The state says 12 influenza cases are the first seasonal flu reports it has confirmed in Michigan during the 2012-2013 season.
The Michigan Department of Community Health announced Monday that the illnesses occurred in children and adults in lower Michigan.
The state says at least two people were hospitalized. Nine cases have been confirmed as influenza B viruses, two as influenza A (H3N2) virus and one as influenza A (H1N1) 2009 virus.
Officials say it's too early to tell what influenza viruses will circulate this influenza season or how severe it might be. Precautions including flu shots when appropriate are recommended.
The Centers for Disease Control and Prevention is expected to report Michigan's flu activity as "sporadic" - the lowest of four levels of influenza activity.