Background Some research groups have hypothesized that human rhinoviruses （HRVs） delayed the circulation of the 2009 pandemic influenza A（H1N1） virus （A（H1N1）pdm09） at the beginning of Autumn 2009 in France.Th...Background Some research groups have hypothesized that human rhinoviruses （HRVs） delayed the circulation of the 2009 pandemic influenza A（H1N1） virus （A（H1N1）pdm09） at the beginning of Autumn 2009 in France.This study aimed to evaluate the relationship between HRV and A（H1N1）pdm09 in pediatric patients with influenza-like illness in Beijing,China.Methods A systematic analysis to detect A（H1N1）pdm09 and seasonal influenza A virus （FLU A） was performed on 4 349 clinical samples from pediatric patients with influenza-like illness during the period June 1,2009 to February 28,2010,while a one-step real-time RT-PCR （rRT-PCR） assay was used to detect HRV in 1 146 clinical specimens selected from those 4 349 specimens.Results During the survey period,only one wave of A（H1N1）pdm09 was observed.The percentage of positive cases for A（H1N1）pdm09 increased sharply in September with a peak in November 2009 and then declined in February 2010.Data on the monthly distribution of HRVs indicated that more HRV-positive samples were detected in September （2.2％） and October （3.3％）,revealing that the peak of HRV infection in 2009 was similar to that of other years.Among the 1 146 specimens examined for HRVs,21 （1.8％） were HRV-positive,which was significantly lower than that reported previously in Beijing （15.4％ to 19.2％） （P ＜0.01）.Overall,6 samples were positive for both A（H1N1）pdm09 and HRV,which represented a positive relative frequency of 1.60％ and 2.08％ HRV,considering the A（H1N1）pdm09-positive and-negative specimens,respectively.The odds ratio was 0.87 （95％ CI 0.32; 2.44,P=0.80）.Conclusions HRVs and A （H1N1）pdm09 co-circulated in this Chinese population during September and October 2009,and the HRV epidemic in 2009 did not affect A（H1N1）pdm09 infection rates in Beijing,China as suggested by other studies.However,the presence of A（H1N1）pdm09 might explain the unexpected reduction in the percentage of HRV positive cases during the period studied.展开更多
Objective: To know the natural history of the first wave of pandemic influenza A(H1N1)pdm09 in the Southern hemisphere, through the detection of antibodies against influenza A(H1N1)pdm09 in a selected community, to es...Objective: To know the natural history of the first wave of pandemic influenza A(H1N1)pdm09 in the Southern hemisphere, through the detection of antibodies against influenza A(H1N1)pdm09 in a selected community, to estimate the population attack rate and its variations, the consultation rates, hospitallization and mortality rates. Methodology: A representative random sample of the population of a commune in Chile (San Felipe) was interviewed and taken blood samples between January and March 2010. A study against the antibodies of the influenza A(H1N1) pdm09 virus was conducted, by the technique of the Hemaglutination Inhibition (HAI) according to standardized methodology. Subjects with antibody titers ≥1:40 were considered positive. Results: 13.5% of the population of San Felipe had antibodies against influenza A(H1N1)pdm09;this percentage reached 30% of the population between 0 and 18 years and 6.1% among those over 19 years. The age variable was the only factor that evidenced significant differences in the prevalence of antibodies. There were no significant differences related to gender, vaccination history against seasonal inluenza, or comorbidity. 51% of people with positive serology showed IN-FLUENZA-LIKE SYMPTOMS. Conclusions: A relevant percentage of subclinical disease was detected in the first pandemic wave in Chile and the proportion of people with SARI and deaths was small. Data from epidemiological surveillance were useful to estimate the trend of TSI but not its magnitude.展开更多
基金This study was supported by the grants from the National Natural Science Foundation of China （No. 30872153） and the Beijing Outstanding Personnel Training Grant from the Beijing Municipal Committee for Science and Technology （No. 2006A63）.Acknowledgements： We would like to thank all the doctors and nurses in the Department of Emergency and the Outpatient Department at the Affiliated Children＇s Hospital of the Capital Institute of Pediatrics for collecting specimens from patients and information from their parents.
文摘Background Some research groups have hypothesized that human rhinoviruses （HRVs） delayed the circulation of the 2009 pandemic influenza A（H1N1） virus （A（H1N1）pdm09） at the beginning of Autumn 2009 in France.This study aimed to evaluate the relationship between HRV and A（H1N1）pdm09 in pediatric patients with influenza-like illness in Beijing,China.Methods A systematic analysis to detect A（H1N1）pdm09 and seasonal influenza A virus （FLU A） was performed on 4 349 clinical samples from pediatric patients with influenza-like illness during the period June 1,2009 to February 28,2010,while a one-step real-time RT-PCR （rRT-PCR） assay was used to detect HRV in 1 146 clinical specimens selected from those 4 349 specimens.Results During the survey period,only one wave of A（H1N1）pdm09 was observed.The percentage of positive cases for A（H1N1）pdm09 increased sharply in September with a peak in November 2009 and then declined in February 2010.Data on the monthly distribution of HRVs indicated that more HRV-positive samples were detected in September （2.2％） and October （3.3％）,revealing that the peak of HRV infection in 2009 was similar to that of other years.Among the 1 146 specimens examined for HRVs,21 （1.8％） were HRV-positive,which was significantly lower than that reported previously in Beijing （15.4％ to 19.2％） （P ＜0.01）.Overall,6 samples were positive for both A（H1N1）pdm09 and HRV,which represented a positive relative frequency of 1.60％ and 2.08％ HRV,considering the A（H1N1）pdm09-positive and-negative specimens,respectively.The odds ratio was 0.87 （95％ CI 0.32; 2.44,P=0.80）.Conclusions HRVs and A （H1N1）pdm09 co-circulated in this Chinese population during September and October 2009,and the HRV epidemic in 2009 did not affect A（H1N1）pdm09 infection rates in Beijing,China as suggested by other studies.However,the presence of A（H1N1）pdm09 might explain the unexpected reduction in the percentage of HRV positive cases during the period studied.
文摘Objective: To know the natural history of the first wave of pandemic influenza A(H1N1)pdm09 in the Southern hemisphere, through the detection of antibodies against influenza A(H1N1)pdm09 in a selected community, to estimate the population attack rate and its variations, the consultation rates, hospitallization and mortality rates. Methodology: A representative random sample of the population of a commune in Chile (San Felipe) was interviewed and taken blood samples between January and March 2010. A study against the antibodies of the influenza A(H1N1) pdm09 virus was conducted, by the technique of the Hemaglutination Inhibition (HAI) according to standardized methodology. Subjects with antibody titers ≥1:40 were considered positive. Results: 13.5% of the population of San Felipe had antibodies against influenza A(H1N1)pdm09;this percentage reached 30% of the population between 0 and 18 years and 6.1% among those over 19 years. The age variable was the only factor that evidenced significant differences in the prevalence of antibodies. There were no significant differences related to gender, vaccination history against seasonal inluenza, or comorbidity. 51% of people with positive serology showed IN-FLUENZA-LIKE SYMPTOMS. Conclusions: A relevant percentage of subclinical disease was detected in the first pandemic wave in Chile and the proportion of people with SARI and deaths was small. Data from epidemiological surveillance were useful to estimate the trend of TSI but not its magnitude.
