Help and Background

Q:

How do I find information about a specific state?

A:

To find specific information about a state, first, narrow the search by selecting from the choices available from the items to the left of the map. Then, click on the desired state.  An information box containing additional links to information will appear.

Q:

What do the different map “views” show (available on the top right of the map)

A:

• The “Map” view shows a map with a traditional depiction of roads, parks, borders, bodies of water and more.
• The “Satellite” view shows aerial imagery.
• The “Hybrid” view shows a combination of the “Map view, by providing state names, with the aerial view and imagery of the “Satellite” view.
• The “Terrain” view shows the physical elevation as shaded relief and elevation lines.

Q:

Where does the information for CDC Influenza Activity map come from?

A:

The information for this map comes from the Surveillance reports provided by the state to the Centers for Disease Control and Prevention (CDC).

Q:

What does regular influenza surveillance consist of?

A:

Regular surveillance includes:

1. Viral surveillance, which monitors
   • The percentage of specimens tested for influenza that are positive for influenza;
   • The types and subtypes of influenza viruses circulating;
   • Resistance to influenza antiviral medications, and
   • The emergence of new strains
2. Sentinel physician surveillance for influenza-like illness (ILI), which monitors the percentage of doctor visits for symptoms that could be the flu.
3. Hospitalization surveillance, which tracks numbers of hospitalizations with laboratory-confirmed flu infections among adults and children.
4. Summary of the geographic spread of flu, which tracks the number of states affected by flu and the degree to which they are affected.
5. Deaths from 122 Cities that report the total number of deaths and the percentage of those that are coded as influenza or pneumonia.
6. The number of laboratory-confirmed deaths from influenza among children.
   
   

Q:

How do states report the estimated level of spread of influenza?

A:

State health departments report the estimated level of spread of influenza activity in their states each week through the State and Territorial Epidemiologists Reports. States report influenza activity as no activity, sporadic, local, regional, or widespread.

How are these levels of activity defined?

• No Activity: No laboratory-confirmed cases of influenza and no reported increase in the number of cases of ILI.
• Sporadic: Small numbers of laboratory-confirmed influenza cases or a single laboratory-confirmed influenza outbreak has been reported, but there is no increase in cases of ILI.
• Local: Outbreaks of influenza or increases in ILI cases and recent laboratory-confirmed influenza in a single region of the state.
• Regional: Outbreaks of influenza or increases in ILI and recent laboratory confirmed influenza in at least two but less than half the regions of the state with recent laboratory evidence of influenza in those regions.
• Widespread: Outbreaks of influenza or increases in ILI cases and recent laboratory-confirmed influenza in at least half the regions of the state with recent laboratory evidence of influenza in the state.
  
  

Q:

Where does information on the Influenza-like Illness (ILI) Visits Map come from?

A:

Information on patient visits to health care providers for influenza-like illness is collected through the US Outpatient Influenza-like Illness Surveillance Network (ILINet).