Health officials say the H1N1 influenza virus is ravaging Coos County.

The bug is partially to blame for hundreds of absences at area schools. But unlike in the spring, when school officials sent students home when one suspected case of swine flu appeared at North Bend High School, classes have stayed in session despite the bug's arrival.

Officials say school doors will remain open unless illnesses overwhelm a different segment of the districts' population: teachers.

The area's superintendents met Thursday with health officials and discussed the potential for school closures.

"Everyone was confirming that the deciding factor would be staff," said Bruce Shull, Myrtle Point's superintendent of schools.

When teachers start sniffling and sneezing, districts rely on a cast of substitutes.

The South Coast Education Service District compiles a list of subs and ensures they have the proper certification. There are 145 substitute teachers available on the South Coast, said Sharon Smith, executive secretary to the ESD superintendent.

"It may sound like a lot of subs, but it's really not that many," she said.

The problem is these teachers aren’t equally distributed among districts. While Coos Bay and North Bend have dozens to choose from, smaller districts can rely on only a handful.

Port Orford-Langlois School District has about 16 teaching subs who are considered regulars, said Superintendent Mick Lane. But some of them can only fill in for specific subjects or grade levels.

"Even if they were all available, we wouldn’t be able to function if 25 percent of our teachers became ill," he said.

Myrtle Crest Elementary School has come close to having a quarter of its teachers out, though Shull said there have been enough substitute teachers.

Another problem the district had to confront was getting students to school when bus drivers were calling in sick. They were able to find enough substitute drivers, but the problem illustrates how there are many factors in keeping schools open.

"Being in such a rural district, getting our kids here is a problem if we don’t run the buses," Shull said.

School officials also have been scrambling in Powers. They only have about four or five substitute teachers to call on, said Ellen Baldwin, administrative assistant. Some teachers have taken on additional classes during their prep periods.

"It's not real easy, but we’ve managed," Baldwin said.

The area's larger school districts haven’t been hit with too many absent teachers. North Bend Middle School Principal Ralph Brooks said there were a couple of teachers in North Bend out Thursday, and the middle school’s nurse had sent some others home Monday.

 Angie Webster, a nurse in the Coos Bay district, said only a handful of staff have been unable to come in to work.

Schools everywhere have put out hand sanitizer, taught children to cover their coughs and encouraged good hygiene.

"When I hear coughs, I see a lot of elbows going up," Brooks said, of students avoiding coughs in their hands. "They are getting it."

Students are returning to classrooms in North Bend days after half the seats were empty in the district's middle school due in part to illness.

More than 250, out of 573 students, stayed home Monday from North Bend Middle School, while 115 Hillcrest Elementary's 575 students took the day off. The absentee rate has stayed steady at the elementary school, while North Bend Middle School had only 206 absent students Tuesday and 166 gone Wednesday.

"We are getting better," said Brooks. "It seems to go through them pretty quickly."

North Bend students aren’t the only ones who haven’t been feeling well.

Between 15 and 20 percent of students in Powers, Myrtle Point, and Driftwood Elementary School in Port Orford have been absent the past week. Tuesday at Reedsport Junior/Senior High School, 88 out of 315 kids were absent.

Some schools haven't been affected as severely. Coos Bay schools have seen a typical number of absences, said Webster. And Bandon High School had only 15 of its 273 students out of class Monday.

Coquille schools have seen about 10 percent absentee rates this week.

Students and school employees who have been coming down with flu-like symptoms can’t have the seasonal flu, because it's too early in the year for that, said Dr. Hugh Tyson, Coos County’s health officer.

"It's almost certainly swine flu and it’s arrived in a very real way," he said.