Lymphatic Filariasis Research Articles

CRISPR-based gene drives generate super-Mendelian inheritance in the disease vector Culex quinquefasciatus

Culex mosquitoes pose a significant public health threat as vectors for a variety of diseases including West Nile virus and lymphatic filariasis, and transmit pathogens threatening livestock, companion animals, and endangered birds. Rampant insecticide resistance makes controlling these mosquitoes challenging and necessitates the development of new control strategies. Gene drive technologies have made significant progress in other mosquito species, although similar advances have been lagging in Culex. Here we test a CRISPR-based homing gene drive for Culex quinquefasciatus, and show that the inheritance of two split-gene-drive transgenes, targeting different loci, are biased in the presence of a Cas9-expressing transgene although with modest efficiencies. Our findings extend the list of disease vectors where engineered homing gene drives have been demonstrated to include Culex alongside Anopheles and Aedes, and pave the way for future development of these technologies to control Culex mosquitoes.

“Whenever I tell her to wear slippers, she turns a deaf ear. She never listens”: a qualitative descriptive research on the barriers to basic lymphedema management and quality of life in lymphatic filariasis patients in a rural block of eastern India

BackgroundChronic lymphatic filariasis patients in Bihar, India, need management of lymphedema to live a disability-free life. For patients who have recurrent attacks of acute dermato-lymphangio-adenitis (ADLA), World Health Organization (WHO) has recommended simple home-based measures that include maintaining hygiene, skin care, and limb movement. However, patients in rural areas are unable to adopt them, resulting in a vicious cycle of ADLA attacks. There might be multiple realities from patients’ and healthcare workers’ perspectives that were unexplored. Qualitative research was deemed best suitable to identify the barriers to carrying out home-based lymphedema practices that adversely affected quality of life.MethodsThe qualitative descriptive study was conducted in two villages in the rural field practice area under a tertiary care hospital in Bihar. Researchers purposively selected ten participants, including patients affected by lymphedema, their caregivers, the grassroots healthcare workers, and the block health manager. In-depth interviews were conducted using a semi-structured interview guide. Data were entered into QDA Miner Lite, where researchers did attribute, in-vivo, process, descriptive, emotion, and holistic coding, followed by content analysis, where categories and themes emerged from the codes.ResultsThree themes emerged: the inherent nature of disease, patient-related factors, and healthcare system-related factors. The fifteen identified barriers were low awareness, low adherence, low health-seeking behavior, poor personal hygiene, and categories like signs and symptoms, seasonal factors, hampered activities of daily living, hopelessness from not getting cured, psychosocial difficulty, lack of capacity building and receipt of incentives by healthcare workers, unavailability of laboratory diagnosis and management of complications at the facility, inconsistent drug supply, and no financial assistance.ConclusionsAccessibility to WaSH, regular training of home-based care, increasing the capacity and motivation of grassroots workers, and the generation of in-depth awareness among the patients are required to achieve the elimination of filariasis, with MMDP as a key component of that strategy for endemic districts across the whole country.Graphical

Longitudinal study of cross-reactive antigenemia in individuals with high Loa loa microfilarial density reveals promising biomarkers for distinguishing lymphatic filariasis from loiasis.

Circulating Loa loa antigens are often detected in individuals with heavy L. loa infections by diagnostic tests for lymphatic filariasis (LF) caused by Wuchereria bancrofti. This is a major challenge to LF mapping and elimination efforts in loiasis co-endemic areas. However, it also provides an opportunity to identify antigen biomarkers for loiasis. To determine which L. loa antigens might be promising biomarkers for distinguishing true LF from loiasis, we screened for L. loa antigens in a group of individuals with heavy L. loa infections living in the Okola Health District of Cameroon. In this longitudinal study, participants were tested for cross-reactive antigenemia by filariasis test strip (FTS), ELISA, and western blot, and were monitored for FTS status at 6, 9, 12, and 15 months post-enrollment. We then identified specific circulating L. loa antigens by liquid chromatography-tandem mass spectrometry (LC-MS/MS) from baseline and 15-month plasma samples. Among 73 FTS-positive (FTS+) and 13 FTS-negative (FTS-) participants with high L. loa microfilarial loads, 83% maintained their FTS status over the course of the study, while 17% experienced at least one FTS conversion event (from FTS+ to FTS- or vice versa). Cross-reactive antigens were detected in both FTS+ and FTS- sera by western blot, and there was poor agreement in antigen detection by FTS, western blot, and ELISA methods. One protein family, a group of Nas-14 metalloproteases, was detected by LC MS/MS in >80% of tested samples, including FTS- samples. These data identify Nas-14 as a promising loiasis biomarker potentially capable of distinguishing loiasis from lymphatic filariasis.

In silico exploration and in vitro validation of the filarial thioredoxin reductase inhibitory activity of Scytonemin and its derivatives

Lymphatic filariasis (LF) caused by the vector borne parasitic nematode Wuchereria bancrofti is of major concern of the World Health Organization (WHO). Lack of potential drug candidates worsens the situation. Presently available drugs are promising in killing the microfilaria (mf) but are not effective as adulticidal therapeutics. Previous studies have revealed that routine administration of the available drugs (albendazole, ivermectin and albendazole) sometime is associated with severe adverse effects (SAEs) in co-infection state. Therefore, potential and safe therapeutics are still required. Earlier studies on filarial thioredoxin reductase (TrxR) have shown that successful inhibition of it can lead to apoptotic death of the parasites. TrxR in filarial parasites plays a significant role in disease progression and pathogenesis, hence efficient non-reversible inhibition of TrxR can be a good strategy to treat LF. In this research, inhibitory potential of Scytonemin, a cyanobacterial metabolite on filarial TrxR was evaluated via different in silico methods and validated through in vitro experiments. Parasite death upon exposure to Scytonemin can be correlated with the TrxR inhibiting capacity of the compound. Therefore, this cyanobacterial-derived compound may possibly be used further as novel and safe therapeutic candidate against filarial infection. Communicated by Ramaswamy H. Sarma

A nationwide epidemiological and geodemographic analysis of lymphatic filariasis in Ecuador: a neglected and often forgotten disease in Ecuador.

Lymphatic filariasis (LF) is a neglected parasitic disease transmitted by mosquitoes and affecting the lymphatic system. The aim of this study was to analyze the epidemiological and sociodemographic characteristics of patients with LF during the last 11 years of available data in Ecuador. A 11-year nationwide analysis of hospital admission and in-hospital mortality based on the National Institute of Statistics and Census (INEC) data was conducted in Ecuador from 2011 to 2021. The International Classification of Diseases 10th Revision (ICD-10) code for filariasis (ICD: B74) was used to retrieve information on severe LF as a proxy for incidence among 221 Ecuadorian cities. A total of 26 hospital admissions and 3 deaths due to LF were registered. The highest mortality rate was found in populations over 80 years. Men accounted for 62.5% (n = 17) of total number of cases with an average incidence rate of 1.7 cases per/1,000,000, while females accounted for 34.6% (n = 9), representing 1 case per/1,000,000 woman. Cities located at lower altitude (459/1,000,000) reported higher incidence rates than those located at higher altitudes (7.4/1,000,000). This is the first study on LF in Ecuador. Although, Ecuador is not considered endemic for LF, we found evidence of the presence of this disease in recent years. The implementation and improvement of an adequate integrated epidemiological surveillance system will allow early identification of cases and therefore their respective treatment.

Gendered lives, gendered Vulnerabilities: An intersectional gender analysis of exposure to and treatment of schistosomiasis in Pakwach district, Uganda.

Schistosomiasis is a neglected tropical disease (NTD) that is endemic in Uganda, despite several interventions to eliminate it. It is transmitted when people infected with it pass on their waste matter into fresh water bodies used by others, consequently infecting them. Several studies have demonstrated gender and age differences in prevalence of schistosomiasis and NTDs such as lymphatic filariasis and soil transmitted helminths. However, few intersectional gender analysis studies of schistosomiasis have been undertaken. Using the World Health Organisation (WHO)'s intersectional gender analysis toolkit, this study was undertaken to identify which social stratifiers most intersected with gender to influence vulnerability to and access to treatment for schistosomiasis disease, to understand how best to implement interventions against it. This was a qualitative study comprising eight focus group discussions (FGDs) of community members, disaggregated by age, sex and location, and 10 key informant interviews with health care providers and community leaders. The Key informants were selected purposively while the community members were selected using stratified random sampling (to cater for age, sex and location). The data was analysed manually to identity key themes around gender, guided by a gender and intersectionality lens. The study established that while the River Nile provided livelihoods it also exposed the community to schistosomiasis infection. Gender relations played a significant role in exposure to and access to treatment for schistosomiasis. Traditional gender roles determined the activities men and women performed in the private and public spheres, which in turn determined their exposure to schistosomiasis and treatment seeking behaviour. Gender relations also affected access to treatment and decision making over family health care. Men and some women who worked outside the home were reported to prioritise their income earning activities over seeking health care, while women who visited the health facilities more regularly for antenatal care and to take sick children were reported to have higher chance of being tested and treated in time, although this was undermined by the irregular and infrequent provision of praziquantel (PZQ) mass drug administration. These gender relations were further compounded by underdevelopment and limited economic opportunities, insufficient health care services, as well as the respondent's age and location. The study concludes that vulnerability to schistosomiasis disease and treatment occurred within a complex web of gender relations, culture, poverty, limited economic opportunities and insufficient health services delivery, which together undermined efforts to eliminate schistosomiasis. This study recommends the following: a) increased public health campaigns around schistosomiasis prevention and treatment; b) more regular PZQ MDA at home and schools; c) improved health services delivery and integration of services to include vector control; d) prioritising NTDs; e) providing alternative economic activities; and f) addressing negative gender norms that promote social behaviours which negatively influence vulnerability, treatment seeking and decision making for health.

Detection of Wuchereria bancrofti in human blood samples and mosquitoes in Matayos, Busia County-Kenya

Lymphatic filariasis is a mosquito borne disease which leads to abnormal painful enlarged body parts, severe disability and social stigma. We screened Wuchereria bancrofti in Matayos constituency in Busia County. Blood samples were collected from 23 villages selected purposively based on clinical case reports. Finger prick and/or venous blood sampling and mosquito collections was carried out. Antigenaemia and filarial DNA prevalence were determined. Infection rates on mosquito pools were estimated and SPSS version 26 was used for descriptive statistics analysis. A total of 262 participants were recruited, 73.3% (n = 192) of the participants had no symptoms, 14.1% (n = 5.3) had swollen legs, 5.3% (n = 14) had painful legs and 3.8% (n = 10) with scrotal swellings. Average antigenemia prevalence was 35.9% (n = 94) and DNA prevalence was at 8.0% (n = 21). A total of 1305 mosquitoes were collected and pooled into 2–20 mosquitoes of the same species and from the same village. Two pools out of 78 were positive for filarial DNA with a minimum infection rate of 0.15%. From this study, antigenaemia and infected mosquitoes are an indication of active transmission. The clinical signs are evidence that filarial infections have been in circulation for over 10 years. The global climate change phenomenon currently happening has been shown to adversely affect the transmission of vector borne diseases and is likely to increase lymphatic filariasis transmission in the area. This study therefore recommends further screening before Mass Drug Administration, morbidity management and enhanced mosquito control Programmes are recommended in the study area.

Immune Response Profiling of Cocktails of Brugia malayi Vaccine Candidates DIM-1, Calponin and Troponin 1in BALB/c Mice.

In search of a vaccine for the control of human lymphatic filariasis (LF) caused by Wuchereria bancrofti, Brugia malayi and B. timori, we identified three parasite-specific potential candidates: the disorganized muscle protein-1 (D), calponin (C) and troponin 1 (T) in B. malayi adult worm. In the present study, we investigated the immune response profile of the cocktails of the recombinant D, T and C proteins. Groups of BALB/c mice were immunized with individual rproteins or their cocktails DT, TC, DC and DTC, and the immunogen-specific IgG and its subclasses and IgE were determined. Cells from the immunized animals were challenged in vitro with the respective rproteins and cocktails and the release of nitric oxide (NO) from macrophages and Th1 and Th2 cytokines from splenocytes were determined. Among the immunized groups, DTC elicited comparatively a stronger response which included augmented release of NO, Th1 (IL-1β, IL-2, IFN-γ and TNF-α) and Th2 (IL-4, IL-6, IL-10 and TGF-β) cytokines, and increased levels of immunogen-specific IgG, IgG1 and IgG2b and low levels of immunogen-specific IgG2a and IgE and the Th2 cytokine IL-13. Immune responses that play important role in host protection were elicited strongly by DTC cocktail compared to the individual rproteins or DT, TC and DC cocktails. The findings provide a sound rationale for further studies on DTC cocktail as a vaccine candidate for the control of LF.

Mini-TAS as a confirmatory mapping tool for remapping areas with uncertain filarial endemicity to exclude/ include for mass drug administration: A report from field validation in India.

India has targeted elimination of lymphatic filariasis (LF) through mass drug administration (MDA) by 2027. Mapping of LF endemic areas is a priority for implementation of MDA. Current national LF remapping tool for unsurveyed/uncertain districts, have many limitations. The WHO has recommended a sensitive and rapid remapping protocol (Mini-TAS), that needs validation in Indian setting. Hence, in the present study a comparative assessment of these two protocols (national protocol vs Mini-TAS) was undertaken in two non-MDA districts of Odisha, with unknown filarial endemicity but reporting chronic cases. Purposive sampling was done in five top sites based on filarial case count as per the national protocol. Random 30 cluster survey was done by conducting school based Mini-TAS, Microfilariae (Mf) survey among adults (>10 years) in villages/wards with schools and Molecular Xenomonitoring (MX) of infection in vectors. Costing by activity and items of the surveys was acomplished using itemized cost menu. In Kalahandi, one of the five purposive sampling sites showed Mf prevalence above threshold (> 1%). But except Mini-TAS neither MX nor house-hold Mf survey among adults could detect the infection above the threshold. While in Balangir, Mf prevalence in all purposive sampling sites,Mini-TAS, Mf prevalence among adult and MX were above the respective thresholds confirming endemicity of LF in the district. The per sample cost of purposive sampling for Mf was the lowest INR 41, followed by adult Mf sampling INR 93. Mini-TAS and MX were expensive with INR 659 and 812 respectively. The study demonstrates that though all the sampling methods could detect filarial infection above the threshold in high-risk areas, Mini-TAS could only detect infection in low-risk areas. Therefore, in the national programme Mini-TAS can be used as a decision-making tool to determine whether to exclude/ include a district having uncertain endemicity for MDA.

A hierarchical model-based framework for evaluating probabilities of area-wide freedom from lymphatic filariasis infection based on sentinel site surveillance data

The design of population surveys to substantiate the elimination of disease transmission across large implementation units (IUs) has become important as many parasite control efforts approach their final stages. This is especially true for the global program to eliminate lymphatic filariasis (LF), which has successfully reduced infection prevalence in many endemic countries, such that the focus has shifted to how best to determine that the area-wide elimination of this macroparasitic disease has been achieved. The WHO has recommended a two-stage lot quality assurance sampling (LQAS) framework based on sampling children from selected clusters within an IU, called the Transmission Assessment Survey (TAS), for supporting such decision-making, but questions have emerged regarding the reliability of this strategy for assessing if LF transmission is broken effectively everywhere within an area. In this study, we develop and describe an alternative probabilistic framework that combines infection status information from longitudinal parasitological surveys of whole communities carried out in sentinel sites, imperfect diagnostic tests, and locally-applicable extinction thresholds predicted by transmission models, to overcome the problems associated with TAS. We applied the framework to LF infection and intervention data from the country of Malawi, and demonstrated how our hierarchical coupled model-sentinel site survey tool can be used to estimate the probability that LF transmission has occurred at the individual survey, village, and countrywide scales. We also further demonstrated how the framework can be used in conjunction with zonal or areal design prevalences to estimate the number of sentinel sites and durations of interventions required to acquire sufficiently high confidence that an area is free from infection. Our results indicate that the application of the spatially driven model-data freedom-from-infection tool developed here to follow up data from high-risk sentinel sites in a region may offer a highly cost-effective framework for guiding the making of high-fiducial and defensible area-wide LF intervention stopping decisions.

Household Survey to Evaluate the Coverage of Mass Drug Administration for the Lymphatic Filariasis in District Umaria, Madhya Pradesh, India in Year 2023

Background: In 2023, the Umaria district in Madhya Pradesh, India, was identified as an endemic district for Lymphatic Filariasis (LF). The National Programme for Elimination of Lymphatic Filariasis conducted annual mass drug administration (MDA) campaigns in February to eliminate LF by 2027. Objective: This study aimed to estimate the coverage and compliance rate of MDA in the Umaria district of Madhya Pradesh, India, in 2023. Methodology: A cluster sampling method was used for evaluation. The district was divided into three implementation units, corresponding to its three administrative blocks. Four clusters were selected within each unit, consisting of one urban and three rural clusters. Thirty households were randomly selected as respondents from each cluster. Data was collected in May 2023 using a standardized coverage evaluation form designed by the World Health Organization. Result: Among the 360 households surveyed, information on 1606 beneficiaries was obtained. MDA was offered to 94% of the total population, with a coverage and compliance rate of 98.5% among the eligible population. The most common reasons for not consuming the drugs were "not present at house during the campaign" and "fear of drugs." Less than one percent of beneficiaries reported any side effects following the consumption of MDA. Conclusion & Implication: The coverage and compliance of MDA in the district appear to be optimal. The National Programme for Elimination of Lymphatic Filariasis should now consider conducting Transmission Assessment Surveys to determine the endemicity of districts that have reached the critical threshold of LF infection. Additionally, establishing adequate sentinel sites, organizing night blood examination camps in endemic areas, and improving Information Education Communication activities may aid in achieving LF elimination by 2027.

A Health Survey Revealing Prevalence of Vector-Borne Diseases and Tuberculosis in Papua New Guinea Defence Force Personnel and Families.

The Papua New Guinean Defence Force (PNGDF) and the Australian Defence Force (ADF) work and train closely. Infectious diseases pose a health threat to both forces, but recent knowledge about the risk at military bases in Papua New Guinea is limited. To improve understanding, a collaborative cross-sectional survey was conducted (March-April 2019) at Lombrum Naval base (Manus province) and Moem Army barracks (Wewak, East Sepik province) plus its Vanimo outpost (Sandaun province). Clinical data, venous blood, and sputum were collected from PNGDF personnel (DF) from the three sites, with point-of-care testing conducted for malaria (microscopy and rapid diagnostic test [RDT]), lymphatic filariasis (RDT), glucose-6-phosphate-dehydrogenase (G6PD) deficiency (RDT), tuberculosis (GeneXpert), and hemoglobin level. Finger prick blood collected from family members residing at the Wewak base was tested for malaria and hemoglobin level. Overall, 235 DF and 793 family members completed the survey. Microscopy revealed malaria prevalence as 0.4% Plasmodium falciparum and 3.1% Plasmodium vivax among DF and 3.5% P. falciparum, 14.3% P. vivax, and 0.3% mixed P. falciparum/P. vivax among family members. Among DF, 3.9% were G6PD deficient and none tested positive for tuberculosis or for lymphatic filariasis antigen. Anemia was present in 6.5% of DF and 47.3% of family members, predominantly females. Results suggest ongoing exposure to malaria, particularly P. vivax, at study sites, whereas infections of lymphatic filariasis and tuberculosis were not detected. Survey results will inform the PNGDF and the ADF regarding vector-borne disease risk for future sustainable health and disease control interventions.

Knowledge and perceptions of lymphatic filariasis patients in selectedhotspot endemic communities in southern Ghana.

Lymphatic filariasis (LF) is a mosquito-borne neglected tropical disease that is one of the leading global causes of permanent disability. To date, LF interventions have been largely biomedical, focusing on drug treatments to disrupt parasite transmission and manage disease morbidity. Although important, these Mass Drug Administration (MDA) programs neglect the significance of socio-economic burden to the health of LF patients, which are compounded by social stigmatization, discrimination and associated depressive illnesses. The MDA program also typically fails to engage with local community beliefs and perceptions of LF, which may differ markedly from biomedical explanations and may have fueled non-compliance to treatments which is one of the major challenges of the Mass Drug Administration program. LF is not only a biomedical issue but also a social issue and LF interventions need to understand people's world views and the contexts through which they interpret bodily maladies. Hence, an effective LF intervention must bring together both the biomedical and the social components. The goal of this exploratory study was to assist in refining a large qualitative study (currently underway) that seeks to integrate culturally appropriate LF interventions into current LF control programs in Ghana. In this paper, we discuss the findings of a pre-intervention, exploratory study aimed at gaining a baseline grasp of a local culturally informed understanding of lymphatic filariasis and the knowledge gaps looking at three endemic Ghanaian communities in the Ahanta West District. A structured questionnaire was employed to assess the wellbeing, social inclusion, and cultural understanding of LF with a geographic focus within LF-endemic areas in Ghana. Interestingly, 45.8% of the 72 participants reported to have received information about LF from health care providers and the MDA program but only 5 out of the 72 (6.9%) respondents believed that LF was transmitted by mosquitos. This baseline study revealed several alternative interpretations and misconceptions about the disease, as well as the social and economic impacts, and importantly, the need to integrate qualitative research to develop culturally appropriate interventions and increase engagement with existing control programs.

Pyrethroid insecticides susceptibility profiles and evaluation of L1014F kdr mutant alleles in Culex quinquefasciatus from lymphatic filariasis endemic communities

This study investigated the dynamics in pyrethriod resistance and the presence/frequencies of L1014F knockdown resistance mutant allelles in Culex quinquefasciatus vector populations from Uruan Local Government Area of AkwaIbom State, Southern Nigeria between the months of March and November, 2021. Uruan LGA is among the endemic LGAs for lymphatic filariasis in AkwaIbomState. Female Anopheles mosquitoes from Eman Uruan, Ituk Mbang and Idu Uruan were exposed to permethrin, deltamethrin and alphacypermethrin in CDC insecticide coated bottles for susceptibility bioassay following standard protocols. The mosquitoes were obtained as aquatic forms from the study sites and reared under laboratory conditions to adults. The adult mosquitoes were used for this study. All the mosquitoes used for the insecticide susceptibility bioassay were morphologically identified. Standard Polymerase chain reaction (PCR) was used for authenticating the Culex quinquefasciatus species. A portion of the vgsc (917 bp) gene spanning the entire intron and the exon containing the L1014F mutation associated with knockdown resistance (kdr) in the vectorswere amplified using Allele-SPECIFIC POLYMERASE CHAIN REACTION (AS-PCR) in order to detect target site insensitivity in the vectors from the study sites. Results obtained revealed that vectors from all the study sites were resistant to permethrin insecticide (mortality rate: 18–23%). Suspected resistance (mortality rate: 90–93%) to deltamethrin and low resistance (mortality rate: 82–85%) to alphacypermethrin insecticides were detected. knockdown was more rapid with deltamethrin and alphacypermethrin than with permethrin across the study sites considering their KDT50 and KDT95. The frequency of the resistant phenotypes ranged from 35.14 to 55.3% across the study sites with a net of 45.1% resistant phenotype recorded in this study. The 1014F allelic frequency calculated from Hardy–Weinberg principle for vector populations across the study sites ranged from 0.500 (50.00%) to 0.7763 (77.63%). All populations witnessed significant (p < 0.05) deviations from Hardy–Weinberg equilibrium in the distribution of these alleles. The findings of this study show that there is a tendency to record an entire population of resistant vectors in this study area over time due to natural selection. The public health implication of these findings is that the use of pyrethroid based aerosols, coils, sprays, LLITNs and others for the purpose of controlling vectors of lymphatic filariasis and other diseases may be effort in futility.

Wuchereria bancrofti infection is associated with progression to clinical visceral leishmaniasis in VL- endemic areas in Muzaffarpur, Bihar, India.

Co-endemicity of neglected tropical diseases (NTDs) necessitates that these diseases should be considered concomitantly to understand the relationship between pathology and to support disease management and control programs. The aims of the study were to assess the prevalence of filarial infection in asymptomatic Leishmania donovani infected individuals and the correlation of Wuchereria bancrofti infection with progression to clinical visceral leishmaniasis (VL) in Bihar, India. Within the Muzaffarpur-TMRC Health and Demographic Surveillance System (HDSS) area, a cohort of Leishmania seropositive (n = 476) or seronegative individuals (n = 1130) were sampled annually for three years for filarial infection and followed for progression to clinical VL. To corroborate the results from the cohort study, we also used a retrospective case-control study of 36 VL cases and 71 controls selected from a subset of the HDSS population to investigate the relationship between progression to clinical VL and the prevalence of filarial infection at baseline. Our findings suggest a higher probability of progression to clinical VL in individuals with a history of filarial infection: in both the cohort and case-control studies, progression to clinical VL was higher among filaria infected individuals (RR = 2.57, p = 0.056, and OR = 2.52, p = 0.046 respectively). This study describes that progression to clinical VL disease is associated with serological evidence of prior infection with W. bancrofti. The integration of disease programs for Leishmania and lymphatic filariasis extend beyond the relationship of sequential or co-infection with disease burden. To ensure elimination targets can be reached and sustained, we suggest areas of co-endemicity would benefit from overlapping vector control activities, health system networks and surveillance infrastructure.

Mhealth tools for community-based infectious disease surveillance in Africa: a scoping review

Abstract Background Community-based surveillance may encourage early detection of outbreaks and other health threats. Mobile digital tools for health (mHealth) can potentially support the role of community health workers (CHW) in disease surveillance. However, limited information is available on mhealth use by CHW for infectious disease surveillance in Africa. The purpose of this review was to provide an overview of available mhealth tools used by CHW for community-based infectious disease surveillance in Africa. Methods The scoping review protocol was registered in OSF registries (doi: 10.17605/OSF.IO/W7MTY). We followed a mixed-methods approach in line with the framework of Arksey and O'Malley amended by Levac et al. and the Joanna Briggs Institute. We searched PubMed, Scopus, Web of Science, CINAHL, Google Scholar, Google and websites of relevant organizations for peer-reviewed and grey literature. Search terms included a range of synonyms for the three concepts of (1) mhealth, (2) CHW and (3) Africa. Reports were included if they reported on mHealth tools used by CHW for infectious disease surveillance in Africa. Results We identified 2,496 titles during our search but only 7 met our inclusion criteria. Studies were conducted in Tanzania, Zambia, Nigeria, Malawi, Kenya and Ghana, and focused on one or more diseases or symptoms: Acute Flaccid Paralysis, Lymphatic Filariasis (LF), COVID-19 and cough with fast respiratory rate. All interventions relied on CHW sending text messages to supervisors via the mhealth tool. Users’ perspective of mhealth tools included: improved surveillance, better linkage with the community and greater efficiency. Conclusions We found a small number of mhealth tools used by CHW for infectious disease surveillance in Africa. Tools focused on epidemic-prone and neglected tropical diseases, and linked CHW with their supervisors. Results indicate that mhealth holds potential for strengthening community-based surveillance in Africa.

Prevalence of zoonotic (brugian) filariasis in Asia: A proportional meta-analysis

Lymphatic filariasis is a public health problem and targeted for global elimination. WHO recommends mass drug administration to interrupt transmission of the parasites involved. There are concerns that transmission interruption may be difficult in areas of zoonotic filarial infections. This study aimed to estimate the pooled prevalence of zoonotic brugian filariasis, and to compare the pooled prevalence of brugian filariasis in human and animal populations in the same area based on available studies. A comprehensive literature search was conducted in health-related electronic databases (PubMed, Ovid MEDLINE, Index Medicus, google scholar). A random-effect meta-analysis of the pooled overall prevalence of filariasis in animal populations was conducted. Sixteen studies from four different Asian countries were identified. Studies were conducted most frequently in Thailand (n = 7), followed by Malaysia (n = 5), India (n = 3), and Sri Lanka (n = 1). Regardless of animal group, the pooled overall prevalence of animal Brugia infections was 13% (95%CI: 7–21%, I2:98%, 16 studies). On stratification, the pooled overall prevalence in the animal population was 19% (95%CI: 1–50%, I2: 99%, 3 studies) in India, 8% (95%CI: 2–7%, I2: 97%, 5 studies) in Malaysia, and 13% (95%CI: 7–20%, I2: 94%, 7 studies) in Thailand. The prevalence in the animal population was 17% (95%CI: 13–21%, 1 study) in Sri Lanka. The pooled overall prevalence of Brugia malayi was 13% (95%CI: 7–21%, I2:98%, 12 studies), while for Brugia pahangi this was 12% (95%CI: 7–19%, I2:86%, 7 studies). Regardless of animal group, geographic area, or diagnostic test, the prevalence of B. malayi was consistently high. On stratification by animal category, the pooled overall prevalence was 10% (95%CI: 6–14%, I2:92%, 13 studies) in cats, 12% (95%CI: 2–28%, I2: 99%, 6 studies) in dogs, and 55% (95%CI: 47–63%, 1 study) in leaf-eating monkeys. The findings show the extent of zoonotic Brugiainfections in domestic cats and dogs, suggesting that these animals are potential reservoirs for human brugian filariasis in the study countries. To substantiate this with more accuracy, future well designed whole genomic sequencing of individual mf collected from humans and B. malayi infected animals in the same area are needed.

Burden of dengue, leishmaniasis and lymphatic filariasis in India and its states from 1990-2019: Analysis from the Global Burden of Disease study (GBD 2019).

Vector-borne diseases such as dengue, leishmaniasis, and lymphatic filariasis, constitute significant sources of illness, disability, and mortality among the poor and vulnerable in many countries around the world, including India. Based on the global burden of diseases, injuries, and risk factors study 2019, we analyse the burden of dengue, leishmaniasis, and lymphatic filariasis, in India from 1990 to 2019. Over this period, there was a reduction in the burden of lymphatic filariasis and leishmaniasis. Notably, dengue emerged as the most common vector-borne disease, exhibiting high fatality rate above 15 years of age and the highest DALY within 15-49 age group. Additionally, dengue cases surged substantially between 1990 and 2019. Leishmaniasis related mortality and DALY declined in the year 2019 compared to the year 1990, with high mortality and DALY in the 0-49-year-old age group. For lymphatic filariasis, DALY was more pronounce among those in the 15-49-year age group, which underwent reduction in 2019. Males had a higher burden in other vector-borne diseases than females, although females had a slightly elevated dengue burden. These findings highlight the evolving epidemiological trends related to vector-borne diseases in India, over the last three decades and underline the critical significance of sustained efforts for the elimination and control of vector-borne diseases.

Educational technologies for children about parasitic diseases: an integrative review

Introduction: Parasitic diseases have been causing serious public health problems around the world, especially in developing countries, with children being considered a more vulnerable group. This study aimed to identify educational technologies developed for or aimed at children about parasitic diseases in the scientific literature. Outlining: This is an integrative review, carried out in the following databases: MEDLINE, via PubMed; Embase; Web of Science; SCOPUS (Elsevier); LILACS and CINAHL. The population, interest, context strategy was used, combined with controlled and uncontrolled descriptors and the Boolean operators AND and OR. The analysis of the studies occurred in a descriptive way. Two categories emerged: digital educational technologies developed for or aimed at children about parasitic diseases and non-digital educational technologies developed for or aimed at children about parasitic diseases. Results: Eleven studies were included. Digital technologies were identified, such as cartoons, videos, and PowerPoint presentations, as well as non digital technologies, such as comic books, leaflets, board games and printed booklets. Educational technologies developed in school environments and/or in the community were found. The parasitic diseases covered were intestinal ones, the visceral leishmaniasis, malaria, Chagas disease, lymphatic filariasis and schistosomiasis mansoni. Implications: Digital and non-digital educational technologies have proven to be motivational, attractive, and complementary technological resources that contribute to children's active learning.

Persons 'never treated' in mass drug administration for lymphatic filariasis: identifying programmatic and research needs from a series of research review meetings 2020-2021.

As neglected tropical disease programs rely on participation in rounds of mass drug administration (MDA), there is concern that individuals who have never been treated could contribute to ongoing transmission, posing a barrier to elimination. Previous research has suggested that the size and characteristics of the never-treated population may be important but have not been sufficiently explored. To address this critical knowledge gap, four meetings were held from December 2020 to May 2021 to compile expert knowledge on never treatment in lymphatic filariasis (LF) MDA programs. The meetings explored four questions: the number and proportion of people never treated, their sociodemographic characteristics, their infection status and the reasons why they were not treated. Meeting discussions noted key issues requiring further exploration, including how to standardize measurement of the never treated, adapt and use existing tools to capture never-treated data and ensure representation of never-treated people in data collection. Recognizing that patterns of never treatment are situation specific, participants noted measurement should be quick, inexpensive and focused on local solutions. Furthermore, programs should use existing data to generate mathematical models to understand what levels of never treatment may compromise LF elimination goals or trigger programmatic action.