Transmissibility and mortality impact of epidemic and pandemic influenza, with emphasis on the unusually deadly 1951 epidemic.

There are important gaps in our current understanding of the influenza virus behavior. In particular, it remains unclear why some inter-pandemic seasons are associated with unusually high mortality impact, sometimes comparable to that of pandemics. Here we compare the epidemiological patterns of the unusually deadly 1951 influenza epidemic (A/H1N1) in England and Wales and Canada with those of surrounding epidemic and pandemic seasons, in terms of overall mortality impact and transmissibility. Based on the statistical and mathematical analysis of vital statistics and morbidity epidemic curves in these two countries, we show that the 1951 epidemic was associated with both higher mortality impact and higher transmissibility than the 1957 and 1968 pandemics. Surprisingly in Liverpool, considered the 'epicenter' of the severe 1951 epidemic, the mortality impact and transmissibility even surpassed the 1918 pandemic.

[1]  E. Kopf.  Report on the Pandemic of Influenza, 1918-1919 , 1921 .

[2]  A. Semple,et al.  Discussion: Influenza 1951 , 1951, Proceedings of the Royal Society of Medicine.

[3]  I M Longini,et al.  Predicting the global spread of new infectious agents. , 1986, American journal of epidemiology.

[4]  A. J. Hall.  Infectious diseases of humans: R. M. Anderson & R. M. May. Oxford etc.: Oxford University Press, 1991. viii + 757 pp. Price £50. ISBN 0-19-854599-1 , 1992 .

[5]  L. Simonsen,et al.  The impact of influenza epidemics on mortality: introducing a severity index. , 1997, American journal of public health.

[6]  N. Cox,et al.  Global epidemiology of influenza: past and present. , 2000, Annual review of medicine.

[7]  Influenza activity--United States, 1999-2000 season. , 1999, MMWR. Morbidity and mortality weekly report.

[8]  Jeffery K. Taubenberger,et al.  Characterization of the 1918 influenza virus polymerase genes , 2005, Nature.

[9]  J. Robins,et al.  Transmissibility of 1918 pandemic influenza , 2004, Nature.

[10]  Mark A. Miller,et al.  1951 Influenza Epidemic, England and Wales, Canada, and the United States , 2006, Emerging infectious diseases.

[11]  J. Nguyen-Van-Tam,et al.  The epidemiology and clinical impact of pandemic influenza. , 2003, Vaccine.

[12]  Mark A. Miller,et al.  Influenza Epidemic , England and Wales , Canada , and the United States , 2022 .

[13]  A. Lapedes,et al.  Mapping the Antigenic and Genetic Evolution of Influenza Virus , 2004, Science.

[14]  Cécile Viboud,et al.  Multinational impact of the 1968 Hong Kong influenza pandemic: evidence for a smoldering pandemic. , 2005, The Journal of infectious diseases.

[15]  Bryan T Grenfell,et al.  Whole-Genome Analysis of Human Influenza A Virus Reveals Multiple Persistent Lineages and Reassortment among Recent H3N2 Viruses , 2005, PLoS biology.

[16]  Niall Johnson,et al.  Updating the Accounts: Global Mortality of the 1918-1920 "Spanish" Influenza Pandemic , 2002, Bulletin of the history of medicine.

[17]  S. Salzberg,et al.  Large-scale sequencing of human influenza reveals the dynamic nature of viral genome evolution , 2005, Nature.

[18]  Steve Leach,et al.  Potential Impact of Antiviral Drug Use during Influenza Pandemic , 2005, Emerging infectious diseases.

[19]  Cecile Viboud,et al.  Impact of influenza vaccination on seasonal mortality in the US elderly population. , 2005, Archives of internal medicine.

[20]  C. Spicer.  The mathematical modelling of influenza epidemics. , 1979, British medical bulletin.

[21]  W. Logan,et al.  Development of influenza epidemics. , 1951, Lancet.

[22]  A. Flahault,et al.  Modelling the 1985 influenza epidemic in France. , 1988, Statistics in medicine.

[23]  L. Simonsen.  The global impact of influenza on morbidity and mortality. , 1999, Vaccine.

[24]  J. Davies,et al.  Influenza in Liverpool. , 1958, The Lancet.

[25]  C. Andrewes,et al.  Influenza A viruses; laboratory studies, with special reference to European outbreak of 1950-1. , 1952, Bulletin of the World Health Organization.

[26]  Jonathan Dushoff,et al.  Hemagglutinin sequence clusters and the antigenic evolution of influenza A virus , 2002, Proceedings of the National Academy of Sciences of the United States of America.