Skip directly to search Skip directly to A to Z list Skip directly to navigation Skip directly to page options Skip directly to site content


NIOSH Activities: Surveillance

Man Sneezing into tissue

Tracking Influenza Cases and Preventive Measures


Public health surveillance is the ongoing, systematic collection, analysis, and interpretation of health-related data essential to the planning, implementation, and evaluation of public health practice, closely integrated with the timely dissemination of these data to those responsible for prevention and control.

NIOSH’s influenza surveillance activities fit into the bigger picture of CDC influenza surveillance activities, which monitor disease burden, virus characteristics, vaccine (availability, use, adverse events, etc.), antivirals (availability, use, adverse events, etc.), medical care/infrastructure, school and workforce protection, and other non-pharmaceutical interventions.

CDC divides influenza disease surveillance into 5 categories, which are described at

  • Viral Surveillance
  • Outpatient Illness Surveillance
  • Mortality Surveillance
  • Hospitalization Surveillance
  • Summary of the Geographic Spread of Influenza

NIOSH works to ensure that occupational factors that affect influenza activity are tracked by incorporating occupational information into broad influenza surveillance systems developed and maintained by other parts of CDC and by creating new occupational-health-specific surveillance systems.

Occupational Distribution of Persons with Confirmed 2009 H1N1 Influenza

General Description: Knowledge is limited regarding the epidemiology of 2009 H1N1 influenza by occupational grouping. During April–July, 2009, work status information was available for 1,361 of 4,334 (31.8%) persons aged 16 years or older with laboratory-confirmed 2009 H1N1 influenza from Florida, Kansas, Oregon, and Wisconsin. A NAICS 2007 code ; was assigned to each employed person. For a subset of these persons, an occupation code was also assigned.

Relevance to Worker Safety and Health: This analysis identifies occupations and industry sectors that may be associated with higher risk of influenza infection.

Key Findings:

  • Of 898 employed individuals, 32% were health-care personnel and 68% worked in the non-health-care sectors.
  • The non-health-care industry sectors representing the highest proportions of influenza cases were public administration, educational services, and accommodation and food services
  • Among the affected Wisconsin health-care personnel, 54% were health paraprofessionals; 34% were health professionals; and 13% were other workers.

NIOSH investigators made the following observation and recommendation: This analysis highlights the need to collect data on occupation and industry more consistently in future influenza surveillance.

Status: A paper summarizing this work has been published in a peer-reviewed journal:

Point of Contact: CDC-INFO

Influenza Hospitalization Network (FluSurv-NET)

General Description: FluSurv-NET conducts surveillance for population-based, laboratory-confirmed influenza related hospitalizations. The network covers over 80 counties in the 10 CDC Emerging Infections Program (EIP) states (CA, CO, CT, GA, MD, MN, NM, NY, OR, and TN) and six additional states (ID, MI, OH, OK, RI and UT).

The NIOSH Division of Surveillance, Hazard Evaluations, and Field Studies (DSHEFS), in coordination with CDC colleagues, collected occupational data on adults hospitalized with influenza in 2009-2010 through the EIP states. These data are also being collected for the 2010-2011 influenza season.

Relevance to Worker Safety and Health: More information is needed about which specific groups of workers are at highest risk of acquiring both pandemic and seasonal influenza. This is one of the first times occupational information has been collected in a traditional CDC influenza surveillance system.

Key Findings: During the 2009-2010 influenza season, the proportion of workers hospitalized for influenza was lower than their proportion in the general population. However, among those workers who were hospitalized with laboratory-confirmed influenza, certain industry sectors were overrepresented compared with what would be expected if workers from all industry sectors had the same risk for hospitalization because of influenza. These industry sectors were: transportation and warehousing; administrative and support and waste management and remediation services; healthcare; and accommodation and food service.

Status: A manuscript describing the key findings from 2009-2010 ; is now available.

Point of Contact: CDC-INFO

National 2009 H1N1 Flu Survey (NHFS)

General Description: CDC conducted the NHFS from October 2009 through June 2010 to track 2009 H1N1 and seasonal influenza vaccination coverage nationally on a weekly basis. NHFS was a random-digit--dialed telephone survey based on a rolling weekly sample of respondents with landline and cellular telephones. Monthly targets were set to achieve approximately 4,889 completed interviews from landline households and 1,111 from cellular-only or cellular-mostly households, or approximately 6,000 interviews in all. (From )

The NIOSH Division of Surveillance, Hazard Evaluations, and Field Studies (DSHEFS) worked with CDC colleagues to add four questions to the NHFS to address occupational issues (employment status, occupation, industry, missed work)

Relevance to worker safety and health: The four occupational questions will enable analyses of:

  • incidence of self-reported respiratory illness among workers by industry and occupation
  • knowledge, attitudes, and practices of workers regarding 2009 H1N1 influenza
  • vaccination uptake among workers (seasonal and 2009 H1N1 influenza)
  • days of work missed due to respiratory illness

Key Findings: Not yet available.

Status: In process.

Point of Contact: CDC-INFO

Behavioral Risk Factor Surveillance System (BRFSS)

General description: BRFSS is a state-based system of health surveys (reaching 400,000 respondents) that collects information (by phone) on health risk behaviors, preventive health practices, and healthcare access primarily related to chronic disease and injury. Two special modules were added during the 2009-2010 influenza season to address the 2009 H1N1 influenza pandemic. A module on influenza-like illness (ILI) ran from September 1, 2009-March, 2010. A module on vaccination ran from October, 2009-June, 2010. The content for these was set before NIOSH got involved, therefore information on industry and occupation was not systematically collected. Every state except VT used them.

Relevance to worker safety and health: Two States currently include questions about industry and occupation in the BRFSS as "state-added questions." NIOSH is working with colleagues to have industry and occupation questions regularly and systematically tracked in the core annual BRFSS survey for all States, so that health outcomes measured in BRFSS (including ILI) can be tracked by industry and occupation.

Key Findings: Not yet available.

Status: In process.

Point of Contact: CDC-INFO

Demonstration and Sentinel PPE Usage Surveillance in US Healthcare Workers

General Description: This project identifies, describes, and evaluates surveillance systems used at the Vanderbilt University Medical Center to track activities, resources and outcomes related to personal protective equipment (PPE). This work compliments other infection control measures being used to control transmission of infectious diseases during an influenza pandemic or other disasters. The project uses existing and new systems at VUMC to collect data by active and passive surveillance methods, and will share data in a standardized way. The data include key fields regarding training, fitting, utilization, resources, exposures, and outcomes relating to PPEs and facilitating development of recommended best practices for collection and maintenance of such data.

Relevance to worker safety and health: Descriptions of existing systems in use by medical centers across the country, along with VUMC data will be used to demonstrate a standard dataset for export to a national surveillance system. Such a dataset will provide information useful to CDC in an evolving infectious disease situation, allowing CDC to provide clear and useful PPE guidance to healthcare facilities in real time.

Key Findings: Not yet available.

Status: The project is in the second year of a three year term.

Point of Contact: CDC-INFO

Respirator Evaluation in Acute Care Hospitals Study (REACH I)

General Description: This project assessed the usage of respiratory protection for influenza exposure among healthcare workers (HCWs) in 16 California hospitals during the H1N1 influenza. 204 HCWs participated in this study representing a variety of clinical specialties (i.e. ER, ICU, Peds,) and roles including unit managers, respiratory protection administrators and direct care providers. Observational methods were also employed to better understand donning and doffing practices.

Relevance to worker safety and health: Findings from Reach I serve as a 'snap shot' of: 1) the extent to which hospitals in California have implemented required elements of a respiratory protection program for influenza; and 2) the usage of personal respiratory protection for influenza exposure among California healthcare workers.

Key Findings:

  • 50% of the hospital managers reported that their facility had experienced a shortage of respirators between April 2009 and the survey period (January 20- February 23, 2010).
  • The observational data indicates improper use of respiratory protective equipment as evidenced by donning and doffing practices.
    • Not performing a seal check
    • Improper strap placement
    • Touching the face piece upon doffing
  • In response to a question what healthcare workers believe, 65% felt that they were at a high risk of becoming ill with influenza due to their work, 96% felt that wearing an N95 or better respirator could help protect them from on-the-job exposures to influenza and 94% indicated that N95 respirators are more effective at protecting them from influenza than surgical masks.
  • In response to a question related to how respondents knew that they needed to wear a respirator, the top two responses indicated that they waited to be "cued" by signage on the door or to be told during shift report.
  • A paper summarizing this work has been published in a peer-reviewed journal: Occupational Distribution of Personas With Confirmed 2009 H1N1 Influenza. Journal of Occupational and Environmental Medicine.

Status: Completed

Point of Contact: CDC-INFO

Respirator Evaluation in Acute Care Hospitals Study Intervention and Evaluation (REACH I & E)

General Description: The objective of this project is to extend and build upon the work previously completed under REACH I by examining the effectiveness of various interventions for improving respiratory protection programs in California acute care facilities.

Relevance to worker safety and health: Findings from REACH I suggest that N95 respirators are being widely used, although gaps in training, appropriate donning and evaluation have been identified. This project identified and evaluated effective interventions and best practices to strengthen California hospitals' respiratory protection programs and reinforce healthcare workers' proper use of respiratory protection.

Key Findings: A toolkit of effective strategies was developed and tested in 14 California hospitals. The California Respirator Program Administrators toolkit can be accessed at:

Status: Completed

Point of Contact: CDC-INFO

Respirator Evaluation in Acute Care Hospitals Study (REACH II)

General Description: Expanded upon REACH I to evaluate hospitals' written respiratory protection programs and assess healthcare workers' usage of respiratory protection for influenza (droplet) and aerosol-transmissible exposures in five regions of the United States (Northeast, Southeast, Midwest, Southwest, and the West).

Relevance to worker safety and health: Findings from Reach II will serve as a 'snap shot' of: 1) the extent to which hospitals across the United States have implemented required elements of a respiratory protection program for influenza and 2) the usage of personal respiratory protection for seasonal influenza exposure among healthcare workers.

Key Findings: Not yet available.

Status: Data collection completed in all five regions. To date: 98 hospitals, over 1500 participants (i.e. HCWs, Hospital and Unit Managers) completed the surveys and 300 demonstrations of respirator donning and doffing have been obtained.

Point of Contact: CDC-INFO