern Madagascar and explores how spatial heterogeneity in prevalence and age-specific MDA compliance may affect the risk of LF resurgence after transmission interruption. METHODOLOGY: We used LYMFASIM model with parameters in line with the context of southeastern Madagascar and explored a wide range of scenarios with different MDA compliance for adults and children (40-100%) to estimate the proportion of elimination, non-elimination and resurgence events associated with each scenario. Finally, we evaluated the risk of resurgence associated with different levels of migration (2-6%) from surrounding districts combined with varying levels of LF microfilaria (mf) prevalence (0-24%) during that same study period. RESULTS: Differences in MDA compliance between adults and children better explained the observed heterogeneity in LF prevalence for these age groups than differences in exposure alone. The risk of resurgence associated with differences in MDA compliance scenarios ranged from 0 to 19% and was highest when compliance was high for children (e.g. 90%) and low for adults (e.g. 50%). The risk of resurgence associated with migration was generally higher, exceeding 60% risk for all the migration levels explored (2-6% per year) when mf prevalence in the source districts was between 9% and 20%. CONCLUSION: Gaps in the implementation of LF elimination programme can increase the risk of resurgence and undermine elimination efforts. In Madagascar, districts that have not attained elimination pose a significant risk for those that have achieved it. More research is needed to help guide LF elimination programme on the optimal strategies for surveillance and control that maximize the chances to sustain elimination and avoid resurgence.

Assessment of Culicidae collection methods for xenomonitoring lymphatic filariasis in malaria co-infection context in Burkina Faso.

BACKGROUND: Entomological surveillance of lymphatic filariasis and malaria infections play an important role in the decision-making of national programs to control, or eliminate these both diseases. In areas where both diseases prevalence is low, a large number of mosquitoes need to be sampled to determine vectors infection rate. To do this, efficient mosquito collection methods must be used. This study is part in this framework, to assess appropriate mosquito collection methods for lymphatic filariasis xenomonitoring in a coexistence context with malaria in Burkina Faso. METHODOLOGY/PRINCIPAL FINDINGS: Mosquito collections were performed between August and September 2018 in four villages (Koulpissi, Seiga, and Péribgan, Saptan), distributed in East and South-West health regions of Burkina Faso. Different collection methods were used: Human Landing Catches (HLC) executed indoor and outdoor, Window Exit-Trap, Double Net Trap (DNT) and Pyrethrum Spray Catches (PSC). Molecular analyses were performed to identify Anopheles gambiae s.l. sibling species and to detect Wuchereria bancrofti and Plasmodium falciparum infection in Anopheles mosquitoes. A total of 3 322 mosquitoes were collected among this, Anopheles gambiae s.l. was the vector caught in largest proportion (63.82%). An. gambiae s.l. sibling species molecular characterization showed that An. gambiae was the dominant specie in all villages. The Human Landing Catches (indoor and outdoor) collected the highest proportion of mosquitoes (between 61.5% and 82.79%). For the sampling vectors infected to W. bancrofti or P. falciparum, PSC, HLC and Window Exit-Trap were found the most effective collection methods. CONCLUSIONS/SIGNIFICANCE: This study revealed that HLC indoor and outdoor remained the most effective collection method. Likewise, the results showed the probability to use Window Exit-Trap and PSC collection methods to sample Anopheles infected.

A pilot study to address the mental health of persons living with lymphatic filariasis in Léogâne, Haiti: Implementing a chronic disease self-management program using a stepped-wedge cluster design.

BACKGROUND: Neglected tropical diseases (NTDs) inflict significant comorbid disability on the most vulnerable communities; yet interventions targeting the mental health of affected communities are lacking. A pilot study to assess the effectiveness of a chronic disease self-management program (CDSMP) was introduced to lymphatic filariasis peer support groups in Léogâne, Haiti. METHODS: Using a closed-cohort stepped-wedge cluster trial design, Hope Clubs were assigned into Arm 1 (n=118 members) and Arm 2 (n=92). Household surveys, measuring self-rated health, depression, disease self-efficacy, perceived social support, and quality of life, were conducted at baseline (before CDSMP); midpoint (after Arm 1/before Arm 2 completed CDSMP); and endpoint (after CDSMP). Non-Hope Club member patients (n=74) were evaluated at baseline for comparison. RESULTS: Fifty percent of Hope Club members (Arm 1: 48.3%, Arm 2: 52.2%) screened positive for depression at baseline, compared with 36.5% of non-Hope Club members. No statistically significant differences were found in outcome measures between intervention observation periods. At endpoint, depressive illness reduced to 28.7% (Arm 1) and 27.6% (Arm 2). CONCLUSIONS: The intervention was feasible to integrate into Hope Clubs, showed overall positive effects and reduced depressive symptoms. More studies are needed to evaluate the efficacy of implementing CDSMP in the NTD context. CONTEXTE: Les maladies tropicales négligées (MTN) infligent d'importantes incapacités comorbides aux communautés les plus vulnérables; pourtant, les interventions ciblant la santé mentale des communautés affectées font défaut. Une étude pilote visant à évaluer l'efficacité d'un programme d'autogestion des maladies chroniques (CDSMP) a été introduite dans des groupes de soutien par les pairs pour la filariose lymphatique à Léogâne, en Haïti. MÉTHODES: Dans le cadre d'un essai en grappe à cohorte fermée, les clubs Hope ont été répartis entre le bras 1 (n=118 membres) et le bras 2 (n=92). Des enquêtes auprès des ménages, mesurant l'auto-évaluation de la santé, la dépression, l'auto-efficacité face à la maladie, le soutien social perçu et la qualité de vie, ont été menées au départ (avant le CDSMP), à mi-parcours (après que le bras 1 / avant que le bras 2 ait terminé le CDSMP) et à la fin (après le CDSMP). Les patients non membres du Hope Club (n=74) ont été évalués au début de l'étude à des fins de comparaison. RÉSULTATS: Cinquante pourcent des membres du Hope Club (bras 1 : 48,3%, bras 2 : 52,2%) ont été dépistés positifs pour la dépression au début de l'étude, contre 36,5% des non-membres du Hope Club. Aucune différence statistiquement significative n'a été constatée dans les mesures des résultats entre les périodes d'observation de l'intervention. À la fin de l'étude, la maladie dépressive était réduite à 28,7% (bras 1) et 27,6% (bras 2). CONCLUSIONS: L'intervention a pu être intégrée dans les clubs Hope, elle a montré des effets globalement positifs et a permis de réduire les symptômes dépressifs. D'autres études sont nécessaires pour évaluer l'efficacité de la mise en œuvre du CDSMP dans le contexte des MTD. ANTECEDENTES: Las enfermedades tropicales desatendidas (ETDs) infligen una importante discapacidad comórbida a las comunidades más vulnerables; sin embargo, faltan intervenciones dirigidas a la salud mental de las comunidades afectadas. Se introdujo un estudio piloto para evaluar la eficacia de un programa de autogestión de enfermedades crónicas (CDSMP, por sus siglas en inglés) en grupos de apoyo entre pares de filariasis linfática en Léogâne, Haití. MÉTODOS: Utilizando un diseño de ensayo por conglomerados de cohortes cerradas escalonadas, los Clubes Esperanza fueron asignados al Grupo 1 (n=118 miembros) y al Grupo 2 (n=92). Se realizaron encuestas en los hogares para medir la autoevaluación de la salud, la depresión, la autoeficacia frente a la enfermedad, el apoyo social percibido y la calidad de vida en la línea de base (antes del CDSMP), en el punto medio (después de que el Grupo 1/antes de que el Grupo 2 completara el CDSMP) y en el punto final (después del CDSMP). Los pacientes que no pertenecían al Club Esperanza (n=74) fueron evaluados al inicio del estudio a modo de comparación. RESULTADOS: El 50% de los miembros del Club Esperanza (Grupo 1: 48,3%, Grupo 2: 52,2%) dieron positivo en depresión al inicio del estudio, en comparación con el 36,5% de los no miembros del Club Esperanza. No se encontraron diferencias estadísticamente significativas en las medidas de resultado entre los periodos de observación de la intervención. Al final, la enfermedad depresiva se redujo al 28,7% (Grupo 1) y al 27,6% (Grupo 2). CONCLUSIONES: La intervención fue factible de integrar en los Clubes Esperanza, mostróefectos positivos generales y redujo los síntomas depresivos. Se necesitan más estudios para evaluar la eficacia de la aplicación del CDSMP en el contexto de las ETD.

Unpacking Immune Modulation as a Site of Therapeutics Innovation for Nematode Parasite Wuchereria bancrofti: A Temporal Quantitative Phosphoproteomics Profiling of Macrophage Migration Inhibitory Factor 2.

Nematode infections are common in both humans and livestock, with major adverse planetary health and economic impacts. Wuchereria bancrofti is a parasitic nematode that causes lymphatic filariasis, a neglected tropical disease that can lead to severe disability and deformity worldwide. For the long-term survival of the bancroftian parasites in the host, a complex immune invasion strategy is involved through immunomodulation. Therefore, immunomodulation can serve as a site of research and innovation for molecular targets. Macrophage migration inhibitory factor (MIF) is a pleiotropic cytokine crucial to the host antimicrobial alarm system and stress response. Interestingly, the nematode parasite W. bancrofti also produces two homologs of MIF (Wba-MIF1 and 2). Using a mass spectrometry-based phosphoproteomics approach, we report new findings on the immunomodulatory effect and signaling mechanism of Wba-MIF2 in macrophage cells. Accordingly, we observed 1201 phosphorylated sites on 467 proteins. Out of the 1201 phosphorylated sites, 1075, 117, and 9 were found on serine (S), threonine (T), and tyrosine (Y) residues, respectively. Our bioinformatics analysis led to identification of major pathways, including spliceosomes, T cell receptor signaling pathway, Th17 differentiation pathway, interleukin-17 signaling pathway, and insulin signaling pathway upon Wba-MIF2 treatment. Wba-MIF2 treatment also enriched CDK4, CDK1, and DNAPK kinases. The comparison of the signaling pathway of Wba-MIF2 with that of human-MIF suggests both share similar signaling pathways. These findings collectively offer new insights into the role and mechanism of Wba-MIF2 as an immunomodulator and inform future diagnostics and drug discovery research for W. bancrofti.

Elimination of lymphatic filariasis as a public health problem in Malawi.

BACKGROUND: Lymphatic filariasis (LF) is a parasitic disease transmitted by mosquitoes, causing severe pain, disfiguring, and disabling clinical conditions such as lymphoedema and hydrocoele. LF is a global public health problem affecting 72 countries, primarily in Africa and Asia. Since 2000, the World Health Organization (WHO) has led the Global Programme to Eliminate Lymphatic Filariasis (GPELF) to support all endemic regions. This paper focuses on the achievements of the Malawi LF Elimination Programme between 2000 and 2020 to eliminate LF as a public health problem, making it the second sub-Saharan country to receive validation from the WHO. METHODOLOGY/PRINCIPAL FINDINGS: The Malawi LF Programme addressed the widespread prevalence of LF infection and disease across the country, using the recommended WHO GPELF strategies and operational research initiatives in collaboration with key national and international partners. First, to stop the spread of infection (i.e., interrupt transmission) and reduce the circulating filarial antigen prevalence from as high as 74.4% to below the critical threshold of 1-2% prevalence, mass drug administration (MDA) using a two-drug regime was implemented at high coverage rates (>65%) of the total population, with supplementary interventions from other programmes (e.g., malaria vector control). The decline in prevalence was monitored and confirmed over time using several impact assessment and post-treatment surveillance tools including the standard sentinel site, spot check, and transmission assessment surveys and alternative integrated, hotspot, and easy-access group surveys. Second, to alleviate suffering of the affected populations (i.e., control morbidity) the morbidity management and disability prevention (MMDP) package of care was implemented. Specifically, clinical case estimates were obtained via house-to-house patient searching activities; health personnel and patients were trained in self-care protocols for lymphoedema and/or referrals to hospitals for hydrocoele surgery; and the readiness and quality of treatment and services were assessed with new survey tools. CONCLUSIONS: Malawi's elimination of LF will ensure that future generations are not infected and suffer from the disfiguring and disabling disease. However, it will be critical that the Malawi LF Elimination programme remains vigilant, focussing on post-elimination surveillance and MMDP implementation and integration into routine health systems to support long-term sustainability and ongoing success. SUMMARY: Lymphatic filariasis, also known as elephantiasis, is a disabling, disfiguring, and painful disease caused by a parasite that infected mosquitoes transmit to millions of people worldwide. Since 2000, the Global Programme to Eliminate Lymphatic Filariasis (GPELF) has supported endemic countries such as Malawi in south-eastern Africa, to eliminate the disease as a public health problem. The Malawi National LF Elimination Programme has worked tirelessly over the past two decades to implement the GPELF recommended strategies to interrupt the transmission with a two-drug regime, and to alleviate suffering in patients with lymphoedema and/or hydrocoele through morbidity management and disability prevention. Additionally, the LF Programme has collaborated with national and international stakeholders to implement a range of supplementary operational research projects to address outstanding knowledge gaps and programmatic barriers. In 2020, the World Health Organisation validated that Malawi had successfully eliminated LF as a public health problem, making it the second country in sub-Saharan Africa to achieve this, which is remarkable given that Malawi previously had very high infection rates. The LF Programme now remains vigilant, putting its efforts towards post-elimination surveillance and the continued implementation of care for patients with chronic conditions. Malawi's elimination of LF will ensure that future generations are not affected by this devastating disease.

Detection of Wuchereria bancrofti DNA in wild caught vector and non-vector mosquitoes: implications for elimination of lymphatic filariasis.

BACKGROUND: Transmission Assessment Survey (TAS) is the WHO recommended method used for decision-making to stop or continue the MDA in lymphatic filariasis (LF) elimination programme. The WHO has also recommended Molecular Xenomonitoring (MX) of LF infection in vectors as an adjunct tool in settings under post-MDA or validation period. Screening of non-vectors by MX in post-MDA / validation settings could be useful to prevent a resurgence of LF infection, as there might be low abundance of vectors, especially in some seasons. In this study, we investigated the presence of LF infection in non-vectors in an area endemic for LF and has undergone many rounds of annual MDA with two drugs (Diethylcarbamazine and Albendazole, DA) and two rounds of triple drug regimens (Ivermectin + DA). METHODS AND RESULTS: Mosquitoes were collected from selected villages of Yadgir district in Karnataka state, India, during 2019. A total of 680 female mosquitoes were collected, identified morphologically by species and separated as pools. The female mosquitoes belonging to 3 species viz., Anopheles subpictus, Culex gelidus and Culex quinquefaciatus were separated, pooled, and the DNA extracted using less expensive method and followed by LDR based real-time PCR assay for detecting Wuchereria bancrofti infection in vector as well as non-vector mosquitoes. One pool out of 6 pools of An. subpictus, 2 pools out of 6 pools of Cx. gelidus, and 4 pools out of 8 pools of Cx. quinquefaciatus were found to be positive for W. bancrofti infection by RT-PCR. The infection rate in vectors and non-vectors was found to be 1.8% (95% CI: 0.5-4.2%) and 0.9% (95% CI: 0.2-2.3%), respectively. CONCLUSIONS: Our study showed that non-vectors also harbour W. bancrofti, thus opening an opportunity of using these mosquitoes as surrogate vectors for assessing risk of transmission to humans in LF endemic and post MDA areas.

Postintervention Immunological and Entomological Survey of Lymphatic Filariasis in the City of Olinda, Brazil, 2015-2016.

Lymphatic filariasis (LF) is a leading cause of disability due to infectious disease worldwide. The Recife Metropolitan Region (RMR) is the only remaining focus of LF in Brazil, where the parasite Wuchereria bancrofti is transmitted solely by the mosquito Culex quinquefasciatus. This study reports the results of transmission assessment surveys and molecular xenomonitoring in the city of Olinda, RMR, after nearly 15 years (2015-2016) of interventions for LF elimination. Participants were screened for W. bancrofti antigen via immunochromatographic card tests (ICT) in: 1) door-to-door surveys conducted for all children aged 5-7 years from 4 out of 17 intervention areas treated with at least five annual doses of mass drug administration (MDA), and 2) a two-stage cluster sampling survey of residents aged 5 years and older in non-MDA areas. Mosquitoes were collected via handheld aspirators in four MDA areas, differentiated by species, sex, and physiological status, pooled into groups of up to 10 blood-fed, semigravid, and gravid mosquitoes, and screened for W. bancrofti infection by real-time quantitative polymerase chain reaction (RT-qPCR). All 1,170 children from MDA areas and the entire population sample of 990 residents in non-MDA areas were ICT negative. In MDA areas, a total of 3,152 female Cx. quinquefasciatus mosquitoes in 277 households (range, 0-296 mosquitoes per house) were collected via aspiration. RT-qPCR of 233 pools of mosquitos were negative for W. bancrofti RNA; an independent reference laboratory confirmed these results. These results provide evidence that LF transmission has been halted in this setting.