2009 H1N1 Influenza Infection-Related Hospital Admissions: A Single Center Experience with Adult Patients in West Texas

Background. Clinical information collected during the first wave of influenza pandemics may provide important projections about disease activity during subsequent waves. Methods. We performed a retrospective study of hospitalized patients with 2009 H1N1 influenza infection during the second wave and compared our findings with literature reports from the first wave. Results. There were 31 admissions, including 15 to the intensive care unit (ICU). Twenty-five patients (81%) had at least one chronic medical condition; 12 patients (39%) were obese. Thirty-three percent of the ICU patients and 75% of the non-ICU patients were admitted within 48 hours of symptom onset (𝑃=0.03). Infiltrates on CXR were seen in 60% of the ICU group and 19% of the non-ICU group within 48 hours of admission (𝑃=0.03). Forty-three percent of the ICU patients and 71% of the non-ICU patients received oseltamivir within 48 hours of illness. All non-ICU patients survived; 73% of the ICU patients survived (𝑃=0.043). Conclusions. Our patients in the second wave resembled patients reported from the first wave of the 2009 pandemic and had similar mortality rates. Delayed medical attention possibly explains the high number of ICU admissions in our study.

[1]  Ji-Rong Yang,et al.  New Variants and Age Shift to High Fatality Groups Contribute to Severe Successive Waves in the 2009 Influenza Pandemic in Taiwan , 2011, PloS one.

[2]  Stefano Merler,et al.  Determinants of the Spatiotemporal Dynamics of the 2009 H1N1 Pandemic in Europe: Implications for Real-Time Modelling , 2011, PLoS Comput. Biol..

[3]  C. Bauch,et al.  Can Interactions between Timing of Vaccine-Altered Influenza Pandemic Waves and Seasonality in Influenza Complications Lead to More Severe Outcomes? , 2011, PloS one.

[4]  Mark A. Miller,et al.  Spatial and Temporal Characteristics of the 2009 A/H1N1 Influenza Pandemic in Peru , 2011, PloS one.

[5]  Ronald L Burke,et al.  The Global Emerging Infection Surveillance and Response System (GEIS), a U.S. government tool for improved global biosurveillance: a review of 2009 , 2011, BMC public health.

[6]  Jianhong Wu,et al.  Public health interventions for epidemics: implications for multiple infection waves , 2011, BMC public health.

[7]  L. Pelletier,et al.  Incidence of hospital admissions and severe outcomes during the first and second waves of pandemic (H1N1) 2009 , 2010, Canadian Medical Association Journal.

[8]  Gerardo Chowell,et al.  Mortality patterns associated with the 1918 influenza pandemic in Mexico: evidence for a spring herald wave and lack of preexisting immunity in older populations. , 2010, The Journal of infectious diseases.

[9]  Miguel O'Ryan,et al.  Impact of the novel influenza A (H1N1) during the 2009 autumn-winter season in a large hospital setting in Santiago, Chile. , 2010, Clinical infectious diseases : an official publication of the Infectious Diseases Society of America.

[10]  L. Pelletier,et al.  Risk of severe outcomes among patients admitted to hospital with pandemic (H1N1) influenza , 2010, Canadian Medical Association Journal.

[11]  Lyn Finelli,et al.  Hospitalized patients with 2009 H1N1 influenza in the United States, April-June 2009. , 2009, The New England journal of medicine.

[12]  Cecile Viboud,et al.  The signature features of influenza pandemics--implications for policy. , 2009, The New England journal of medicine.

[13]  Marc Lipsitch,et al.  Estimates of the Prevalence of Pandemic (H1N1) 2009, United States, April–July 2009 , 2009, Emerging infectious diseases.

[14]  R. Bellomo,et al.  Critical care services and 2009 H1N1 influenza in Australia and New Zealand. , 2009, The New England journal of medicine.

[15]  M. Meade,et al.  Critically ill patients with 2009 influenza A(H1N1) infection in Canada. , 2009, JAMA.

[16]  C. Viboud,et al.  A comparative study of the 1918–1920 influenza pandemic in Japan, USA and UK: mortality impact and implications for pandemic planning , 2009, Epidemiology and Infection.

[17]  C. Viboud,et al.  Cross-protection between successive waves of the 1918-1919 influenza pandemic: epidemiological evidence from US Army camps and from Britain. , 2008, The Journal of infectious diseases.

[18]  Cécile Viboud,et al.  Epidemiologic characterization of the 1918 influenza pandemic summer wave in Copenhagen: implications for pandemic control strategies. , 2008, The Journal of infectious diseases.

[19]  Keiji Fukuda,et al.  Influenza-associated hospitalizations in the United States. , 2004, JAMA.

[20]  Keiji Fukuda,et al.  Mortality associated with influenza and respiratory syncytial virus in the United States. , 2003, JAMA.