Cited by 1,700Influenza Virus Research StudiesRespiratory viral infections researchCOVID-19 Clinical Research Studies

Hospitalized patients with 2009 H1N1 influenza in the United States, April-June 2009

Jain, Seema, Kamimoto, Laurie, Bramley, Anna M., Schmitz, Ann M., Benoit, Stephen R., Louie, Janice, Sugerman, David E., Druckenmiller, Jean K. +17 more·2009·New England Journal of Medicine

Abstract

BACKGROUND: During the spring of 2009, a pandemic influenza A (H1N1) virus emerged and spread globally. We describe the clinical characteristics of patients who were hospitalized with 2009 H1N1 influenza in the United States from April 2009 to mid-June 2009. METHODS: Using medical charts, we collected data on 272 patients who were hospitalized for at least 24 hours for influenza-like illness and who tested positive for the 2009 H1N1 virus with the use of a real-time reverse-transcriptase-polymerase-chain-reaction assay. RESULTS: Of the 272 patients we studied, 25% were admitted to an intensive care unit and 7% died. Forty-five percent of the patients were children under the age of 18 years, and 5% were 65 years of age or older. Seventy-three percent of the patients had at least one underlying medical condition; these conditions included asthma; diabetes; heart, lung, and neurologic diseases; and pregnancy. Of the 249 patients who underwent chest radiography on admission, 100 (40%) had findings consistent with pneumonia. Of the 268 patients for whom data were available regarding the use of antiviral drugs, such therapy was initiated in 200 patients (75%) at a median of 3 days after the onset of illness. Data suggest that the use of antiviral drugs was beneficial in hospitalized patients, especially when such therapy was initiated early. CONCLUSIONS: During the evaluation period, 2009 H1N1 influenza caused severe illness requiring hospitalization, including pneumonia and death. Nearly three quarters of the patients had one or more underlying medical conditions. Few severe illnesses were reported among persons 65 years of age or older. Patients seemed to benefit from antiviral therapy.

Integrity signals

Registry

Crossref · 10.1056/nejmoa0906695

Cites

29 of 29 references verified0 citation errors · 0 not checkable

Statistics

Recomputing p-values needs the paper’s full text.

Claims the paper makes

This paper’s full text isn’t openly available, so its claims and self-check weren’t run. The registry and citation checks still apply.

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

  • Bacterial co-infection was detected in ~30% of cases in the 2009 H1N1 pandemic, with high mortality rates despite administration of appropriate antibiotics.

    “Bacterial co-infection was also detected in ~30% of cases in the 2009 H1N1 pandemic, with high mortality rates despite administration of appropriate antibiotics”

Cites

Flagged first, then by citations

Cited by

Sorted by citations

Authors
Jain, S., Kamimoto, L., Bramley, A. M., Schmitz, A. M., Benoit, S. R., Louie, J., Sugerman, D. E., Druckenmiller, J. K., Ritger, K. A., Chugh, R., Jasuja, S., Deutscher, M., Chen, S., Walker, J. D., Duchin, J. S., Lett, S., Soliva, S., Wells, E. V., Swerdlow, D., Uyeki, T. M., Fiore, A. E., Olsen, S. J., Fry, A. M., Bridges, C. B., & Finelli, L.
Affiliations
  • Centers for Disease Control and Prevention (US)
  • National Center for Immunization and Respiratory Diseases (US)
  • National Center for Emerging and Zoonotic Infectious Diseases (US)
  • National Center for Public Health Informatics (US)
  • California Department of Public Health (US)
  • Wisconsin Division of Public Health (US)
  • Chicago Department of Public Health (US)
  • Dupage County Health Department (US)
  • Arizona Department of Health Services (US)
  • Texas Department of State Health Services (US)
  • Public Health – Seattle & King County (US)
  • Michigan Department of Health and Human Services (US)
  • Epidemic Intelligence Service (US)
Venue
New England Journal of Medicine
Published
2009-11-12
Volume
361
Issue
20
Pages
1935-1944
ISSN
  • 0028-4793 (ISSN-L)
  • 1533-4406
OpenAlex
W2112166111
Cited by
1,700
References
29
Citations by year
2026: 9 · 2025: 20 · 2024: 35 · 2023: 26 · 2022: 37 · 2021: 52 · 2020: 55 · 2019: 43 · 2018: 42 · 2017: 46 · 2016: 51 · 2015: 78 · 2014: 87 · 2013: 137 · 2012: 232
FWCI
218.87
Type
journal article
Language
en
Open access
closed
Locations
  • New England Journal of Medicine (publishedVersion)
  • PubMed (publishedVersion)
Topics
  • Health Sciences › Medicine › Epidemiology › Influenza Virus Research Studies
  • Health Sciences › Medicine › Epidemiology › Respiratory viral infections research
  • Health Sciences › Medicine › Infectious Diseases › COVID-19 Clinical Research Studies
Keywords
2009 H1N1 influenza, pandemic influenza A, hospitalized patients, clinical features, intensive care unit admission, mortality, pneumonia, underlying disease, antiviral therapy, treatment timing, influenza-like illness
MeSH terms
Adolescent, Adult, Aged, Antiviral Agents, Asthma, Cardiovascular Diseases, Child, Child, Preschool, Female, Hospitalization, Humans, Infant, Influenza, Human, Intensive Care Units, Male, Middle Aged, Pregnancy, Pregnancy Complications, Risk Factors, United States, Comorbidity, Body Mass Index, Treatment Outcome, Hospital Mortality, Reverse Transcriptase Polymerase Chain Reaction, Influenza A Virus, H1N1 Subtype, Young Adult

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review