RESUMO

We describe a recent case of lymphatic filariasis in Colombia caused by Wuchereria bancrofti nematodes. Our study combines clinical-epidemiologic findings with phylogenetic data. Resurgence of lymphatic filariasis may be linked to increasing urbanization trends and migration from previously endemic regions. Fieldwork can be a beneficial tool for screening and containing transmission.

Assuntos

RESUMO

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

Assuntos

RESUMO

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

Assuntos

RESUMO

During bacterial and viral pathogen investigation of 30 specimens of bats captured in periurban forest areas in the city of Belém, Pará, Brazil, a case of cerebral filariasis was observed. In the course of histopathological examination, adult filariae were found in pseudocystic cavities brain of Molossus barnesi (Molossidae) and classified morphologically as Litomosoides by the shape of the spicules-left spicule with a handle longer than the blade; right spicule curved, with a sclerotized heel supporting a dorsal notch; the area rugosa constituted by a ventral band of small longitudinal crests; tail rounded in males; long esophagus with a slightly glandular distal portion; and a muscular bent vagina. All the specimens lack a stoma (buccal capsule). We compared our filarioids with the description of specimens of Molossinema wimsatti. Morphological characteristics of M. wimsatti resemble the genus Litomosoides. Thus, we believe that M. wimsatti is a synonym of L. molossi Esslinger, 1973, and filarioid specimens from material reported by Lichtenfels et al. (Trans Am Micros Soc 100:216-219, 1981) and from de Souto et al. (J. Helminthol 1195:e65, 2021) most probably correspond to Litomosoides. We suggest that the reduction of the buccal capsule may be attributable to the ectopic location. No evidence of tissue responses by the host was observed. This is the first record of Litomosoides infecting brain tissue of Molossus barnesi from Brazil, representing a record of a new host species. More specimens of bats should be examined in order to find filarioids in the brain and verify its taxonomic position using molecular techniques.

Assuntos

RESUMO

Introduction: 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. Methods: 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. Results: 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). Conclusion: 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.

Assuntos

RESUMO

BACKGROUND: Mansonellosis is an undermapped insect-transmitted disease caused by filarial nematodes that are estimated to infect hundreds of millions of people. Despite their prevalence, there are many outstanding questions regarding the general biology and health impacts of the responsible parasites. Historical reports suggest that the Colombian Amazon is endemic for mansonellosis and may serve as an ideal location to pursue these questions. METHODS: We deployed molecular and classical approaches to survey Mansonella prevalence among adults belonging to indigenous communities along the Amazon River and its tributaries near Leticia, Colombia. RESULTS: Loop-mediated isothermal amplification (LAMP) assays on whole-blood samples detected a much higher prevalence of Mansonella ozzardi infection (approximately 40%) compared to blood smear microscopy or LAMP performed using plasma, likely reflecting greater sensitivity and the ability to detect low microfilaremias and occult infections. Mansonella infection rates increased with age and were higher among men. Genomic analysis confirmed the presence of M. ozzardi that clusters closely with strains sequenced in neighboring countries. We successfully cryopreserved M. ozzardi microfilariae, advancing the prospects of rearing infective larvae in controlled settings. CONCLUSION: These data suggest an underestimation of true mansonellosis prevalence, and we expect that these methods will help facilitate the study of mansonellosis in endemic and laboratory settings.

Assuntos

RESUMO

Among vector-borne helminths, filarioids of the genus Dipetalonema (Spirurida: Onchocercidae) localize in several tissues and body cavities of several animal species, causing mild to moderate lesions. The pathological findings associated with Dipetalonema spp. infection in Neotropical monkeys from southern Brazil are herein described, along with a fatal case due to filarial polyserositis and entrapment of an intestinal segment. At necropsy, nematodes were observed in abdominal and thoracic cavities, or in the pericardium of 37 (31.3%) out of the 118 individuals examined (i.e., 35 Alouatta guariba clamitans and two Sapajus nigritus). In addition, at histology, 27.0% of positive animals presented microfilarie (inside blood vessels of lung, spleen, liver, and brain) and 8.1% presented adult nematodes in the heart, lung, and liver. In two cases, cross-sections of filarioids were associated with areas of epicardial thickening with intense fibrosis and pyogranulomatous inflammation in the brain, heart, liver, lungs, or spleen. The DNA fragment was amplify using the cox1 gene, sequenced and analyzed to identify the nematode species collected; presence of Wolbachia was assessed in the filarioids using the 16S rRNA gene. At BLAST analysis of the cox1 gene, 10 sequences showed 91.7% nucleotide identity with Dipetalonema gracile, and two with D. gracile (98.5%) and Dipetalonema graciliformis (98.3%). Phylogenetic analyses clustered sequences of the cox1 obtained in this study in two clades corresponding with the host species. Wolbachia sp. endosymbiont was detected in four samples. Data herein reported provide a description of pathological lesions associated with the infection by Dipetalonema spp., suggesting that they may cause disease in Neotropical monkeys. In addition, a better understanding of diversity and biology of Dipetalonema spp. in South America is needed to assess the impact they may cause in native non-human primates from Brazil.

Assuntos

RESUMO

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.

Assuntos

RESUMO

Culex quinquefasciatus is a vector of lymphatic filariasis. One important component in planning filariasis control activities is the mapping of vector distribution. A tool that involves socio-environmental factors and Cx. quinquefasciatus density can contribute to the identification of areas that should be prioritized in surveillance actions. This is an ecological study based on the construction and validation of a risk score of urban areas according to social and environmental variables extracted from a national database. Based on this stratification, female Cx. quinquefasciatus were captured. In total, 30,635 Cx. quinquefasciatus were captured, of which 17,161 (56%) were females. The highest vector density index of mosquitoes were captured in households located in the high-risk stratum and the indicator proved to be a tool that identified an association between social and environmental conditions and areas with the highest vector density index of females Cx. quinquefasciatus.

Assuntos

RESUMO

The primates that inhabit the rainforest surrounding the city of Manaus (Amazonas, Brazil) have long been recognised as potentially important reservoirs of emerging and re-emerging infectious diseases (ERIDs). PCR amplification of filarial sequences from wild-caught Simulium oyapockense has been used to incriminate potentially important Amazon-region ERID bridge vectors by showing they had previously fed on non-human primates. The broader use of filarial parasite sequences for the incrimination of biting insects as potentially important zoonotic disease vectors is limited by a paucity of primate-derived filarial parasite reference sequences which can be matched to the PCR amplified sequences obtained from insect-vector vectors. Here we have used shotgun sequencing to obtain reference data from an adult Dipetalonema gracile parasite which was found infecting a wild pied tamarin (Saguinus bicolor) in a peripheral region of Manaus. We report the parasite´s complete mitochondrial genome (which is 13,647 base pairs in length), 894,846 base pairs of its Wolbachia genome and 6,426 base pairs of its ribosomal DNA locus (spanning from the start of its 18S subunit to the end of its 28S subunit). Despite being critically endangered, S. bicolor is commonly encountered around the periphery of Manaus and in urban forest fragments. The reported sequences may be a useful reference tool for identifying ERID bridge vectors and potentially provide some insights into the amount and the nature of contact between primate pathogen reservoirs and the residents of Manaus.(AU)

Os primatas que habitam a floresta tropical ao redor da cidade de Manaus (Amazonas, Brasil) há muito são reconhecidos como reservatórios potencialmente importantes de doenças infecciosas emergentes e reemergentes. Sequências de DNA de parasitas filariais detectadas por PCR em amostras de Simulium oyapockense foram usadas para demonstrar que eles haviam se alimentado anteriormente de primatas não humanos e, dessa maneira, incriminar vetores-ponte da região amazônica. O uso mais amplo de detecção de parasitas filariais para a incriminação de vetores-ponte é limitado por uma escassez de sequências referência de parasitas filarias obtidas de hospedeiros. Aqui nós usamos o sequenciamento tipo shotgun para obter dados de referência de um parasita adulto Dipetalonema gracile encontrado infectando um sauim-de-coleira, Saguinus bicolor no entorno de Manaus. Relatamos o genoma mitocondrial completo do parasita (que tem 13.647 pares de bases de comprimento), 894.846 pares de bases de seu genoma de Wolbachia e 6.426 pares de bases de seu locus de DNA ribossômico (desde o início de sua subunidade 18S até o final de sua subunidade 28S). Apesar de criticamente ameaçado, S. bicolor é comumente encontrado no entorno de Manaus e em fragmentos florestais urbanos. As sequências relatadas podem ser uma ferramenta de referência útil para identificar vetores ponte e potencialmente fornecer algumas informações sobre o contato entre reservatórios de patógenos de primatas e os moradores de Manaus.(AU)

Assuntos

RESUMO

ABSTRACT Background: Mansonia mosquitoes transmit arboviruses to humans. This study describes the karyotypes and C-banding of Mansonia humeralis, Mansonia titillans, Mansonia pseudotitillans, and Mansonia indubitans. Methods: From the 202 larvae, the brain ganglia were dissected (n=120) for the preparation of slides. Twenty slides with well-distended chromosomes for each species (10 for karyotyping and 10 for C-banding) were selected for further study. Results: The haploid genome and the average lengths of the chromosomal arms differed in relation to the centromere between species, and intraspecific differences also occurred in the distribution of the C-bands. Conclusions: These results are useful for better understanding of the chromosomal variability of Mansonia mosquitoes.

RESUMO

Different nematodes affect canines, however Acanthocheilonema reconditum was considered mostly a non-pathogenic parasite. Climate change, animal migration, and other factors transformed the dynamics of vector-borne diseases, including filariasis. Since 2016, a sudden increase in the number of dogs with microfilaremia was reported by different veterinary centers in Cali, southwest Colombia. The objective of this study was to molecularly identify the etiologic agent of this filariasis outbreak detected in this city, using PCR−RFLP and evaluating dogs' clinical signs. From 2018−2019, canine filariasis cases were prospectively evaluated after a microscopic test, recruiting 82 cases and 43 healthy controls from 2971 samples. Acanthocheilonema reconditum (Nematoda, Onchocercidae) was identified in 61.3% of the cases (49/82) by PCR−RFLP. Sanger sequencing of the 5.8S ribosomal RNA gene and internal transcribed spacer-2 fragment was additionally performed on seven cases, confirming A. reconditum in all of them. The filariasis cases are statistically associated with male dogs who have clinical signs of anemia, low levels of hemoglobin and hematocrit (p < 0.0001), and high levels of plasma proteins (p < 0.001). This emerging canine disease constitutes an important public health concern among veterinarians and active surveillance is advised to explore its zoonotic potential.

RESUMO

Mosquitoes can be vectors of pathogens and transmit diseases to both animals and humans. Species of the genus Culex are part of the cycle of neglected diseases, especially Culex quinquefasciatus, which is an anthropophilic vector of lymphatic filariasis. Natural products can be an alternative to synthetic insecticides for vector control; however, the main issue is the poor water availability of some compounds from plant origin. In this context, nanoemulsions are kinetic stable delivery systems of great interest for lipophilic substances. The objective of this study was to investigate the larvicidal activity of the Hyptis suaveolens essential oil nanoemulsion on Cx. quinquefasciatus. The essential oil showed a predominance of monoterpenes with retention time (RT) lower than 15 min. The average size diameter of the emulsions (sorbitan monooleate/polysorbate 20) was ≤ 200 nm. The nanoemulsion showed high larvicidal activity in concentrations of 250 and 125 ppm. CL50 values were 102.41 (77.5253−149.14) ppm and 70.8105 (44.5282−109.811) ppm after 24 and 48 h, respectively. The mortality rate in the surfactant control was lower than 9%. Scanning micrograph images showed changes in the larvae's integument. This study achieved an active nanoemulsion on Cx. quinquefasciatus through a low-energy-input technique and without using potentially toxic organic solvents. Therefore, it expands the scope of possible applications of H. suaveolens essential oil in the production of high-added-value nanosystems for tropical disease vector control.

Assuntos

RESUMO

Introduction: Studies conducted in 1984 demonstrated the presence of Mansonella ozzardi in the Darien and Colon provinces. Since then, there have not been further reports of this parasitic infection in Panama. Methodology: We conducted a cross-sectional assessment of peripheral blood samples of individuals across Panama over a 4-year period (2013-2016) as part of malaria surveillance activities. Results: We identified microfilaria in 96 cases. Most of these cases were found in East Panama (78%) followed by the Darien region (22%). Mansonella ozzardi was the filarial parasite identified by morphological features in all cases. Conclusion: After 36 years of epidemiological silence, we identified human cases of Mansonella ozzardi infection in Panama. This is, however, the first report of this filarial parasite's presence in the Eastern region of Panama. There is a need for further surveillance efforts to elucidate the epidemiology associated with Mansonella infections in Panama.

RESUMO

A 54 year-old man with lymphopenia secondary to lymphatic filariasis was admitted with dry cough, fever and wasting syndrome. He was diagnosed with sarcoidosis and therapy with corticosteroid was initiated. The patient evolved with worsening of the symptoms. Histoplasma species was recovered in lung biopsy tissue, lung tissue culture, and bone marrow aspirate. The authors describe the first case of disseminated histoplasmosis secondary to lymphatic filariasis, followed by a literature review. 2012 Elsevier Ltd. All rights reserved.

RESUMO

Background: Stephanofilariasis is a parasitic disease caused by the nematode Stephanofilaria spp., considered a zoonotic disease, that affects several species, mainly dairy cattle. The condition causes chronic ulcerative dermatitis, due to the mechanical action of the parasite on the hair follicles and dermal papillae. The recommended diagnostic method is histopathological examination, but alternative methods have been studied for the detection of the agent since it does not demonstrate good results. There is no specific treatment, however, the use of organophosphates is recommended. The objective of this work is to report an outbreak of stephanofilariasis with unusual lesions in cattle from a dairy cattle farm in the city of Boa Vista do Buricá, RS, Brazil, as well as to demonstrate an alternative method for the diagnosis of the disease. Cases: We prospectively evaluated 15 Holstein cows, aged between 1 and 10-year-old whose data and materials for diagnosis, were provided by the property owner. The outbreak occurred in the summer, in a period of greater rainfall, affecting cows of different ages and totaling 48% of the herd. These showed ulcerative lesions on the skin of the groin, limbs and interdigital regions, and less frequently in the udder. The samples were obtained through tissue biopsy and scraped from the lesions, being packed in 10% formaldehyde for fixation. Afterward, the formaldehyde was centrifuged at 800 g for 5 min, which consisted of analyzing the sediment through optical microscopy and without staining, aiming at the direct search of the agent. The tissues, on the other hand, underwent routine processing and stained with Hematoxylin and Eosin. Histopathological analysis did not reveal Stephanofilaria sp. subjects in morphological analysis and revealed acanthosis, spongiosis, ulcers and fibrosis in the analyzed tissue. The examination of direct research with formaldehyde proved to be efficient, and fast. In the direct examination of the agent, structures similar to filarial and compatible with Stephanofilaria sp. in all samples. Thus, the present study demonstrated that filariasis can present in the form of outbreaks and with unusual injuries. The examination of direct research with formaldehyde, proved to be efficient and fast. Discussion: Semi-confined and confined animals may have a higher occurrence of strephanofilariasis, since the parasite needs humid and warm environments to proliferate and that, the proliferation of stephanophilariasis vectors is intensified in environments with low sunlight, high temperatures, high humidity, and low cleaning frequency. The city of Boa Vista do Buricá, where the outbreak occurred, reached a minimum average temperature of 18.5ºC and an average of 29ºC, with an average rainfall of 120.5 mm. Cutaneous lesions have been seen in animals from 1 to 10 years of age and no racial predisposition, age, or blackout stage is reported. The histological diagnosis, although mentioned as a form of diagnosis, has low efficacy in finding parasites in the tissue, is also used as a diagnosis, direct examination of the agent with saline solution, and impression of the lesion stained by the Romanoswsky method. However, in this report, formaldehyde proved to be a new option, as efficiently as saline.

Assuntos

RESUMO

The Global Program to Eliminate Lymphatic Filariasis (GPELF) is a program that aims to eliminate lymphatic filariasis by 2030. The GPELF strategy is based on interrupting transmission using mass drug administration (MDA) and, in parallel, managing morbidity cases. However, it has been seen that there is a shortage of research in the literature and public policies regarding this last pillar. In this study, we reviewed the literature and available information regarding the burden of filarial morbidity. In addition, we identified that in the Americas, the implementation of structured services with regard to morbidity assistance in the Americas was scarce. We formed a review that aimed to assess the pathogenesis, epidemiology, repercussions, and treatment of filarial morbidity in countries in the Americas where lymphatic filariasis is endemic. Structured searches were carried out on PubMed, LILACS, Scopus, and Web of Science databases without time and language restrictions. Three reviewers evaluated the 2150 studies and performed data extraction, and quality assessment by assigning scores to the studies found. The current literature and available information on the burden of filarial morbidity, as well as the implementation of structured services with regard to morbidity assistance in the Americas, were all found to be scarce. Now that this knowledge gap has been identified, both health services and researchers need to seek the implementation and enhancement of the maintenance of GPELF strategies that relate to the morbidity pillar.

Assuntos

RESUMO

BACKGROUND & OBJECTIVES: For decades, the city of Belém in Brazil's eastern Amazon was the second city in the country with highest prevalence of cases of filariasis due to Wuchereria bancrofti infection. However, this prevalence decreased over time until reaching null records, concomitantly with a decrease in frequency of recorded hydrocele cases. In this context, we analyzed cross-sectional data to evaluate the degree of correlation between prevalence of positive blood microfilariae results during surveillance screening occurred along 54 years (1951-2005) and prevalence of hydrocele cases recorded in the same time period. METHODS: The dataset regarding hydrocele cases was obtained from two local hospitals. The Endemic Diseases Control Division of the Health Surveillance Department of the Municipal Health Department of Belém provided dataset regarding positive blood microfilariae cases. Prevalence calculus and linear correlation statistics were performed. RESULTS: Both positive blood microfilariae and hydrocele cases are well correlated statistically in absolute frequency (r = 0.871, 95%CI = 0.788 to 0.923, R2 = 0.759, p < 0.0001) and in prevalence (r = 0.835, 95%CI = 0.732 to 0.901, R2 = 0.698, p < 0.0001). INTERPRETATION & CONCLUSION: We have concluded that blood microfilariae detection and hospitalized hydrocele cases are well correlated in our dataset. In addition, these results support the hypothesis that hydrocele prevalence can be useful to filariasis surveillance and control in endemic areas. However, limitations to hydrocele prevalence as an epidemiological indicator of filariasis are evidenced.

Assuntos

RESUMO

RESUMO O Plano Global de Eliminação da Filariose Linfática, lançado pela Organização Mundial da Saúde em 2000, propõe o uso de testes de detecção de antígeno circulante filarial como ferramenta diagnóstica para avaliação e monitoramento das ações de controle da parasitose. Entretanto, esses testes, apesar de apresentarem alta sensibilidade, não conseguem detectar com eficiência a infecção em seu estágio inicial, quando ainda não existe a presença de helmintos adultos. Considerando essa limitação, a pesquisa de anticorpos antifilariais tem sido apontada como uma alternativa, uma vez que os anticorpos produzidos contra as larvas infectantes do parasito são detectados antes da presença de antígeno circulante filarial. O objetivo deste estudo foi definir o ponto de corte e avaliar a acurácia do kit Filaria Detect™ IgG4 produzido com o antígeno recombinante Wb123 para diagnóstico da filariose linfática no Brasil. Para isso, foi realizado um estudo de avaliação de teste diagnóstico, no qual foram utilizadas 256 amostras de soro: 79 (30,9%) obtidas de indivíduos microfilarêmicos e 177 (60,1%), de indivíduos amicrofilarêmicos e que testaram negativo para os testes imunológicos Bm14 CELISA e Og4C3 ELISA. A definição do ponto de corte ideal, bem como da acurácia do kit Filaria Detect™ IgG4, foi obtida através da construção de curvas ROC, sendo a densidade óptica de 0,239 aquela na qual o teste obteve melhor desempenho, com sensibilidade de 81,0% e especificidade de 96,6%. Os resultados obtidos demonstraram que o kit Filaria Detect™ IgG4 é uma ferramenta promissora para investigação e monitoramento de áreas submetidas ao tratamento em massa para filariose linfática.

ABSTRACT The Global Programme to Eliminate Lymphatic Filariasis, launched by the World Health Organization in the year 2000, proposes the use of circulating filarial antigen tests as a diagnostic tool to assess and monitor initiatives to control filarial infection. However, despite a high sensitivity, these tests are not efficient to detect infection at early stages, before worms have reached the adult stage. Considering this limitation, anti-filarial antibody testing has been suggested as an alternative, given that the antibodies produced against the larvae are detectable before the presence of circulating filarial antigen. The objective of the present study was to determine the diagnostic cut-off and the accuracy of the Filaria Detect™ IgG4 kit employing recombinant Wb123 antigen for diagnosis of lymphatic filariasis in Brazil. For that, we performed a diagnostic evaluation study in which 256 serum samples were analyzed: 79 (30.9%) obtained from microfilaremic individuals and 177 (60.1%) from amicrofilaremic individuals who tested negative with the Bm14 CELISA and Og4C3 ELISA immunologic tests. The ideal cutoff as well as the Filaria Detect™ IgG4 kit accuracy were determined based on ROC curve analyses, with an optical density of 0.239 identified as the cutoff with the best performance, with 81.0% sensitivity and 96.6% specificity. The results show that the Filaria Detect™ IgG4 kit is a promising tool for investigation and monitoring of areas undergoing mass drug administration for lymphatic filariasis.

RESUMEN En el programa mundial de eliminación de la filariasis linfática, puesto en marcha por la Organización Mundial de la Salud en el año 2000, se propone el uso de pruebas de detección del antígeno filárico circulante como instrumento de diagnóstico para la evaluación y el seguimiento de las medidas de control de la parasitosis. Sin embargo, esas pruebas, a pesar de tener un alto grado de sensibilidad, no permiten detectar con eficiencia la infección en su fase inicial, cuando todavía no existen helmintos adultos. En vista de esa limitación, se ha señalado como una opción el estudio de anticuerpos antifiláricos, puesto que los anticuerpos producidos contra las larvas infectantes del parásito se detectan antes de la existencia de antígeno filárico circulante. El objetivo de este estudio fue definir el punto de corte y evaluar la exactitud del estuche Detect™ para pruebas de anticuerpos antifiláricos IgG4, fabricado con el antígeno recombinante Wb123, para el diagnóstico de la filariasis linfática en Brasil. Para ello, se realizó un estudio de evaluación de la prueba diagnóstica, en el cual se utilizaron 256 muestras de suero, a saber, 79 (30,9%) obtenidas de personas microfilarémicas y 177 (60,1%) de personas amicrofilarémicas, que arrojaron resultados seronegativos en las pruebas inmunológicas CELISA Bm14 y ELISA Og4C3. La definición del punto de corte ideal y de la exactitud del estuche Detect™ se obtuvo con la construcción de curvas de la característica operativa del receptor (ROC); una densidad óptica de 0,239 marcó el mejor nivel de desempeño de la prueba, con una sensibilidad de 81,0% y una especificidad de 96,6%. Los resultados obtenidos demostraron que el estuche Detect™ es un instrumento prometedor para la investigación y el seguimiento de las regiones donde se realiza un tratamiento masivo de la filariasis linfática.

Assuntos

RESUMO

ABSTRACT Objective. To confirm the absence of Wuchereria bancrofti autochthonous cases in Manaus, a former focus of lymphatic filariasis in the Western Brazilian Amazon. Methods. A field survey was carried out in 2016 using immunochromatographic rapid tests (ICT card) for the detection of circulating filarial antigens in blood. The sample included a group of 3 000 schoolchildren aged 6 to 10 years enrolled in schools from different urban areas of Manaus (including the former lymphatic filariasis focus in the city) and a group of 709 adolescents and adults, between the ages of 11 and 85 years, born and raised in different areas of Manaus. Results. All of the individuals tested negative for W. bancrofti antigen. Conclusions. Although Manaus was once considered endemic, this focus no longer seems to be active for lymphatic filariasis transmission. The results of this study could support the certification by the World Health Organization of the lymphatic filariasis transmission elimination exercise in Brazil.

RESUMEN Objetivo. Confirmar la ausencia de casos autóctonos de Wuchereria bancrofti en Manaos, anteriormente un foco de filariasis linfática en la Amazonia occidental de Brasil. Métodos. En el 2016 se llevó a cabo una encuesta en el terreno con pruebas rápidas inmunocromatográficas (tiras inmunocromatográficas) para detectar antígenos filáricos circulantes en sangre. La muestra constó de un grupo de 3 000 escolares de 6 a 10 años matriculados en escuelas de diferentes zonas urbanas de Manaos (incluida la zona que anteriormente era el foco de filariasis linfática en la ciudad) y de un grupo de 709 adolescentes y adultos, de edades comprendidas entre 11 y 85 años, nacidos y criados en diferentes áreas de Manaos. Resultados. Todas las personas dieron negativo en la prueba de antígeno de Wuchereria bancrofti. Conclusiones. Aunque hubo un tiempo en que Manaos se consideraba zona endémica, parece que este foco de transmisión de la filariasis linfática ya no está activo. Los resultados de este estudio podrían brindar apoyo a la certificación de la Organización Mundial de la Salud respecto de los esfuerzos realizados en Brasil para eliminar la transmisión de la filariasis linfática.

RESUMO Objetivo. Confirmar a ausência de casos autóctones de Wuchereria bancrofti em Manaus, anteriormente um foco da filariose linfática na parte leste da Amazônia brasileira. Métodos. Uma pesquisa de campo foi realizada em 2016 com o uso de teste rápido por imunocromatografia (cartão ICT) para detecção de antígenos de microfilárias circulantes no sangue. A amostra estudada consistiu de um grupo de 3 000 crianças escolares entre 6 e 10 anos de idade matriculados em escolas de diferentes áreas da zona urbana de Manaus (englobando a área anteriormente com o foco de filariose linfática) e um grupo de 709 adolescentes e adultos entre 11 e 85 anos de idade nascidos e crescidos em diferentes áreas de Manaus. Resultados. Todos os indivíduos pesquisados tiveram teste negativo para o antígeno da W. bancrofti. Conclusões. Apesar de Manaus ter sido anteriormente uma área endêmica, parece que não existe mais foco ativo de transmissão da filariose linfática na cidade. Os resultados deste estudo podem servir para embasar a certificação pela Organização Mundial da Saúde da eliminação da transmissão da filariose linfática no Brasil.

Assuntos