The severity of pandemic H1N1 influenza in the United States, from April to July 2009: a Bayesian analysis.

<h4>Background</h4>Accurate measures of the severity of pandemic (H1N1) 2009 influenza (pH1N1) are needed to assess the likely impact of an anticipated resurgence in the autumn in the Northern Hemisphere. Severity has been difficult to measure because jurisdictions with large numbers of...

Descripción completa

Guardado en:
Detalles Bibliográficos
Autores principales: Anne M Presanis, Daniela De Angelis, New York City Swine Flu Investigation Team, Angela Hagy, Carrie Reed, Steven Riley, Ben S Cooper, Lyn Finelli, Paul Biedrzycki, Marc Lipsitch
Formato: article
Lenguaje:EN
Publicado: Public Library of Science (PLoS) 2009
Materias:
R
Acceso en línea:https://doaj.org/article/4ed5fa1437214dd69d2adcf20838207d
Etiquetas: Agregar Etiqueta
Sin Etiquetas, Sea el primero en etiquetar este registro!
id oai:doaj.org-article:4ed5fa1437214dd69d2adcf20838207d
record_format dspace
spelling oai:doaj.org-article:4ed5fa1437214dd69d2adcf20838207d2021-12-02T19:55:52ZThe severity of pandemic H1N1 influenza in the United States, from April to July 2009: a Bayesian analysis.1549-12771549-167610.1371/journal.pmed.1000207https://doaj.org/article/4ed5fa1437214dd69d2adcf20838207d2009-12-01T00:00:00Zhttps://www.ncbi.nlm.nih.gov/pmc/articles/pmid/19997612/?tool=EBIhttps://doaj.org/toc/1549-1277https://doaj.org/toc/1549-1676<h4>Background</h4>Accurate measures of the severity of pandemic (H1N1) 2009 influenza (pH1N1) are needed to assess the likely impact of an anticipated resurgence in the autumn in the Northern Hemisphere. Severity has been difficult to measure because jurisdictions with large numbers of deaths and other severe outcomes have had too many cases to assess the total number with confidence. Also, detection of severe cases may be more likely, resulting in overestimation of the severity of an average case. We sought to estimate the probabilities that symptomatic infection would lead to hospitalization, ICU admission, and death by combining data from multiple sources.<h4>Methods and findings</h4>We used complementary data from two US cities: Milwaukee attempted to identify cases of medically attended infection whether or not they required hospitalization, while New York City focused on the identification of hospitalizations, intensive care admission or mechanical ventilation (hereafter, ICU), and deaths. New York data were used to estimate numerators for ICU and death, and two sources of data--medically attended cases in Milwaukee or self-reported influenza-like illness (ILI) in New York--were used to estimate ratios of symptomatic cases to hospitalizations. Combining these data with estimates of the fraction detected for each level of severity, we estimated the proportion of symptomatic patients who died (symptomatic case-fatality ratio, sCFR), required ICU (sCIR), and required hospitalization (sCHR), overall and by age category. Evidence, prior information, and associated uncertainty were analyzed in a Bayesian evidence synthesis framework. Using medically attended cases and estimates of the proportion of symptomatic cases medically attended, we estimated an sCFR of 0.048% (95% credible interval [CI] 0.026%-0.096%), sCIR of 0.239% (0.134%-0.458%), and sCHR of 1.44% (0.83%-2.64%). Using self-reported ILI, we obtained estimates approximately 7-9 x lower. sCFR and sCIR appear to be highest in persons aged 18 y and older, and lowest in children aged 5-17 y. sCHR appears to be lowest in persons aged 5-17; our data were too sparse to allow us to determine the group in which it was the highest.<h4>Conclusions</h4>These estimates suggest that an autumn-winter pandemic wave of pH1N1 with comparable severity per case could lead to a number of deaths in the range from considerably below that associated with seasonal influenza to slightly higher, but with the greatest impact in children aged 0-4 and adults 18-64. These estimates of impact depend on assumptions about total incidence of infection and would be larger if incidence of symptomatic infection were higher or shifted toward adults, if viral virulence increased, or if suboptimal treatment resulted from stress on the health care system; numbers would decrease if the total proportion of the population symptomatically infected were lower than assumed.Anne M PresanisDaniela De AngelisNew York City Swine Flu Investigation TeamAngela HagyCarrie ReedSteven RileyBen S CooperLyn FinelliPaul BiedrzyckiMarc LipsitchPublic Library of Science (PLoS)articleMedicineRENPLoS Medicine, Vol 6, Iss 12, p e1000207 (2009)
institution DOAJ
collection DOAJ
language EN
topic Medicine
R
spellingShingle Medicine
R
Anne M Presanis
Daniela De Angelis
New York City Swine Flu Investigation Team
Angela Hagy
Carrie Reed
Steven Riley
Ben S Cooper
Lyn Finelli
Paul Biedrzycki
Marc Lipsitch
The severity of pandemic H1N1 influenza in the United States, from April to July 2009: a Bayesian analysis.
description <h4>Background</h4>Accurate measures of the severity of pandemic (H1N1) 2009 influenza (pH1N1) are needed to assess the likely impact of an anticipated resurgence in the autumn in the Northern Hemisphere. Severity has been difficult to measure because jurisdictions with large numbers of deaths and other severe outcomes have had too many cases to assess the total number with confidence. Also, detection of severe cases may be more likely, resulting in overestimation of the severity of an average case. We sought to estimate the probabilities that symptomatic infection would lead to hospitalization, ICU admission, and death by combining data from multiple sources.<h4>Methods and findings</h4>We used complementary data from two US cities: Milwaukee attempted to identify cases of medically attended infection whether or not they required hospitalization, while New York City focused on the identification of hospitalizations, intensive care admission or mechanical ventilation (hereafter, ICU), and deaths. New York data were used to estimate numerators for ICU and death, and two sources of data--medically attended cases in Milwaukee or self-reported influenza-like illness (ILI) in New York--were used to estimate ratios of symptomatic cases to hospitalizations. Combining these data with estimates of the fraction detected for each level of severity, we estimated the proportion of symptomatic patients who died (symptomatic case-fatality ratio, sCFR), required ICU (sCIR), and required hospitalization (sCHR), overall and by age category. Evidence, prior information, and associated uncertainty were analyzed in a Bayesian evidence synthesis framework. Using medically attended cases and estimates of the proportion of symptomatic cases medically attended, we estimated an sCFR of 0.048% (95% credible interval [CI] 0.026%-0.096%), sCIR of 0.239% (0.134%-0.458%), and sCHR of 1.44% (0.83%-2.64%). Using self-reported ILI, we obtained estimates approximately 7-9 x lower. sCFR and sCIR appear to be highest in persons aged 18 y and older, and lowest in children aged 5-17 y. sCHR appears to be lowest in persons aged 5-17; our data were too sparse to allow us to determine the group in which it was the highest.<h4>Conclusions</h4>These estimates suggest that an autumn-winter pandemic wave of pH1N1 with comparable severity per case could lead to a number of deaths in the range from considerably below that associated with seasonal influenza to slightly higher, but with the greatest impact in children aged 0-4 and adults 18-64. These estimates of impact depend on assumptions about total incidence of infection and would be larger if incidence of symptomatic infection were higher or shifted toward adults, if viral virulence increased, or if suboptimal treatment resulted from stress on the health care system; numbers would decrease if the total proportion of the population symptomatically infected were lower than assumed.
format article
author Anne M Presanis
Daniela De Angelis
New York City Swine Flu Investigation Team
Angela Hagy
Carrie Reed
Steven Riley
Ben S Cooper
Lyn Finelli
Paul Biedrzycki
Marc Lipsitch
author_facet Anne M Presanis
Daniela De Angelis
New York City Swine Flu Investigation Team
Angela Hagy
Carrie Reed
Steven Riley
Ben S Cooper
Lyn Finelli
Paul Biedrzycki
Marc Lipsitch
author_sort Anne M Presanis
title The severity of pandemic H1N1 influenza in the United States, from April to July 2009: a Bayesian analysis.
title_short The severity of pandemic H1N1 influenza in the United States, from April to July 2009: a Bayesian analysis.
title_full The severity of pandemic H1N1 influenza in the United States, from April to July 2009: a Bayesian analysis.
title_fullStr The severity of pandemic H1N1 influenza in the United States, from April to July 2009: a Bayesian analysis.
title_full_unstemmed The severity of pandemic H1N1 influenza in the United States, from April to July 2009: a Bayesian analysis.
title_sort severity of pandemic h1n1 influenza in the united states, from april to july 2009: a bayesian analysis.
publisher Public Library of Science (PLoS)
publishDate 2009
url https://doaj.org/article/4ed5fa1437214dd69d2adcf20838207d
work_keys_str_mv AT annempresanis theseverityofpandemich1n1influenzaintheunitedstatesfromapriltojuly2009abayesiananalysis
AT danieladeangelis theseverityofpandemich1n1influenzaintheunitedstatesfromapriltojuly2009abayesiananalysis
AT newyorkcityswinefluinvestigationteam theseverityofpandemich1n1influenzaintheunitedstatesfromapriltojuly2009abayesiananalysis
AT angelahagy theseverityofpandemich1n1influenzaintheunitedstatesfromapriltojuly2009abayesiananalysis
AT carriereed theseverityofpandemich1n1influenzaintheunitedstatesfromapriltojuly2009abayesiananalysis
AT stevenriley theseverityofpandemich1n1influenzaintheunitedstatesfromapriltojuly2009abayesiananalysis
AT benscooper theseverityofpandemich1n1influenzaintheunitedstatesfromapriltojuly2009abayesiananalysis
AT lynfinelli theseverityofpandemich1n1influenzaintheunitedstatesfromapriltojuly2009abayesiananalysis
AT paulbiedrzycki theseverityofpandemich1n1influenzaintheunitedstatesfromapriltojuly2009abayesiananalysis
AT marclipsitch theseverityofpandemich1n1influenzaintheunitedstatesfromapriltojuly2009abayesiananalysis
AT annempresanis severityofpandemich1n1influenzaintheunitedstatesfromapriltojuly2009abayesiananalysis
AT danieladeangelis severityofpandemich1n1influenzaintheunitedstatesfromapriltojuly2009abayesiananalysis
AT newyorkcityswinefluinvestigationteam severityofpandemich1n1influenzaintheunitedstatesfromapriltojuly2009abayesiananalysis
AT angelahagy severityofpandemich1n1influenzaintheunitedstatesfromapriltojuly2009abayesiananalysis
AT carriereed severityofpandemich1n1influenzaintheunitedstatesfromapriltojuly2009abayesiananalysis
AT stevenriley severityofpandemich1n1influenzaintheunitedstatesfromapriltojuly2009abayesiananalysis
AT benscooper severityofpandemich1n1influenzaintheunitedstatesfromapriltojuly2009abayesiananalysis
AT lynfinelli severityofpandemich1n1influenzaintheunitedstatesfromapriltojuly2009abayesiananalysis
AT paulbiedrzycki severityofpandemich1n1influenzaintheunitedstatesfromapriltojuly2009abayesiananalysis
AT marclipsitch severityofpandemich1n1influenzaintheunitedstatesfromapriltojuly2009abayesiananalysis
_version_ 1718375837017833472