NEWS RELEASE
January 10, 2000

Michigan Sees Increase in Reported Cases of Influenza

Michigan Department of Community Health Deputy Director for Public Health and Chief Medical Executive, Dr. David R. Johnson, confirmed an increase in reported cases of influenza and influenza-like illness throughout Michigan. In late December the percentage of influenza-like illness among patients reported by influenza surveillance sites rose to 10-15%. Previous weeks this season were at baseline levels of 0-3% influenza-like illness.

"This pattern appears to be the classic flu pattern in Michigan with a sudden increase in cases reported at the end of December and beginning of January," said Johnson. Last year at this time, influenza-like illness remained at baseline levels of 0-3%. In the 1998/99 season, influenza was later than usual, beginning in January and peaking in February.

The greatest identified increases in influenza have been in the Southeastern and Northern sections of the state, including the Upper Peninsula. Several local outbreaks of acute respiratory illnesses in long-term care facilities have also been reported in lower Michigan. It is still too early to know when influenza activity will peak or whether we could see elevated numbers overall this season.

The Department of Community Health monitors influenza using several different sources around the state, including physicians and hospital reports along with school-based reporting of flu-like illness. Michigan also operates a Sentinel Physician Surveillance Network for influenza as part of a national system sponsored by the Centers for Disease Control and Prevention. The sentinel network is designed to collect weekly influenza-like illness data throughout the flu season. The Department of Community Health Laboratory periodically tests sentinel respiratory specimens (throat swabs from patients with suspect influenza illness) for respiratory viruses. This data is key to evaluating vaccine match with circulating virus, as well as early recognition of new and unanticipated influenza strains.

For sentinel purposes, the Department of Community Health Laboratory has identified 22 cases of influenza via virus isolation since October. To date, all isolates are type A viruses, subtype H3N2. Influenza A (H3N2) is one of three strains (along with A H1N1 and type B/Beijing virus) covered by the current year influenza vaccine. There have been no indications that the effectiveness of this vaccine is less than the expected rate of 70-90% protection.

True influenza is caused by a virus which infects the respiratory tract. Symptom onset is usually abrupt and typically involves cough, high fever, muscular aches, and pronounced weakness or fatigue, with pneumonia as a complication. Gastro-intestinal upset is not a primary symptom of influenza.

"There are simple, preventative things people can do to protect themselves from influenza. Proper hand washing with warm water and soap can greatly decrease the transmission of germs," said Johnson. "Keeping your immune system strong is also helpful in the fight against influenza. It is important to drink plenty of liquids, eat well balanced meals, get enough sleep and incorporate exercise into your daily routine."

"Although the ideal time to get the annual influenza vaccination is in October or November, those who haven't yet been vaccinated may still benefit from it," said Johnson. "Check with your health care provider concerning availability and advisability of getting vaccinated in January."