Influenza Hospitalization Surveillance Network

The New Mexico Emerging Infections Program (NMEIP) conducts active, population-based surveillance for laboratory-confirmed, influenza-related hospitalizations (FluSurv-NET). Surveillance activities began in Bernalillo County during the 2004-2005 influenza season and have expanded to include additional counties. The current seven-county catchment area includes Bernalillo, Chaves, Doña Ana, Grant, Luna, San Juan, and Santa Fe Counties and represents 62% of the total New Mexico population (based on data from the University of New Mexico Bureau of Business and Economic Research, 2011). NMEIP also conducts surveillance in El Paso, Texas hospitals where residents of southern New Mexico counties may seek care.

The primary objectives of FluSurv-NET include the following:

• Estimate age-specific rates for laboratory-confirmed, influenza-related hospitalizations.
• Describe the temporal trends of laboratory-confirmed influenza hospitalizations, including by influenza subtype.
• Describe characteristics of persons hospitalized with severe influenza illness.
• Describe the clinical features and course of influenza disease (e.g., severe illness and influenza-associated complications) among persons hospitalized with influenza.

Secondary objectives include examining risk and protective factors for severe sequelae of influenza infections, including co-morbid conditions; assessing the burden of hospital-acquired influenza infections, including any association between hospital infection control policies and the incidence of hospital-acquired influenza; and examining etiologic agents associated with pneumonia among influenza-infected adults.

NMEIP conducts active surveillance for the duration of each influenza season, typically October 1 through April 30. NMEIP surveillance officers identify influenza-related hospitalizations through direct communication with hospital infection preventionists and by laboratory reports.

For surveillance purposes, a case is defined as a person who is:

• A resident of a county in which surveillance is conducted
• Admitted to a catchment area hospital from October 1 through April 30
• Admitted within 14 days of a positive influenza test. (viral culture, fluorescent antibody, Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR), rapid test, serology, or unspecified positive influenza test in the medical chart)

NMEIP surveillance officers record information pertaining to demographics, diagnoses, clinical management, treatment, vaccination history, and underlying health conditions on a standardized case report form for all identified cases using medical charts, laboratory and pharmacy records, and the state vaccination registry. NMEIP transmits de-identified data to the Centers for Disease Control and Prevention on a weekly basis. These data are combined with data from other FluSurv-NET sites to provide an Estimate of Incidence Rates for Influenza-Related Hospitalizations.

FluSurv-NET Data

• Visit the Influenza Surveillance section of our website for statewide reports on influenza.
• Visit the New Mexico Indicator-Based Information System (NM-IBIS) website for more influenza health data.
• Visit the Influenza Activity & Surveillance page for national information on influenza.

Special Projects

EIP provides additional mechanisms to collect data on influenza season severity, statewide testing practices, and emerging issues regarding influenza. Information is collected through population-based, active surveillance as well as through surveys and special projects.

Pediatric Antiviral Effectiveness Project

In the 2012–13 influenza season, NMEIP began participating in a retrospective observational cohort project examining the use of antiviral medication among children hospitalized with laboratory-confirmed influenza and certain co-morbidities and/or admission to the intensive care unit.

Evaluation of the Trivalent Inactivated Influenza Vaccine in Preventing Laboratory-Confirmed Influenza Hospitalizations Among Adults Aged 50 Years and Older

NMEIP participated in a case-control study evaluating the effectiveness of trivalent, inactivated influenza vaccine in preventing laboratory-confirmed influenza-related hospitalizations in adults 50 years and older during the 2008–09 and 2010–11 influenza seasons._{[data not yet published]}

Assessing the Effectiveness of Trivalent Inactivated Influenza Vaccine Among Children Aged 6-59 Months in Preventing Hospitalization With Influenza

NMEIP participated in a case-control study evaluating the effectiveness of influenza vaccine in preventing influenza-related hospitalizations in children during the 2006–07 influenza season._{[data not yet published]}

Evaluation of Monovalent nH1N1 Vaccine Effectiveness Case-Control in Hospitalized Individuals Older Than Seven Months of Age With Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR)-Confirmed nH1N1 Influenza

NMEIP contributed to an evaluation of the nH1N1 influenza vaccine in preventing influenza-related hospitalizations in persons older than seven months of age during the 2009 H1N1 pandemic._{[data not yet published]}

Monovalent nH1N1 Vaccine-Associated Guillain-Barré Syndrome

In collaboration with other states and CDC, NMEIP conducted active surveillance for Guillain-Barré syndrome during the 2009 H1N1 pandemic through the development of a network of neurologists statewide, comprising all major medical facilities and greater than 90% of neurologists likely to see Guillain-Barré syndrome cases._[1]

Influenza Burden Estimation Project

NMEIP was one of five EIP sites to pilot the influenza burden estimation project during the 2010–11 influenza season and one of three to continue the project for 2011-12 season data. The primary aim of this project was to refine the “pyramid” multiplier model created to estimate the number of cases, hospitalizations, and deaths due to seasonal influenza in the US._{[data not yet published]}

Association Between Use of Statin Medication and Influenza Mortality

NMEIP contributed information to CDC regarding the use of statin medication in patients hospitalized with laboratory-confirmed influenza._[2]

Pneumonia Etiology Study

NMEIP provided transcriptions from X-ray results to contribute to the identification of pneumonia in patients hospitalized with laboratory-confirmed influenza._{[data not yet published]}

Emergency Department (ED) Survey

NMEIP led a survey intended for clinicians at hospitals participating in the 10-state EIP network to obtain baseline understanding of current testing and treatment practices._[3]

Efforts to Improve Testing Practices in Southern New Mexico

An emergency department (ED) survey indicated little to no rapid influenza testing in one southern New Mexico county. NMEIP supplied 400 rapid influenza tests to the single ED in that county as part of a pilot evaluation to be used during the 2007-08 influenza season._[4]

References

1. Guillain-Barré Syndrome During the 2009–2010 H1N1 Influenza Vaccination Campaign: Population-based Surveillance Among 45 Million Americans
   American Journal of Epidemiology. 2012 May 11. 1110-1119.
2. Association Between Use of Statins and Mortality Among Patients Hospitalized With Laboratory-Confirmed Influenza Virus Infections: A Multistate Study
   Journal of Infectious Diseases. 2012 January 1. 13-19.
3. Influenza Testing and Antiviral Prescribing Practices Among Emergency Department Clinicians in 9 States During the 2006 to 2007 Influenza Season
   Annals of Emergency Medicine. 2010 January. 32-39.
4. Efforts to Increase Influenza Testing in New Mexico
   New Mexico Epidemiology. 2011 May.