Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2012 May;6(3):e63-71.
doi: 10.1111/j.1750-2659.2012.00343.x. Epub 2012 Feb 23.

Estimating age-specific influenza-related hospitalization rates during the pandemic (H1N1) 2009 in Davidson Co, TN

Astride Jules  1 , Carlos G Grijalva, Yuwei Zhu, Keipp H Talbot, John V Williams, William D Dupont, Kathryn M Edwards, William Schaffner, David K Shay, Marie R Griffin
Affiliations

Estimating age-specific influenza-related hospitalization rates during the pandemic (H1N1) 2009 in Davidson Co, TN

Astride Jules et al. Influenza Other Respir Viruses. 2012 May.

Abstract

Background: In April 2009, a pandemic caused by a novel influenza strain, the A(H1N1)pdm09 virus, started. Few age-specific estimates of hospitalizations associated with the first year of circulation of the pandemic virus are available.

Objectives: To estimate age-specific hospitalization rates associated with laboratory-confirmed A(H1N1)pdm09 virus in Davidson County, TN, from May 2009 to March 2010.

Patients/methods: Two separate strategies were applied: capture-recapture and surveillance-sampling methods. For the capture-recapture estimates, we linked data collected via two independent prospective population-based surveillance systems: The Influenza Vaccine Effectiveness Network (Flu-VE) tested consenting county patients hospitalized with respiratory symptoms at selected hospitals using real-time reverse transcriptase polymerase chain reaction (rRT-PCR); the Emerging Infections Program identified county patients with positive influenza tests in all area hospitals. For the surveillance-sampling estimates, we applied the age-specific proportions of influenza-positive patients (from Flu-VE) to the number of acute respiratory illness hospitalizations obtained from the Tennessee Hospital Discharge Data system.

Results: With capture-recapture, we estimated 0·89 (95% CI, 0·72-1·49), 0·62 (0·42-1·11), 1·78 (0·99-3·63), and 0·76 (0·50-1·76) hospitalizations per 1000 residents aged < 5, 5-17, 18-49, and ≥ 50 years, respectively. Surveillance-sampling estimated rates were 0·78 (0·46-1·22), 0·32 (0·14-0·69), 0·99 (0·64-1·52), and 1·43 (0·80-2·48) hospitalizations per 1000 residents aged <5, 5-17, 18-49, and ≥ 50 years, respectively. In all age-groups combined, we estimated approximately 1 influenza-related hospitalization per 1000 residents.

Conclusions: Two independent methods provided consistent results on the burden of pandemic virus in Davidson County and suggested that the overall incidence of A(H1N1)pdm09-associated hospitalization was 1 per 1000 county residents.

PubMed Disclaimer

Figures

Figure 1
Figure 1
Estimated hospitalization rates associated with A(H1N1)pdm09 virus during the pandemic (H1N1) 2009 estimated by capture–recapture and surveillance‐sampling methods in Davidson County residents aged <5, 5–17, 18–49, and ≥50 years.
Figure 2
Figure 2
Proportion of hospitalized patients tested positive for A(H1N1)pdm09 during the pandemic (H1N1) 2009 among the total Davidson County residents aged <5, 5–17, 18–49, ≥50 years with symptoms of acute respiratory illnesses tested for A(H1N1)pdm09 through Flu‐VE from May 2009 to March 2010.
See this image and copyright information in PMC

References

    1. Centers for Disease Control and Prevention (CDC) . Update: influenza activity – United States, August 30, 2009–March 27, 2010, and composition of the 2010–11 influenza vaccine. MMWR Morb Mortal Wkly Rep 2010; 59:423–430. - PubMed
    1. Tennessee Department of Health Influenza‐Like Illness Surveillance Summary Archive. 2010.
    1. Centers for Disease Control and Prevention (CDC) . Update: influenza activity – United States, August 30, 2009–January 9, 2010. MMWR Morb Mortal Wkly Rep 2010; 59:38–43. - PubMed
    1. Reed C, Angulo FJ, Swerdlow DL et al. Estimates of the Prevalence of Pandemic (H1N1) 2009, United States, April–July 2009. Emerg Infect Dis 2009; 15:2004–2007. - PMC - PubMed
    1. Census Bureau . Annual Estimates of the Resident Population by sex, race, age, and Hispanic Origin for the United States: April 1, 2000 to July 1, 2009 (NC‐EST 2009‐03). 2010.

Publication types

MeSH terms

Substances