Child, household, and caregiver characteristics associated with hospitalization for influenza among children 6-59 months of age: an emerging infections program study.

Background: Young children are at increased risk of severe outcomes from influenza illness, including hospitalization. We conducted a case-control study to identify risk factors for influenza-associated hospitalizations among children in US Emerging Infections Program sites.

Methods: Cases were children 6-59 months of age hospitalized for laboratory-confirmed influenza infections during 2005-2008.

Lower respiratory tract hemorrhage associated with 2009 pandemic influenza A (H1N1) virus infection.

Background: Influenza-associated lower respiratory tract hemorrhage (LRTH) has been reported in previous pandemics and is a rare complication of seasonal influenza virus infection. We describe patients with LRTH associated with 2009 pandemic influenza A (H1N1) (pH1N1) virus infection identified from April 2009 to April 2010 in the United States.

Methods: We ascertained patients with pH1N1-associated LRTH through state and local surveillance, the Emerging Infections Program, and CDCs Infectious Diseases Pathology Branch.

Seasonal influenza morbidity estimates obtained from telephone surveys, 2007.

Objectives: We assessed telephone surveys as a novel surveillance method, comparing data obtained by telephone with existing national influenza surveillance systems, and evaluated the utility of telephone surveys.

Methods: We used the 2007 Behavioral Risk Factor Surveillance System (BRFSS) and the 2007 National Immunization Survey-Adult (NIS-Adult) to estimate the incidence of influenza-like illness (ILI), medically attended ILI, provider-diagnosed influenza, influenza testing, and treatment of influenza with antiviral medications during the 2006-2007 influenza season.

Results: With the January-May BRFSS, among persons aged 18 years and older, the cumulative incidence of seasonal ILI and provider-diagnosed influenza was 37.

Self-reported influenza-like illness and receipt of influenza antiviral drugs during the 2009 pandemic, United States, 2009-2010.

Objectives: The purpose of our study was to more accurately characterize people reporting influenza-like illness (ILI) and evaluate trends in health care seeking and influenza diagnosis and treatment during the 2009 influenza pandemic.

Methods: From September 2009 to March 2010, we ascertained ILI (fever with cough or sore throat), health care seeking, and clinical diagnosis and treatment of influenza with influenza antiviral drugs among adults in 51 jurisdictions, and ILI and health care seeking among children in 41 jurisdictions.

Results: Among 216,431 adults and 43,511 children, 8.

Intensive care unit patients with 2009 pandemic influenza A (H1N1pdm09) virus infection - United States, 2009.

Background: The influenza A (H1N1pdm09) [pH1N1] virus resulted in intensive care unit (ICU) admissions, acute respiratory distress syndrome (ARDS), and death.

Objectives:   To describe the characteristics of ICU patients with pH1N1 virus infection in the United States during the spring and fall of 2009 and to describe the factors associated with severe complications including ARDS and death.

Patients/methods:   Through two national case-series conducted during spring and fall of 2009, medical charts were reviewed on ICU patients with laboratory-confirmed pH1N1 infection by real-time reverse-transcriptase polymerase chain reaction.

Association between use of statins and mortality among patients hospitalized with laboratory-confirmed influenza virus infections: a multistate study.

Background: Statins may have anti-inflammatory and immunomodulatory effects that could reduce the risk of mortality from influenza virus infections.

Methods: The Centers for Disease Control and Prevention's Emerging Infections Program conducts active surveillance for persons hospitalized with laboratory-confirmed influenza in 59 counties in 10 states. We analyzed data for hospitalized adults during the 2007-2008 influenza season to evaluate the association between receiving statins and influenza-related death.

Global burden of respiratory infections due to seasonal influenza in young children: a systematic review and meta-analysis.

Background: The global burden of disease attributable to seasonal influenza virus in children is unknown. We aimed to estimate the global incidence of and mortality from lower respiratory infections associated with influenza in children younger than 5 years.

Methods: We estimated the incidence of influenza episodes, influenza-associated acute lower respiratory infections (ALRI), and influenza-associated severe ALRI in children younger than 5 years, stratified by age, with data from a systematic review of studies published between Jan 1, 1995, and Oct 31, 2010, and 16 unpublished population-based studies.

Description of antiviral treatment among adults hospitalized with influenza before and during the 2009 pandemic: United States, 2005-2009.

Background: The 2009 influenza pandemic led to guidelines emphasizing antiviral treatment for all persons hospitalized with influenza, including pregnant women. We compared antiviral use among adults hospitalized with influenza before and during the pandemic.

Methods: The Emerging Infections Program conducts active population-based surveillance for persons hospitalized with community-acquired, laboratory-confirmed influenza in 10 states.

Racial and ethnic disparities in hospitalizations and deaths associated with 2009 pandemic Influenza A (H1N1) virus infections in the United States.

Purpose: Concerns have been raised regarding possible racial-ethnic disparities in 2009 pandemic influenza A (H1N1) (pH1N1) illness severity and health consequences for U.S. minority populations.

Findings from a household randomized controlled trial of hand washing and face masks to reduce influenza transmission in Bangkok, Thailand.

Background: Evidence is needed on the effectiveness of non-pharmaceutical interventions (NPIs) to reduce influenza transmission.

Methodology: We studied NPIs in households with a febrile, influenza-positive child. Households were randomized to control, hand washing (HW), or hand washing plus paper surgical face masks (HW + FM) arms.

Children with asthma hospitalized with seasonal or pandemic influenza, 2003-2009.

Objective: To describe the characteristics and clinical courses of asthmatic children hospitalized with seasonal or 2009 pandemic H1N1 influenza and compare complications by influenza type.

Methods: During the 2003-2009 influenza seasons and the 2009 pandemic, we conducted surveillance of 5.3 million children aged 17 years or younger for hospitalization with laboratory-confirmed influenza and identified those with asthma (defined as those aged 2-17 years with a history of asthma in their medical record or a discharge code for acute asthma exacerbation or status asthmaticus).

Seasonal and 2009 pandemic influenza A (H1N1) virus infection during pregnancy: a population-based study of hospitalized cases.

We sought to describe characteristics of hospitalized reproductive-aged (15-44 years) women with seasonal (2005/2006 through 2008/2009) and 2009 pandemic influenza A (H1N1) virus infection. We used population-based data from the Emerging Infections Program in 10 US states, and compared characteristics of pregnant (n = 150) and nonpregnant (n = 489) seasonal, and pregnant (n = 489) and nonpregnant (n = 1088) pandemic influenza cases using χ(2) and Fisher's exact tests. Pregnant women represented 23.

Serial intervals and the temporal distribution of secondary infections within households of 2009 pandemic influenza A (H1N1): implications for influenza control recommendations.

A critical issue during the 2009 influenza A (H1N1) pandemic was determining the appropriate duration of time individuals with influenza-like illness (ILI) should remain isolated to reduce onward transmission while limiting societal disruption. Ideally this is based on knowledge of the relative infectiousness of ill individuals at each point during the course of the infection. Data on 261 clinically apparent pH1N1 infector-infectee pairs in households, from 7 epidemiological studies conducted in the United States early in 2009, were analyzed to estimate the distribution of times from symptom onset in an infector to symptom onset in the household contacts they infect (mean, 2.

Estimating the burden of 2009 pandemic influenza A (H1N1) in the United States (April 2009-April 2010).

To calculate the burden of 2009 pandemic influenza A (pH1N1) in the United States, we extrapolated from the Centers for Disease Control and Prevention's Emerging Infections Program laboratory-confirmed hospitalizations across the entire United States, and then corrected for underreporting. From 12 April 2009 to 10 April 2010, we estimate that approximately 60.8 million cases (range: 43.

Surveillance for influenza during the 2009 influenza A (H1N1) pandemic-United States, April 2009-March 2010.

The emergence in April 2009 and subsequent spread of the 2009 pandemic influenza A (H1N1) virus resulted in the first pandemic of the 21st century. This historic event was associated with unusual patterns of influenza activity in terms of the timing and persons affected in the United States throughout the summer and fall months of 2009 and the winter of 2010. The US Influenza Surveillance System identified 2 distinct waves of pandemic influenza H1N1 activity--the first peaking in June 2009, followed by a second peak in October 2009.

Epidemiology of 2009 pandemic influenza A (H1N1) in the United States.

In April 2009, the Centers for Disease Control and Prevention confirmed 2 cases of 2009 pandemic influenza A (H1N1) virus infection in children from southern California, marking the beginning of what would be the first influenza pandemic of the twenty-first century. This report describes the epidemiology of the 2009 H1N1 pandemic in the United States, including characterization of cases, fluctuations of disease burden over the course of a year, the age distribution of illness and severe outcomes, and estimation of the overall burden of disease.

Characteristics of patients with oseltamivir-resistant pandemic (H1N1) 2009, United States.

During April 2009-June 2010, thirty-seven (0.5%) of 6,740 pandemic (H1N1) 2009 viruses submitted to a US surveillance system were oseltamivir resistant. Most patients with oseltamivir-resistant infections were severely immunocompromised (76%) and had received oseltamivir before specimen collection (89%).

Adult hospitalizations for laboratory-positive influenza during the 2005-2006 through 2007-2008 seasons in the United States.

Background: Rates of influenza-associated hospitalizations in the United States have been estimated using modeling techniques with data from pneumonia and influenza hospitalization discharge diagnoses, but they have not been directly estimated from laboratory-positive cases.

Methods: We calculated overall, age-specific, and site-specific rates of laboratory-positive, influenza-associated hospitalization among adults and compared demographic and clinical characteristics and outcomes of hospitalized cases by season with use of data collected by the Emerging Infections Program Network during the 2005-2006 through 2007-2008 influenza seasons.

Results: Overall rates of adult influenza-associated hospitalization per 100,000 persons were 9.

Influenza-associated pneumonia in children hospitalized with laboratory-confirmed influenza, 2003-2008.

Background: Pneumonia is one of the most common complications in children hospitalized with influenza. We describe hospitalized children with influenza-associated pneumonia and associated risk indicators.

Methods: Through Emerging Infections Program Network population based surveillance, children aged <18 years hospitalized with laboratory confirmed influenza with a chest radiograph during hospitalization were identified during the 2003-2008 influenza seasons.

Burden of seasonal influenza hospitalization in children, United States, 2003 to 2008.

Objectives: To estimate the rates of hospitalization with seasonal influenza in children aged <18 years from a large, diverse surveillance area during 2003 to 2008.

Study Design: Through the Emerging Infections Program Network, population-based surveillance for laboratory-confirmed influenza was conducted in 10 states, including 5.3 million children.

Morbid obesity as a risk factor for hospitalization and death due to 2009 pandemic influenza A(H1N1) disease.

Background: Severe illness due to 2009 pandemic A(H1N1) infection has been reported among persons who are obese or morbidly obese. We assessed whether obesity is a risk factor for hospitalization and death due to 2009 pandemic influenza A(H1N1), independent of chronic medical conditions considered by the Advisory Committee on Immunization Practices (ACIP) to increase the risk of influenza-related complications.

Methodology/principal Findings: We used a case-cohort design to compare cases of hospitalizations and deaths from 2009 pandemic A(H1N1) influenza occurring between April-July, 2009, with a cohort of the U.

Influenza testing and antiviral prescribing practices among emergency department clinicians in 9 states during the 2006 to 2007 influenza season.

Study Objective: Influenza causes significant widespread illness each year. Emergency department (ED) clinicians are often first-line providers to evaluate and make treatment decisions for patients presenting with influenza. We sought to better understand ED clinician testing and treatment practices in the Emerging Infections Program Network, a federal, state, and academic collaboration that conducts active surveillance for influenza-associated hospitalizations.

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

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.

Influenza-associated pediatric mortality in the United States: increase of Staphylococcus aureus coinfection.

Objective: Pediatric influenza-associated death became a nationally notifiable condition in the United States during 2004. We describe influenza-associated pediatric mortality from 2004 to 2007, including an increase of Staphylococcus aureus coinfections.

Methods: Influenza-associated pediatric death is defined as a death of a child who is younger than 18 years and has laboratory-confirmed influenza.

Oseltamivir prescribing in pharmacy-benefits database, United States, 2004-2005.

We reviewed information from a US pharmacy benefits manager database from 2004 through 2005 during periods with little influenza activity. We calculated rates of oseltamivir prescriptions to enrollees. Prescription rates increased significantly from 27.