RESUMO
OBJECTIVES: This study evaluated the occurrence of Schistosoma mansoni and soil-transmitted helminths in an endemic area in the Eastern Brazilian Amazon, analysing prevalence and spatial distribution. METHODS: The study was conducted in four localities of Primavera Municipality, in Pará state. Data was obtained from the Decit 40/2012 project and the participants were divided into five age range categories for evaluation: children, adolescents, young adults, adults and elderly individuals. For the diagnostic tests, Kato-Katz slides were prepared to detect S. mansoni and soil-transmitted helminths eggs. The spatial distribution map and the Kernel Density Estimation were performed to assess the presence and location of infections. RESULTS: Stool samples revealed the presence of hookworms, S. mansoni, Ascaris lumbricoides and Trichuris trichiura eggs. Mono-, bi- and poly-parasitic infections were observed, with a significant prevalence of hookworm monoparasitism. CONCLUSIONS: The high frequency of children infected with soil-transmitted helminths confirms their significance as an ongoing public health problem in the poorest municipalities of Brazil. The Geographic Information System plays a crucial role in environmental surveillance and in the control of epidemics and endemic diseases, enabling accurate assessment and informed decision-making for their control.
Assuntos
Doenças Endêmicas , Fezes , Helmintíase , Schistosoma mansoni , Esquistossomose mansoni , Solo , Humanos , Brasil/epidemiologia , Criança , Esquistossomose mansoni/epidemiologia , Adolescente , Prevalência , Animais , Solo/parasitologia , Adulto , Adulto Jovem , Masculino , Fezes/parasitologia , Feminino , Schistosoma mansoni/isolamento & purificação , Helmintíase/epidemiologia , Helmintíase/transmissão , Pré-Escolar , Análise Espacial , Pessoa de Meia-Idade , Idoso , Sistemas de Informação Geográfica , Ascaris lumbricoides/isolamento & purificaçãoRESUMO
Schistosoma mansoni worms cause a waterborne parasitic disease called schistosomiasis. It commonly affects individuals in lack of sanitation structure. In Brazil, Pará state has Belém as one of the worst sanitation-ranking places in 2023, where schistosomiasis transmission was already documented. This study reports the occurrence of schistosomiasis in residents of Ilha das Onças, an island next to Belém. Stool samples were obtained from participants over 2 years old, all residents from Furo do Rio Grande, one of the rivers on the island. The Kato-Katz technique was performed for parasite investigation in the stool samples. Each participant responded to a sociodemographic and clinical questionnaire. The residences were georeferenced for map designing. Three out of 263 participants were S. mansoni positive, all men, ages ranging from 19 to 41 years old, with low parasitic load. Malacological surveys were carried out, but no Biomphalaria snails were found. Risk factors for schistosomiasis establishment are present on the island, and the lack of sanitation makes it a potential risk area. Malacological surveys are highly encouraged as preventive measures, as well as health surveillance for riverside populations, generating data that will help health authorities in the management and planning of preventive control actions.
Assuntos
Rios , Schistosoma mansoni , Esquistossomose mansoni , Humanos , Brasil/epidemiologia , Adulto , Esquistossomose mansoni/epidemiologia , Masculino , Schistosoma mansoni/isolamento & purificação , Animais , Adulto Jovem , Rios/parasitologia , Feminino , Fezes/parasitologia , Adolescente , Pessoa de Meia-Idade , CriançaRESUMO
The laboratory diagnosis of intestinal schistosomiasis, carried out by detecting parasite eggs in feces, has low sensitivity when applied to individuals with low parasitic load. Serological tests can be more sensitive for the diagnosis of the disease. Therefore, the objective of this work was to develop and evaluate an ELISA-based immunoenzymatic assay, using a Schistosoma mansoni multiepitope antigen (ELISA IgG anti-SmME). For this, the amino acid sequences of S. mansoni cathepsin B and asparaginyl endopeptidase were submitted to the prediction of B cell epitopes and, together with peptide sequences obtained from earlier works, were used in the construction of a minigene. The multiepitope protein was expressed in Escherichia coli and the performance of the ELISA IgG anti-SmME for schistosomiasis was evaluated using serum samples from 107 individuals either egg positive or negative. In addition, 11 samples from individuals with other helminth infections were included. The ELISA IgG anti-SmME showed a sensitivity of 81.1% and a specificity of 46.1%. Further analysis revealed a 77.2% sensitivity in diagnosis of individuals with egg counts of ≤12 epg (eggs per gram feces) and 87.5% for individuals with 1399 epg. It is worth mentioning that, to our knowledge, this was the first study using a multiepitope recombinant antigen in an ELISA for diagnosis of intestinal schistosomiasis, which demonstrated promising results in the diagnosis of individuals with low parasitic loads.
Assuntos
Esquistossomose mansoni , Animais , Humanos , Esquistossomose mansoni/diagnóstico , Schistosoma mansoni/genética , Antígenos de Helmintos , Sensibilidade e Especificidade , Contagem de Ovos de Parasitas , Ensaio de Imunoadsorção Enzimática/métodos , Fezes/parasitologia , Anticorpos Anti-Helmínticos , Imunoglobulina GRESUMO
BACKGROUND: Schistosomiasis is a neglected tropical disease that occurs in locations with inadequate sanitation conditions. The geographic distribution of Schistosoma mansoni trematode depends directly on the presence of its intermediate host, Biomphalaria mollusks. Studies involving recently isolated and laboratory strains are not common due to the difficulty in cycle maintenance. This study evaluated the susceptibility and infectivity responses in intermediate and definitive hosts with strains of S. mansoni, one isolated and kept in laboratory environment for 34 years (BE) and the other recently collected (BE-I) METHODS: For experimental infection, a total of 400 B. glabrata mollusks were divided in four infection groups. Thirty mice were divided in two groups for infection with the two strains. RESULTS: It was possible to notice differences about S. mansoni infection in both strains. The laboratory strain was more harmful to freshly collected mollusks. Differences in the patterns of infection in mice could be observed. CONCLUSION: Particularities occurred in each group of infection by S. mansoni strains, despite having the same geographic origin. Effects from the parasite-host interaction are visible in terms of infection in definitive and intermediate hosts.
Assuntos
Biomphalaria , Esquistossomose mansoni , Animais , Camundongos , Schistosoma mansoni/fisiologia , Brasil/epidemiologia , Vetores de Doenças , Doenças NegligenciadasRESUMO
INTRODUCTION: Mollusks belonging to Biomphalaria genus are intermediate hosts of Schistosoma mansoni. In the Pará State, Northern Region of Brazil, there are reports of B. glabrata, B. straminea, B. schrammi, B. occidentalis, and B. kuhniana occurrence. Here, we report for the first time the presence of B. tenagophila in Belém, capital of Pará state. METHODS: A total of 79 mollusks were collected and examined to search for possible S. mansoni infection. The specific identification was made by morphological and molecular assays. RESULTS: No specimens parasitized by trematode larvae were detected. For the first time the presence of B. tenagophila in Belém, capital of Pará state, was reported. CONCLUSION: The result increases the knowledge about Biomphalaria mollusks occurrence in the Amazon Region and specifically alerts on the possible role of B. tenagophila in schistosomiasis transmission in Belém.
Assuntos
Biomphalaria , Esquistossomose mansoni , Animais , Esquistossomose mansoni/epidemiologia , Brasil/epidemiologia , Schistosoma mansoni , Vetores de DoençasRESUMO
Due to the efforts to control schistosomiasis transmission in tropical countries, a large proportion of individuals from endemic areas present low parasite loads, which hinders diagnosis of intestinal schistosomiasis by the Kato-Katz (KK) method. Therefore, the development of more sensitive diagnostic methods is essential for efficient control measures. The aim was to evaluate the accuracy of a real-time polymerase chain reaction (RT-PCR) to detect Schistosoma mansoni DNA in fecal samples of individuals with low parasite loads. A cross-sectional population-based study was conducted in a rural community (n = 257) in Brazil. POC-CCA® was performed in urine and feces were used for RT-PCR. In addition, fecal exams were completed by 18 KK slides, saline gradient and Helmintex techniques. The combined results of the three parasitological tests detected schistosome eggs in 118 participants (45.9%) and composed the consolidated reference standard (CRS). By RT-PCR, 117 out of 215 tested samples were positive, showing 91.4% sensitivity, 80.2% specificity and good concordance with the CRS (kappa = 0.71). RT-PCR identified 86.9% of the individuals eliminating less than 12 eggs/g of feces, demonstrating much better performance than POC-CCA® (50.8%). Our results showed that RT-PCR is a valuable alternative for the diagnosis of intestinal schistosomiasis in individuals with very low parasite loads.
Assuntos
Fezes/parasitologia , Contagem de Ovos de Parasitas , Carga Parasitária , Reação em Cadeia da Polimerase em Tempo Real/métodos , Schistosoma mansoni/isolamento & purificação , Esquistossomose mansoni/epidemiologia , Urina/parasitologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Brasil/epidemiologia , Criança , Pré-Escolar , Estudos Transversais , DNA de Helmintos/análise , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prevalência , População Rural/estatística & dados numéricos , Sensibilidade e Especificidade , Adulto JovemRESUMO
This study evaluated parasitological and molecular techniques for the diagnosis and assessment of cure of schistosomiasis mansoni. A population-based study was performed in 201 inhabitants from a low transmission locality named Pedra Preta, municipality of Montes Claros, state of Minas Gerais, Brazil. Four stool samples were analysed using two techniques, the Kato-Katz® (KK) technique (18 slides) and the TF-Test®, to establish the infection rate. The positivity rate of 18 KK slides of four stool samples was 28.9% (58/201) and the combined parasitological techniques (KK+TF-Test®) produced a 35.8% positivity rate (72/201). Furthermore, a polymerase chain reaction (PCR)-ELISA assay produced a positivity rate of 23.4% (47/201) using the first sample. All 72 patients with positive parasitological exams were treated with a single dose of Praziquantel® and these patients were followed-up 30, 90 and 180 days after treatment to establish the cure rate. Cure rates obtained by the analysis of 12 KK slides were 100%, 100% and 98.4% at 30, 90 and 180 days after treatment, respectively. PCR-ELISA revealed cure rates of 98.5%, 95.5% and 96.5%, respectively. The diagnostic and assessment of cure for schistosomiasis may require an increased number of KK slides or a test with higher sensitivity, such as PCR-ELISA, in situations of very low parasite load, such as after therapeutic interventions.
Assuntos
Doenças Endêmicas , Fezes/parasitologia , Técnicas de Diagnóstico Molecular/métodos , Esquistossomose mansoni/diagnóstico , Esquistossomose mansoni/tratamento farmacológico , Animais , Anti-Helmínticos/uso terapêutico , Brasil , Ensaio de Imunoadsorção Enzimática , Feminino , Seguimentos , Humanos , Masculino , Carga Parasitária , Reação em Cadeia da Polimerase , Praziquantel/uso terapêutico , Schistosoma mansoni/genética , Schistosoma mansoni/isolamento & purificação , Esquistossomose mansoni/epidemiologiaRESUMO
BACKGROUND: In 1970, Brazil implemented the Schistosomiasis Control Program (PCE, Portuguese acronym for Programa de Controle da Esquistossomose) was implemented in Brazil, where, through successive treatment interventions, the epidemiology and transmission of schistosomiasis have changed significantly over time. This study aimed to evaluate the PCE's effectiveness by critically analyzing the disease notification system. METHODS: An ecological study was conducted using data on reported schistosomiasis cases in Brazil between 2007 and 2020. RESULTS: The highest number of municipalities actively participating in the PCE was 750, recorded in 2007. Conversely, participation reached its lowest point in 2020, with only 259 municipalities involved. Over the past decade, there has been a drastic decline in the number of municipalities with active schistosomiasis control programs. During the same period, there was an observed increase in the number of deaths caused by schistosomiasis, while the number of reported cases decreased. This suggests an inverse correlation. CONCLUSIONS: The present data suggest that schistosomiasis cases are not correctly diagnosed or reported, reflecting a twisted image of the magnitude of this public health problem in Brazil.
Assuntos
Esquistossomose , Humanos , Brasil/epidemiologia , Notificação de Doenças , Esquistossomose/prevenção & controle , Esquistossomose/epidemiologia , Esquistossomose/transmissão , Avaliação de Programas e Projetos de SaúdeRESUMO
INTRODUCTION: Toxocariasis is caused by nematodes of Toxocara genus, which infest dogs and cats, with humans serving as paratenic hosts. METHODS: The epidemiological profile of patients examined for toxocariasis between October 2014 and October 2019 at Evandro Chagas Institute (IEC) was outlined. The frequency of anti-T. canis IgG antibodies were evaluated using the Enzyme Linked Immunosorbent Assay (ELISA) method. RESULTS: From a total of 734 samples, 56% were from male (p < 0.05). Regarding age, the group with the most solicitations were from ≤11 years old individuals (p < 0.05). Pará state had the highest number of exams requested (92%), with the majority from residents of urban areas, accounting for 81.5% of samples (p < 0.05). The overall toxocariasis seroprevalence was 41.8%, the male sex being the most frequent with 60.9% (p < 0.05). The most affected age group was ≤11 years old, with a total of 67.8% of positive samples (p < 0.05). CONCLUSION: The high rates obtained emphasize the need for complementary studies on toxocariasis in Brazil, especially in Pará state, contributing to epidemiological surveillance actions in the control of this infection. Besides, health campaigns for domestic and stray animals, also can contribute to a more effective surveillance in controlling parasitic infections and encourages the One Health approach.
Assuntos
Doenças do Gato , Doenças do Cão , Toxocaríase , Humanos , Masculino , Animais , Cães , Gatos , Criança , Toxocaríase/epidemiologia , Toxocaríase/parasitologia , Estudos Soroepidemiológicos , Doenças do Gato/epidemiologia , Toxocara , Ensaio de Imunoadsorção Enzimática/métodos , Ensaio de Imunoadsorção Enzimática/veterinária , Anticorpos Anti-Helmínticos , Fatores de RiscoRESUMO
Schistosomiasis diagnosis is based on the detection of eggs in the faeces, which is laborious and lacks sensitivity, especially for patients with a low parasite burden. Immunological assays for specific antibody detection are available, but they usually demonstrate low sensitivity and/or specificity. In this study, two simple immunological assays were evaluated for the detection of soluble Schistosoma mansoni adult worm preparation (SWAP) and egg-specific IgGs. These studies have not yet been evaluated for patients with low parasite burdens. Residents of an endemic area in Brazil donated sera and faecal samples for our study. The patients were initially diagnosed by a rigorous Kato-Katz analysis of 18 thick smears from four different stool samples. The ELISA-SWAP was successful for human diagnosis with 90% sensitivity and specificity, confirming the Kato-Katz diagnosis with nearly perfect agreement, as seen by the Kappa index (0.85). Although the ELISA-soluble S. mansoni egg antigen was 85% sensitive, it exhibited low specificity (80%; Kappa index: 0.75) and was more susceptible to cross-reactivity. We believe that immunological assays should be used in conjunction with Kato-Katz analysis as a supplementary tool for the diagnosis of schistosomiasis for patients with low infection burdens, which are usually hard to detect.
Assuntos
Ensaio de Imunoadsorção Enzimática/métodos , Schistosoma mansoni/imunologia , Esquistossomose mansoni/diagnóstico , Adulto , Animais , Anticorpos Anti-Helmínticos/sangue , Antígenos de Helmintos/imunologia , Fezes/parasitologia , Feminino , Humanos , Masculino , Esquistossomose mansoni/epidemiologia , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: The World Health Organization recommends a market-ready, urine-based point-of-care diagnostic test for circulating cathodic antigens (CCA) to determine the prevalence of S. mansoni. This study evaluated the performance of the URINE CCA (SCHISTO) ECO TESTE® (POC-ECO), which is currently available in Brazil. METHODS: Residents from eight sites with different prevalence estimates provided one urine sample for POC-ECO and one stool sample for Kato-Katz (KK) and Helmintex® (HTX) testing as an egg-detecting reference for infection status. RESULTS: None of the study sites had significantly higher POC-ECO accuracy than KK. CONCLUSIONS: POC-ECO is not currently recommended in Brazilian schistosomiasis elimination programs.
Assuntos
Esquistossomose mansoni , Animais , Humanos , Esquistossomose mansoni/diagnóstico , Esquistossomose mansoni/epidemiologia , Schistosoma mansoni , Brasil/epidemiologia , Sistemas Automatizados de Assistência Junto ao Leito , Sensibilidade e Especificidade , Antígenos de Helmintos/urina , Prevalência , FezesRESUMO
The World Health Organization (WHO) recognizes schistosomiasis as one of the Neglected Tropical Diseases targeted for global elimination in the 2030 Agenda of the Sustainable Development Goals. In Brazil, schistosomiasis mansoni is considered a public health problem, particularly prevalent among vulnerable populations living in areas with poor environmental and sanitary conditions. In 2022, the WHO published a Guideline encompassing recommendations to assist national programs in endemic countries in achieving morbidity control, eliminating schistosomiasis as a public health problem, and advancing towards interrupting transmission. The perspectives presented here, collectively prepared by members of the Oswaldo Cruz Foundation's (Fiocruz) Schistosomiasis Translational Program (FioSchisto), along with invited experts, examine the feasibility of the WHO recommendations for the Brazilian settings, providing appropriate recommendations for public health policies applicable to the epidemiological reality of Brazil, and suggests future research to address relevant issues. In Brazil, the provision of safe water and sanitation should be the key action to achieve schistosomiasis elimination goals. The agencies involved in measures implementation should act together with the Primary Care teams for planning, executing, monitoring, and evaluating actions in priority municipalities based on their epidemiological indicators. Host snails control should prioritize judicious ecological interventions at breeding sites. The Information, Education, and Communication (IEC) strategy should be associated with water and sanitation and other control actions, actively involving school community. To identify infected carriers, FioSchisto recommends a two-stage approach of immunological and molecular tests to verify transmission interruption during the intervention and beyond. Praziquantel administration should be done under medical supervision at the Primary Care level. MDA should be considered in exceptional settings, as a measure of initial attack strategy in locations presenting high endemicity, always integrated with water and sanitation, IEC, and snail control. To assist decision-making, as well as the monitoring and evaluation of strategic actions, there is a need for an Information System. FioSchisto considers this systematization essential to make investments in strategic research to support the improvement of schistosomiasis control actions. Efforts toward schistosomiasis elimination in Brazil will succeed with a paradigm shift from the vertical prescriptive framework to a community-centered approach involving intersectoral and interdisciplinary collaboration.
Assuntos
Esquistossomose , Humanos , Brasil/epidemiologia , Esquistossomose/epidemiologia , Esquistossomose/prevenção & controle , Praziquantel , Organização Mundial da Saúde , ÁguaRESUMO
BACKGROUND: The World Health Organization recommends reliable point-of-care (POC) diagnostic testing to eliminate schistosomiasis. Lateral flow immunoassay that detects schistosome circulating cathodic antigen (CCA) in urine to establish prevalence thresholds for intervention in endemic areas is recommended. Stored urine may be useful if surveying at-risk populations is delayed or interrupted by unforeseen circumstances, such as the current COVID-19 pandemic. This study evaluated the manufacturer's claim that Schistosoma mansoni infection can be reliably diagnosed in urine samples stored at -20°C for one year. METHODS: Two-hundred-forty-two subjects from an endemic site in Brazil provided one urine sample each for testing with URINE CCA (SCHISTO) ECO TESTE® (POC-ECO) and one stool sample each for testing with Kato-Katz (KK) and Helmintex® (HTX) as a robust reference standard for infection status. At least 2 ml of urine from each participant was stored at -20°C; after one year, 76 samples were randomly selected for POC-ECO retesting. RESULTS: The POC-ECO agreement between freshly collected and stored urine was inadequate considering trace results as positive (Cohen's kappa coefficient κ = 0.08) and negative (κ = 0.36). POC-ECO accuracy was not significantly greater than that of routine KK (54%; 95% confidence interval: 42.1%-65.5%). CONCLUSIONS: The precision and accuracy of POC-ECO have to be optimized in both freshly collected and stored urine before it can be recommended for use in control programs in Brazil.
Assuntos
COVID-19 , Esquistossomose mansoni , Animais , Antígenos de Helmintos/urina , Brasil/epidemiologia , Fezes , Humanos , Pandemias , Sistemas Automatizados de Assistência Junto ao Leito , Prevalência , Reprodutibilidade dos Testes , SARS-CoV-2 , Schistosoma mansoni , Esquistossomose mansoni/diagnóstico , Esquistossomose mansoni/epidemiologia , Sensibilidade e EspecificidadeRESUMO
This population study, which evaluated two parasitological methods for the diagnosis of schistosomiasis mansoni, was performed in a low-transmission area in Pedra Preta, Montes Claros, Minas Gerais, Brazil. A total of 201 inhabitants of the rural area participated in this research. Four stool samples were obtained from all participants and analysed using the Kato-Katz method (18 slides) and a commercial test, the TF-Test®, which was performed quantitatively. The data were analysed to determine prevalence, the sensitivity of the diagnostic methods, the worm burden and the definition of the "gold standard", which was obtained by totalling the results of all samples examined using the Kato-Katz technique and the TF-Test®. The results showed that the prevalence obtained from the examination of one Kato-Katz slide (the methodology adopted by the Brazilian control programme) was 8% compared to 35.8% from the "gold standard", which was a 4.5-fold difference. This result indicates that the prevalence of schistosomiasis in so-called low-transmission areas is significantly underestimated.
Assuntos
Fezes/parasitologia , Contagem de Ovos de Parasitas/métodos , Schistosoma mansoni/isolamento & purificação , Esquistossomose mansoni/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Brasil/epidemiologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Prevalência , População Rural , Esquistossomose mansoni/epidemiologia , Sensibilidade e Especificidade , Adulto JovemRESUMO
Health surveillance aims to monitor adverse health events, and to set disease prevention and control goals, especially for communicable diseases, such as tuberculosis (TB). Older people have a higher risk of TB, due to their specific characteristics, whichpredispose them to infectious disease. Thus, the objective of this study was to demonstrate the importance of scan statistics for detecting spatiotemporal clusters of TB. We conducted a quantitative is an ecological, descriptive study, with a quantitative approach, using the spatial analysis techniques, specifically scan statistics. The study was conducted in the municipality of Belém, Pará, in Brazil using data on 1,134 new cases of TB diagnosed in individuals aged ≥60 years from 2011 to 2015.The data were analyzed using SaTScan software. The analysis of the spatiotemporal dynamics of TB in the municipality showed thatthe high-risk areas includedthe most densely populated neighborhoods, highlighting the priority of theseareas for disease control measures. Spatial analysis can be used to guide more effective interventions according to the characteristics of the location and the local population.
Assuntos
Doenças Endêmicas , Tuberculose , Idoso , Brasil/epidemiologia , Cidades/epidemiologia , Humanos , Análise Espacial , Tuberculose/epidemiologia , Tuberculose/prevenção & controleRESUMO
A point-of-care test for detecting schistosome circulating cathodic antigen in urine (POCCCA) has been proposed for mapping infection and defining prevalence thresholds for mass drug administration (MDA). However, there is increasing evidence that POCCCA may yield false-positive results, which requires rigorous specificity evaluation in non-endemic areas. POCCCA was applied in an area known to be free from infection and devoid of any condition for schistosomiasis transmission as part of a multicentre study to evaluate the performance of POCCCA in Brazil's low or potentially endemic settings. Besides POCCCA detection in urine, a search for eggs in stool was performed by Kato-Katz (KK) and Helmintex (HTX) methods. One-hundred-and-seventy-four participants returned urine samples, 140 of which delivered stool samples. All these were HTX-negative for Schistosoma mansoni, and all 118 tested with KK were negative for both S. mansoni and soil-transmitted helminths. POCCCA results from freshly collected urine yielded a specificity of 62.1% (95% CI: 53.6% - 70.2%), taking trace outcomes as positive according to the manufacturer's instructions. Retesting urine from the 140 HTX-negatives after one-year storage at -20 °C with two new POCCCA batches simultaneously yielded significantly different specificities (34.3%; 95%CI: 26.5% - 42.8% and 75.0%; 95% CI: 67.0% - 81.9%). These two batches had a weak agreement (Cohen's kappa: 0.56; 95%CI: 0.44-0.68) among the 174 urine samples retested. At present, POCCCA cannot be recommended either as a cut-off point for MDA or a reliable diagnostic tool for treatment of the infection carriers (selective chemotherapy) in low endemic areas and at final stages of transmission interruption. Manufacturers should be required to optimize production standardization and to assure quality and reproducibility of the test. Extended rigorous performance evaluations by different users from different regions are needed before POCCCA is widely recommended.
Assuntos
Antígenos de Helmintos/sangue , Testes Imediatos , Esquistossomose mansoni/sangue , Esquistossomose mansoni/diagnóstico , Adolescente , Animais , Brasil/epidemiologia , Criança , Fezes/parasitologia , Feminino , Humanos , Masculino , Prevalência , Reprodutibilidade dos Testes , Esquistossomose mansoni/tratamento farmacológico , Esquistossomose mansoni/imunologia , Sensibilidade e EspecificidadeRESUMO
In this transversal study, factors related to infection with and transmission of Schistosoma mansoni were explored. Based on stool examinations of two Kato-Katz smears of a single sample, the prevalences of schistosomiasis and geohelminths were established. In a multivariable analysis, sets of demographic, socio-economic and water contact pattern variables were tested for strength of relation with infection. Males presented a 3.39-times higher risk for infection than females. The age groups between 10-19 years and 20-30 years showed risks of infection 7.1- and 7.5-times higher, respectively, than the control age group between 0-10 years. Individuals practicing leisure activities had a 1.96-times higher risk than those without these activities. The malacological survey identified snails of the species Biomphalaria glabrata, Biomphalaria straminea and Biomphalaria tenagophila. Two exemplars of B. glabrata (0.53%) proved positive for S. mansoni. The socio-economic improvements observed in the locality suggest a protective and preventive effect towards infection with schistosomiasis, which requires further investigation with a longitudinal and more detailed study design. Considering our findings, a proposal for an integrated control program should be based on two pillars: one horizontal, which involves social empowerment and health education, and another more vertical, which delivers treatment and infrastructure improvements.
Assuntos
Albendazol/uso terapêutico , Fezes/parasitologia , Praziquantel/uso terapêutico , Schistosoma mansoni/isolamento & purificação , Esquistossomose mansoni/transmissão , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Biomphalaria/parasitologia , Brasil/epidemiologia , Criança , Pré-Escolar , Estudos Transversais , Vetores de Doenças , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Prevalência , Fatores de Risco , Esquistossomose mansoni/diagnóstico , Esquistossomose mansoni/epidemiologia , Fatores Socioeconômicos , Adulto JovemRESUMO
Geographical Information System (GIS) is a tool that has recently been applied to better understand spatial disease distributions. Using meteorological, social, sanitation, mollusc distribution data and remote sensing variables, this study aimed to further develop the GIS technology by creating a model for the spatial distribution of schistosomiasis and to apply this model to an area with rural tourism in the Brazilian state of Minas Gerais (MG). The Estrada Real, covering about 1,400 km, is the largest and most important Brazilian tourism project, involving 163 cities in MG with different schistosomiasis prevalence rates. The model with three variables showed a R(2) = 0.34, with a standard deviation of risk estimated adequate for public health needs. The main variables selected for modelling were summer vegetation, summer minimal temperature and winter minimal temperature. The results confirmed the importance of Remote Sensing data and the valuable contribution of GIS in identifying priority areas for intervention in tourism regions which are endemic to schistosomiasis.
Assuntos
Doenças Endêmicas , Sistemas de Informação Geográfica , Esquistossomose/epidemiologia , Viagem , Animais , Biomphalaria , Brasil/epidemiologia , Clima , Vetores de Doenças , Humanos , Modelos Biológicos , Prevalência , Medição de Risco , Saneamento , Comunicações Via Satélite , Estações do Ano , Fatores SocioeconômicosRESUMO
This paper reports an outbreak of acute schistosomiasis among 38 tourists who rented a country house in the district of Igarapé, the metropolitan region of Belo Horizonte, Brazil, during a holiday period in 2006. A total number of 32 individuals were positive for Schistosoma mansoni. Results of stool examinations revealed individual S. mansoni egg counts per gram of faeces (epg) ranging from 4-768 epg with a geometric mean egg count of 45. The most frequent clinical symptoms were abdominal pain (78.1%), headache (75%), fever (65.6%), dry cough (65.2%) and both diarrhoea and asthenia (59.4%). A malacological survey of the area, where 22 specimens of Biomphalaria glabrata were collected, revealed three (13.6%) specimens eliminating Schistosoma cercariae. This investigation re-confirms a recently described pattern of schistosomiasis infection, resulting in the acute form of the disease and connected to rural tourism, which contributes to the spread of the disease among the middle-class and into non-endemic areas. The lack of specific knowledge about acute schistosomiasis among health services causes an increased number of unnecessary diagnostic procedures and delays in accurate diagnosis and treatment, resulting in considerable discomfort for the patients.
Assuntos
Surtos de Doenças , Fezes/parasitologia , Schistosoma mansoni/isolamento & purificação , Esquistossomose mansoni/transmissão , Viagem , Doença Aguda , Adolescente , Adulto , Idoso , Animais , Biomphalaria/parasitologia , Brasil/epidemiologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Masculino , Pessoa de Meia-Idade , Contagem de Ovos de Parasitas , Esquistossomose mansoni/diagnóstico , Esquistossomose mansoni/epidemiologia , Adulto JovemRESUMO
INTRODUCTION: Schistosomiasis is a poverty-related disease that affects people in 78 countries worldwide. This study aimed to evaluate the point-of-care circulating cathodic antigen (POC-CCA) test performance using sensitive parasitological methods as a reference standard (RS) in individuals before and after treatment. METHODS: The RS was established by combining the results of 16 Kato-Katz slides and the Helmintex® method. Positivity rates of the POC-CCA test and Kato-Katz and Helmintex® methods were calculated before treatment and 30 days afterward. Furthermore, the sensitivity, specificity, accuracy, and kappa coefficient before treatment were determined by comparing the methods. The cure rate was defined 30 days after treatment. RESULTS: Among the 217 participants, the RS detected a total of 63 (29.0%) positive individuals. The POC-CCA test identified 79 (36.4%) infections. The evaluation of POC-CCA test performance in relation to the RS revealed a sensitivity of 61.9%, specificity of 74.0%, accuracy of 70.5%, and kappa coefficient of 0.33. Out of the 53 remaining participants after treatment, a total of 45 (81.1%) showed egg negative results, and 8 (18.9%) were egg positive according to the RS. A total of 5 (9.4%) egg-positive and 37 (69.8%) egg-negative individuals were positive by the POC-CCA test. CONCLUSIONS: Our data show that the POC-CCA test has potential as an auxiliary tool for the diagnosis of Schistosoma mansoni infection, yielding better results than 16 Kato-Katz slides from three different stool samples. However, the immunochromatographic test lacks sufficient specificity and sensitivity for verifying the cure rate after treatment.