ABSTRACT
Leptospirosis severity may be increasing, with pulmonary involvement becoming more frequent. Does this increase result from an intense immune response to leptospire? Notice that renal failure, thrombocytopenia and pulmonary complications are found during the immune phase. Thirty-five hospitalized patients with Weil's disease had 5 blood samples drawn, from the 15th day to the 12th month of symptoms, for ELISA-IgM, -IgG and -IgA specific antibody detection. According their 1st IgG titer, the patients were divided into: group 1 (n = 13) titer > 1:400 (positive) and group 2 (n = 22) titer <=1:400 (negative). Early IgG antibodies in group 1 showed high avidity which may indicate reinfection. Group 1 was older, had worse pulmonary and renal function, and fever for a longer period than group 2. Throughout the study, IgG and IgA titers remained higher in group 1. In conclusion, the severity of Weil's disease may be associated with the intensity of the humoral immune response to leptospire
Subject(s)
Humans , Male , Female , Adolescent , Adult , Middle Aged , Weil Disease , Antibody Affinity , Antibody Formation , Severity of Illness Index , Immunoglobulin A , Immunoglobulin G , Enzyme-Linked Immunosorbent Assay , Chi-Square Distribution , Prospective Studies , Age Factors , Statistics, Nonparametric , Antibodies, ViralABSTRACT
The high sensitivity and the possibility of automation of the enzyme-linked-immunosorbent-assay (ELISA) has indicated this technique as one of the most useful serological test for epidemiological studies. In the present study, an ELISA for detection of IgG antibodies against adult worm antigens (IgG-ELISA) was investigated for epidemiological purposes, in a rural area of the municipality of Itariri (Säo Paulo, Brazil). Blood on filter paper (1,180 samples) from about 650 school children were submitted to ELISA and the data compared to the results of the parasitogical method of Kato-Katz and also to the IgM-IFT (immunofluorescence test for IgM antibodies to gut associated antigens). The prevalence rates respectively of 8.5 per cent, 43.0 per cent and 56.2 per cent by the Kato-Katz, IgG-ELISA, and IgM-IFT methods suggest the poor sensitivity of the parasitological method for detection of Schistosoma mansoni eggs in individuals with low worm burden, situation commonly observed in low endemic areas. These results can partially explain the poor degree of agreement between the IgG-ELISA and the Kato-Katz, as suggested by the Kappa index of 0.170. Otherwise, the Kappa index of 0.675 showed substantial agreement between the two serological tests. Some discrepancy of results between the two serological techniques must be better investigated.
Subject(s)
Humans , Child , Brazil , Enzyme-Linked Immunosorbent Assay , Immunoglobulin G , Schistosomiasis , Schistosoma mansoni/parasitologyABSTRACT
Um ensaio clinico, duplo-cego, ao acaso, e controlado com placebo para aferir a eficacia da doxiciclina (200 mg, dose unica) em prevenir leptospirose apos exposiçäo de alto risco com agua potencialmente contaminada foi realizado em Säo Paulo, Brasil. Casos confirmados foram definidos como aqueles que apresentavam anticorpos IgM anti-Leptospira e sintomas; casos assintomaticos eram aqueles que apresentavam somente anticorpo IgM, casos suspeitos apresentavam sintomas, porem sem anticorpo IgM. 40 individuos tomaram dociclina e 42 tomaram placebo. No grupo tratado houve 2 casos confirmados, 11 assintomaticos e 6 casos suspeitos. No grupo placebo houve 5 casos confirmados, 6 assintomaticos e 5 casos suspeitos...
Subject(s)
Humans , Doxycycline , Leptospirosis/diagnosis , Brazil , Double-Blind Method , Immunoglobulin M , Leptospirosis , Placebos , Signs and SymptomsABSTRACT
A Leptospirose e uma das causas de meningite, embora sua importancia seja pouco conhecida. O presente estudo contribui para este conhecimento ao demonstrar anticorpos especificos da classe IgM anti-Leptospira pelo metodo imunoenzimatico (ELISA), em 14,6 por cento das amostras de liquido cefalorraquianos (LCR) de 171 pacientes com meningite considerada de etiologia indeterminada. As frequencias de positividade foram parecidas nos casos com predominio no LCR de leucocitos polimorfonucleares ou linfomonucleares. A distribuicao por idade mostrou predominio na faixa etaria entre 5 e 15 anos (72 por cento) e por sexo o predominio do masculino (68 por cento). Os autores discutem a contribuicao desse metodo na elucidacao etiologica das meningites