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Cases of H1N1 flu seem to be tapering off at schools like Washington State University, where it is suspected of sickening more than 2,000 students, but health officials say the nation needs to remain on high alert for breakouts of the virus.

"It’s good the student population is becoming generally healthier at WSU – but it doesn’t mean they can let their guard down," Joe Quimby, senior press officer for the Centers for Disease Control and Prevention, told FOXNews.com on Tuesday.

"And that same message goes for any other university, college, public school, city or town."

The hardest hit area of the country is currently the Southeast, where schools have been in session for three to four weeks, Quimby said.

"It’s only a theory, but based on what we saw in the spring, and what we’re seeing in the Southeast … is that as more and more schools come into session we’ll continue to see the spread of H1N1."

He said the spike in cases in the Southeast can most likely be attributed to the fact that students are in such close proximity to one another.

In a press briefing last week, Dr. Thomas Frieden, director of the CDC, made the point that the H1N1 virus is here to stay, and in fact it never went away.

"We had H1N1 influenza throughout the summer in summer camps, and now with colleges and schools coming back into session, we're seeing more cases," Frieden said.

"The good news is that so far, everything that we've seen, both in this country and abroad, shows that the virus has not changed to become more deadly. That means that although it may affect lots of people, most people will not be severely ill."

But Frieden stressed that the flu is generally "unpredictable."

"And that means two things," he said. "First, we have to vigorously monitor to see whether it's changing, who it's affecting and what's happening with it. And second, we have to be ready and prepared to change our approach depending on what the virus does."

About half of H1N1 cases affect people between 5 and 24 years old, most of whom don't have to see a doctor and recover within five days.

"There's no reason to see a doctor or go to the emergency department unless you're severely ill," Freiden said. "For example, if you have trouble breathing or you have an underlying condition, such as diabetes, pregnancy, heart disease or lung disease. For people who do have an underlying condition, it's important to be seen promptly if you get a fever."

Frieden said that could make the difference between being severely ill and "recovering well."

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WSU Outbreak

The outbreak at Washington State University, in Pullman, Wash., began soon after classes started two weeks ago, and officials thought it might last six to eight weeks. "But if this weekend is any indication, it could be over in another couple of weeks," said Dr. Dennis Garcia, senior associate director of Health and Wellness Services at WSU.

Over the Labor Day weekend, Garcia said, 40 to 50 students a day contacted the health service center to report flu symptoms. That was down from roughly 150 a day last week.

"It's hard to say exactly what's going on, but it seems like things are slowing down a little bit," Garcia said.

Although things seem to be "slowing down" at WSU, Quimby was quick to point out that it doesn’t mean the virus can’t make a comeback.

"The flu season is from October to May," he said. "Just because it comes into a university or a city or town — it doesn’t mean it can’t come back six weeks later or six weeks later after that — and the same holds true for H1N1.”

Based on estimates from the CDC, Garcia said about 5,000 students can expect to come down with the bug. That's about one-third of the enrollment at the WSU campus.

In accordance with CDC guidelines, the university is no longer testing patients to confirm H1N1 infection.

WSU is urging people who think they have flu-like symptoms to stay home, rest and get plenty of fluids. Officials are handing out free flu kits, which include a thermometer, painkillers, throat lozenges, sport drinks, hand sanitizer and tissues.

Click here for more information on H1N1 from the CDC.

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The Associated Press contributed to this report.