Red de vigilancia de hospitalizaciones a causa de la influenza (FluSurv-NET)

FluSurv-NET

Acerca de FluSurv-NET

The Influenza Hospitalization Surveillance Network (FluSurv-NET) is part of the Respiratory Virus Hospitalization Surveillance Network (RESP-NET), which is designed to conduct population-based surveillance for laboratory-confirmed influenza, COVID-19, and respiratory syncytial virus (RSV)-associated hospitalizations. RESP-NET also includes surveillance networks for COVID-19 and RSV (also known as COVID-NET y RSV-NET, respectively).

FluSurv-NET collects data on laboratory-confirmed influenza-associated hospitalizations among children and adults through a network of acute care hospitals in 14 states.

Por qué los datos de FluSurv-NET son importantes

FluSurv-NET es la fuente de los CDC de los datos más importantes sobre tasas de hospitalización asociadas a la influenza. FluSurv-NET also provides demographic and clinical information including age, sex, race and ethnicity, and underlying medical conditions among persons hospitalized with flu. Data gathered are used to estimate age-specific tasas de hospitalización on a weekly basis and to describe characteristics of persons hospitalized with influenza illness. Additionally, FluSurv-NET data are used with other data sources to estimate annual and weekly influenza disease burden in the United States.

Definición de casos de FluSurv-NET

Para FluSurv-NET, un caso se define como una persona que es residente de un área de captación definida de FluSurv-NET y que obtuvo un resultado positivo en una prueba de laboratorio de detección de la influenza solicitada por un profesional de atención médica dentro de los 14 días anteriores a la hospitalización o durante la hospitalización. La confirmación de laboratorio se define como el resultado positivo de un cultivo viral, una prueba de anticuerpos con tinción fluorescente directa o indirecta, una prueba rápida de antígenos, o una prueba molecular.

Cómo FluSurv-NET realiza los cálculos de las tasas de hospitalización

Se recopila un conjunto mínimo de datos sobre todos los casos identificados para calcular las tasas de hospitalización semanales:

• edad
• género
• raza y etnia
• sitio de vigilancia
• fecha de ingreso en el hospital
• resultado/fecha de la prueba positiva de influenza

Las tasas de hospitalización se calculan con base en la cantidad de residentes de un área definida que están hospitalizados y que obtuvieron un resultado positivo en la prueba de laboratorio de detección de la influenza, dividida por la población total dentro del área definida. NCHS bridged-race population estimates are used as denominators prior to the 2020-2021 season. A partir de la temporada 2020-2021, se utilizan como denominadores las estimaciones de población del censo extendido (Oficina del Censo de EE. UU., División de Población, tabulación especial de la época 2020-2022).

Cobertura de FluSurv-NET

FluSurv-NET coverage area includes more than 90 counties and county equivalents in 14 states that participate in the Programa de infecciones emergentes (EIP) and the Influenza Hospitalization Surveillance Program (IHSP). Participating states include: California, Colorado, Connecticut, Georgia, Maryland, Michigan, Minnesota, New Mexico, New York, North Carolina, Ohio, Oregon, Tennessee and Utah.

FluSurv-NET cubre a más de 30 millones de personas e incluye aproximadamente a un 9 por ciento de la población estadounidense. Los condados con cobertura se encuentran en las 9 regiones del Departamento de Salud y Servicios Humanos (HHS). El área de vigilancia de FluSurv-NET designada por lo general es similar a la población estadounidense por demografía; no obstante, es posible que la información no se pueda generalizar para la población de todo el país.

*Since the 2023-2024 influenza season, Connecticut will use county equivalents instead of counties.

Cómo acceder a los datos de FluSurv-NET

Las tasas de hospitalización asociadas a la influenza son notificadas a los CDC semanalmente cada temporada de influenza. Durante las temporadas con actividad de influenza fuera de la temporada típica de influenza del 1 de octubre al 30 de abril, a los sitios se les ofrecerá la opción de extender la vigilancia de hospitalizaciones por influenza más allá del periodo de vigilancia establecido. Los datos de FluSurv-NET, incluidas las tasas de hospitalización para diferentes grupos de edad y los datos sobre las características de los pacientes, están disponibles en FluView y FluView Interactive.

Los datos de hospitalización de FluSurv-NET son preliminares durante cada temporada; los datos presentados pueden cambiar a medida que se reciben más informes. En particular, el número de casos para los ingresos hospitalarios recientes está sujeto a demoras en la realización de los informes. A medida que se reciben datos cada semana durante la temporada de influenza, es posible que el número de casos y las tasas anteriores sean actualizados.

FluSurv-NET Sampling Methodology for Collection of Clinical Data

Desde la temporada de influenza 2017-18, FluSurv-NET implementó una estrategia de muestreo para la recopilación de datos clínicos. Se obtuvieron datos clínicos de una muestra aleatoria de casos de personas de 50 años de edad o más, estratificada por edad y lugar de vigilancia; en esta temporada se obtuvieron muestras del 100 % de los casos de personas menores de 50 años de edad y algunos sitios optaron por analizar muestras del 100 % de los casos de personas de 50 años de edad o más. Además se analizaron las muestras del 100 % de los casos de muerte ocurridos en el hospital o dentro de los 30 días posteriores al alta. Se generaron números aleatorios de forma automática y se asignaron a cada caso al ser incorporados a la base de datos de vigilancia. Personal de vigilancia capacitado realizó la abstracción de los gráficos médicos sobre los casos muestreados usando un formulario estandarizado de notificación de casos.

Se recopilan los siguientes tipos de datos clínicos de los casos muestreados:

• estado de la vacunación contra la influenza en la temporada actual
• antecedentes (médicos) clínicos (condiciones médicas subyacentes)
• curso clínico (ingreso a la unidad de cuidados intensivos)
• intervenciones médicas (p. ej., recepción de tratamiento antiviral, asistencia respiratoria mecánica)
• resultados (p. ej., alta hospitalaria, fallecimiento dentro del hospital)

Las muestras se tomaron más allá de la temporada 2017-18 con una metodología similar. La tabla a continuación resume las estrategias de toma de muestras durante las temporadas de influenza cuando las tasas eran inferiores al 100 %.

*Para todos los demás grupos de edad con 100 % de muestras, si correspondía, se obtuvieron muestras del 100 % de los pacientes fallecidos en el hospital y dentro de los 60 días posteriores al alta. For the 2024-25 influenza season, sampling rates will be determined mid-season.

En las temporadas en las que la obtención de muestras fue inferior al 100 %, se ponderaron las estimaciones clínicas para reflejar la probabilidad de selección. La metodología de obtención de muestras de FluSurv-NET también está descrita en los siguientes estudios:

Chow EJ, Rolfes MA, O'Halloran A, et al. Respiratory and nonrespiratory diagnoses associated with influenza in hospitalized adults. JAMA Netw Open. 2020; 3(3):e201323. doi:10.1/jamanetworkopen.2 020.13

Chow EJ, Rolfes MA, O'Halloran A, et al. Acute cardiovascular events associated with influenza in hospitalized adults: a cross-sectional study. Ann Intern Med. 2020; 173(8): 605- 613. doi:10.73/M20-1509

Cómo FluSurv-NET contribuye con las estimaciones de la carga de la influenza de los CDC

Los CDC usan los datos de FluSurv-NET junto con otras fuentes de datos para calcular la carga de la enfermedad de la influenza anual y semanalmente en los Estados Unidos. Las estimaciones se realizan por enfermedades sintomáticas, enfermedades con atención médica, hospitalizaciones y muertes. Las tasas informadas se ajustan en un intento de corregir la subdetección de la influenza. Este ajuste se realiza usando el porcentaje de personas hospitalizadas a causa de enfermedades respiratorias a las que se les realizó la prueba de detección de la influenza y la sensibilidad promedio de las pruebas de detección de la influenza usadas en los hospitales participantes de FluSurv-NET. Los cálculos semanales de carga de la influenza están disponibles durante cada temporada de influenza. Los cálculos anuales de la carga de influenza y de la carga de influenza evitada gracias a la vacunación contra la influenza en los EE. UU. están disponibles en línea.

Publicaciones

2020 to Present

• Tenforde M, Noah K, O’Halloran A, et al. Timing of Influenza Antiviral Therapy and Risk of Death in Adults Hospitalized With Influenza-Associated Pneumonia, Influenza Hospitalization Surveillance Network (FluSurv-NET), 2012-2019. Clinical Infectious Diseases. 2024.
• Famati E, Ujamaa D, O’Halloran A, et al. Association of Chronic Medical Conditions with Severe Outcomes among Nonpregnant Adults 18-49 years old Hospitalized with Influenza, FluSurv-NET, 2011-2019. Open Forum Infectious Diseases. 2023.
• Kojima N, Taylor C, Tenforde M, et al. Clinical Outcomes of US Adults Hospitalized for COVID-19 and Influenza in the Respiratory Virus Hospitalization Surveillance Network, October 2021 - September 2022. Open Forum Infectious Diseases. 2023.
• White E, O'Halloran A, Sundaresan D, et al. High Influenza Incidence and Disease Severity Among Children and Adolescents Aged <18 Years ― United States, 2022–23 Season. Morbidity and Mortality Weekly Report (MMWR). 2023.
• Sumner K, Masalovich S, O'Halloran A, et al. Severity of Influenza-Associated Hospitalisations by Influenza Virus Type and Subtype in the USA, 2010-19: A Repeated Cross-Sectional Study. The Lancet Microbe. 2023.
• Tenforde M, Cummings C, O'Halloran A, et al. Influenza Antiviral Use in Patients Hospitalized with Laboratory-Confirmed Influenza in the United States, FluSurv-NET, 2015-2019. Open Forum Infectious Diseases. 2022.
• Adams K, Tastad K, Huang S, et al. Prevalence of SARS-CoV-2 and Influenza Coinfections and Clinical Characteristics Among Children and Adolescents Aged <18 Years Who Were Hospitalized or Died with Influenza – Unite States, 2021-22 Influenza Season. Morbidity and Mortality Weekly Report (MMWR). 2022.
• Black C, O'Halloran A, Hung M, et al. Vital Signs: Influenza Hospitalizations and Vaccination Coverage by Race and Ethnicity – United States, 2009-10 Through 2021-22 Influenza Seasons. Morbidity and Mortality Weekly Report (MMWR). 2022.
• Parisi C, Yousey-Hindes K, Holstein R, et al. Drug Use and Severe Outcomes among Adults Hospitalized with Influenza, 2016-2019. Influenza and Other Respiratory Viruses. 2022.
• Delahoy M, Ujamaa D, Taylor C, et al. Comparison of influenza and COVID-19-associated hospitalizations among children < 18 years old in the United States-FluSurv-NET (octubre-abril 2017-2021) and COVID-NET (octubre del 2020-septiembre del 2021. Clinical Infectious Diseases. 2022.
• Kamidani S, Garg S, Rolfes M, et al. Epidemiology, Clinical Characteristics, and Outcomes of Influenza-Associated Hospitalizations in U.S. Children Over 9 Seasons Following the 2009 H1N1 Pandemic. Clinical Infectious Diseases. 2022.
• Holstein R, Dawood F, O'Halloran A, et al. Characteristics of Outcomes of Hospitalized Pregnant Women with Influenza, 2010-2019. A Repeated Cross-Sectional Study. Annals of Internal Medicine. 2021.
• Cummings C, O'Halloran A, Azenkot T, et al. Hospital-Acquired Influenza in the United States, FluSurv-NET, 2011-2012 through 2018-2019. Infection Control and Hospital Epidemiology. 2021.
• Campbell A, Tokars J, Reynolds S, et al. Influenza Antiviral Treatment and Length of Stay. Pediatrics. 2021.
• O'Halloran A, Holstein R, Cummings C, et al. Rates of Influenza-Associated Hospitalization, Intensive Care Unit Admission, and In-Hospital Death by Race and Ethnicity in the United States From 2009-2019. Journal of American Medical Association (JAMA) Network Open. 2021.
• Chow E, Rolfes M, O'Halloran A, et al. Acute Cardiovascular Events Associated with Influenza in Hospitalized Adults. Annals of Internal Medicine. 2020.
• Sloan C, Chandrasekhar R, Mitchel E, et al. Spatial and Temporal Clustering of Patients Hospitalized with Laboratory-Confirmed Influenza in the United States. Epidemics. 2020.
• Collins J, Campbell A, Openo K, et al. Outcomes of Immunocompromised Adults Hospitalized With Laboratory-Confirmed Influenza in the United States, 2011–2015. Clinical Infectious Diseases. 2020.
• Chow E, Rolfes M, O'Halloran A, et al. Respiratory and Nonrespiratory Diagnoses Associated with Influenza in Hospitalized Adults. Journal of American Medical Association (JAMA) Network Open. 2020.

2015-2019

• Collins J, Campbell A, Openo K, et al. Clinical Features and Outcomes of Immunocompromised Children Hospitalized With Laboratory-Confirmed Influenza in the United States, 2011–2015. Journal of the Pediatric Infectious Diseases Society. 2019.
• Budd A, Beacham L, Smith C, et al. Birth Cohort Effects in Influenza Surveillance Data: Evidence That First Influenza Infection Affects Later Influenza-Associated Illness. The Journal of Infectious Diseases. 2019.
• Czaja C, Miller L, Alden N, et al. Age-Related Differences in Hospitalization Rates, Clinical Presentation, and Outcomes Among Older Adults Hospitalized With Influenza—U.S. Influenza Hospitalization Surveillance Network (FluSurv-NET). Open Forum Infectious Diseases. 2019.
• Biggerstaff M, Kniss K, Jernigan D, et al. Systematic Assessment of Multiple Routine and Near Real-Time Indicators to Classify the Severity of Influenza Seasons and Pandemics in the United States, 2003–2004 Through 2015–2016. American Journal of Epidemiology. 2018.
• Chandrasekhar R, Sloan C, Mitchel E, et al. Social Determinants of Influenza Hospitalization in the United States. Influenza and Other Respiratory Viruses. 2017.
• Kline K, Hadler J, Yousey-Hindes K, et al. Impact of Pregnancy on Observed Sex Disparities Among Adults Hospitalized with Laboratory-Confirmed Influenza, FluSurv-NET, 2010-2012. Influenza and Other Respiratory Viruses. 2017.
• Arriola C, Garg S, Anderson E, et al. Influenza Vaccination Modifies Disease Severity Among Community-dwelling Adults Hospitalized With Influenza. Clinical Infectious Diseases. 2017.
• Appiah G, Chaves S, Kirley P, et al. Increased Antiviral Treatment Among Hospitalized Children and Adults With Laboratory-Confirmed Influenza, 2010–2015. Clinical Infectious Diseases. 2017.
• Havers F, Sokolow L, Shay D, et al. Case-Control Study of Vaccine Effectiveness in Preventing Laboratory-Confirmed Influenza Hospitalizations in Older Adults, United States, 2010–2011. Clinical Infectious Diseases. 2016.
• Su S, Fry A, Kirley P, et al. Survey of Influenza and Other Respiratory Viruses Diagnostic Testing in US Hospitals, 2012-2013. Influenza and Other Respiratory Viruses. 2016.
• Rolfes M, Yousey-Hindes K, Meek J, et al. Respiratory Viral Testing and Influenza Antiviral Prescriptions During Hospitalization for Acute Respiratory Illnesses. Open Forum Infectious Diseases. 2016.
• Oboho I, Reed C, Gargiullo P, et al. Benefit of Early Initiation of Influenza Antiviral Treatment to Pregnant Women Hospitalized With Laboratory-Confirmed Influenza. The Journal of Infectious Diseases. 2016.
• Bramley A, Chaves S, Dawood F, et al. Utility of Keywords from Chest Radiograph Reports for Pneumonia Surveillance Among Hospitalized Patients with Influenza: The CDC Influenza Hospitalization Surveillance Network, 2008–2009. Public Health Reports. 2016.
• Hadler J, Yousey-Hindes K, Perez A, et al. Hospitalizaciones relacionadas con la influenza y niveles de pobreza - Estados Unidos, 2010-2012. Morbidity and Mortality Weekly Report (MMWR). 2016.
• Garg S, Jain S, Dawood F, et al. Pneumonia Among Adults Hospitalized with Laboratory-Confirmed Seasonal Influenza Virus Infection—United States, 2005–2008. BMC Infectious Diseases. 2015.
• Arriola C, Anderson E, Baumbach J, et al. Does Influenza Vaccination Modify Influenza Severity? Data on Older Adults Hospitalized With Influenza During the 2012-2013 Season in the United States. The Journal of Infectious Diseases. 2015.
• Laidler M, Thomas A, Baumbach J, et al. Statin Treatment and Mortality: Propensity Score-Matched Analyses of 2007–2008 and 2009–2010 Laboratory-Confirmed Influenza Hospitalizations. Open Forum Infectious Diseases. 2015.
• Chaves S, Perez A, Miller L, et al. Impact of Prompt Influenza Antiviral Treatment on Extended Care Needs After Influenza Hospitalization Among Community-Dwelling Older Adults. Clinical Infectious Diseases. 2015.
• Millman A, Reed C, Kirley P, et al. Improving Accuracy of Influenza-Associated Hospitalization Rate Estimates. Emerging Infectious Diseases. 2015.
• Chaves S, Lynfield R, Bresee J, et al. The US Influenza Hospitalization Surveillance Network. Emerging Infectious Diseases. 2015.

2010-2014

• Jhung M, D'Mello T, Perez A, et al. Hospital-Onset Influenza Hospitalizations—United States, 2010-2011. American Journal of Infection Control. 2014.
• Greenbaum A, Chaves S, Perez A, et al. Heavy alcohol use as a risk factor for severe outcomes among adults hospitalized with laboratory-confirmed influenza, 2005–2012. Infection. 2014.
• Dawood F, Chaves S, Perez A, et al. Complications and Associated Bacterial Coinfections Among Children Hospitalized With Seasonal or Pandemic Influenza, United States, 2003–2010. The Journal of Infectious Diseases. 2014.
• Chaves S, Perez A, Farley M, et al. The Burden of Influenza Hospitalizations in Infants From 2003 to 2012, United States. The Pediatric Infectious Disease Journal. 2014.
• Dharan N, Sokolow L, Cheng P, et al. Child, Household, and Caregiver Characteristics Associated with Hospitalization for Influenza Among Children 6–59 Months of Age: An Emerging Infections Program Study. The Pediatric Infectious Disease Journal. 2014.
• Su S, Chaves S, Perez A, et al. Comparing Clinical Characteristics Between Hospitalized Adults With Laboratory-Confirmed Influenza A and B Virus Infection. Clinical Infectious Diseases. 2014.
• Reed C, Chaves S, Perez A, et al. Complications Among Adults Hospitalized With Influenza: A Comparison of Seasonal Influenza and the 2009 H1N1 Pandemic. Clinical Infectious Diseases. 2014.
• Fleming-Dutra K, Taylor T, Link-Gelles R, et al. Effect of the 2009 Influenza A(H1N1) Pandemic on Invasive Pneumococcal Pneumonia. The Journal of Infectious Diseases. 2013.
• Chaves S, Aragon D, Bennett N, et al. Patients Hospitalized With Laboratory-Confirmed Influenza During the 2010–2011 Influenza Season: Exploring Disease Severity by Virus Type and Subtype. The Journal of Infectious Diseases. 2013.
• Thompson M, Sokolow L, Almendares O, et al. Effectiveness of Nonadjuvanted Monovalent Influenza A(H1N1)pdm09 Vaccines for Preventing Reverse Transcription Polymerase Chain Reaction–Confirmed Pandemic Influenza Hospitalizations: Case-Control Study of Children and Adults at 10 US Influenza Surveillance Network Sites. Clinical Infectious Diseases. 2013.
• Vandermeer M, Thomas A, Kamimoto L, et al. Association Between Use of Statins and Mortality Among Patients Hospitalized With Laboratory-Confirmed Influenza Virus Infections: A Multistate Study. The Journal of Infectious Diseases. 2012.
• Garg S, Chaves S, Perez A, et al. Reduced Influenza Antiviral Treatment Among Children and Adults Hospitalized With Laboratory-Confirmed Influenza Infection in the Year After the 2009 Pandemic. Clinical Infectious Diseases. 2012.
• Cox C, D'Mello T, Perez A, et al. Increase in Rates of Hospitalization Due to Laboratory-Confirmed Influenza Among Children and Adults During the 2009–10 Influenza Pandemic. The Journal of Infectious Diseases. 2011.
• Fry A, Perez A, Finelli L. Use of Intravenous Neuraminidase Inhibitors During the 2009 Pandemic: Results From Population-Based Surveillance. Journal of American Medical Association (JAMA). 2011.
• Doshi S, Kamimoto L, Finelli L, et al. Description of Antiviral Treatment Among Adults Hospitalized With Influenza Before and During the 2009 Pandemic: United States, 2005–2009. The Journal of Infectious Diseases. 2011.
• Dawood F, Kamimoto L, D'Mello T, et al. Children With Asthma Hospitalized With Seasonal or Pandemic Influenza, 2003–2009. Pediatrics. 2011
• Creanga A, Kamimoto L, Newsome K, et al. Seasonal and 2009 Pandemic Influenza A (H1N1) Virus Infection During Pregnancy: A Population-Based Study of Hospitalized Cases. American Journal of Obstetrics and Gynecology. 2011.
• Dee D, Bensyl D, Gindler J, et al. Racial and Ethnic Disparities in Hospitalizations and Deaths Associated with 2009 Pandemic Influenza A (H1N1) Virus Infections in the United States. Annals of Epidemiology. 2011.
• Brammer L, Blanton L, Epperson S, et al. Surveillance for Influenza during the 2009 Influenza A (H1N1) Pandemic-United States, abril del 2009-marzo del 2010. Clinical Infectious Diseases. 2011.
• Dawood F, Fiore A, Kamimoto L, et al. Influenza-Associated Pneumonia in Children Hospitalized With Laboratory-Confirmed Influenza, 2003–2008. The Pediatric Infectious Disease Journal. 2010.
• Dawood F, Fiore A, Kamimoto L, et al. Burden of Seasonal Influenza Hospitalization in Children, United States, 2003 to 2008. The Journal of Pediatrics. 2010.
• Dao C, Kamimoto L, Nowell M, et al. Adult Hospitalizations for Laboratory-Positive Influenza during the 2005–2006 through 2007–2008 Seasons in the United States. The Journal of Infectious Diseases. 2010.

2003-2009

• Schrag S, Shay D, Gershman K, et al. Multistate Surveillance for Laboratory-Confirmed, Influenza-Associated Hospitalizations in Children, 2003–2004. The Pediatric and Infectious Disease Journal. 2006.

Recursos