On October 18, the Michigan Department of Community Health confirmed the first two cases of influenza identified by the state laboratory during the 2010-2011 Michigan flu season. One of the viruses has been confirmed as influenza A/H3 and the other as the 2009 influenza A/H1N1 subtype. While two different types of influenza A viruses have now been confirmed in Michigan, it is too early to tell what influenza viruses will circulate during this influenza season or how severe the influenza season may be.

The Michigan Department of Community Health (MDCH) determines influenza activity based on many sources of information including data from the MDCH laboratory,Influenza Sentinel Physicians, sentinel laboratories,  Michigan Disease Surveillance System (MDSS), and MDSS syndromic surveillance.

MDCH conducts year-round surveillance for influenza:

• View the current Michigan Flu Focus influenza surveillance report
• or view the Michigan Flu Focus archives

Each week during influenza season (October through May), MDCH reports the estimated level of influenza activity in the state to the Centers for Disease Control and Prevention (CDC).  The five levels, from lowest to highest, are:

• No activity: No laboratory-confirmed cases of influenza and no reported increase in the number of cases of influenza-like illness (ILI)
• Sporadic: Isolated laboratory-confirmed influenza cases or a single influenza outbreak has been reported, but no increase in ILI activity
• 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 2 regions of the state.
• Widespread: Outbreaks of influenza or increases in ILI cases cases and recent laboratory-confirmed influenza in over half the regions of the state. 

A map of the State and Territorial Epidemiologists' Reports from Michigan and throughout the U.S. can be viewed on the CDC influenza website from October through May.