Sporadic cases of influenza infections have surfaced in Michigan, making them among the first cases of influenza virus in the state for the 2013-2014 flu season, local state health officials confirm in a report, according to The Tampa Tribune. 

The Michigan Department of Community Health (MDCH) detailed the findings in an official report released late in October. State officials also recommend flu shots to citizens in light of the report,  

Influenza cases usually appear during fall, and this year's incidences came in just as expected, MDCH director James K. Haveman notes in a statement. "We continue to encourage all Michigan residents to get vaccinated as it is the single best way to prevent contracting the flu," he said.

The department's influenza surveillance report disclosed that the four flu cases involved 3 positive influenza cases linked to a 2009 A/H1N1 strain, and 1 positive influenza infection linked to a A/H3 strain. Children and teenagers aged 5 to 17 years were affected.

The cases occured between October 20 and 24.

According to the Lansing State Journal, two of the four cases occurred in Oakland County, located north of the city of Detroit. Residents can have their flu shots administered for $20 at the Oakland County Health Division offices in Pontiac and Southfield during office hours, the Journal also reported.    

Health division manager Kathy Forzley said residents should prioritize getting the flu shot asap. "The sooner you get the flu shot the better," she told the Journal. "That's because it takes a couple of weeks for the vaccination to take effect so that it could effectively shield you against the flu."

The 2013-2014 season had started in September 29, 2013, according to the influenza surveillance report. The report also stated that only four incidences have occurred so far on a national level.  

Michigan health officials maintain that they're still investigating the influenza trend and frequency in the state, the Tampa Tribune reports. 

The Center for Disease Control and Prevention (CDC) considers flu cases in Michigan as "sporadic", which ranks it second from the lowest in terms of severity, according to the Tampa Tribune.