Dengue virus(DENV) is a mosquito-transmitted virus that is expanding across the world,The incidence of dengue infection,especially severe disease,has been increasing,DENV consist of 4 serotypes of single stranded RNA ...Dengue virus(DENV) is a mosquito-transmitted virus that is expanding across the world,The incidence of dengue infection,especially severe disease,has been increasing,DENV consist of 4 serotypes of single stranded RNA viruses(D1-D4) in the genus Flavivirus,family Flaviviridae,Majority of dengue infections are asymptomatic cases,which cause difficulty in disease control and are important in dengue surveillance,There is still no gold standard to diagnose asymptomatic dengue infection,Plaque reduction neutralization test(PRNT) has been developed for many purposes such as immunological study,clinical study,vaccine trial and is currently the most sensitive and specific method for serological surveillance,However,PRNT shows some degree of cross reaction among different dengue serotypes especially secondary dengue infection cases and to other flaviviruses,Moreover,various modification since the beginning make PRNT lack of inter-laboratory standardization which is an important issue,This paper discusses the important of asymptomatic dengue infection and its diagnostic method.展开更多
Dengue virus (DENV) is the world most prevalent mosquito-transmitted virus. The incidence of dengue infection has been increasing and most of the infected people are asymptomatic or have non specific febrile illness. ...Dengue virus (DENV) is the world most prevalent mosquito-transmitted virus. The incidence of dengue infection has been increasing and most of the infected people are asymptomatic or have non specific febrile illness. Laboratory test is essential to confirm dengue infection in epidemiological studies. We developed an indirect ELISA test based on monoclonal immunoglobulin against all four DENV serotypes and evaluated the test for the diagnosis of asymptomatic dengue infection in paired annual serum samples. The indirect ELISA was found to have a sensitivity 87.5% and specificity 78.3% at optimized cut off. The results from indirect ELISA demonstrate an incidence of asymptomatic dengue infection from children aged 4 - 11 years in Ratchaburi province, Thailand (2006-2009). These findings indicate that the indirect ELISA is suitable for serodiagnosis and seroepidemiological studies of asymptomatic dengue infection.展开更多
The purpose of this study was to test the effectiveness of source virus strain for the manufacture of the inactivated SARS virus vaccine, and establish an experimental method and preliminary standard for potency evalu...The purpose of this study was to test the effectiveness of source virus strain for the manufacture of the inactivated SARS virus vaccine, and establish an experimental method and preliminary standard for potency evaluation. Mice were divided into groups for being immunized with corresponding serially diluted experimental SARS virus inactivated vaccine. And the rabbits were immunized with undiluted vaccine. Challenge assay was conducted with a heterologous SARS virus. And the neutralization antibody was determined with plaque reduction neutralization test (PRNT), to which the neutralization antibody in the convalescent serum of SARS patients was compared. The experimental vaccine viral strains were proved to be suitable for manufacturing the vaccine. Mice immunized by vaccines of serial dilutions were able to elicit neutralizing antibody. The antibody titer from mice immunized with the undiluted vaccine could reach up to 1∶495.2, while those of rabbits immunized with the undiluted vaccine could reach a GMT of 55.0-79.9. The capability of the antibody to neutralize the virus from Guangdong is more efficient than that from Beijing. The GMT of neutralizing antibody in SARS convalescents living in south and north China ranged from 50.12 to 54.95, and the titers of convalescents from north China were higher than those from south China. Mice and rabbits used as the model for evaluation of potency are of sensitivity, and the test is of reproducibility. The candidate challenge viral strains showed a relatively consistent effect on evaluating antibodies produced by various batches and different vaccine-source strains, hence they can be used to evaluate potency of the vaccine. The method for testing the vaccine potency and the evaluation standard was established preliminarily.展开更多
基金supported by Faculty of Tropical Medicine,Mahidol University,Thailand
文摘Dengue virus(DENV) is a mosquito-transmitted virus that is expanding across the world,The incidence of dengue infection,especially severe disease,has been increasing,DENV consist of 4 serotypes of single stranded RNA viruses(D1-D4) in the genus Flavivirus,family Flaviviridae,Majority of dengue infections are asymptomatic cases,which cause difficulty in disease control and are important in dengue surveillance,There is still no gold standard to diagnose asymptomatic dengue infection,Plaque reduction neutralization test(PRNT) has been developed for many purposes such as immunological study,clinical study,vaccine trial and is currently the most sensitive and specific method for serological surveillance,However,PRNT shows some degree of cross reaction among different dengue serotypes especially secondary dengue infection cases and to other flaviviruses,Moreover,various modification since the beginning make PRNT lack of inter-laboratory standardization which is an important issue,This paper discusses the important of asymptomatic dengue infection and its diagnostic method.
文摘Dengue virus (DENV) is the world most prevalent mosquito-transmitted virus. The incidence of dengue infection has been increasing and most of the infected people are asymptomatic or have non specific febrile illness. Laboratory test is essential to confirm dengue infection in epidemiological studies. We developed an indirect ELISA test based on monoclonal immunoglobulin against all four DENV serotypes and evaluated the test for the diagnosis of asymptomatic dengue infection in paired annual serum samples. The indirect ELISA was found to have a sensitivity 87.5% and specificity 78.3% at optimized cut off. The results from indirect ELISA demonstrate an incidence of asymptomatic dengue infection from children aged 4 - 11 years in Ratchaburi province, Thailand (2006-2009). These findings indicate that the indirect ELISA is suitable for serodiagnosis and seroepidemiological studies of asymptomatic dengue infection.
文摘The purpose of this study was to test the effectiveness of source virus strain for the manufacture of the inactivated SARS virus vaccine, and establish an experimental method and preliminary standard for potency evaluation. Mice were divided into groups for being immunized with corresponding serially diluted experimental SARS virus inactivated vaccine. And the rabbits were immunized with undiluted vaccine. Challenge assay was conducted with a heterologous SARS virus. And the neutralization antibody was determined with plaque reduction neutralization test (PRNT), to which the neutralization antibody in the convalescent serum of SARS patients was compared. The experimental vaccine viral strains were proved to be suitable for manufacturing the vaccine. Mice immunized by vaccines of serial dilutions were able to elicit neutralizing antibody. The antibody titer from mice immunized with the undiluted vaccine could reach up to 1∶495.2, while those of rabbits immunized with the undiluted vaccine could reach a GMT of 55.0-79.9. The capability of the antibody to neutralize the virus from Guangdong is more efficient than that from Beijing. The GMT of neutralizing antibody in SARS convalescents living in south and north China ranged from 50.12 to 54.95, and the titers of convalescents from north China were higher than those from south China. Mice and rabbits used as the model for evaluation of potency are of sensitivity, and the test is of reproducibility. The candidate challenge viral strains showed a relatively consistent effect on evaluating antibodies produced by various batches and different vaccine-source strains, hence they can be used to evaluate potency of the vaccine. The method for testing the vaccine potency and the evaluation standard was established preliminarily.
