Swine flu has just about run its course, making it one of the mildest flu outbreaks in recorded history, health officials said.

Hundreds of students on the campus have contracted the swine flu — officially known as the novel H1N1 virus — this semester, causing them to miss classes and stay in bed. But even as the number of swine flu cases plummet, university health officials warn students against letting down their guard, saying students should take more care of themselves more than ever, particularly during the high-stress environment of finals week.

“Influenza activity continued to decrease in the U.S.,” the U.S. Centers for Disease Control and Prevention said in its weekly report Friday. Only 14 states reported “widespread influenza activity” last week, compared with 25 states the week before, according to the CDC’s new report.

A marked decline in H1N1 cases in recent weeks conforms to a recent CDC study that indicated the autumn-winter pandemic wave of the virus could result in considerably fewer deaths than during regular flu season.

But even as the swine flu scare appears to be winding down, students should not become complacent, University Health Center Nursing Supervisor Tina Thorburn said.

Students with weak immune systems and those who are recovering from swine flu will be more vulnerable during the height of flu season — December, January and February — even as they may be the least likely to focus on their health, she said.

“This is high stress time,” Thorburn said. “At the end of the semester projects are due, there are final exams, students are probably not eating right, not getting rest and aren’t taking multi-vitamins. Running on three to four hours of sleep you’re more likely to get sick, and if you’ve had the swine flu your immune system probably is more susceptible to seasonal flu.”

According to the CDC study, about a half a million people die of seasonal flu annually and an average of 36,000 people in the U.S. alone die from “influenza-related causes” every year. The CDC recently reported that nearly 10,000 people in the U.S. had died of the swine flu since April.

At this university, Thorburn said she is “still seeing cases of students testing positive for [Type A] influenza,” but there has been a “significant drop in the past month.” Because swine flu is a strain of Type A, all those who test positive are assumed to have the H1N1 virus.

Thorburn said swine flu has different symptoms than seasonal flu. Students arriving at the health center have not been exhibiting typical seasonal flu symptoms.

“Students in the waiting room, during flu season, look like death warmed over,” Thorburn said. “But they’re not coming in looking like that … 90 percent of cases we’re seeing are H1N1, because it’s too early in the flu season.”

Health center nurse practitioner Donna Jacobs said she has seen “only one to two” students test positive for Type A influenza since Thanksgiving break.

“It’s really slowed down and all of our patients did very well — only a few developed bronchitis or pneumonia — but everyone was OK in the end: no deaths or long-term hospitalizations,” Jacobs said, “though people who went out drinking experienced a slower recovery.”

Thorburn said the university’s massive campaign encouraging students to stay home if they felt ill, to consistently wash their hands and to avoid people who appear sick may have curbed the number of flu-like illness cases on the campus.

“Self-isolation has probably made the biggest difference,” she said. “If they’re not going to class spreading their germs then there’s less likelihood of people picking up those germs.”

Also, Thorburn said 7,000 flu shots have been administered this semester — 5,000 more than usual — and 1,400 H1N1 vaccinations were administered to high-risk individuals in November, which may have also reduced cases of flu-like illness.

botelho at umdbk dot com