Table 1 |
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Comparison of the 1918–1919 and the 2009 H1N1 influenza pandemics |
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1918–1919 |
2009 |
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Influenza virus |
Avian Influenza A H1N1 |
Swine-Origin-Influenza A(H1N1)v |
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Social and political Context |
World War I – U.S. troops being deployed to Europe |
One of the largest economic recessions in the U.S. with worldwide reach |
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Globalization, ease of travel, population overgrowth, megacities |
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Source of viral strain emergence |
Historians have suggested to potential origins for this pandemic viral strain in China or in the Midwestern US military camps during World War I |
Unclear source, phylogeny of the virus demonstrates to be an Eurasian H1N1 swine strain |
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Seasonality and transmissibility |
Highly-transmissible – three succeeding waves of the outbreak |
Cases surfaced in early spring in Mexico City and in California, U.S.A. |
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Initial wave spring 1918 with sustained multifocal transmission |
Sustained transmission (two generations) only in North America |
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Affected age groups |
Most deaths occurred within the first six months of the pandemic. |
Most deaths occurred within a three week time span. |
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Most affected group 15–34 year-old population |
Most affected group is the 5 to 30; case-fatality rate has ranged from 5 to 45 years of age |
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Case management |
Insufficiency of healthcare systems |
Wider availability of healthcare institutions |
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Absence of effective antimicrobials for treating secondary bacterial pneumonias. |
Availability of broad-spectrum antimicrobials for treating secondary bacterial pneumonias |
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Medical intensive care in early phases of development |
Sophisticated medical intensive care and mechanical ventilatory support |
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Insufficient infection control activities |
More established infection control activities and programs |
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Virulence |
Highly virulent |
Virulence only demonstrated as causing most fatalities in Mexico |
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Availability of vaccine |
No |
No |
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Susceptibility to antivirals |
No availability of antivirals |
Susceptibility to neuraminidase inhibitors (oseltamivir). However, there are growing number of resistant viral strains to oseltamivir |
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Nosocomial transmission |
Highly transmissible in hospital settings |
Possibility of nosocomial transmission under investigation with 81 healthcare workers affected in the U.S [23] |
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Molecular characterization |
H1N1 avian strain without evidence of reassortment (4) |
H1N1 (triple reassortant – human – avian – swine) |
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Natural history of the outbreak and outcomes |
More than 300 million cases worldwide |
By June 11, 2009, 74 nation states have cases, with approximately 27,737 confirmed cases and 141 death |
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More than 50 million people deaths worldwide |
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Franco-Paredes et al. Journal of Immune Based Therapies and Vaccines 2009 7:2 doi:10.1186/1476-8518-7-2 |
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