ABSTRACT
The diagnosis of human leptospirosis is mainly based on serological assays. Since the extraction by N-butanol has only been studied as an antigen for the diagnosis of cattle leptospirosis, this study aimed to investigate the feasibility of the N-butanol preparation for the diagnosis of human leptospirosis and compare it with sonicated and thermo-resistant antigens in IgM dot-blot test. Paired serum samples from 147 laboratory-confirmed leptospirosis cases were tested. The control group consisted of 148 serum samples from healthy individuals and nonleptospirosis cases. N-butanol antigens from serovar Copenhageni (ButC3) and serovar Patoc (ButP3) showed reactivity with antileptospiral antibodies from patients with confirmed leptospirosis. In the acute phase, sensitivities of IgM dot-blot assay with ButC3 and ButP3 antigens were 47.6% and 51.0%, respectively. In the convalescent phase, sensitivities were 95.9% (ButC3) and 93.2% (ButP3), and no significant differences were observed among the IgM dot-blot tests with other antigens. The specificity of the IgM dot-blot test with ButC3 antigen was good (92.6%), but with ButP3 (83.1%), it was significantly lower than with the other tests. The IgM dot-blot test described in this study is simple to perform and presents reliable visual results. Antigens prepared by N-butanol proved to be valuable diagnostic markers of leptospirosis.
Subject(s)
Leptospira , Leptospirosis , Animals , Cattle , Humans , 1-Butanol , Butanols , Antigens, Bacterial , Enzyme-Linked Immunosorbent Assay/methods , Antibodies, Bacterial , Leptospirosis/diagnosis , Immunoglobulin M , Sensitivity and SpecificityABSTRACT
A poliomielite é uma doença endêmica no Afeganistão e no Paquistão, apesar dos esforços para ser erradicada, representando uma ameaça para outros países principalmente devido às viagens internacionais. A Organização Mundial da Saúde (OMS) tem como objetivo erradicar a poliomielite causada pelo poliovírus selvagem no mundo. O requisito essencial para a erradicação da poliomielite é a eliminação da cepa do poliovírus selvagem, que é empregada no teste padrão-ouro. Com o intuito de auxiliar na erradicação do poliovírus selvagem, o objetivo deste estudo foi modificar o teste padrão-ouro usando o poliovírus derivado da vacina oral atenuada. Foram testados 63 soros pelo ensaio de neutralização utilizando-se antígenos vacinais. A concordância do sorotipo 1 (k=0,74) foi considerada substancial, enquanto o sorotipo 2 (k=1,00) e sorotipo 3 (k= 0,95) foram consideradas quase perfeitas. A sensibilidade dos testes de soroneutralização utilizando os sorotipos 1, 2 e 3 foi de 94,83%, 100,00% e 100,00%, respectivamente. Em conclusão, o ensaio com antígenos vacinais pode ser usado como procedimento laboratorial seguro, especialmente em estudos de vigilância em larga escala.
Poliomyelitis is an endemic disease in Afghanistan and Pakistan in despite of the efforts to eradicate it, and it represents a threat to other countries mainly due to the international trips. The World Health Organization (WHO) aims at eradicating the polio disease worldwide. An essential requirement for eradicating the poliomyelitis is the elimination of the wild poliovirus strain, which is employed in the gold standard test. As a support for the eradication of wild poliovirus, the present study aimed at modifying the gold standard test by using poliovirus derived from the oral attenuated vaccine. Sixty-three sera samples were tested by neutralization assay using vaccine antigens. The degree of agreement of the serotype 1 (k=0.74) was considered substantial, while the serotype 2 (k=1.00) and 3 (k= 0.95) showed almost perfect agreement. The sensitivity of serotypes 1, 2 and 3 was 94.83%, 100.00% and 100.00%, respectively. In conclusion, the assay with the vaccine antigens can be used as a safe application, especially for large-scale surveillance studies.
Subject(s)
Antibodies, Viral/analysis , Poliomyelitis/diagnosis , Poliomyelitis/prevention & control , Poliovirus/isolation & purification , Poliovirus Vaccines , Reference StandardsABSTRACT
A poliomielite é uma doença endêmica no Afeganistão e no Paquistão, apesar dos esforços para ser erradicada, representando uma ameaça para outros países principalmente devido às viagens internacionais. A Organização Mundial da Saúde (OMS) tem como objetivo erradicar a poliomielite causada pelo poliovírus selvagem no mundo. O requisito essencial para a erradicação da poliomielite é a eliminação da cepa do poliovírus selvagem, que é empregada no teste padrão-ouro. Com o intuito de auxiliar na erradicação do poliovírus selvagem, o objetivo deste estudo foi modificar o teste padrão-ouro usando o poliovírus derivado da vacina oral atenuada. Foram testados 63 soros pelo ensaio de neutralização utilizando-se antígenos vacinais. A concordância do sorotipo 1 (k=0,74) foi considerada substancial, enquanto o sorotipo 2 (k=1,00) e sorotipo 3 (k= 0,95) foram consideradas quase perfeitas. A sensibilidade dos testes de soroneutralização utilizando os sorotipos 1, 2 e 3 foi de 94,83%, 100,00% e 100,00%, respectivamente. Em conclusão, o ensaio com antígenos vacinais pode ser usado como procedimento laboratorial seguro, especialmente em estudos de vigilância em larga escala. (AU)
Poliomyelitis is an endemic disease in Afghanistan and Pakistan in despite of the efforts to eradicate it, and it represents a threat to other countries mainly due to the international trips. The World Health Organization (WHO) aims at eradicating the polio disease worldwide. An essential requirement for eradicating the poliomyelitis is the elimination of the wild poliovirus strain, which is employed in the gold standard test. As a support for the eradication of wild poliovirus, the present study aimed at modifying the gold standard test by using poliovirus derived from the oral attenuated vaccine. Sixty-three sera samples were tested by neutralization assay using vaccine antigens. The degree of agreement of the serotype 1 (k=0.74) was considered substantial, while the serotype 2 (k=1.00) and 3 (k= 0.95) showed almost perfect agreement. The sensitivity of serotypes 1, 2 and 3 was 94.83%, 100.00% and 100.00%, respectively. In conclusion, the assay with the vaccine antigens can be used as a safe application, especially for large-scale surveillance studies. (AU)
Subject(s)
Poliomyelitis , Poliovirus Vaccine, Inactivated , Poliovirus , Antibodies, ViralABSTRACT
O objetivo deste trabalho foi avaliar a capacidade de efetuar o diagnóstico precoce do teste de aglutinação microscópica (MAT) utilizando-se como antígeno leptospiras saprófitas sorovar Patoc (MAT-Patoc). Neste contexto, os resultados obtidos em amostras de soro de casos confirmados de leptospirose foram comparados com aqueles obtidos no teste ELISA IgM. Cento e cinquenta e oito amostras colhidas na fase aguda da doença foram analisadas pelo MAT-Patoc. Os soros com títulos ≥ 50 foram considerados reagentes. A sensibilidade do MAT-Patoc e do ELISA-IgM foi de 13,29% e 28,48%, respectivamente. Nos sete primeiros dias da doença, o MAT-Patoc foi capaz de detectar 12,29% dos casos, enquanto o ELISA-IgM detectou 24,59%. O MAT-Patoc foi reagente em amostras de casos cujos prováveis sorogrupos infectantes foram Icterohaemorrhagiae, Cynopteri e Ballum. Em conclusão, a utilização do teste MAT-Patoc apresentou menor sensibilidade no diagnóstico quando comparado ao ELISA-IgM, embora tenha sido reagente em algumas amostras com resultado não reagente. O MAT-Patoc deve ser utilizado em combinação com ELISA-IgM para melhorar a sensibilidade do diagnóstico de leptospirose na primeira fase da doença, com subsequente confirmação pelo MAT de referência.
The aim of this study was to evaluate the early detection of antibodies by the microscopic agglutination test (MAT) using saprophytic leptospira serovar Patoc (MAT-Patoc), in serum samples from patients with confirmed leptospirosis. The obtained results were compared with those found in ELISA-IgM. A hundred fifty-eight serum samples collected from patients in acute phase of illness were analysed by MAT-Patoc. Samples with titers ≥ 50 were considered positive. The sensitivity of MAT-Patoc and IgM-ELISA was 13.29 % and 28.48 %, respectively. In the first seven days of the disease, MAT-Patoc was positive in 12.29 % of the cases, while the IgM-ELISA was positive in 24.59 %. The MAT-Patoc was positive in sera from confirmed cases, and the infecting serogroups were Icterohaemorrhagiae, Cynopteri and Ballum. In conclusion, the use of MAT-Patoc test showed lower sensitivity for diagnosing leptospirosis when compared with ELISA-IgM, although positive reactivity was found in some samples with negative results. The MAT-Patoc should be used in combination with ELISA-IgM to improve the sensitivity of the diagnosis of leptospirosis in the first phase of the disease, with subsequent confirmation by standard MAT.
Subject(s)
Humans , Male , Female , Agglutination , Enzyme-Linked Immunosorbent Assay , Immunoglobulin M , Leptospirosis/diagnosisABSTRACT
Leptospirosis is a zoonotic disease caused by the pathogenic Leptospira spp. The clinical presentations are diverse, ranging from undifferentiated fever to fulminant disease including meningeal forms. The neurological leptospirosis forms are usually neglected. The aim of this study was to investigate leptospirosis as the cause of aseptic meningitis using different diagnostic techniques including the polymerase chain reaction (PCR). Thirty-nine cerebrospinal fluid (CSF) samples from patients presenting with meningeal abnormalities, predominance of lymphocytes and negative results by traditional microbiological tests were processed by leptospiral culture, anti-leptospiral antibody response and PCR. Leptospira spp DNA was detected in 23 (58.97 percent) of the CSF samples. Anti-leptospiral antibodies were found in 13 (33.33 percent) CSF samples. Twelve CSF samples were positive by PCR assay and negative by microscopic agglutination test (MAT) assay. Two CSF samples were positive by MAT and negative by PCR. The positive and negative agreement between both tests was 11 and 14, respectively. CSF samples from six cases of unknown diagnosis were positive by PCR assay. Eight cases showed positive results using PCR and MAT. Leptospirosis could be detected by PCR assay from the 3rd-26th day after illness onset. The sensitivity of the PCR was assessed with confirmed cases of leptospirosis (by MAT) and found to be 89.5 percent. All CSFs were negative by culture. PCR was found to be a powerful tool for diagnosing meningitis cases of leptospirosis. We recommend that it may be used as a supplementary diagnostic tool, especially in the early stages of the disease, when other diagnostic techniques such as serology are not sensitive.