LANSING, Mich. -

The Michigan Department of Community Health (MDCH) on Tuesday said it had confirmed four cases of influenza, the first identified by the state for the 2013-2014 flu season.

The illnesses occurred in both children and adults, from two Southeast Michigan counties.

Three cases have been confirmed as influenza A(H1N1) 2009 viruses and one as an influenza A(H3N2) virus.

Special section: Influenza prevention

The state said it's still too early to tell what influenza viruses will circulate during this influenza season or how severe the season will be.

The Centers for Disease Control and Prevention (CDC) reports Michigan's flu activity as "sporadic," the second lowest of five influenza activity categories the federal government tracks. Nationally, a mix of sporadic influenza viruses have been detected during the past month.

What is flu season: Flu activity typically peaks in late January through February, but can sometimes peak earlier or later, depending on the strain of flu and severity of the season. Because of the unpredictability of each flu season, it is important to get vaccinated early before flu activity is widespread in the community. It takes about two weeks from the time of flu vaccination to develop protection, so no one should delay getting immunized.

What is the flu: The flu is a contagious respiratory illness caused by influenza viruses. It can cause mild to severe illness, and at times can lead to death. The flu is much more serious than the common cold but can be easily prevented. An annual flu vaccine is the single best way to protect against influenza.

Options for the vaccine: For the first time there are more options for the flu vaccine available. Previously, flu vaccines only protected against three types of influenza virus but this year, some of the vaccines will protect against four strains. Health care providers should have ample supply of vaccine.

Everyone 6 months of age and older is recommended by CDC to receive an annual seasonal flu vaccine. Vaccination is especially important for those at high risk for serious flu complications, including older people, pregnant women, children who are 6 months through 18 years of age, people with certain health conditions, as well as contacts of high risk individuals - new parents, health care professionals, household members, and caregivers.

MDCH's Vaccines for Children (VFC) program gives childhood vaccines to eligible children in families who are in need of affordable immunizations. In VFC, doctors and clinics enroll in VFC and give vaccines to children who qualify. Check with your doctor or your local health department to see if they participate in the VFC program. For more information on the VFC program, visit www.michigan.gov/vfc.

Residents can call their physician, local health department, or check the Health Map Vaccine Finder at http://flushot.healthmap.org/ to find nearby influenza vaccination locations. For more information, visit www.michigan.gov/flu.