The emerging story of disability associated with lymphatic filariasis: a critical review

A Phase 1, Randomized, Double-Blind, Placebo-Controlled, Single Ascending Dose Trial of AWZ1066S, an Anti-Wolbachia Candidate Macrofilaricide

AWZ1066S has been developed as a potential treatment for the neglected tropical diseases lymphatic filariasis and onchocerciasis. AWZ1066S targets the Wolbachia bacterial endosymbiont present in the causative nematode parasites. This phase 1, first-in-human study aimed to assess the safety and pharmacokinetics of AWZ1066S in healthy human participants. In a randomized double-blind, placebo-controlled, single ascending dose study, healthy adults received a single oral dose of AWZ1066S (or placebo) and were followed up for 10 days. The planned single doses of AWZ1066S ranged from 100 to 1600 mg, and each dose was administered to a cohort of 8 participants (6 AWZ1066S and 2 placebo). In total 30 people participated, 18 (60%) female, median age 30.0 years (minimum 20, maximum 61). The cohorts administered 100, 200, 300, and 400 mg of AWZ1066S progressed unremarkably. After single 700-mg doses all 4 participants developed symptoms of acute gastritis and transient increases in liver enzymes. The severity of these adverse events ranged from mild to severe, with 1 participant needing hospital admission. Pharmacokinetic analysis indicated that AWZ1066S is rapidly absorbed with predictable pharmacokinetics. In conclusion, safety concerns prevented this study from reaching the human exposures needed for AWZ1066S to be clinically effective against lymphatic filariasis and onchocerciasis.

An Overview of Management Considerations for Mongolian Gerbils (Meriones unguiculatus), Cats (Felis catus), and Dogs (Canis familiaris) as Hosts for Brugia Infection

Lymphatic filariasis is a mosquito-borne parasitic infection affecting an estimated 51.4 million people. Brugia malayi and Brugia pahangi are used in research because common nonprimate research species such as Mongolian gerbils (Meriones unguiculatus), cats (Felis catus), and dogs (Canis familiaris) can maintain the life cycle of these species of filarial nematodes. Although overall care and management of animals infected with Brugia spp. is relatively straightforward, there are some unique challenges and special considerations that must be addressed when managing a research colony infected with these parasites. In this review, we discuss our experience, share insight into biosafety and clinical management, and describe the expected clinical signs associated with Brugia infection in gerbils, cats, and dogs.

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.

Factors associated with never treatment and acceptability of mass drug administration for the elimination of lymphatic filariasis in Guyana, 2021

Guyana remains one of four countries in the Americas endemic for lymphatic filariasis (LF). Elimination of LF requires repeated annual mass drug administration (MDA) with sufficient levels of coverage for success. This study assesses the acceptability and never treatment of LF MDA using data from a routine assessment survey in 2021. A subset of individuals, over 20 years of age (n = 2498), were selected to receive an expanded questionnaire to examine factors associated with acceptability and never treatment. Assessed factors include respondent demographics, knowledge, risk perceptions of LF, and opinions on the MDA programme. The majority (73%) of those with scores above the acceptability threshold (score ≥22.5) reported participating in MDA two or more times. Factors strongly and positively associated with scoring above the acceptability threshold include beliefs in importance of participation in MDA for their community (aOR = 2.8, 95%CI (1.1-7.2)), perception of importance of LF treatment (6.9 (3.2-14.7)), receiving treatment in 2021 (2.9 (1.5-5.4)), and the number of self-reported times taking treatment for LF (2.2 (1.1-4.4)). Ten percent of respondents participated in the MDA for the first time in 2021, while 15% reported never treatment during any round of LF MDA. Three factors were statistically associated with participation in MDA across the two levels of the models (level 1: took LF treatment once versus never, and level 2: took LF treatment twice versus never) included: 1) scoring above the acceptability threshold (aOR = 6.2, 95%CI(3.8-10.0)), 2) self-reported importance of participation in MDA for their community (7.1 (2.9-17.8)), and 3) personal beliefs that they should take LF treatment even if they are not sick (2.6 (1.7-3.9)). As Guyana moves closer to LF elimination, these results provide further insight and understanding into programmatic results and could inform further action following MDA activities-particularly if an approach is needed to address never treatment during MDA.

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.

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.

Zambia: A Narrative Review of Success and Challenges in Lymphatic Filariasis Elimination

The establishment of the Global Programme to Eliminate Lymphatic Filariasis (GPELF) to stop the transmission of infection has significantly reduced the incidence of lymphatic filariasis, a debilitating mosquito-borne neglected tropical disease. The primary strategies that have been employed include mass drug administration (MDA) of anthelminthics and morbidity management and disability prevention (MMDP). While some countries have been able to reach elimination status in Africa, there is still active transmission of LF in Zambia. The nematode responsible for the disease is Wuchereria bancrofti, which is transmitted by Anopheles mosquitoes. To alleviate the suffering of those infected by the disease, the Zambian Ministry of Health launched a program to eliminate LF as a public health problem in 2003. This project reviewed the efforts to achieve the elimination of LF in Zambia, past and present government policies, and the anticipated challenges. MDAs have been conducted since 2014 and coverage has been between 87% and 92%. Zambia has now moved towards pre-transmission assessment surveys (PRETAS) and transmission assessment surveys (TAS). MMDP is a major priority and planned to be conducted between 2022 and 2026. COVID-19 presented a new challenge in the control of LF, while climate change, immigration, co-infections, and funding limitations will complicate further progress.

Lymphatic filariasis in Zambia: A scoping review protocol

BACKGROUND

Zambia is among the countries making major progress in limiting cases of the neglected tropical disease lymphatic filariasis on the path to reaching global elimination targets. For this trend to continue, it is essential for strategies and policies targeting the disease in Zambia to be based on the most recent and relevant literature. The scope of research on lymphatic filariasis in the Zambian context is currently poorly understood. Therefore, this study describes a scoping review protocol which will be used to analyze the body of literature on lymphatic filariasis in Zambia.

METHODS

The scoping review protocol was developed following the PRISMA reporting guidelines for Scoping Reviews (PRISMA-ScR) and the JBI Scoping Review Methodology Group's guidance on conducting scoping reviews. In consultation with a research librarian, these guidelines will be applied to a literature search of articles from peer-reviewed journals, or government and international regulatory bodies using PubMed, Embase, Web of Science, Cochrane CENTRAL, WHO ICTRP, Pan African Clinical Trials Registry, and ClinicalTrials.gov. Each record will be screened at the abstract and full-text level by two independent reviewers, and results reported via summary statistics.

DISCUSSION

Understanding the current state of research on lymphatic filariasis in Zambia will identify major knowledge and intervention gaps in this context, and serve as a source of information for surrounding countries in the region. As the disease prevalence drops, efforts for elimination will require carefully targeted strategies which can be informed from the literature identified in this protocol.

Stage-Dependent Increase of Systemic Immune Activation and CCR5+CD4+ T Cells in Filarial Driven Lymphedema in Ghana and Tanzania

Chronic lymphedema caused by infection of Wuchereria bancrofti is a disfiguring disease that leads to physical disability, stigmatization, and reduced quality of life. The edematous changes occur mainly on the lower extremities and can progress over time due to secondary bacterial infections. In this study, we characterized participants with filarial lymphedema from Ghana and Tanzania as having low (stage 1-2), intermediate (stage 3-4), or advanced (stage 5-7) lymphedema to determine CD4⁺ T cell activation patterns and markers associated with immune cell exhaustion. A flow cytometry-based analysis of peripheral whole blood revealed different T cell phenotypes within participants with different stages of filarial lymphedema. In detail, increased frequencies of CD4⁺HLA-DR⁺CD38⁺ T cells were associated with higher stages of filarial lymphedema in patients from Ghana and Tanzania. In addition, significantly increased frequencies of CCR5⁺CD4⁺ T cells were seen in Ghanaian participants with advanced LE stages, which was not observed in the Tanzanian cohort. The frequencies of CD8⁺PD-1⁺ T cells were augmented in individuals with higher stage lymphedema in both countries. These findings show distinct activation and exhaustion patterns in lymphedema patients but reveal that immunological findings differ between West and East African countries.

The Impact of the COVID-19 Pandemic on People With Lymphedema in an Endemic Area for Lymphatic Filariasis in Brazil

Objectives: To investigate the repercussions of the COVID-19 pandemic on lymphedema patients from an endemic area of lymphatic filariasis. Methods: The study descriptive compared sociodemographic and clinical aspects, risk of falling and quality of life, prior and during the COVID-19 pandemic in 28 lymphedema patients, older than 18 years old and under investigation of filarial infection. For the evaluation of functional mobility, the Time Up and Go test and The Medical Outcome Study Short Form-36 Health for quality of life, was used. Results: An increase in interdigital and dermal lesions, a higher frequency of acute dermatolymphangioadenitis crises and risk of falling, worsening of quality of life in the domains of physical functioning, general health, vitality, and mental health during the pandemic was observed. Conclusion: Our findings of clinical worsening and quality of life of patients during the COVID-19 pandemic indicate the need to reinforce the goal of the Lymphatic Filariasis Program regarding the follow-up of these patients in the actions of the Global Program for the Elimination of Lymphatic Filariasis, due to the discontinuity in the care during the pandemic.

High pyrethroid-resistance intensity in Culex quinquefasciatus (Say) (Diptera: Culicidae) populations from Jigawa, North-West, Nigeria

This study examined pyrethroid resistance intensity and mechanisms in Culex quinquefasciatus (Say) (Diptera: Culicidae) populations from Jigawa, North-West Nigeria. Resistance statuses to permethrin, lambda-cyhalothrin and alphacypermethrin were determined with both WHO and CDC resistance bioassays. Synergist assay was conducted by pre-exposing the populations to Piperonyl butoxide (PBO) using the WHO method. Resistance intensities to 2x, 5x and 10x of diagnostic concentrations were determined with the CDC bottle method. Species analysis and presence of knockdown mutation (Leu-Phe) were done using Polymerase Chain Reaction (PCR). Results showed that Cx. quinquefasciatus was the only Culex spp. present and “Kdr-west” mutation was not detected in all analyzed samples. Using WHO method, Cx. quinquefasciatus resistance to permethrin was detected in Dutse (12.2%) and Kafin-Hausa (77.78%). Lambda-cyhalothrin resistance was recorded only in Kafin-Hausa (83.95%) with resistance suspected in Ringim (90%). Resistance to alphacypermethrin was recorded in all locations. Pre-exposure to PBO led to 100% mortality to alphacypermethrin and lambda-cyhalothrin in Ringim while mortality to permethrin and alphacypermethrin in Dutse increased from 12.2% to 97.5% and 64.37% to 79.52% respectively. Using CDC bottle bioassay, resistance was also recorded in all populations and the result shows a significant positive correlation (R² = 0.728, p = 0.026) with the result from the WHO bioassay. Results of resistance intensity revealed a very high level of resistance in Kafin-Hausa with susceptibility to lambda-cyhalothrin and alphacypermethrin not achieved at 10x of diagnostic doses. Resistance intensity was also high in Dutse with susceptibility to all insecticides not achieved at 5x of diagnostic doses. Widespread and high intensity of resistance in Cx. quinquefasciatus from North-West Nigeria is a major threat to the control of diseases transmitted by Culex and other mosquito species. It is a challenge that needs to be adequately addressed so as to prevent the failure of pyrethroid-based vector control tools.

Development of resistance to insecticide by mosquitoes has been identified to be a major challenge in the prevention and control of diseases transmitted by mosquitoes. This informs this study that investigated the level of resistance of Culex mosquitoes from Jigawa, North-West Nigeria to Pyrethroids. The main type of Culex mosquitoes found in the sampled area was Cx. quinquefasciatus. The Cx. quinquefasciatus populations were found to be resistant to permethrin, lambda-cyhalothrin and alphacypermethrin. Resistance in Cx. quinquefasciatus from the three LGAs is more pronounced to alphacypermethrin. The methods employed by the mosquitoes in developing resistance involve detoxification of the insecticides by metabolic enzymes. Cx. quinquefasciatus from the three LGAs were observed to be highly resistant and can withstand multiple of the recommended doses. This development whereby Cx. quinquefasciatus populations were highly resistant to these recommended insecticides is of serious concern as it can lead to failure of all efforts geared towards prevention and control of diseases transmitted by Culex mosquitoes in North-West Nigeria.

Family-based intervention for prevention and self-management of disabilities due to leprosy, podoconiosis and lymphatic filariasis versus usual care in Ethiopia: study protocol for a cluster-randomised controlled trial

INTRODUCTION

Leprosy, podoconiosis and lymphatic filariasis (LF) are three skin-related neglected tropical diseases. All three conditions can lead to temporary and permanent impairments. These impairments progressively worsen and are major determinants of stigma, discrimination and participation restrictions. Self-care is essential to prevent disabilities and chronic disease complications. Many persons with leprosy-related, LF-related and podoconiosis-related disabilities need to practice self-management routines their entire life. This is difficult without support and encouragement of others. The objective of this study was to assess the effectiveness of a family-based intervention in terms of physical outcomes related to prevention and self-management of disabilities due to leprosy, podoconiosis and LF and family quality of life and well-being compared with usual practice and care.

METHODS AND ANALYSIS

The study will use a cluster-randomised controlled trial design with two study arms. The project will be carried out in endemic districts in East and West Gojjam zones in the Amhara region in Ethiopia. Clusters consist of kebeles (lower administrative structures in the district) that have been merged, based on their geographical proximity and the number of cases in each kebele. A total of 630 participants will be included in the study. The intervention group will consist of 105 persons affected by leprosy, 105 persons affected by LF or podoconiosis, and 210 family members. The control group will consist of 105 persons affected by leprosy and 105 persons affected by LF or podoconiosis. The family-based intervention comprises an essential care package that consists of the following three main components: (1) self-management of disabilities, (2) economic empowerment and (3) psychosocial support. Participants in the control areas will receive usual practice and care. Data analysis includes, but is not limited to, calculating the percentage of change and corresponding 95% CI of physical impairment outcomes in each group, before and after the intervention is implemented, effect sizes, intention to treat and difference in difference analysis.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from the Debre Markos University Health Sciences Institutional Research Ethics Review Committee. Results will be disseminated through peer-reviewed publications, conference presentations and workshops.

TRIAL REGISTRATION NUMBER

PACTR202108907851342.

Safety and efficacy of mass drug administration with a single-dose triple-drug regimen of albendazole + diethylcarbamazine + ivermectin for lymphatic filariasis in Papua New Guinea: An open-label, cluster-randomised trial

Background

Papua New Guinea (PNG) has a high burden of lymphatic filariasis (LF) caused by Wuchereria bancrofti, with an estimated 4.2 million people at risk of infection. A single co-administered dose of ivermectin, diethylcarbamazine and albendazole (IDA) has been shown to have superior efficacy in sustained clearance of microfilariae compared to diethylcarbamazine and albendazole (DA) in small clinical trials. A community-based cluster-randomised trial of DA versus IDA was conducted to compare the safety and efficacy of IDA and DA for LF in a moderately endemic, treatment-naive area in PNG.

Methodology

All consenting, eligible residents of 24 villages in Bogia district, Madang Province, PNG were enrolled, screened for W. bancrofti antigenemia and microfilaria (Mf) and randomised to receive IDA (N = 2382) or DA (N = 2181) according to their village of residence. Adverse events (AE) were assessed by active follow-up for 2 days and passive follow-up for an additional 5 days. Antigen-positive participants were re-tested one year after MDA to assess treatment efficacy.

Principal findings

Of the 4,563 participants enrolled, 96% were assessed for AEs within 2 days after treatment. The overall frequency of AEs were similar after either DA (18%) or IDA (20%) treatment. For those individuals with AEs, 87% were mild (Grade 1), 13% were moderate (Grade 2) and there were no Grade 3, Grade 4, or serious AEs (SAEs). The frequency of AEs was greater in Mf-positive than Mf-negative individuals receiving IDA (39% vs 20% p<0.001) and in Mf-positive participants treated with IDA (39%), compared to those treated with DA (24%, p = 0.023). One year after treatment, 64% (645/1013) of participants who were antigen-positive at baseline were re-screened and 74% of these participants (475/645) remained antigen positive. Clearance of Mf was achieved in 96% (52/54) of infected individuals in the IDA arm versus 84% (56/67) of infected individuals in the DA arm (relative risk (RR) 1.15; 95% CI, 1.02 to 1.30; p = 0.019). Participants receiving DA treatment had a 4-fold higher likelihood of failing to clear Mf (RR 4.67 (95% CI: 1.05 to 20.67; p = 0.043). In the DA arm, a significant predictor of failure to clear was baseline Mf density (RR 1.54; 95% CI, 1.09 to 2.88; p = 0.007).

Conclusion

IDA was well tolerated and more effective than DA for clearing Mf. Widespread use of this regimen could accelerate LF elimination in PNG.

Trial registration

Registration number NCT02899936; https://clinicaltrials.gov/ct2/show/NCT02899936.

Lymphatic filariasis (LF) is a mosquito-transmitted parasitic nematode that can live in human hosts for up to 6–8 years, disrupting the normal functions of the lymphatic system leading to the abnormal enlargement of body parts, causing pain, severe disability, and social stigma. Lymphatic filariasis can be eliminated by stopping the spread of infection through preventive chemotherapy with safe medicine combinations repeated annually. Several small-scale trials demonstrated that a single dose of a triple-drug regimen (ivermectin, diethylcarbamazine, and albendazole or IDA) was more effective at clearing infection than the standard two-drug regimen (diethylcarbamazine and albendazole or DA). This study was conducted to investigate the safety and efficacy of IDA in a large community-randomised trial in a moderate transmission setting. IDA was shown to be as safe as the standard two-drug DA treatment and more effective for clearing microfilariae compared to DA. These results show that IDA is well tolerated in PNG and has the potential to accelerate LF elimination.

Lymphatic filariasis vaccine development: neglected for how long?

INTRODUCTION

Lymphatic filariasis (LF), also known as elephantiasis, has been recognized by the world health organization and the centers for disease control and prevention as one of the neglected tropical diseases. The huge prevalence and risk of manifestation to date reflect the poor management of this disease. The disease poses vast public health and socio-economic burdens and generates a dire need for the development of a prophylactic solution for mass administration.

AREAS COVERED

Vaccination has been a sought-out strategy for dealing with ever-evolving infectious diseases and can be duly tuned to become a cost effective means of disease control and eventual eradication. In this review, we highlight the epidemiology of LF with the current diagnosis and treatment modules. The need for the development of a potential vaccine candidates, and challenges are discussed. The evidence presented in this review aims to enlighten the readers regarding the essential factors governing LF and its management using prophylactic measures.

EXPERT OPINION

The complex nature of filarial parasites is evident from the absence of a single vaccine for LF. The development and selection of an appropriate preclinical model and its translation into clinical practice is deemed to be a major task needing in-depth evaluation to formulate an effective vaccine. Explorations of the existing vaccine platforms would serve to be an apt strategy in this direction.

Assessing factors influencing communities' acceptability of mass drug administration for the elimination of lymphatic filariasis in Guyana

BACKGROUND

Guyana is one of four countries in the Latin American Region where lymphatic filariasis (LF) remains endemic. In preparation for the introduction of a new triple drug therapy regimen (ivermectin, diethylcarbamazine, and albendazole (IDA)) in 2019, an acceptability study was embedded within sentinel site mapping in four regions to assess mass drug administration (MDA) coverage and compliance, acceptability, and perceptions about treatment and disease. The results from this survey would inform the rollout of IDA in Guyana in 2019.

METHODS

Data collection for the study occurred in August 2019, using a validated questionnaire administered by trained enumerators. Across all regions, a total of 1,248 participants were sampled by the Filarial Mapping team. Four-hundred and fifty-one participants aged over 18 years were randomly selected for participation in an expanded acceptability questionnaire. All data were captured in Secure Data Kit (SDK).

RESULTS

Acceptability was measured using a mean acceptability score. Unadjusted mean scores ranged from 24.6 to 29.3, with 22.5 as the threshold of acceptability. Regional variation occurred across many indicators of interest: self-rated understanding about LF, mechanisms of LF transmission, LF drug safety and history of treatment during MDA. Region IV (Georgetown) recorded higher knowledge about LF, but lower compliance and acceptability. Number of pills was not perceived as a concern.

CONCLUSION

Acceptability of MDA was good across all four regions under study. Results from this study set a baseline level for key indicators and acceptability, from which the acceptability of IDA can be measured. Regional variations across indicators suggest that localized approaches should be considered for social mobilization and MDA delivery to capture these contextual differences.

A multicenter, community-based, mixed methods assessment of the acceptability of a triple drug regimen for elimination of lymphatic filariasis

Background

Many countries will not reach elimination targets for lymphatic filariasis in 2020 using the two-drug treatment regimen (diethylcarbamazine citrate [DEC] and albendazole [DA]). A cluster-randomized, community-based safety study performed in Fiji, Haiti, India, Indonesia and Papua New Guinea tested the safety and efficacy of a new regimen of ivermectin, DEC and albendazole (IDA).

Methodology/Principal findings

To assess acceptability of IDA and DA, a mixed methods study was embedded within this community-based safety study. The study objective was to assess the acceptability of IDA versus DA. Community surveys were performed in each country with randomly selected participants (>14 years) from the safety study participant list in both DA and IDA arms. In depth interviews (IDI) and focus group discussions (FGD) assessed acceptability-related themes. In 1919 individuals, distribution of sex, microfilariae (Mf) presence and circulating filarial antigenemia (CFA), adverse events (AE) and age were similar across arms. A composite acceptability score summed the values from nine indicators (range 9–36). The median (22.5) score indicated threshold of acceptability. There was no difference in scores for IDA and DA regimens. Mean acceptability scores across both treatment arms were: Fiji 33.7 (95% CI: 33.1–34.3); Papua New Guinea 32.9 (95% CI: 31.9–33.8); Indonesia 30.6 (95% CI: 29.8–31.3); Haiti 28.6 (95% CI: 27.8–29.4); India 26.8 (95% CI: 25.6–28) (P<0.001). AE, Mf or CFA were not associated with acceptability. Qualitative research (27 FGD; 42 IDI) highlighted professionalism and appreciation for AE support. No major concerns were detected about number of tablets. Increased uptake of LF treatment by individuals who had never complied with MDA was observed.

Conclusions/Significance

IDA and DA regimens for LF elimination were highly and equally acceptable in individuals participating in the community-based safety study in Fiji, Haiti, India, Indonesia, and Papua New Guinea. Country variation in acceptability was significant. Acceptability of the professionalism of the treatment delivery was highlighted.

The acceptability of a new combination treatment regimen for lymphatic filariasis (ivermectin, plus DEC and albendazole, or IDA) was assessed as part of a larger community-based safety study in Fiji, Haiti, India, Indonesia and Papua New Guinea. To understand how trial participants and communities felt about the new treatment, a survey was carried out with people who had participated in the safety study receiving either the standard treatment [DEC plus albendazole (DA)] or the new treatment regimen (IDA). Focus group discussions and in-depth interviews were performed in the same communities. Results showed that there was no difference in acceptability between the DA and IDA. Adverse events and presence of filarial infection did not affect acceptability. The most important indicator associated with acceptability was country. All countries accepted the treatment regimens. Fiji had the highest acceptability scores, followed by Papua New Guinea, Indonesia, Haiti and India. Results from the qualitative research showed that study participants appreciated the professionalism of the drug delivery team and the support offered for the management of any adverse events.

Lymphatic filariasis, infection status in Culex quinquefasciatus and Anopheles species after six rounds of mass drug administration in Masasi District, Tanzania

Background

Lymphatic filariasis (LF) elimination program in Tanzania started in 2000 in response to the Global program for the elimination of LF by 2020. Evidence shows a persistent LF transmission despite more than a decade of mass drug administration (MDA). It is advocated that, regular monitoring should be conducted in endemic areas to evaluate the progress towards elimination and detect resurgence of the disease timely. This study was therefore designed to assess the status of Wuchereria bancrofti infection in Culex quinqefasciatus and Anopheles species after six rounds of MDA in Masasi District, South Eastern Tanzania.

Methods

Mosquitoes were collected between June and July 2019 using Center for Diseases Control (CDC) light traps and gravid traps for indoor and outdoor respectively. The collected mosquitoes were morphologically identified into respective species. Dissections and PCR were carried out to detect W. bancrofti infection. Questionnaire survey and checklist were used to assess vector control interventions and household environment respectively. A Poisson regression model was run to determine the effects of household environment on filarial vector density.

Results

Overall, 12 452 mosquitoes were collected of which 10 545 (84.7%) were filarial vectors. Of these, Anopheles gambiae complex, An. funestus group and Cx. quinquefasciatus accounted for 0.1%, 0.7% and 99.2% respectively. A total of 365 pools of Cx. quinquefasciatus (each with 20 mosquitoes) and 46 individual samples of Anopheles species were analyzed by PCR. For Cx. quinquefasciatus pools, 33 were positive for W. bancrofti, giving an infection rate of 0.5%, while the 46 samples of Anopheles species were all negative. All 1859 dissected mosquitoes analyzed by microscopy were also negative. Households with modern latrines had less mosquitoes than those with pit latrines [odds ratio (OR) = 0.407, P < 0.05]. Houses with unscreened windows had more mosquitoes as compared to those with screened windows (OR = 2.125, P < 0.05). More than 80% of the participants own bednets while 16.5% had no protection.

Conclusions

LF low transmission is still ongoing in Masasi District after six rounds of MDA and vector control interventions. The findings also suggest that molecular tools may be essential for xenomonitoring LF transmission during elimination phase.

Exploring determinants of hydrocele surgery coverage related to Lymphatic Filariasis in Nepal: An implementation research study

Background

Hydrocele is a chronic condition in males in which there is an excessive collection of straw-colored fluid, which leads to enlargement of the scrotum. It is a common manifestation of lymphatic filariasis (LF) affecting nearly 25 million men worldwide. Surgery is the recommended treatment for hydrocele and is available free of cost in all government hospitals in Nepal. This research explored patient, provider, and community factors related to accessing hydrocele surgery services by the patients.

Methods

This study employed a qualitative method. The research was conducted in two LF endemic districts, namely Kanchanpur and Dhading, which are reported to have the highest number of hydrocele cases during morbidity mapping conducted in 2016. In addition to five key informant interviews with the LF focal persons (one national and 4 district-level), nine in-depth interviews were conducted with hydrocele patients (5 of whom had undergone surgery and 4 who had not undergone surgery) and with 3 family members, and two focus group discussions with the female community health volunteers.

Results

Most of the respondents did not have knowledge of hydrocele as one of the clinical manifestations of LF nor that it is transmitted through a mosquito bite. Although perceived as treatable with surgery, most of the patients interviewed believed in as well as practiced home remedies. Meanwhile, fear of surgery, embarrassment, lack of money, along with no knowledge of the free hydrocele surgery acted as barriers for accessing the surgery. On the other hand, financial support, flexible guidelines enabling the hospital to conduct surgery, decentralization and scaling up of morbidity mapping along with free hydrocele surgery camps in any remaining endemic districts were identified as enablers for accessing surgery.

Conclusion

Hydrocele surgery coverage could be improved if the program further addresses community awareness. There is a need for more focus on information dissemination about hydrocele and hydrocele surgery.

Evaluating context-specific evidence-based quality improvement intervention on lymphatic filariasis mass drug administration in Northern Ghana using the RE-AIM framework

Background

Over a decade of implementing a global strategy to eliminate lymphatic filariasis in Ghana through mass drug administration, the disease is still being transmitted in 11 districts out of an initial 98 endemic districts identified in 2000. A context-specific evidence-based quality improvement intervention was implemented in the Bole District of Northern Ghana after an initial needs assessment to improve the lymphatic filariasis mass drug administration towards eliminating the disease. Therefore, this study aimed to evaluate the process and impact of the lymphatic filariasis context-specific evidence-based quality improvement intervention in the Bole District of Northern Ghana.

Method

A cross-sectional mixed methods study using the RE-AIM (Reach, Effectiveness, Adoption, Implementation, and Maintenance) framework to evaluate the context-specific evidence-based quality improvement intervention was employed. Quantitative secondary data was extracted from the neglected tropical diseases database. A community survey was conducted with 446 randomly selected participants. Qualitative data were collected from 42 purposively selected health workers, chiefs/opinion leaders and community drug distributors in the study area.

Results

The evaluation findings showed an improvement in social mobilisation and sensitisation, knowledge about lymphatic filariasis and mass drug administration process, willingness to ingest the medication and adherence to the direct observation treatment strategy. We observed an increase in coverage ranging from 0.1 to 12.3% after implementing the intervention at the sub-district level and reducing self-reported adverse drug reaction. The level of reach, effectiveness and adoption at the district, sub-district and individual participants’ level suggest that the context-specific evidence-based quality improvement intervention is feasible to implement in lymphatic filariasis hotspot districts based on initial context-specific needs assessment.

Conclusion

The study provided the groundwork for future application of the RE-AIM framework to evaluate the implementation of context-specific evidence-based quality improvement intervention to improve lymphatic filariasis mass drug administration towards eliminating the disease as a public health problem.

A family-based intervention for prevention and self-management of disabilities due to leprosy, podoconiosis and lymphatic filariasis in Ethiopia: A proof of concept study

A key issue for persons with leprosy-, lymphatic filariasis- and podoconiosis-related disabilities is the life-long need to practice self-management routines. This is difficult to sustain without regular encouragement and support of others. Family-based support may be a sustainable and feasible strategy to practice self-management routines. This proof of concept study aimed to develop and pilot a family-based intervention to support prevention and self-management of leprosy, lymphatic filariasis and podoconiosis-related disabilities in Ethiopia.

We used a quasi-experimental pre/post intervention study design with a mixed methods approach. The study population included persons affected by leprosy, lymphatic filariasis and podoconiosis and their family members. All persons affected had visible impairments due to their condition. We collected physical impairment outcomes, data on activity limitations, stigma and family quality of life using the SALSA scale (range 0–80), the SARI stigma scale (range 0–63) and the Beach Centre Family Quality of Life scale (range 0–125) and conducted in-depth interviews and focus group discussions. Quantitative data were analysed using paired t-tests, unequal variances t-tests, linear regression and binary logistic regression. Qualitative data were coded using open, inductive coding and content analysis.

The family-based intervention consisted of self-management of disabilities, awareness raising and socio-economic empowerment. The intervention was delivered over several monthly group meetings over the course of several months. A total of 275 (100%) persons affected attended at least one session with a family member, and 215 (78%) attended at least three sessions. There was no significant improvement in eye and hand problems after the intervention. However, foot and leg impairments, number of acute attacks, lymphedema and shoe wearing all significantly improved at follow-up. In addition, family quality of life significantly improved from 67.4 at baseline to 89.9 at follow-up for family members and from 76.9 to 84.1 for persons affected (p<0.001). Stigma levels significantly decreased from 24.0 at baseline to 16.7 at follow-up (p<0.001). Activity levels improved, but not significantly.

This proof of concept study showed that the family-based intervention had a positive effect on impairments and self-management of disabilities, family quality of life and stigma. We recommend a large-scale efficacy trial, using a randomised controlled trial and validated measurement tools, to determine its effectiveness and long-term sustainability.

A key issue for persons with leprosy-, lymphatic filariasis- and podoconiosis-related disabilities is the life-long need to practice self-management routines. Family-based support may be a sustainable and feasible strategy to practice self-management. This proof of concept study aimed to develop and pilot a family-based intervention to support prevention and self-management of leprosy, lymphatic filariasis and podoconiosis-related disabilities in Ethiopia. We collected data on physical impairments, activity limitations, stigma and family quality of life, and conducted in-depth interviews and focus group discussions. The family-based intervention consisted of self-management of disabilities, awareness raising and socio-economic empowerment. The intervention was delivered over several monthly group meetings. A total of 275 persons affected attended at least one session with a family member. There was no significant improvement in eye and hand problems after the intervention. However, foot and leg impairments, number of acute attacks, lymphedema and shoe wearing all significantly improved. In addition, family quality of life significantly improved, and stigma levels significantly decreased after the intervention. Activity levels improved, but not significantly. This proof of concept study showed that the family-based intervention had a positive effect on impairments and self-management of disabilities, family quality of life and stigma.

The use of molecular xenomonitoring for surveillance of mosquito-borne diseases

The scientific community recognizes that molecular xenomonitoring (MX) can allow infected mosquitoes to serve as a proxy for human infection in vector-borne disease surveillance, but developing reliable MX systems for programmatic use has been challenging. The primary aim of this article is to examine the available evidence to recommend how MX can best be used for various purposes. Although much of the literature published within the last 20 years focuses on using MX for lymphatic filariasis elimination, a growing body of evidence supports its use in early warning systems for emerging infectious diseases (EIDs). An MX system design must consider the goal and target (e.g. diseases targeted for elimination versus EIDs), mosquito and pathogen characteristics, and context (e.g. setting and health system). MX is currently used as a 'supplement' to human surveillance and will not be considered as a 'replacement' until the correlation between pathogen-infection rates in human and mosquito populations is better understood. Establishing such relationships may not be feasible in elimination scenarios, due to increasingly dwindling human infection prevalence after successful control, but may still be possible for EIDs and in integrated disease surveillance systems. This article is part of the theme issue 'Novel control strategies for mosquito-borne diseases'.

Genome engineering in insects for the control of vector borne diseases

Insects cause many vector-borne infectious diseases and have become a major threat to human health. Although many control measures are undertaken, some insects are resistant to it, exacerbated by environmental changes which is a major challenge for control measures. Genetic studies by targeting the genomes of insects may offer an alternative strategy. Developments with novel genome engineering technologies have stretched our ability to target and modify any genomic sequence in Eukaryotes including insects. Genome engineering tools such as zinc-finger nucleases (ZFNs), transcription activator-like effector nucleases (TALENs), and most recently discovered, clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated protein 9 (Cas9) systems hold the potential to control the vector-borne diseases. In this chapter, we review the vector control strategy undertaken by employing three major genome engineering tools (ZFNs, TALENs, and CRISPR/Cas9) and discuss the future prospects of this system to control insect vectors. Finally, we also discuss the CRISPR-based gene drive system and its concerns due to ecological impacts.

A review on the interactions between dendritic cells, filarial parasite and parasite-derived molecules in regulating the host immune responses

Lymphatic filariasis (LF) is the second leading cause of parasitic disabilities that affects millions of people in India and several other tropical countries. The complexity of this disease is endorsed by various immunopathological consequences such as lymphangitis, lymphadenitis and elephantiasis. The immune evasion strategies that a filarial parasite usually follows are chiefly initiated with the communication between the invaded parasites and parasite-derived molecules, with the Toll-like receptors (TLRs) present on the surface of the antigen-presenting cells (APCs). Classically, the filarial parasites interact with the DCs resulting in lowering of CD4⁺ T-cell responses. These CD4⁺ T-cell responses are the key players behind the immune-mediated pathologies associated with LF. In chronic stage, the canonical pro-inflammatory immune responses are shifted towards an anti-inflammatory subtype, which is favouring the parasite survivability within the host. The central theme of this review article is to present the overall immune response elicited when an APC, particularly a DC, encounters a filarial parasite.

Lymphatic filariasis in Fiji: progress towards elimination, 1997-2007

Background

Lymphatic filariasis (LF) is a major public health problem in the Pacific Region, including in Fiji. Through transmission by the mosquito vector Aedes, Fiji has suffered the burden of remaining endemic with LF despite efforts at elimination prior to 1999. In the year 1999, Fiji agreed to take part in the Pacific Programme for Elimination of LF (PacELF) and the Global Programme to Eliminate LF.

Methods

This study reviewed and collated past data on LF in Fiji between 1997 and 2007. Sources included published papers as well as unpublished PacELF and WHO program meeting and survey reports. Records were held at Fiji’s Department of Health and Medical Services, James Cook University and the WHO office in Suva, Fiji.

Results

Baseline surveys between 1997 and 2002 showed that Fiji was highly endemic for LF with an estimated 16.6% of the population antigen positive and 6.3% microfilaria positive at that time. Five rounds of annual mass drug administration (MDA) using albendazole and diethylcarbamazine commenced in 2002. Programmatic coverage reported was 58–70% per year, but an independent coverage survey in 2006 in Northern Division after the fifth MDA suggested that actual coverage may have been higher. Monitoring of the program consisted of antigen prevalence surveys in all ages with sentinel and spot check surveys carried out in 2002 (pre MDA), 2004, and 2005, together with knowledge, attitude, and practice surveys. The stop-MDA survey (C survey) in 2007 was a nationwide stratified cluster survey of all ages according to PacELF guidelines, designed to sample by administrative division to identify areas still needing MDA. The national antigen prevalence in 2007 was reduced by more than a third to 9.5%, ranging from 0.9% in Western Division to 15.4% in Eastern Division, while microfilaria prevalence was reduced by almost four-fifths to 1.4%. Having not reached the target threshold of 1% prevalence in all ages, Fiji wisely decided to continue MDA after 2007 but to move from nationwide implementation to four (later five) separate evaluation units with independent timelines using global guidelines, building on program experience to put more emphasis on increasing coverage through prioritized communication strategies, community participation, and morbidity alleviation.

Conclusion

Fiji conducted nationwide MDA for LF annually between 2002 and 2006, monitored by extensive surveys of prevalence, knowledge, and coverage. From a high baseline prevalence in all divisions, large reductions in overall and age-specific prevalence were achieved, especially in the prevalence of microfilariae, but the threshold for stopping MDA was not reached. Fiji has a large rural and geographically widespread population, program management was not consistent over this period, and coverage achieved was likely not optimal in all areas. After learning from these many challenges and activities, Fiji was able to build on the progress achieved and the heterogeneity observed in prevalence to realign towards a more stratified and improved program after 2007. The information presented here will assist the country to progress towards validating elimination in subsequent years.

COVID-19 in LMICs: The Need to Place Stigma Front and Centre to Its Response

COVID-19 has caused unprecedented health, economic and societal impacts across the world, including many low- and middle-income countries (LMICs). The pandemic and its fallout have laid bare deep-seated social and economic inequalities with marginalised groups being at greater risk of infection and being disproportionately affected by containment measures and their socioeconomic consequences. Stigma is a central element to such inequalities but remains largely overlooked in the debate on the response to COVID-19, including in LMICs. Yet we know from experiences with other infectious diseases such as HIV/AIDS and Ebola that disease-related stigma is detrimental to halting and controlling pandemics and achieving equitable development. Emerging evidence suggests that stigma associated with COVID-19 is already taking hold. This paper assesses potential driving factors of COVID-19-related stigma, and how this intersects with existing stigma fault lines and explores mechanisms through which COVID-19-related stigma may be counteracted, with a focus on LMICs.

Significant improvement in quality of life following surgery for hydrocoele caused by lymphatic filariasis in Malawi: A prospective cohort study

Background

Lymphatic filariasis (LF) is a mosquito-borne parasitic infection that causes significant disabling and disfiguring clinical manifestations. Hydrocoele (scrotal swelling) is the most common clinical condition, which affects an estimated 25 million men globally. The recommended strategy is surgical intervention, yet little is known about the impact of hydrocoele on men’s lives, and how it may change if they have access to surgery.

Methodology/Principal findings

We prospectively recruited and followed-up men who underwent surgery for hydrocoele at six hospitals in an LF endemic area of Malawi in December 2015. Men were interviewed at hospitals pre-surgery and followed-up at 3-months and 6-months post-surgery. Data on demographic characteristics, clinical condition, barriers to surgery, post-surgery symptoms/complications and quality of life indicators were collected and analysed pre- and post-surgery, by age group and stage of disease (mild/moderate vs. severe), using chi-square tests and student’s t test (paired).

201 men were interviewed pre-surgery, 152 at 3-months and 137 at 6-months post-surgery. Most men had unilateral hydrocoeles (65.2%), mild/moderate stages (57.7%) with an average duration of 11.4 years. The most reported cause of hydrocoele was it being sexually transmitted (22.4%), and the main barrier to surgery was the cost (36.3%). Pre-surgery, a significant difference in the scrotum side affected was found by age group (X² = 5.978, p = 0.05), and men with severe stage hydrocoele reported more problems with their quality of life than those with mild/moderate stage (t = 2.793; p = 0.0006). Post-surgery, around half of the men reported some pain/discomfort (55.9%), swelling (8.6%), bleeding (3.3%) and infection (5.9%), most of which had resolved at 3-months when the most significant improvements in their quality of life were found (t = 21.3902; p = 0.000). Post-surgery at 6 months all men reported no physical, social, psychological problems and took no time off work.

Conclusion/Significance

Surgery had a significant positive impact on many aspects of a patient’s life, and the expansion of this treatment to all those affected in LF endemic areas would greatly improve the quality of men’s and their families’ lives, and greatly contribute to the global goal of providing universal health care.

Lymphatic filariasis is a mosquito-borne infection that causes significant disabling and disfiguring clinical conditions. Hydrocoele (scrotal swelling) is the most common condition affecting an estimated 25 million men worldwide. Surgery is the main intervention, however, there is limited information on its impact. This study assessed men before and after surgery in an endemic region of Malawi, to identify potential barriers and determine how surgery may change the quality of their life. Before surgery, 201 men reported to have moderate to severe problems with many aspects of their life including pain, mobility, usual activities, self-care, social issues, psychological health and ability to work. The main barrier to hydrocoele surgery was the cost, including associated transport and accommodation costs. After surgery, follow-up surveys at 3-months and 6- months found that men reported minimal or no physical, social, psychological problems and took no time off work. Surgery had a significant positive and lasting impact on men’s lives. National programmes need to advocate for resources to increase funding to support men and the uptake and demand for quality surgical services.

Quantifying the socio-economic impact of leg lymphoedema on patient caregivers in a lymphatic filariasis and podoconiosis co-endemic district of Ethiopia

Background

Lymphoedema caused by lymphatic filariasis (LF) or podoconiosis can result in physical disability and social exclusion, which is exacerbated by painful acute dermatolymphangioadenitis (ADLA) episodes. These conditions have a significant impact on patients, however, little is known about the indirect effects on their caregivers. This study, therefore, aimed to determine the impact on caregivers for patients with leg lymphoedema in a co-endemic district of Ethiopia.

Methodology/Principal findings

A cross-sectional survey of lymphoedema patients and their caregivers was conducted using semi-structured questionnaires in the Southern Nation Nationalities Peoples Region (SNNPR) of Ethiopia. Lymphoedema patient information on clinical severity (mild, moderate, severe), frequency of ADLAs, their socio-demographic characteristics and the identity of main caregiver(s) was collected. Caregiver information on socio-demographic characteristics, types of care provided, their quality of life (QoL) measured across nine domains, and productivity was collected, with key indicators compared in the presence and absence of patients’ ADLAs.

A total of 73 patients and 76 caregivers were included. Patients were grouped by mild/moderate (n = 42, 57.5%) or severe (n = 31, 42.5%) lymphoedema, and reported an average of 6.1 (CI± 2.18) and 9.8 (CI± 3.17) ADLAs respectively in the last six months. A total of 48 (65.8%) female and 25 (34.2%) male patients were interviewed. Caregivers were predominately male (n = 45, 59.2%), and spouses formed the largest caregiving group for both female and male patients.

In the absence of an ADLA, most caregivers (n = 42, 55.2%) did not provide care, but only one caregiver did not provide care during an ADLA. In the absence of an ADLA, the average time (hour:minute) spent by mild/moderate (00:17, CI: ± 00:08) and severe (00:10, CI: ± 00:07) patient caregiver per task was minimal. The time mild/moderate (00:47, CI: ± 00:11) and severe (00:51, CI: ± 00:16) patient caregivers spent per task significantly increased in the presence of an ADLA. In addition, caregivers’ QoL was negatively impacted when patients experienced an ALDA, and they had to forfeit an average of 6 to 7 work/school days per month.

Conclusion/Significance

Lymphoedema and ADLAs impact negatively on patients’ and their caregivers’ lives. This emphasises the importance of increasing access to effective morbidity management and disability prevention services to reduce the burden and help to address the Sustainable Development Goal (SDG) 5, target 5.4, which seeks to recognise and value unpaid care and domestic work.

Lymphatic filariasis and podoconiosis can result in chronic severe lymphoedema of the limbs, which is aggravated by frequent painful episodes of acute bacterial infection known as ‘acute attacks’. The debilitating impact of these conditions on patients are well documented, however, the extent to which the hardship extends to their caregivers is unknown. To address this knowledge gap, a survey of 73 lymphoedema patients and their caregivers was conducted in an endemic region of Ethiopia. Patients were found to be predominately female and caregivers predominately male, mostly spouses. Caregivers provided a wide range of care, and the type, frequency and time spent on tasks significantly increased when patients experienced an acute attack. Caregivers reported a negative impact on their quality of life and provided care for an average of 15 days and forfeited an average of 7 days of work or school per month. This study has revealed a previously hidden burden of lymphoedema that not only affects patients, but their caregivers who are mostly family members. This emphasises the importance of increasing access to effective morbidity management and disability prevention programmes to reduce the burden and help to address the Sustainable Development Goal (SDG) 5, target 5.4, which seeks to recognise and value unpaid and domestic work.

Economic benefits and costs of surgery for filarial hydrocele in Malawi

BACKGROUND

Lymphatic filariasis (LF) is endemic in 72 countries of Africa, Asia, Oceania, and the Americas. An estimated 25 million men live with the disabling effects of filarial hydrocele. Hydrocele can be corrected with surgery with few complications. For most men, hydrocelectomy reduces or corrects filarial hydrocele and permits them to resume regular activities of daily living and gainful employment.

METHODOLOGY AND PRINCIPAL FINDINGS

This study measures the economic loss due to filarial hydrocele and the benefits of hydrocelectomy and is based on pre- and post-operative surveys of patients in southern Malawi. We find the average number of days of work lost due to filarial hydrocele and daily earnings for men in rural Malawi. We calculate average annual lost earnings and find the present discounted value for all years from the time of surgery to the end of working life. We estimate the total costs of surgery. We compare the benefit of the work capacity restored to the costs of surgery to determine the benefit-cost ratio. For men younger than 65 years old, the average annual earnings loss attributed to hydrocele is US$126. The average discounted present value of lifetime earnings loss for those men is US$1684. The average budgetary cost of the hydrocelectomy is US$68. The ratio of the benefit of surgery to its costs is US$1684/US$68 or 24.8. Sensitivity analysis demonstrates that the results are robust to variations in cost of surgery and length of working life.

CONCLUSION

The lifetime benefits of hydrocelectomy-to the man, his family, and his community-far exceed the costs of repairing the hydrocele. Scaling up subsidies to hydrocelectomy campaigns should be a priority for governments and international aid organizations to prevent and alleviate disability and lost earnings that aggravate poverty among the many millions of men with filarial hydrocele.

A Study on Serological Reactivity Profile of Different Antigen Preparations with Bancroftian filariasis Human Infection Sera

BACKGROUND

Lymphatic Filariasis (LF) is one of the incapacitating and mosquito-borne sicknesses that on progression may prompt a few recognizable types of clutters like extreme lymphedema, hydrocele, and elephantiasis.

METHODS

Antigenic preparations of B. malayi adult (BmA), S. cervi adult parasites and microfilariae (mf) total parasite extract were used to analyze the serological reactivity profile with human infectious sera collected from endemic areas of Bancroftian filariasis by performing Western blot and ELISA analysis. Sera from healthy human subjects were also included in the study to determine the variation incurred in the reactivity due to the filariasis infection. Gelelectrophoresis analysis of the crude-extract of BmA revealed seven protein bands while more than ten bands were recognized in S. cervi.

RESULTS

our results represent a clear variation in protein patterns among the crude-antigens. ELISA results showed highest prevalence of IgG, IgM and IgG4 antibodies against all antigen preparations when recorded among microfilaraemic chronic infected patients. In both the antigenic preparations, the positive reactions were in the order of microfilaraemic>endemic normal>chronic>acute>nonendemic normal subjects. All sera of Mf+ patients were uniformly positive, while sera of both chronic and endemic normal subjects showed less reactivity.

CONCLUSION

In the present study, we endeavoured to establish the extent of cross-reactivity of antigens derived from animal filarial parasites such as B. malayi and S. cervi with W. bancrofti filariasis sera of human patients. Besides, we further analyzed antibody-isotype profile of IgG, IgG4 and IgM in various human infection sera of bancroftian filarial subjects reactive to heterologous parasite antigens derived from adult worms of S. cervi from bovine and B. malayi from bovine and jirds.

Are Alternative Strategies Required to Accelerate the Global Elimination of Lymphatic Filariasis? Insights From Mathematical Models

Background

With the 2020 target year for elimination of lymphatic filariasis (LF) approaching, there is an urgent need to assess how long mass drug administration (MDA) programs with annual ivermectin + albendazole (IA) or diethylcarbamazine + albendazole (DA) would still have to be continued, and how elimination can be accelerated. We addressed this using mathematical modeling.

Methods

We used 3 structurally different mathematical models for LF transmission (EPIFIL, LYMFASIM, TRANSFIL) to simulate trends in microfilariae (mf) prevalence for a range of endemic settings, both for the current annual MDA strategy and alternative strategies, assessing the required duration to bring mf prevalence below the critical threshold of 1%.

Results

Three annual MDA rounds with IA or DA and good coverage (≥65%) are sufficient to reach the threshold in settings that are currently at mf prevalence <4%, but the required duration increases with increasing mf prevalence. Switching to biannual MDA or employing triple-drug therapy (ivermectin, diethylcarbamazine, and albendazole [IDA]) could reduce program duration by about one-third. Optimization of coverage reduces the time to elimination and is particularly important for settings with a history of poorly implemented MDA (low coverage, high systematic noncompliance).

Conclusions

Modeling suggests that, in several settings, current annual MDA strategies will be insufficient to achieve the 2020 LF elimination targets, and programs could consider policy adjustment to accelerate, guided by recent monitoring and evaluation data. Biannual treatment and IDA hold promise in reducing program duration, provided that coverage is good, but their efficacy remains to be confirmed by more extensive field studies.

Lessons from lymphatic filariasis elimination and the challenges of post-elimination surveillance in China

Background

The Global Programme to Eliminate Lymphatic Filariasis (GPELF) was launched in response to the call proposed at the 50th World Health Assembly. The goal of the GPELF is to ensure that all the countries where the disease is endemic would have been transmission-free or would have entered post-intervention mass drug administration (MDA) surveillance by 2020. However, several countries are still not on track to discontinue MDA as planned. Thus, issues remain regarding the achievement of stated goals and how to effectively monitor the disease in the post-control and post-elimination phases.

Main text

China was once a lymphatic filariasis (LF) endemic country with heavy disease burden. There were three milestones in the LF control phase of China, including: the proposal that the major focus of the control strategy should be on infectious sources; the three regimens of diethylcarbamazine (DEC) administration according to LF endemic extent; and the establishment of the threshold for LF transmission interruption. It has been ten years since China entered the post-elimination stage (declaration of LF elimination in China was in 2007). Two schemes and a diagnostic criterion were issued to guide all levels of disease control and prevention workers that conduct LF surveillance, as well as those caring for chronic filariasis patients. Regular training courses are held to maintain LF control skills in grass-root institutions. The Notifiable Diseases Reporting System, which included LF in 2004, plays an important role in LF post-elimination surveillance. Until now, no resurgence of LF cases has been detected, except for LF residue foci being found in Fuchuan County of the Guangxi Zhuang Autonomous Region. To confirm that transmission is no longer achievable after a decade since the declaration of LF elimination in China, it is expected within the next two years a transmission assessment survey, conducted in previous LF-endemic areas.

Conclusions

DEC-fortified salt can help accelerate the progress of GPELF before the sprite phase. Sophisticated diagnostic criteria, systematic surveillance regimes, the Direct Network Report system, and regular trainings can effectively prevent the recrudescence of LF during surveillance phases.

Electronic supplementary material

The online version of this article (10.1186/s40249-019-0578-9) contains supplementary material, which is available to authorized users.

Lymphatic Filariasis

Lymphatic filariasis (LF) is a parasitic infection that is spread by mosquitos infected with worm larvae. Several factors will affect the global prevalence of LF in the future. A growing body of evidence suggests that climate change will influence the spread of parasitic diseases and their vectors. Lymphatic filariasis is the leading cause of permanent disfigurement and the second most common cause of long-term disability in the world.

Perceived threat and benefit toward community compliance of filariasis' mass drug administration in Pekalongan district, Indonesia

PURPOSE

Lymphatic filariasis (LF) is a chronic infection of Brugia malayi, Brugia timori, and Wuchereria bancrofti and is a mosquito-transmitted disease. Mass drug administration (MDA) needs to be done annually to control LF and requires adherence of endemic populations to take medication properly. Maintaining high coverage of MDA is a challenge because the activity needs to be done in several years. This study would like to know the compliance of the community in taking medication during MDA periods in Pekalongan district using the health belief model (HBM) approach.

PATIENTS AND METHODS

Study population was people living in endemic areas in Pekalongan district, Central Java Province. This was a cross-sectional study. HBM approach was used to analyze community perceived in regard to MDA. There were six of the 19 subdistrict selected as study location, and 100 subjects were selected from each sub-district. Therefore, a total of 600 subjects participated in this study. Data were collected using the structured questionnaire. Data were analyzed quantitatively using the Chi-squared test. Multivariate analysis was used for logistic regression.

RESULTS

Results of this study showed that the mean age of subjects was 38.6 years and had been staying in their villages for more than 30 years. Gender, marital status, history of LF, history of LF in the family, and external cues to action did not relate to MDA compliance. Perceived susceptibility, perceived severity, perceived benefits, and perceived barriers were factors related to the compliance of MDA. After multivariate analysis, the perceived susceptibility did not have relationship with compliance.

CONCLUSION

This study showed HBM variables, ie, perceived susceptibility, perceived severity, perceived benefit, and perceived barrier associated with the medication adherence of LF. The role of elimination officers was important to increase community knowledge about MDA program and the benefit to control LF disease.

Development of an urban molecular xenomonitoring system for lymphatic filariasis in the Recife Metropolitan Region, Brazil

Introduction

Molecular xenomonitoring (MX)—pathogen detection in the mosquito rather than human—is a promising tool for lymphatic filariasis (LF) surveillance. In the Recife Metropolitan Region (RMR), the last LF focus in Brazil, Culex quinquefasciatus mosquitoes have been implicated in transmitting Wuchereria bancrofti parasites. This paper presents findings on the ideal mosquito collection method, mosquito dispersion, W. bancrofti infection in mosquitoes and W. bancrofti antigen in humans to aid MX development.

Methods

Experiments occurred within two densely populated urban areas of Olinda, RMR, in July and August 2015. U.S. Centers for Disease Control and Prevention (CDC) light traps were compared to battery-powered aspirators as collection methods, and mosquito dispersion was measured by mosquito mark release recapture (MMRR). Female Cx. quinquefasciatus were tested by PCR for W. bancrofti infection, and study area residents were screened by rapid tests for W. bancrofti antigen.

Results

Aspirators caught 2.6 times more total Cx. quinquefasciatus, including 38 times more blood-fed and 5 times more gravid stages, than CDC light traps. They also collected 123 times more Aedes aegypti. Of the 9,644 marked mosquitoes released, only ten (0.01%) were recaptured, nine of which were < 50m (34.8m median, 85.4m maximum) from the release point. Of 9,169 unmarked mosquitoes captured in the MMR, 38.3% were unfed, 48.8% blood-fed, 5.5% semi-gravid, and 7.3% gravid. PCR on 182 pools (1,556 mosquitoes) found no evidence of W. bancrofti infection in Cx. quinquefasciatus. Rapid tests on 110 of 111 eligible residents were all negative for W. bancrofti antigen.

Conclusions

Aspirators were more effective than CDC light traps at capturing Ae. aegypti and all but unfed stages of Cx. quinquefasciatus. Female Cx. quinquefasciatus traveled short (< 86m) distances in this urban area. Lack of evidence for W. bancrofti infection in mosquitoes and antigen in humans in these fine-scale studies does not indicate that LF transmission has ceased in the RMR. A MX surveillance system should consider vector-specific collection methods, mosquito dispersion, and spatial scale but also local context, environmental factors such as sanitation, and host factors such as infection prevalence and treatment history.

Lymphatic filariasis (LF) is a parasitic disease transmitted by mosquitoes, and can cause elephantiasis. It is the world’s leading cause of disability due to infectious diseases, affects over 120 million people globally, and is scheduled for global elimination via mass drug administration (MDA) and mosquito control. Molecular xenomonitoring (MX) is a process of screening mosquitoes—not humans—for parasites to estimate whether they are circulating in human populations. MX is especially useful during and following MDA, when new case detection becomes difficult, but is challenging to design and conduct in cities. Using two study sites in the Recife Metropolitan Region, Brazil, we investigated two crucial questions for urban MX development—“What is the best operationally feasible tool to catch adult mosquitoes?” and “How far do mosquitoes disperse in cities?”—in order to determine placement of future surveillance sites. We also screened a proportion of mosquitoes and all eligible residents from the study sites for LF infection. We determined that handheld battery powered aspirators were the best mosquito collection tool; that mosquitoes flew no more than about 85m; and—in this small sample of mosquitoes and very small sample of humans—there was no evidence of LF infection in mosquitoes or study area residents.

The Prevalence of Lymphatic Filariasis in Elementary School Children Living in Endemic Areas: A Baseline Survey Prior to Mass Drug Administration in Pekalongan District-Indonesia

BACKGROUND

WHO initiated lymphatic filariasis (LF) elimination globally. Pekalongan District, as LF endemic area, started a program of mass drug administration (MDA) to combat LF in 2015. This study aimed to determine prevalence of Wuchereria bancrofti infection prior to the MDA.

METHODS

LF infection was detected by the existence of circulating filarial antigen (CFA) W. bancrofti using immunochromatographic card test (ICT). The study population consisted of 1404 elementary school (ES) students living in Pekalongan District. Overall, 1033 were selected as study subjects. Prevalence survey was also conducted on 436 general population in areas where infected students were found.

RESULTS

The subjects ranged from 7-17 yr old (mean 9.85±1.296) and equally distributed between both sexes. Prevalence of W. bancrofti infection was 1.98% in children. Infection was mostly found in older students (12 yr old), male, in 6th grade, but did not differ significantly (P=0.129, 0.376, and 0.212 respectively). On the other hand, distribution of infection was significantly different by school (P=0.009) and sub-district (P=0000). Most of children with LF infection were found in Tirto Sub District. In general population, the prevalence of W. bancrofti infection in Tirto was 4.4%. Proportion of infection in males (12.2%) was greater than females (3.8%), with 78.9% of positive cases were in adult over 20 yr old.

CONCLUSION

Cases of W. bancrofti infection exist in Pekalongan District, both in children and adults. Implementation of MDA must be carefully monitored in order to achieve elimination target.

Vector biology meets disease control: using basic research to fight vector-borne diseases

Human pathogens that are transmitted by insects are a global problem, particularly those vectored by mosquitoes; for example, malaria parasites transmitted by Anopheles species, and viruses such as dengue, Zika and chikungunya that are carried by Aedes mosquitoes. Over the past 15 years, the prevalence of malaria has been substantially reduced and virus outbreaks have been contained by controlling mosquito vectors using insecticide-based approaches. However, disease control is now threatened by alarming rates of insecticide resistance in insect populations, prompting the need to develop a new generation of specific strategies that can reduce vector-mediated transmission. Here, we review how increased knowledge in insect biology and insect-pathogen interactions is stimulating new concepts and tools for vector control. We focus on strategies that either interfere with the development of pathogens within their vectors or directly impact insect survival, including enhancement of vector-mediated immune control, manipulation of the insect microbiome, or use of powerful new genetic tools such as CRISPR-Cas systems to edit vector genomes. Finally, we offer a perspective on the implementation hurdles as well as the knowledge gaps that must be filled in the coming years to safely realize the potential of these novel strategies to eliminate the scourge of vector-borne disease.

Stigma and intersectionality: a systematic review of systematic reviews across HIV/AIDS, mental illness, and physical disability

Background

Stigma across HIV/AIDS, mental illness, and physical disability can be co-occurring and may interact with other forms of stigma related to social identities like race, gender, and sexuality. Stigma is especially problematic for people living with these conditions because it can create barriers to accessing necessary social and structural supports, which can intensify their experiences with stigma. This review aims to contribute to the knowledge on stigma by advancing a cross-analysis of HIV/AIDS, mental illness, and physical disability stigma, and exploring whether and how intersectionality frameworks have been used in the systematic reviews of stigma.

Methods

A search of the literature was conducted to identify systematic reviews which investigated stigma for HIV/AIDS, mental illness and/or physical disability. The electronic databases MEDLINE, CINAHL, EMBASE, COCHRANE, and PsycINFO were searched for reviews published between 2005 and 2017. Data were extracted from eligible reviews on: type of systematic review and number of primary studies included in the review, study design study population(s), type(s) of stigma addressed, and destigmatizing interventions used. A keyword search was also done using the terms “intersectionality”, “intersectional”, and “intersection”; related definitions and descriptions were extracted. Matrices were used to compare the characteristics of reviews and their application of intersectional approaches across the three health conditions.

Results

Ninety-eight reviews met the inclusion criteria. The majority (99%) of reviews examined only one of the health conditions. Just three reviews focused on physical disability. Most reviews (94%) reported a predominance of behavioural rather than structural interventions targeting stigma in the primary studies. Only 17% of reviews used the concept and/or approach of intersectionality; all but one of these reviews examined HIV/AIDS.

Conclusions

The lack of systematic reviews comparing stigma across mental illness, HIV/AIDS, and physical disability indicates the need for more cross-comparative analyses among these conditions. The integration of intersectional approaches would deepen interrogations of co-occurring social identities and stigma.

Lymphatic filariasis control in Tanzania: infection, disease perceptions and drug uptake patterns in an endemic community after multiple rounds of mass drug administration

BACKGROUND

Lymphatic filariasis (LF) control in most countries of sub-Saharan Africa is based on annual mass drug administration (MDA) with a combination of ivermectin and albendazole, in order to interrupt transmission. However, attaining and maintaining high treatment coverage has been a challenge in many LF control programmes. This study was designed to elucidate reasons for continued transmission of LF in an endemic area of Tanga, northeastern Tanzania, where control activities based on MDA had been in place for eight years by the time of this study in 2012.

METHODS

A cross-sectional questionnaire survey was conducted in three sentinel villages used for monitoring the impact of MDA on LF transmission. A total of 747 individuals were interviewed, out of which 172 (23.0%), 27 (3.6%) and 49 (6.5%) had been shown to have circulating filarial antigens (CFA), microfilaraemia (MF) and LF gross lesions, respectively, prior to the interviews.

RESULTS

The interviewed population had a mean age of 33.7 years and a male to female ratio of 0.8. Males, individuals aged 30 years and above, peasants/fishermen and recent immigrants to the study communities were significantly more affected (CFA, MF and/ or LF gross lesions) than the other population groups. However, drug uptake rates were not significantly different between LF affected (those with CFA, MF and/ or LF gross lesions) and non-affected individuals. Likewise, drug uptake rates were not significantly different across different demographic parameters of the study population, some of which differed significantly in the level of infection. Moreover, it was found that misconceptions on how LF can be acquired were still evident, linking its transmission to witchcraft, heredity and sexual behaviour.

CONCLUSIONS

The findings indicated that misconceptions about LF and its transmission still existed despite eight years of control activities in the area. Improved communication on the rationale of MDA and an enhanced drug delivery strategy that is adapted to the local settings and targeting important demographic groups that serve as reservoir of infection will help in reaching the elimination target within a reasonable timeframe.

Integrated morbidity mapping of lymphatic filariasis and podoconiosis cases in 20 co-endemic districts of Ethiopia

Background

Lymphatic filariasis (LF) and podoconiosis are neglected tropical diseases (NTDs) that pose a significant physical, social and economic burden to endemic communities. Patients affected by the clinical conditions of LF (lymphoedema and hydrocoele) and podoconiosis (lymphoedema) need access to morbidity management and disability prevention (MMDP) services. Clear estimates of the number and location of these patients are essential to the efficient and equitable implementation of MMDP services for both diseases.

Methodology/Principle findings

A community-based cross-sectional study was conducted in Ethiopia using the Health Extension Worker (HEW) network to identify all cases of lymphoedema and hydrocoele in 20 woredas (districts) co-endemic for LF and podoconiosis. A total of 612 trained HEWs and 40 supervisors from 20 districts identified 26,123 cases of clinical morbidity. Of these, 24,908 (95.3%) reported cases had leg lymphoedema only, 751 (2.9%) had hydrocoele, 387 (1.5%) had both leg lymphoedema and hydrocoele, and 77 (0.3%) cases had breast lymphoedema. Of those reporting leg lymphoedema, 89.3% reported bilateral lymphoedema. Older age groups were more likely to have a severe stage of disease, have bilateral lymphoedema and to have experienced an acute attack in the last six months.

Conclusions/Significance

This study represents the first community-wide, integrated clinical case mapping of both LF and podoconiosis in Ethiopia. It highlights the high number of cases, particularly of leg lymphoedema that could be attributed to either of these diseases. This key clinical information will assist and guide the allocation of resources to where they are needed most.

Patients affected by the clinical conditions of lymphatic filariasis (lymphoedema and hydrocoele) and podoconiosis (lymphoedema) require access to a minimum package of care to prevent progression of the disease, and to improve their quality of life. Clear estimates of the number and location of these patients is essential for the delivery of this care. To address this, a community-based cross-sectional study was conducted in Ethiopia using the Health Extension Worker (HEW) network to identify all cases of lymphoedema and hydrocoele in 20 co-endemic woredas (districts). A total of 26,123 cases of clinical morbidity were identified. Of these, 24,908 (95.3%) had leg lymphoedema, of which 89.3% were bilateral. The results of this study will help assist the Neglected Tropical Disease (NTD) programme at the Federal Ministry of Health (FMOH) in Ethiopia to effectively and equitably plan the delivery of a basic package of care to those suffering from the clinical manifestations of both diseases.

The History of Bancroftian Lymphatic Filariasis in Australasia and Oceania: Is There a Threat of Re-Occurrence in Mainland Australia?

Lymphatic filariasis (LF) infects an estimated 120 million people worldwide, with a further 856 million considered at risk of infection and requiring preventative chemotherapy. The majority of LF infections are caused by Wuchereria bancrofti, named in honour of the Australian physician Joseph Bancroft, with the remainder due to Brugia malayi and B. timori. Infection with LF through the bite of an infected mosquito, can lead to the development of the condition known as elephantiasis, where swelling due to oedema leads to loss of function in the affected area and thickening of the skin, 'like an elephant'. LF has previously been endemic in Australia, although currently, no autochthonous cases occur there. Human immigration to Australia from LF-endemic countries, including those close to Australia, and the presence of susceptible mosquitoes that can act as suitable vectors, heighten the possibility of the reintroduction of LF into this country. In this review, we examine the history of LF in Australia and Oceania and weigh up the potential risk of its re-occurrence on mainland Australia.

Emotional Difficulties and Experiences of Stigma among Persons with Lymphatic Filariasis in Plateau State, Nigeria

Lymphatic filariasis (LF) is a chronic and often disfiguring condition that predominantly affects the rural poor and leads to social exclusion, stigma, and discrimination. Little is currently known about the emotional difficulties and stigma experiences among persons living with LF in Nigeria. Our study evaluated the emotional difficulties and stigma experienced by persons with LF in Plateau State, Nigeria. We utilized a combination of qualitative data instruments comprising focus group discussions, McGill's Illness Narrative Interviews, and key informant interviews. We transcribed and analyzed the data using a combination of inductive and deductive coding approaches. Sixty-nine respondents were interviewed: 37 females and 32 males. The prevalent community perception of LF was the belief that it was a spiritual problem. Emotional reactions included feelings of sadness, hopelessness, anger, frustration, worry, and suicidal ideation. These experiences, including those of stigma, discrimination, and social exclusion, culminated in difficulties with occupational functioning, marital life, and community participation. Our findings highlight the value of a rights-based approach that emphasizes state and non-state actors' need to provide access to the highest attainable standard of health, including mental health, and to protect persons with LF from stigma, discrimination, and social exclusion.

Assessing the feasibility of integration of self-care for filarial lymphoedema into existing community leprosy self-help groups in Nepal

BACKGROUND

Lymphatic filariasis (LF) and leprosy are disabling infectious diseases endemic in Nepal. LF infection can lead to lymphoedema and hydrocoele, while secondary effects of leprosy infection include impairments to hands, eyes and feet. The disabling effects of both conditions can be managed through self-care and the supportive effects of self-help groups (SHGs). A network of SHGs exists for people affected by leprosy in four districts in Nepal's Central Development Region, however no such service exists for people affected by LF. The aim of this study was to determine the feasibility of integrating LF affected people into existing leprosy SHGs in this area.

METHODS

A survey was conducted using a semi-structured questionnaire to elicit information on: (i) participant characteristics, clinical manifestation and disease burden; (ii) participants' knowledge of management of their condition and access to services; and (iii) participants' knowledge and perceptions of the alternate condition (LF affected participants' knowledge of leprosy and vice versa) and attitudes towards integration.

RESULTS

A total of 52 LF affected and 53 leprosy affected participants were interviewed from 14 SHGs. On average, leprosy affected participants were shown to have 1.8 times greater knowledge of self-care techniques, and practiced 2.5 times more frequently than LF affected participants. Only a quarter of LF affected participants had accessed a health service for their condition, compared with 94.3% of leprosy affected people accessing a service (including SHGs), at least once a week. High levels of stigma were perceived by both groups towards the alternate condition, however, the majority of LF (79%) and leprosy (94.3%) affected participants stated that they would consider attending an integrated SHG.

CONCLUSIONS

LF affected participants need to increase their knowledge of self-care and access to health services. Despite stigma being a potential barrier, attitudes towards integration were positive, suggesting that the SHGs may be a good platform for LF affected people to start self-care in this area.

TRIAL REGISTRATION

This is not a registered trial.

Lymphatic filariasis transmission on Mafia Islands, Tanzania: Evidence from xenomonitoring in mosquito vectors

Introduction

Lymphatic filariasis (LF) is a chronic nematode infection transmitted by mosquitoes and in sub-Saharan Africa it is caused by Wuchereria bancrofti. The disease was targeted for global elimination by 2020 using repeated community-wide mass drug administration (MDA) distributed in endemic areas. However, recently, there has been a growing recognition of the potential role of including vector control as a supplement to MDA to achieve elimination goal. This study was carried out to determine mosquito abundance and transmission of bancroftian filariasis on Mafia Islands in Tanzania as a prerequisite for a search for appropriate vector control methods to complement the ongoing MDA campaign.

Methods

Mosquitoes were collected indoor and outdoor using Centre for Disease Control (CDC) light and gravid traps, respectively. Collected mosquitoes were identified based on their differential morphological features and Anopheles gambiae complex and An. funestus group were further identified to their respective sibling species by polymerase chain reaction (PCR). Filarial mosquito vectors were then examined for infection with Wuchereria bancrofti by microscopy and PCR technique.

Results

Overall, a total of 35,534 filarial mosquito vectors were collected, of which Anopheles gambiae complex, An. funestus group and Culex quinquefasciatus Say accounted for 1.3, 0.5 and 98.2%, respectively. Based on PCR identification, An. gambiae sensu stricto (s.s) and An. funestus s.s sibling species accounted for 88.3% and 99.1% of the identified members of the An. gambiae complex and An. funestus group, respectively. A total of 7,936 mosquitoes were examined for infection with W. bancrofti by microscopy. The infection and infectivity rates were 0.25% and 0.08%, respectively. Using pool screen PCR technique, analysis of 324 mosquito pools (each with 25 mosquitoes) resulted to an estimated infection rate of 1.7%.

Conclusion

The study has shown that Cx. quinquefasciatus is the dominant mosquito on Mafia Islands. By using mosquito infectivity as proxy to human infection, the study indicates that W. bancrofti transmission is still ongoing on Mafia Islands after more than a decade of control activities based on MDA.

Lymphatic filariasis is a chronic human disease caused by parasitic worms and transmitted by mosquitoes. The disease is targeted for elimination by 2020 through the treatment of the entire population at risk in endemic areas using a mass drug administration (MDA) strategy. After several years of MDA, there is now growing interest in including vector control as a supplement to MDA to achieve elimination goal. This study was carried out to determine mosquito abundance and transmission of lymphatic filariasis on Mafia Islands in Tanzania after nine rounds of MDA. Mosquitoes were collected indoor and outdoor using Centre for Disease Control (CDC) light and gravid traps, respectively. Filarial mosquito vectors were examined for infection with Wuchereria bancrofti by microscopy and PCR technique. A total of 35,534 filarial mosquito vectors were collected, of which Anopheles gambiae complex, An. funestus group and Culex quinquefasciatus Say accounted for 1.3, 0.5 and 98.2%, respectively. Using PCR, An. gambiae sensu stricto (s.s) and An. funestus s.s sibling species accounted for 88.3% and 99.1% of the identified members of the An. gambiae complex and An. funestus group, respectively. A total of 7,936 mosquitoes were examined for infection with W. bancrofti by microscopy. The infection and infectivity rates were 0.25% and 0.08%, respectively. Using PCR technique, of 324 mosquito pools (each with 25 mosquitoes) tested, 115 were found to be infected with at least a larval stage of W. bancrofti. The study concludes that Cx. quinquefasciatus is the dominant mosquito on Mafia Islands and that W. bancrofti transmission is still ongoing on Mafia Islands after a decade of control activities based on MDA.

Lymphatic filariasis patient identification in a large urban area of Tanzania: An application of a community-led mHealth system

BACKGROUND

Lymphatic filariasis (LF) is best known for the disabling and disfiguring clinical conditions that infected patients can develop; providing care for these individuals is a major goal of the Global Programme to Eliminate LF. Methods of locating these patients, knowing their true number and thus providing care for them, remains a challenge for national medical systems, particularly when the endemic zone is a large urban area.

METHODOLOGY/PRINCIPLE FINDINGS

A health community-led door-to-door survey approach using the SMS reporting tool MeasureSMS-Morbidity was used to rapidly collate and monitor data on LF patients in real-time (location, sex, age, clinical condition) in Dar es Salaam, Tanzania. Each stage of the phased study carried out in the three urban districts of city consisted of a training period, a patient identification and reporting period, and a data verification period, with refinements to the system being made after each phase. A total of 6889 patients were reported (133.6 per 100,000 population), of which 4169 were reported to have hydrocoele (80.9 per 100,000), 2251 lymphoedema-elephantiasis (LE) (43.7 per 100,000) and 469 with both conditions (9.1 per 100,000). Kinondoni had the highest number of reported patients in absolute terms (2846, 138.9 per 100,000), followed by Temeke (2550, 157.3 per 100,000) and Ilala (1493, 100.5 per 100,000). The number of hydrocoele patients was almost twice that of LE in all three districts. Severe LE patients accounted for approximately a quarter (26.9%) of those reported, with the number of acute attacks increasing with reported LE severity (1.34 in mild cases, 1.78 in moderate cases, 2.52 in severe). Verification checks supported these findings.

CONCLUSIONS/SIGNIFICANCE

This system of identifying, recording and mapping patients affected by LF greatly assists in planning, locating and prioritising, as well as initiating, appropriate morbidity management and disability prevention (MMDP) activities. The approach is a feasible framework that could be used in other large urban environments in the LF endemic areas.

Prevalence of depression and associated clinical and socio-demographic factors in people living with lymphatic filariasis in Plateau State, Nigeria

Background

Lymphatic filariasis is a chronic, disabling and often disfiguring condition that principally impacts the world’s poorest people. In addition to the well-recognised physical disability associated with lymphedema and hydrocele, affected people often experience rejection, stigma and discrimination. The resulting emotional consequences are known to impact on the quality of life and the functioning of the affected individuals. However, the management of this condition has focused on prevention and treatment through mass drug administration, with scant attention paid to the emotional impact of the condition on affected individuals. This study aimed to determine the prevalence and severity of depression among individuals with physical disfigurement from lymphatic filariasis in Plateau State, Nigeria.

Methodology

A cross-sectional 2-stage convenience study was conducted at 5 designated treatment centers across Plateau State, Nigeria. All available and consenting clients with clearly visible physical disfigurement were recruited. A semi-structured socio-demographic questionnaire, Rosenberg Self-esteem and a 9-item Patient Health Questionnaire (PHQ-9) were administered at the first stage. Those who screened positive (with a PHQ-9 score of five and above) were further interviewed using the Depression module of the Composite International Diagnostic Interview (CIDI).

Results

Ninety-eight individuals met the criteria and provided consent. Twenty percent of the respondents met criteria for depression, with the following proportions based on severity: Mild (42.1%), Moderate (31.6%) and Severe (26.3%). History of mental illness (OR 40.83, p = 0.008); Median duration of the illness was 17 years (IQR 7.0–30 years) and being unemployed (OR 12.71, p = 0.003) were predictive of depression. High self-esteem was negatively correlated (OR 0.09, p<0.004).

Conclusion

Prevalence of depression is high among individuals with lymphatic filariasis and depression in sufferers is associated with low self-esteem and low levels of life satisfaction.

Lymphatic filariasis is a chronic illness that is disabling and often results in disfigurement. Affected people experience rejection, and stigma and discrimination, which can result in significant emotional consequences. Overall functioning and the quality of life of such individuals can be further affected by this exclusion and psychosocial impacts. Little or no attention is presently paid to the emotional impact of this disease in the overall management of people affected. The study, therefore, aimed to determine the prevalence and severity of depression, as well as associated socio-demographic factors, in individuals with physical disfigurement from lymphatic filariasis in Plateau State, Nigeria. Ninety-four consecutive consenting individuals with physically disfiguring lymphatic filariasis at 5 established treatment centers across Plateau State, Nigeria, were recruited and had semi-structured sociodemographic, Patient Health (PHQ-9), the depression module of Composite International Diagnostic Interview (CIDI) and Rosenberg Self-esteem questionnaires administered using a 2-stage design. Twenty percent of the sample were found to be depressed, while history of mental illness, duration of the illness, being unemployed, and religion were predictive of depression. High self-esteem was negatively correlated. The study underscores the need to go beyond just the physical needs of individuals with lymphatic filariasis. Management must be holistic and attention must be focused on the emotional sequelae of lymphatic filariasis.

New developments in chyluria after global programs to eliminate lymphatic filariasis

Chyluria, commonly seen in south Asian countries, is mainly a manifestation of lymphatic filariasis as a result of infestation with Wuchereria bancrofti, although many other causes can contribute. Many patients can be effectively treated with dietary modifications and drug therapy. The most widely used drug is diethyl carbamazine. The recurrences are common after such treatment. Such patients would benefit from sclerotherapy to obliterate the lympatico-renal fistulae located mainly in the renal pelvicalyceal system. The commonly used sclerosing agent is a combination of 5% povidone-iodine and 50% dextrose instilled through a ureteric catheter. A small percentage of patients who recur after sclerotherapy and those with systemic complications, such as hypoproteinemia and edema, might require surgery in the form of renal hilar lymphatic disconnection. Although it is a major operation, the success rates are >90%. Laparoscopic and robotic techniques have minimized the morbidity related to such surgery. With the advent of the global program for eradication of filariasis initiated by the World Health Organization, the incidence of the disease is decreasing. Mass chemotherapy with diethyl carbamazine is the mainstay of this global program. Many years after eliminating filariasis, chyluria continue to occur in such populations, though in dwindling numbers. Future research should aim at finding more efficacious sclerosing agents with minimal recurrences.

Lymphatic filariasis elimination efforts in Rufiji, southeastern Tanzania: decline in circulating filarial antigen prevalence in young school children after twelve rounds of mass drug administration and utilization of long-lasting insecticide-treated nets

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Interventions based on mass drug administration and insecticide-treated nets led to a marked decline in Wuchereria bancrofti circulating filarial antigen (CFA) in young school children.

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The official reported treatment coverage was relatively higher than the surveyed coverage.

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There has been an increase in ownership and utilization of insecticide-treated nets in the study areas.

Background

Lymphatic filariasis (LF) is a parasitic infection transmitted by mosquito vectors, and in Sub-Saharan Africa it is caused by the nematode Wuchereria bancrofti. The disease has been targeted for global elimination with the annual mass drug administration (MDA) strategy. Vector control is known to play an important complementary role to MDA in reducing the transmission of LF. The effects of an MDA and insecticide-treated net intervention implemented in an endemic area of southeastern Tanzania are reported here.

Methods

A cross-sectional study assessing W. bancrofti circulating filarial antigen (CFA) was conducted in five primary schools in five different villages. Standard one pupils aged 6–9 years were screened for CFA using immunochromatographic test cards (ICT), with a total of 413 screened in 2012 and 659 in 2015. Just after CFA testing, the children were interviewed on their participation in the MDA campaign. Moreover, 246 heads of households in 2012 and 868 in 2015 were interviewed on their participation in MDA and utilization of long-lasting insecticide-treated nets (LLINs).

Results

The prevalence of CFA for the 413 children tested in 2012 was 14.3%, while it was 0.0% for the 659 children tested in 2015. The Tanzanian National Lymphatic Filariasis Elimination Programme reported annual treatment coverage for Rufiji District ranging from 54.3% to 94.0% during the years 2002–2014. The surveyed treatment was 51.6% in 2011 and 57.4% in 2014. With regard to LLINs, possession and utilization increased from 63.4% and 59.2%, respectively, in 2012, to 92.5% and 75.4%, respectively, in 2015.

Conclusions

The findings suggest that 12 rounds of MDA complemented with vector control through the use of insecticide-treated nets resulted in a marked reduction in W. bancrofti CFA in young school children.

Measuring the physical and economic impact of filarial lymphoedema in Chikwawa district, Malawi: a case-control study

BACKGROUND

Lymphatic filariasis (LF) is one of the primary causes of lymphoedema in sub-Saharan Africa, and has a significant impact on the quality of life (QoL) of those affected. In this paper we assess the relative impact of lymphoedema on mobility and income in Chikwawa district, Malawi.

METHODS

A random sample of 31 people with lymphoedema and 31 matched controls completed a QoL questionnaire from which both an overall and a mobility-specific score were calculated. Two mobility tests were undertaken, namely the 10 m walking test [10MWT] and timed up and go [TUG] test, and a subset of 10 cases-control pairs wore GPS data loggers for 3 weeks to measure their mobility in a more natural setting. Retrospective economic data was collected from all 31 case-control pairs, and each participant undertaking the GPS activity recorded daily earnings and health expenditure throughout the observation period.

RESULTS

Cases had a significantly poorer overall QoL (cases = 32.2, controls = 6.0, P < 0.01) and mobility-specific (cases = 43.1, controls = 7.4, P < 0.01) scores in comparison to controls. Cases were also significantly slower (P < 0.01) at completing the timed mobility tests, e.g. mean 10MWT speed of 0.83 m/s in comparison to 1.10 m/s for controls. An inconsistent relationship was observed between mobility-specific QoL scores and the timed test results for cases (10MWT correlation = -0.06, 95% CI = (-0.41, 0.30)), indicating that their perceived disability differed from their measured disability, whereas the results were consistent for controls (10MWT correlation = -0.61, 95% CI = (-0.79, -0.34)). GPS summaries indicated that cases generally walk shorter distances at slower speeds than control, covering a smaller geographical area (median area by kernel smoothing: cases = 1.25 km², controls = 2.10 km², P = 0.16). Cases reported earning less than half that earned by controls per week (cases = $0.70, controls = $1.86, P = 0.064), with a smaller proportion of their earnings (16% vs 22%, P = 0.461) being spent on healthcare.

CONCLUSIONS

Those affected by lymphoedema are at a clear disadvantage to their unaffected peers, experiencing a lower QoL as confirmed by both subjective and objective mobility measures, and lower income. This study also indicates that objective measures of mobility may be a useful supplement to self-assessed QoL questionnaires when assessing the future impact of lymphoedema management interventions.

Modeling the Parasitic Filariasis Spread by Mosquito in Periodic Environment

In this paper a mosquito-borne parasitic infection model in periodic environment is considered. Threshold parameter R0 is given by linear next infection operator, which determined the dynamic behaviors of system. We obtain that when R0 < 1, the disease-free periodic solution is globally asymptotically stable and when R0 > 1 by Poincaré map we obtain that disease is uniformly persistent. Numerical simulations support the results and sensitivity analysis shows effects of parameters on R0, which provided references to seek optimal measures to control the transmission of lymphatic filariasis.