As Michigan reported a second suspected case of swine flu Tuesday, health officials urged people not to panic while saying it was only a matter of time before more cases emerge.
The state Department of Community Health said a 34-year-old Ottawa County woman had a "probable" case of the flu strain that is suspected of killing more than 150 people in Mexico but no one in the United States.
The woman was released from a Kent County hospital Friday. Other details, including her name, travel history and hometown, were not released. Ottawa County runs west from Grand Rapids to Lake Michigan.
The state will send the lab results to the Centers for Disease Control and Prevention to see if she tests positive for the virus.
Michigan is still awaiting word from the CDC on a probable case out of Livingston County, which is located 45 miles northwest of Detroit. A 34-year-old woman is recovering at home after returning by car from a vacation in Texas.
Also Tuesday, the state partially activated its Emergency Operations Center in Lansing to coordinate the response of state agencies and local governments to the flu outbreak. The center was partially opened during a 2007 tornado storm and during Hurricane Katrina in 2005.
People with flu-like symptoms who show up at Michigan doctor's offices, clinics and emergency rooms are being tested for influenza A. If the test is positive and the patient has traveled in an area where swine flu is known to have been, then the swab is sent to the state for testing.
If the state lab determines the sample is an untypeable strain of influenza A, it rules it a "probable" case of swine flu and asks the CDC for confirmation.
"Know that testing is happening all over the state just to be sure," Gov. Jennifer Granholm told reporters at an education summit in Lansing. "I'm sure there are scores of tests that have been taken that have been found to be negative. But everyone is on alert, of course, and making sure that we are not missing anything."
People are being urged to wash their hands frequently, cover their mouths when coughing or sneezing, avoid touching their eyes, nose or mouth, and -- if sick -- stay home from work and school.
The number of confirmed swine flu cases in the U.S. stood at 64.
Dr. James Wilson, medical director for a 10-county health department in western and northern Michigan, said he expects more cases to be found.
"You're going to see a lot of it," Wilson said. "Whether this is mild or turns into a big deal, we'll have to see."
Ordinary human flu accounts for 36,000 deaths every year in the U.S.
When asked if the media is overplaying the flu outbreak, Granholm said it is important for states to be prepared.
"I also know with cable news, they have to fill some hours. So if you watched that all day, you'd be thinking that there was a pandemic. We're not there yet."
Michigan has stockpiled 1 million doses of Tamiflu, an anti-viral medication, with another 250,000 doses on the way, according to the state.