tetano
Editor, Senior Moderator
Clin Infect Dis. 2010 Apr 9. [Epub ahead of print]
Mixed Infections of Pandemic H1N1 and Seasonal H3N2 Viruses in 1 Outbreak.
Liu W, Li ZD, Tang F, Wei MT, Tong YG, Zhang L, Xin ZT, Ma MJ, Zhang XA, Liu LJ, Zhan L, He C, Yang H, Boucher CA, Richardus JH, Cao WC.
Beijing Institute of Microbiology and Epidemiology, State Key Laboratory of Pathogen and Biosecurity, 2Center for Diseases Control and Prevention of Chinese Peoples' Armed Police Forces, and 3Chinese National Human Genome Center, Beijing, and 4College of Biology and Environmental Science, Jishou University, Jishou, People's Republic of China; and Departments of 5Virology and 6Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands.
Abstract
Background. In early September 2009, an outbreak of influenza occurred at a college campus in Beijing, China, in which both pandemic H1N1 and seasonal H3N2 viruses were detected. Methods. Outbreak investigation was performed in the campus. Epidemiologic, clinical data were collected by interviewing patients and retrieving medical records. Individual contact tracing was performed for detailed contact information. Viruses were identified by reverse-transcription polymerase chain reaction assays followed by sequence analysis. The hemagglutination inhibition test was used to detect antibodies to both viruses for paired serum samples. Results. Forty of 45 people with influenza-like illness had laboratory-confirmed influenza A infection; 22 of these 40 people were infected with pandemic H1N1 virus, 12 were infected with seasonal H3N2 virus, and 6 were coinfected with both viruses. In the subsequent generation of cases with mixed infection, we detected pandemic H1N1 virus infection more often than seasonal H3N2 virus infection. The clinical patterns were essentially similar for patients with different virus infections. No substantial differences in sequences were observed in either pandemic H1N1 or seasonal H3N2 virus between patients with mixed and single infection. Sequence analyses revealed that all of the detected viruses were susceptible to oseltamivir but resistant to adamantane. Hemagglutination inhibition tests of paired serum samples confirmed mixed infection in the outbreak. Conclusions. Cocirculation of pandemic H1N1 virus and seasonal H3N2 virus led to a mixed infection in patients. Pandemic H1N1 virus, however, took prevalence over seasonal influenza virus in the course of transmission. Therefore, competitive circulation of seasonal influenza A virus with the pandemic H1N1 virus seems less likely.
PMID: 20380566 [PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/20380566?dopt=Abstract
Mixed Infections of Pandemic H1N1 and Seasonal H3N2 Viruses in 1 Outbreak.
Liu W, Li ZD, Tang F, Wei MT, Tong YG, Zhang L, Xin ZT, Ma MJ, Zhang XA, Liu LJ, Zhan L, He C, Yang H, Boucher CA, Richardus JH, Cao WC.
Beijing Institute of Microbiology and Epidemiology, State Key Laboratory of Pathogen and Biosecurity, 2Center for Diseases Control and Prevention of Chinese Peoples' Armed Police Forces, and 3Chinese National Human Genome Center, Beijing, and 4College of Biology and Environmental Science, Jishou University, Jishou, People's Republic of China; and Departments of 5Virology and 6Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, the Netherlands.
Abstract
Background. In early September 2009, an outbreak of influenza occurred at a college campus in Beijing, China, in which both pandemic H1N1 and seasonal H3N2 viruses were detected. Methods. Outbreak investigation was performed in the campus. Epidemiologic, clinical data were collected by interviewing patients and retrieving medical records. Individual contact tracing was performed for detailed contact information. Viruses were identified by reverse-transcription polymerase chain reaction assays followed by sequence analysis. The hemagglutination inhibition test was used to detect antibodies to both viruses for paired serum samples. Results. Forty of 45 people with influenza-like illness had laboratory-confirmed influenza A infection; 22 of these 40 people were infected with pandemic H1N1 virus, 12 were infected with seasonal H3N2 virus, and 6 were coinfected with both viruses. In the subsequent generation of cases with mixed infection, we detected pandemic H1N1 virus infection more often than seasonal H3N2 virus infection. The clinical patterns were essentially similar for patients with different virus infections. No substantial differences in sequences were observed in either pandemic H1N1 or seasonal H3N2 virus between patients with mixed and single infection. Sequence analyses revealed that all of the detected viruses were susceptible to oseltamivir but resistant to adamantane. Hemagglutination inhibition tests of paired serum samples confirmed mixed infection in the outbreak. Conclusions. Cocirculation of pandemic H1N1 virus and seasonal H3N2 virus led to a mixed infection in patients. Pandemic H1N1 virus, however, took prevalence over seasonal influenza virus in the course of transmission. Therefore, competitive circulation of seasonal influenza A virus with the pandemic H1N1 virus seems less likely.
PMID: 20380566 [PubMed - as supplied by publisher]
http://www.ncbi.nlm.nih.gov/pubmed/20380566?dopt=Abstract