RESUMEN

BACKGROUND: Lymphatic filariasis (LF) is a globally significant, vector-borne, neglected tropical disease that can result in severe morbidity and disability. As the World Health Organization (WHO) Global Programme to Eliminate Lymphatic Filariasis makes progress towards LF elimination, there is greater need to develop sensitive strategies for post-intervention surveillance. Molecular xenomonitoring (MX), the detection of pathogen DNA in vectors, may provide a sensitive complement to traditional human-based surveillance techniques, including detection of circulating filarial antigen and microfilaraemia (Mf). This study aims to explore the relationship between human Mf prevalence and the prevalence of polymerase chain reaction (PCR)-positive mosquitoes using MX. METHODS: This study compared Mf and MX results from a 2019 community-based survey conducted in 35 primary sampling units (PSUs) in Samoa. This study also investigated concordance between presence and absence of PCR-positive mosquitoes and Mf-positive participants at the PSU level, and calculated sensitivity and negative predictive values for each indicator using presence of any Mf-positive infection in humans or PCR-positive mosquitoes as a reference. Correlation between prevalence of filarial DNA in mosquitoes and Mf in humans was estimated at the PSU and household/trap level using mixed-effect Bayesian multilevel regression analysis. RESULTS: Mf-positive individuals were identified in less than half of PSUs in which PCR-positive mosquito pools were present (13 of 28 PSUs). Prevalence of PCR-positive mosquitoes (each species separately) was positively correlated with Mf prevalence in humans at the PSU level. Analysed at the species level, only Aedes polynesiensis demonstrated strong evidence of positive correlation (r) with human Mf prevalence at both PSU (r: 0.5, 95% CrI 0.1-0.8) and trap/household levels (r: 0.6, 95% CrI 0.2-0.9). CONCLUSIONS: Findings from this study demonstrate that MX can be a sensitive surveillance method for identifying residual infection in low Mf prevalence settings. MX identified more locations with signals of transmission than Mf-testing. Strong correlation between estimated PCR-positive mosquitoes in the primary vector species and Mf in humans at small spatial scales demonstrates the utility of MX as an indicator for LF prevalence in Samoa and similar settings. Further investigation is needed to develop MX guidelines to strengthen the ability of MX to inform operational decisions.

Asunto(s)

RESUMEN

Some military organizations in the U.S. Indo-Pacific Command (INDOPACOM) give returning soldiers presumptive treatment for filariasis. As there have been few clinical cases in recent decades, the historical basis for this chemotherapy was reviewed. During the Second World War, U.S. Marines stationed on Polynesian islands such as Tonga, Samoa, and Fiji experienced clinical lymphatic filariasis. Although thousands of both U.S. and Australian soldiers served in New Guinea, few, if any, cases of lymphatic filariasis were ascribed to Melanesia. While the French Army reported dozens of cases of filariasis among its service members during the 1950s Vietnam conflict, the U.S. military experienced only a few cases among the nearly 2 million service members who served in Vietnam in the 1960s. Australian soldiers deployed to Timor Leste in the 21st century showed rare seroconversions to filaria but no clinical disease. Following mass drug administration to eliminate lymphatic filaria in the INDOPACOM region, exposure in deployed soldiers rarely occurs and preventive chemotherapy should cease.

Asunto(s)

RESUMEN

Parasitic infections like filariasis are uncommon causes of secondary membranous nephropathy (MN) which requires serological tests to detect circulating Wuchereria bancrofti antigens for its diagnosis or the identification of microfilariae in the capillary lumen on kidney biopsy. The immunochromatographic card tests is simple, non invasive and has high sensitivity and specificity. We report a case of 30 year old lady who presented to us with nephrotic syndrome which on kidney biopsy showed features of membranous nephropathy with negative staining for Anti PLA2R, THSD7A and exostosin. A thorough workup was done to find out any secondary cause of MN where she was found positive with filiarial antibody test. Hence, a diagnosis of secondary membranous pattern nephropathy was considered for which she was treated with diethylcarbamazine (DEC) and other supportive medications which on follow up showed marked resolution of proteinuria.

RESUMEN

Obligate intracellular endobacteria of the genus Wolbachia are widespread in arthropods and several filarial nematodes. Control programs for vector-borne diseases (dengue, Zika, malaria) and anti-filarial therapy with antibiotics are based on this important endosymbiont. Investigating Wolbachia, however, is impeded by the need for host cells. In this study, the requirements for Wolbachia wAlbB growth in a host cell-free in vitro culture system were characterized via qPCRs. A cell lysate fraction from Aedes albopictus C6/36 insect cells containing cell membranes and medium with fetal bovine serum were identified as requisite for cell-free replication of Wolbachia. Supplementation with the membrane fraction of insect cell lysate increased extracellular Wolbachia replication by 4.2-fold. Replication rates in the insect cell-free culture were lower compared to Wolbachia grown inside insect cells. However, the endobacteria were able to replicate for up to 12 days and to infect uninfected C6/36 cells. Cell-free Wolbachia treated with the lipid II biosynthesis inhibitor fosfomycin had an enlarged phenotype, seen previously for intracellular Wolbachia in C6/36 cells, indicating that the bacteria were unable to divide. In conclusion, we have developed a cell-free culture system in which Wolbachia replicate for up to 12 days, providing an in vitro tool to elucidate the biology of these endobacteria, e.g., cell division by using compounds that may not enter the C6/36 cells. A better understanding of Wolbachia biology, and in particular host-symbiont interactions, is key to the use of Wolbachia in vector control programs and to future drug development against filarial diseases.

RESUMEN

This study investigates the medicinal potential of Mitragyna parvifolia (M. parvifolia) leaves for the management of Lymphatic filariasis (LF). Phytochemical screening of the methanolic leaf extract revealed the presence of alkaloids, terpenoids, phenols, tannins, and flavonoids. The GC-MS analysis identified 24 phytoconstituents, including the major alkaloid "mitraphylline." Infrared spectroscopy confirmed the presence of various functional groups corresponding to the identified compounds. The extract exhibited significant antibacterial activity against Staphylococcus epidermidis, Bacillus cereus, and Salmonella typhi. In vitro macrofilaricidal screening demonstrated dose-dependent inhibition of worm motility and MTT reduction, indicating its potential as a macrofilaricidal agent. The larvicidal bioassay showed notable effectiveness against Culex quinquifasciatus larvae, with 1% concentration displaying the highest larvicidal activity. Concentration-dependent antioxidant activity was observed using the DPPH assay, with 100 µg/ml showing the highest antioxidant potential. The findings suggest the potential of M. parvifolia leaves for LF management, supporting further research to identify active compounds and elucidate their mechanisms of action. The study highlights the plant's diverse bioactive compounds, antibacterial and macrofilaricidal activities, larvicidal efficacy, and significant antioxidant properties. Future investigations, including in vivo experiments and clinical trials, are warranted to validate the safety and efficacy of M. parvifolia as a potential therapeutic agent for LF.

RESUMEN

Although lymphatic filariasis and onchocerciasis have been targeted for global elimination, these helminth infections are still a major public health problem across the tropics and subtropics. Despite decades of research, treatment options remain limited and drugs that completely clear the infections, and can be used on a large scale, are still unavailable. In the present review we discuss the strengths and weaknesses of currently available treatments and new ones in development. Novel candidates (corallopyronin A, DNDi-6166, emodepside, and oxfendazole) are currently moving through (pre)clinical development, while the development of two candidates (AWZ1066S and ABBV-4083/flubentylosin) was recently halted. The preclinical R&D pipeline for filarial infections continues to be limited, and recent setbacks highlight the importance of continuous drug discovery and testing.

Asunto(s)

RESUMEN

Lymphatic filariasis (LF) causes disfiguring and disabling lymphoedema, which can lead to mental distress and requires life-long self-care treatment. This study applies syndemic theory to understand the biosocial relationship between LF and mental distress in Malawi. Using in-depth qualitative methods, we critically evaluate experiences of mental distress and LF through 21 life-history interviews, to narrate experiences from the perspective of persons affected by LF, and to understand how enhanced self-care (ESC) for lymphoedema management disrupts the syndemic relationship. Complementary key informant interviews with Ministry of Health LF programme staff were conducted to further understand intervention and health system delivery. All interviews were recorded, transcribed, and translated, and then subject to thematic analysis. Our findings suggest that for persons affected by LF in Malawi, before being trained in ESC, absent referral pathways, inequalities in healthcare provision or available treatment, and limited knowledge of the condition (LF) drove the syndemic of LF and mental distress. Distress was often exacerbated by stigma and social exclusion, and shaped by intersections of gender, generation, poverty, and extreme climate conditions. We argue that addressing the syndemic suffering associated with LF and mental distress through interventions which center the needs of persons affected is critical in effective and equitable LF care delivery.

Asunto(s)

RESUMEN

Lymphatic filariasis (LF) is a crippling and disfiguring parasitic condition. India accounts for 55% of the world's LF burden. The filarial parasite Wuchereria bancrofti is known to cause 99.4% of the cases while, Brugia malayi accounts for 0.6% of the issue occurring mainly in some pockets of Odisha and Kerala states. The Balasore (Baleswar) district of Odisha has been a known focus of B. malayi transmission. We employed molecular xenomonitoring to detect filarial parasite DNA in vectors. In six selected villages, Gravid traps were used to collect Culex mosquitoes and hand catch method using aspirators was followed for collection of mansonioides. A total of 2903 mosquitoes comprising of Cx. quinquefasciatus (n = 2611; 89.94%), Cx. tritaeniorhynchus (n = 100; 3.44%), Mansonia annuliferea (n = 139; 4.78%) and Mansonia uniformis (n = 53; 1.82%) were collected from six endemic villages. The species wise mosquitoes were made into 118 pools, each with a maximum of 25 mosquitoes, dried and transported to the laboratory at VCRC, Puducherry. The mosquito pools were subjected to parasite DNA extraction, followed by Real-time PCR using LDR and HhaI probes to detect W. bancrofti and B. malayi infections, respectively. Seven pools (6.66%) of Cx. quinquefasciatus, showed infection with only W. bancrofti while none of the pools of other mosquito species showed infection with either W. bancrofti or B. malayi. Although the study area is endemic to B. malayi, none of the vectors of B. malayi was found with parasite infection. This study highlights the ongoing transmission of bancroftian filariasis in the study villages of Balasore district of Odisha and its implications for evaluating LF elimination programme.

Asunto(s)

RESUMEN

(1) Background and rationale: To validate the reported therapeutic coverage, a lymphatic filariasis post-mass drug administration (MDA) campaign survey was conducted in the Lukonga health zone from 10 June to 15 July 2023. (2) Materials and methods: This was a descriptive, cross-sectional study conducted at the community level in 30 villages in the Lukonga health zone from 10 June to 15 July 2023. The study population included all individuals from the visited communities. The study variables included age, sex, drug use (ivermectin + albendazole), adverse events, and adherence to MDA guidelines for supervised drug use. Questionnaires were administered on Android phones using the SurveyCTO platform. Stata version 17 was used for data analysis. (3) Results: Of the 1092 respondents, 54.8% were female and one-third were between the ages of 5 and 14. Two-thirds of the households surveyed, or 64%, had more than six people living in them, and 1031 individuals, or 94%, reported being present during the community mass drug distribution. Notably, 678 individuals, or 66%, reported taking the drugs offered, and 66.4% of those who took the drugs reported doing so in the presence of drug distributors. Thus, the survey coverage was 65.7% [95% CI: 62.9-68.7]. The results of this study show that the survey coverage was above the 65% threshold recommended by the WHO but below the 82.3% reported by the Lukonga health zone. The main reason for non-compliance was a fear of ivermectin-related side effects (47%). Supervised or directly observed treatment was not adhered to (66.4%). (4) Discussion and conclusions: Key challenges to further increase treatment coverage include assessing data quality, building capacity, motivating drug distributors, improving data reporting tools, proper recording by drug distributors, and accurate reporting on non-residents who take the drugs during the MDA. In addition, harmonization of the numerator for calculating drug coverage in the health zone is critical. It is imperative to provide the public with explicit information regarding the objective of drug distribution and the probable adverse effects.

RESUMEN

Context: Medical colleges regularly examine mass drug administration (MDA) programs to determine their effectiveness and pinpoint areas for development. These analyses frequently show a discrepancy between the program's coverage and actual drug use. This study was conducted in the Chamorshi and Armori blocks of the Gadchiroli District in Maharashtra. Aim: This study aimed to find out the coverage and compliance of MDA in the Chamorshi and Armori blocks of Gadchiroli, Maharashtra. Settings and Design: This study was a cross-sectional study. Materials and Methods: Thirty houses from each of the three randomly chosen villages and a ward were surveyed in each implementing unit. Thus, a total of 120 households' worth of data were gathered and examined. Information was gathered from each individual in the chosen home at the individual level. Statistical Analysis Used: Data were collected and duly filled out on questionnaire forms, which were then entered in Microsoft (MS) Excel. Statistical Package for the Social Sciences (SPSS) version 16.0 (Chicago) was used as a statistical tool in the analysis. Results: Consumption rates in rural areas were much higher than in urban areas. A minimum consumption rate was found in the 2- to 5-year-old age range. Conclusions: In this study, the percentage of coverage and compliance rates was 89.5% and 99.4% and 90.81% and 99.2% for the Armori and Chamorshi blocks, respectively. In comparison, coverage was better in rural areas than in urban areas. The MDA program must therefore be significantly strengthened in urban areas, particularly by guaranteeing improved compliance through monitored drug consumption.

RESUMEN

BACKGROUND: Loiasis is one of the significant filarial diseases for people living in West and Central Africa with wide endemic area but is not seen in China. As economy booms and international traveling increase, China faces more and more imported parasitic diseases that are not endemic locally. Loiasis is one of the parasitic diseases that enter China by travelers infected in Africa. The better understanding of the clinical and laboratory features of loa loa infection will facilitate the diagnosis and treatment of loiasis in China. METHODS: The study targeted travelers who were infected with L. loa in endemic Africa regions and returned to Beijing between 2014 and 2023. Epidemiological, clinical, and biological data as well as treatment of these patients were collected. RESULTS: Total 21 cases were identified as L. loa infection based on their typical clinical manifestations and parasite finding. All cases had a history of travel to Africa for more than 6 months, most of them are the construction workers dispatched to West Africa with outdoor activities. Calabar swelling (n = 19; 90.5%) and pruritus (n = 11; 52.4%) were among the most common clinical symptoms followed by muscle pain (n = 7; 33.3%) and skin rash (n = 2; 9.5%). The adult worms were observed in the eyelid or subconjunctiva (n = 2; 9.5%) and subcutaneous tissues (n = 2; 9.5%). Although all patients presented with a high eosinophil count (> 0.52 × 109/L), only two cases displayed microfilariae in fresh venous blood and positive for filarial antigen. A cut section of adult worm was observed through biopsy on a skin nodule surrounded by lymphocytes, plasma cells and eosinophils. All subjects were positive in PCR targeting L. loa ITS-1. The constructed phylogenetic tree based on the amplified ITS-1 sequences identified their genetical relation to the L. Loa from Africa. All patients treated with albendazole and diethylcarbamazine were recovered without relapse. CONCLUSION: This study provides useful information and guideline for physicians and researchers in non-endemic countries to diagnose and treat loiasis and L. loa infections acquired from endemic regions.

Asunto(s)

RESUMEN

Background: In 2018, the US Food and Drug Administration approved the macrocylic lactone moxidectin (MOX) at 8 mg dosage for onchocerciasis treatment in individuals aged ≥12 years. Severe adverse reactions have occurred after ivermectin (IVM), also a macrocyclic lactone, in individuals with high Loa microfilarial density (MFD). This study compared the safety and efficacy of a 2 mg MOX dose and the standard 150 µg/kg IVM dose in individuals with low L loa MFD. Methods: A double-blind, randomized, ivermectin-controlled trial of a 2 mg moxidectin dose was conducted in Cameroon between May and July 2022. It enrolled 72 adult men with L loa MFD between 5 and 1000 microfilariae/mL. Outcomes were occurrence of adverse events (AEs) and L loa MFD reduction rate during the first month off treatment. Results: No serious or severe AEs occurred among the 36 MOX- or the 36 IVM-treated individuals. Forty-nine AEs occurred in the MOX arm versus 59 AEs in the IVM arm. Grade 2 AE incidence was higher among IVM- than MOX-treated participants (38.5% and 14.3%, respectively, P = .043). Median MFD reduction rates were significantly higher after IVM than MOX at day 3 (70.2% vs 48.5%), day 7 (76.4% vs 50.0%), and day 30 (79.8% vs 48.1%). Conclusions: A single 2 mg MOX dose is as safe as 150 µg/kg IVM in patients with low L loa MFD. Further studies with higher MOX doses and in patients with higher MFD are warranted. Clinical Trials Registration: NCT04049851.

RESUMEN

The enzyme aspartate semialdehyde dehydrogenase (ASDH) plays a pivotal role in the amino acid biosynthesis pathway, making it an attractive target for the development of new antimicrobial drugs due to its absence in humans. This study aims to investigate the presence of ASDH in the filarial parasite Wolbachia endosymbiont of Brugia malayi (WBm) using both in vitro and in silico approaches. The size exclusion chromatography (SEC) and Native-PAGE analysis demonstrate that WBm-ASDH undergoes pH-dependent oligomerization and dimerization. To gain a deeper understanding of this phenomenon, the modelled monomer and dimer structures were subjected to pH-dependent dynamics simulations in various conditions. The results reveal that residues Val240, Gln161, Thr159, Tyr160, and Trp316 form strong hydrogen bond contacts in the intersurface area to maintain the structure in the dimeric form. Furthermore, the binding of NADP+ induces conformational changes, leading to an open or closed conformation in the structure. Importantly, the binding of NADP+ does not disturb either the dimerization or oligomerization of the protein, a finding confirmed through both in vitro and in silico analysis. These findings shed light on the structural characteristics of WBm-ASDH and offer valuable insights for the development of new inhibitors specific to WBm, thereby contributing to the development of potential therapies for filarial parasitic infections.

Asunto(s)

RESUMEN

OBJECTIVES: Circulating filarial antigen (Ag) is used by elimination programs to monitor lymphatic filariasis (LF) transmission; however, antifilarial antibodies (Ab) may be more sensitive than Ag for detecting LF. Our objectives were to describe Ab seroprevalence, identify risk factors for Ab seropositivity, investigate age-specific associations between Ag and Ab, and evaluate geographic clustering of seropositivity. METHODS: Community-based serosurveys of participants aged ≥5 years were conducted in 35 primary sampling units (PSUs). Ag-positivity was detected using Alere™ Filariasis Test Strips and Ab-seropositivity using multiplex bead assays. Seroprevalence was adjusted for study design. RESULTS: Of 3795 participants (range:5-90 years), adjusted prevalence for Ag, Bm14 Ab, Wb123 Ab, and Bm33 Ab were 3.7% (n=117), 20.3% (n=583), 32.2% (n=987), and 51.0% (n=1659), respectively. Male sex, older age, and residents of suspected hotspots had higher odds of seropositivity to all seromarkers. Seroprevalence was lower in 5-9-year-olds vs ≥10-year-olds (P<0.001). Clustering was significantly higher in households (intra-cluster correlation for Ag:0.45; Bm14 Ab:0.32; Bm33 Ab:0.31; Wb123 Ab:0.29) compared to PSUs or region. CONCLUSIONS: Abs enabled identification of risk factors for seropositivity and geographical clustering to inform targeted interventions for LF programmes. Further research is needed to define Ab thresholds for active versus past infection and elimination targets.

RESUMEN

Lymphatic filariasis is an endemic parasitic infection in 72 countries. It is caused by a filarial worm transmitted through mosquito bites. Acute nonspecific symptoms can occur, such as fever and edematous inflammatory plaques, while its chronic state is commonly characterized by lymphedema.

RESUMEN

Filariasis is a major public health concern in tropical and subtropical countries like India with Wuchereria bancrofti accounting for 90% of lymphatic filariasis. Rarely observed are extra lymphatic manifestations caused by interaction of immune system with microfilaria and their diffusible products. Among various organs involved, splenic involvement is a rare extra lymphatic manifestation of filariasis and can masquerade clinicoradiologically as metastasis when associated with a known malignancy or as a primary malignancy like lymphoma. Hereby, we present an unusual case of coincidence of splenic filariasis with pancreatic solid pseudopapillary epithelial neoplasm in a 20-year-old woman associated with peripheral blood eosinophilia.

RESUMEN

Filariasis is recognised as a global public health threat, particularly in tropical and subtropical regions. It is caused by infection with a nematode parasite of the superfamily Filarioidea, including Wuchereria bancrofti, Brugia malayi, Onchocerca volvulus, and Onchocerca lupi. Three main types of filariasis have been classified: lymphatic filariasis, subcutaneous filariasis, and serous cavity filariasis. The symptoms exhibited by individuals afflicted with filariasis are diverse and contingent upon several variables, including the species of parasite, the host's health and immune response, and the stage of infection. While many classical parasitological techniques are considered indispensable tools for the diagnosis of parasitic infections in humans, alternative methods are being sought due to their limitations. Novel tests based on host-parasite interactions offer a rapid, simple, sensitive, and specific diagnostic tool in comparison to traditional parasitological methods. This article presents methods developed in the 21st century for the diagnosis of filariasis caused by invasion from W. bancrofti, B. malayi, O. volvulus, and O. lupi, as well as techniques that are currently in use. The development of modern diagnostic methods based on molecular biology constitutes a significant advancement in the fight against filariasis.

RESUMEN

Lymphatic filariasis is a neglected tropical disease that affects the lymphatic system of humans. The major etiologic agent is a nematode called Wuchereria bancrofti, but Brugia malayi and Brugia timoriare sometimes encountered as causative agents. Mosquitoes are the vectors while humans the definitive hosts respectively. The burden of the disease is heavier in Nigeria than in other endemic countries in Africa. This occurs with increasing morbidity and mortality at different locations within the country, the World Health Organization recommended treatments for lymphatic filariasis include the use of Albendazole (400mg) twice per year in co-endemic areas with loa loa, Ivermectin (200mcg/kg) in combination with Albendazole (400mg) in areas that are co-endemic with onchocerciasis, ivermectin (200mcg/kg) with diethylcarbamazine citrate (DEC) (6mg/kg) and albendazole (400mg) in areas without onchocerciasis. This paper covered a systematic review, meta-analysis, and scoping review on lymphatic filariasis in the respective geopolitical zones within the country. The literature used was obtained through online search engines including PubMed and Google Scholar with the heading "lymphatic filariasis in the name of the state", Nigeria. This review revealed an overall prevalence of 11.18% with regional spread of Northwest (1.59%), North Central and North East, (4.52%), South West (1.26%), and South-South with South East (3.81%) prevalence. The disease has been successfully eliminated in Argungu local government areas (LGAs) of Kebbi State, Plateau, and Nasarawa States respectively. Most clinical manifestations (31.12%) include hydrocele, lymphedema, elephantiasis, hernia, and dermatitis. Night blood samples are appropriate for microfilaria investigation. Sustained MDAs, the right testing methods, early treatment of infected cases, and vector control are useful for the elimination of lymphatic filariasis for morbidity management and disability prevention in the country. Regional control strategies, improved quality monitoring of surveys and intervention programs with proper records of morbidity and disability requiring intervention are important approaches for the timely elimination of the disease in Nigeria.

Asunto(s)

RESUMEN

Lymphatic filariasis is endemic in a few states of India and is one of the most common public health concerns. Wuchereria bancrofti (W. bancrofti) is the most common parasite that causes lymphatic filariasis in India. Microfilariae have been commonly found in the peripheral blood and body fluid, as well as demonstrated in fine needle aspirates (FNA) and bronchial cytology. They have been rarely reported in bone marrow aspirates. Due to the nocturnal periodicity of W. bancrofti, it may be missed in peripheral blood during the day. Though peripheral eosinophilia is a presenting feature of filariasis, it may be absent in the majority of cases, as in this case. We report an incidental finding of W. bancrofti in the bone marrow aspirate of a 72-year-old male who had chronic kidney disease.