TY - JOUR
T1 - Impact of the 2009 influenza pandemic on pneumococcal pneumonia hospitalizations in the United States
AU - Weinberger, Daniel M.
AU - Simonsen, Lone
AU - Jordan, Richard
AU - Steiner, Claudia
AU - Miller, Mark
AU - Viboud, Cécile
N1 - Funding Information:
Potential conflicts of interest. L. S. has received research support from Pfizer for an observational study of pneumococcal vaccine program benefits. All other authors report no conflicts.
Funding Information:
Financial support. The MISMS study is funded by the International Influenza Unit, Office of Global Affairs, US Department of Health and Human Services. L. S. acknowledges support from the RAPIDD program (Research And Policy for Infectious Diseases Dynamics) funded by the Fogarty International Center, National Institutes of Health (NIH), and the Department of Homeland Security.
PY - 2012/2/1
Y1 - 2012/2/1
N2 - Background. Infection with influenza virus increases the risk for developing pneumococcal disease. The A/H1N1 influenza pandemic in autumn 2009 provided a unique opportunity to evaluate this relationship. Methods. Using weekly age-, state-, and cause-specific hospitalizations from the US State Inpatient Databases of the Healthcare Cost and Utilization Project 2003-2009, we quantified the increase in pneumococcal pneumonia hospitalization rates above a seasonal baseline during the pandemic period. Results. We found a significant increase in pneumococcal hospitalizations from late August to mid-December 2009, which corresponded to the timing of highest pandemic influenza activity. Individuals aged 5-19 years, who have a low baseline level of pneumococcal disease, experienced the largest relative increase in pneumococcal hospitalizations (ratio, 1.6 [95% confidence interval {CI}, 1.4-1.7]), whereas the largest absolute increase was observed among individuals aged 40-64 years. In contrast, there was no excess disease in the elderly. Geographical variation in the timing of excess pneumococcal hospitalizations matched geographical patterns for the fall pandemic influenza wave. Conclusions. The 2009 influenza pandemic had a significant impact on the rate of pneumococcal pneumonia hospitalizations, with the magnitude of this effect varying between age groups and states, mirroring observed variations in influenza activity.
AB - Background. Infection with influenza virus increases the risk for developing pneumococcal disease. The A/H1N1 influenza pandemic in autumn 2009 provided a unique opportunity to evaluate this relationship. Methods. Using weekly age-, state-, and cause-specific hospitalizations from the US State Inpatient Databases of the Healthcare Cost and Utilization Project 2003-2009, we quantified the increase in pneumococcal pneumonia hospitalization rates above a seasonal baseline during the pandemic period. Results. We found a significant increase in pneumococcal hospitalizations from late August to mid-December 2009, which corresponded to the timing of highest pandemic influenza activity. Individuals aged 5-19 years, who have a low baseline level of pneumococcal disease, experienced the largest relative increase in pneumococcal hospitalizations (ratio, 1.6 [95% confidence interval {CI}, 1.4-1.7]), whereas the largest absolute increase was observed among individuals aged 40-64 years. In contrast, there was no excess disease in the elderly. Geographical variation in the timing of excess pneumococcal hospitalizations matched geographical patterns for the fall pandemic influenza wave. Conclusions. The 2009 influenza pandemic had a significant impact on the rate of pneumococcal pneumonia hospitalizations, with the magnitude of this effect varying between age groups and states, mirroring observed variations in influenza activity.
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U2 - 10.1093/infdis/jir749
DO - 10.1093/infdis/jir749
M3 - Article
C2 - 22158564
AN - SCOPUS:84863393331
SN - 0022-1899
VL - 205
SP - 458
EP - 465
JO - Journal of Infectious Diseases
JF - Journal of Infectious Diseases
IS - 3
ER -