Subclinical signs of podocyte injury associated with Circulating Anodic Antigen (CAA) in Schistosoma mansoni-infected patients in Brazil

ABSTRACT Background: The long-term effects of schistosomiasis on the glomerulus may contribute to the development of chronic kidney disease. This study aimed to investigate baseline Schistosoma mansoni-Circulating Anodic Antigen (CAA) levels and their association with kidney biomarkers related to podocyte injury and inflammation in long-term follow-up after praziquantel (PZQ) treatment. Methods: Schistosoma infection was diagnosed by detecting CAA in urine using a quantitative assay based on lateral flow using luminescent up-converting phosphor reporter particles. A cutoff threshold of 0.1 pg/mL CAA was used to diagnose Schistosoma infection (baseline) in a low-prevalence area in Ceará, Northeast, Brazil. Two groups were included: CAA-positive and CAA-negative individuals, both of which received a single dose of PZQ at baseline. Urinary samples from 55 individuals were evaluated before (baseline) and at 1, 2, and 3 years after PZQ treatment. At all time points, kidney biomarkers were quantified in urine and adjusted for urinary creatinine levels. Results: CAA-positive patients had increased baseline albuminuria and proteinuria and showed greater associations between kidney biomarkers. CAA levels correlated only with Vascular Endothelial Growth Factor (VEGF) (podocyte injury) levels. Increasing trends were observed for malondialdehyde (oxidative stress), monocyte chemoattractant protein-1 (inflammation marker), and VEGF. In the follow-up analysis, no relevant differences were observed in kidney biomarkers between the groups and different periods. Conclusions: S. mansoni-infected individuals presented subclinical signs of glomerular damage that may reflect podocyte injury. However, no causal effect on long-term renal function was observed after PZQ treatment.

Detection of schistosomiasis in an area directly affected by the São Francisco River large-scale water transposition project in the Northeast of Brazil

Abstract INTRODUCTION: The development of the São Francisco River Integration Project [Projeto de Integração do Rio São Francisco (PISF)] in the State of Ceará, Brazil, has resulted in environmental and socioeconomic changes with potential risks to public health. We aimed to determine the presence of Schistosoma mansoni infections in schoolchildren (aged 7-14 years) and workers from the construction site in an area under the direct influence of the PISF in the municipality of Brejo Santo-CE, to aid in the prevention and control of schistosomiasis. METHODS: We conducted a cross-sectional study using two S. mansoni-detection methods: detection of S. mansoni eggs by the Kato-Katz parasitological method in stool samples (assessed in triplicate for each sample) and S. mansoni circulating cathodic antigen by the point-of-care immunochromatographic rapid test (POC-CCA) in urine. RESULTS In general, the positivity rates for S. mansoni detection were 1.9% (2/106) among schoolchildren and 2.9% (4/138) among workers. No child had evidence of S. mansoni eggs in their stools; 1.9% tested positive by the POC-CCA method. Among workers, two (1.4%) tested positive by the Kato-Katz test and three (2.2%) by the POC-CCA test. If the POC-CCA test results that were scored as traces were considered negative, then the positivity rates dropped to 0.9% and 0.7% for schoolchildren and workers, respectively. CONCLUSIONS: The active transmission of schistosomiasis in a region covered by the PISF was recognized, reinforcing the necessity to consolidate surveillance and control actions, as well as structural sanitation measures to reverse the social determinants of the disease.

Evolução eletrocardiográfica e sorológica de pacientes com doença de Chagas crônica acompanhados por seis anos após o tratamento com benzonidazol / Electrocardiographic and serological evolution of patients with chronic Chagas disease followed-up for six years after treatment with benzonidazole

Introdução: O tratamento com benzonidazol na fase crônica da doença de Chagas ainda permanece controverso. O presente estudo objetiva avaliar a efetividade da quimioterapia com benzonidazol em pacientes chagásicos crônicos por meio de análises sorológica e eletrocardiográfica. Método: Estudo prospectivo histórico, com acompanhamento eletrocardiográfico e sorológico pelos métodos imunoenzimático (ELISA) e de imunofluorescência indireta uma vez por ano, antes e após o tratamento, entre 2005 e 2011. No perfil sociodemográfico dos 30 pacientes acompanhados o predomínio era do sexo masculino, faixa etária entre 25-64 anos, com primeiro grau incompleto e em sua maioria agricultores. Resultados: A análise sorológica por ELISA demonstrou queda significativa da densidade óptica das amostras coletadas antes (2005) e após o tratamento com benzonidazol (2011). Em relação à imunofluorescência indireta, os pacientes se mantiveram inalterados durante o acompanhamento (variação de no máximo uma diluição entre as amostras basal e final). Na avaliação eletrocardiográfica, 76,2% (16/21) dos pacientes apresentaram manutenção dos laudos eletrocardiográficos ao longo do estudo. Conclusão: Foram observadas regressões nas análises sorológicas dos pacientes tratados com benzonidazol, acompanhados por 6 anos, além da manutenção dos padrões eletrocardiográficos iniciais na maioria dos casos, o que pode sugerir um efeito benéfico do fármaco no tratamento desses pacientes na fase crônica da doença de Chagas.

Background: Treatment with benzonidazole in the chronic phase of Chagas disease remains controversial. This study is aimed at evaluating the effectiveness of chemotherapy with benzonidazole in chronic Chagas disease using serological and electrocardiographic analysis. Method: Historical prospective study with electrocardiographic and serological monitoring by enzyme immunoassay (ELISA) and indirect immunofluorescence once a year, before and after the treatment, from 2005 to 2011. In the socio-demographic profile of the 30 patients followed-up, there was a prevalence of males, ages ranged between 25-64 years, incomplete school education and most of them farmers. Results: ELISA serology showed a significant decrease in the optical density of the samples collected before (2005) and after treatment with benzonidazole (2011). Indirect immunofluorescence demonstrated patients remained unchanged during follow-up (maximum variation of one dilution between the baseline sample and 2011). In the electrocardiographic assessment, 76.2% (16/21) of the patients maintained their electrocardiographic reports throughout the study. Conclusion: Patients treated with benzonidazole and followed-up for 6 years presented a regression in serological analysis and maintenance of their baseline ECG patterns in most cases, which may suggest a beneficial effect of the drug in the chronic treatment of Chagas disease.

Association between allergic responses and Schistosoma mansoni infection in residents in a low-endemic setting in Brazil

Introduction Schistosomiasis is endemic in 76 countries and territories. Several studies have found an inverse correlation between parasitic disease and the development of allergies. The purpose of the present study was to determine whether infection with Schistosoma mansoni in subjects with a low parasite load is protective against allergy. The final sample consisted of 39 S. mansoni-positive and 52 S. mansoni-negative residents of a small community in northeastern Brazil. Methods All subjects were submitted to the Kato-Katz test, anti-S. mansoni IgG measurement, the prick test for aeroallergens, eosinophil counts and serum IgE measurement. Results Subjects who reacted to one or more antigens in the prick test were considered allergic. Only 7 S. mansoni-positive subjects (17.9%) reacted to one or more antigens, whereas 20 S. mansoni-negative subjects (38.5%) tested positive for allergy. Conclusions Our findings suggest that, in areas of low endemicity, infection with S. mansoni significantly reduces the risk of the development of allergy in subjects with a low parasite load. .

Effect of gamma radiation on the activity of hemocytes and on the course of Schistosoma mansoni infection in resistant Biomphalaria tenagophila snails

High doses of gamma radiation (10 Krad) in Biomphalaria tenagophila snails (Taim strain), which have been found to be resistant to Schistosoma mansoni, were not sufficient to impair their resistance to the parasite. The number of hemocytes, as well as their phagocytic activity, were not affected by irradiation, thus showing resemblance with mammal macrophages, which are resistant to gamma irradiation also

Incidência de parasitos intestinais em material sub-ungueal e fecal em crianças da Creche Aprisco - Fortaleza, CE / Incidence of intestinal parasites in sub-nail and fecal materials in children of Daycare Center Aprisco - Fortaleza, CE

Dentre as doenças que ocorrem na infância, os parasitos intestinais têm uma grande importância em medicina social. Admitindo o possível papel do material sub-ungueal na transmissão das enteroparasitoses foram analisadas amostras de material sub-ungueal e fecal de 47 crianças da Creche Aprisco de ambos os sexos de 1 a 6 anos de idade, através dos métodos de Hoffman e direto. Das 47 amostras de fezes e sub-ungueal analizadas 41 (87 porcento) e 21 (44,7 porcento) apresentaram resultados positivos, respectivamente, para um ou mais parasitos. Nós observamos um índice de 68,8 porcento para protozoários contra 31,2 porcento para helmintos em fezes, enquanto que no material sub-ungueal a ocorrência foi de 76,2 porcento contra 23,8 porcento. A maior ocorrência de material sub-ungueal foi na faixa etária entre 1-3 anos enquanto que nas fezes a faixa etária mais acometida foi de 4-6 anos. Os parasitos achados com maior freqüência nas amostras sub-ungueais foram Entamoeba coli (15 porcento) e Hymenolepis nana (8 porcento). Não obstante, nas fezes a ocorrência maior foi para Giardia lamblia (38,1 porcento) e Ascaris lumbricoides (40 porcento). Nós concluímos que existe correlação entre o tipo de parasita achado nas fezes e nas unhas indicando a provável participação dos depósitos sub-ungueais na transmissão dos parasitos.

Schistosoma mansoni: protective immunity in mice cured by chemotherapy at the chronic phase of the disease

Aiming at demonstrating a decrease of acquired immunity after chemotherapeutic cure, a group of mice was infected with 25 Schistosoma mansoni cercariae (LE strain). A part of these animals was treated with 400 mg/kg oxamniquine, at 120 days after infection. Challenge infections were carried out at 45, 90 and 170-day-intervals after treatment (185, 210 and 290 days after primo-infection, respectively). Recovery of worms at 20 days after reinfections showed that a residual immunity remains up to 90 days after treatment, and disappears at 170 days after cure. Using the ELISA method, it was possible to detect a decrease of antibody levels (total IgG) in the treated group, when antigens from different evolutive stages of S. mansoni were used. The epidemiological implications of the present results, and the possible mechanisms involved in the decrease of acquired immunity after treatment are discussed.