No it's not a holdup, but instead an attempt to stop the spread of both the seasonal and H1N1 influenza viruses.

Patients at Butler Health System's outpatient clinics and the triage area at Butler Memorial Hospital now are being greeted by lab technicians required to wear masks.

Dr. Tom McGill, BMH vice president of quality and safety and an infectious disease control specialist, said Wednesday H1N1 has been confirmed in several cases in the county, and it already has sickened several health care workers.

"This is an attempt to stop that transmission," McGill said of the special N95 masks being worn by clinic and hospital workers who see the most patients. N95 masks are better at stopping the viral transmission by air.

In some cases, technicians also wear gowns, gloves and eye protection.

In a typical flu season, about 50 percent of all health care workers get the flu, McGill said.

Both McGill and Fred Peterson, vice president of professional services and emergency management for the Hospital Council of Western Pennsylvania in Wexford, pointed to the infectious capabilities of the H1N1 flu, especially among younger, healthier people than usual.

Its aggressive nature was seen in Pittsburgh when universities went into their fall semesters with dozens of students becoming sick almost immediately. Similar, these illnesses have occurred at Slippery Rock University and Grove City College.

But it is the case of the University of Washington in Seattle that caught McGill's attention. Of the 20,000 students there, about 2,000, or 10 percent of the campus, became ill with H1N1 in the first three weeks of school.

"What we are seeing is that people who get this flu get real sick," Peterson said. "We have young people, who are well, get sick, and within 24 hours are in the intensive care unit."

This type of aggressive virus requires that hospitals and other health care providers take "universal precautions" when dealing with potential patients, such as strict hand washing routines and mask wearing, Peterson said.

BHS has also taken these steps to attempt limiting transmission of the flu in its facilities:

• At the hospital and outpatient clinics, signs have been posted asking patients with flu symptoms to grab surgical masks, which are provided at the doors, to wear while either visiting or seeking treatment;

• Flu patients are being isolated in clinics and in the hospital emergency room area in a way they haven't before, trying to cut down on exposing other patients to the viruses.

McGill added that while everyone is waiting for the new H1N1 flu vaccine, which is expected to be available in October, it will take about two weeks to develop immunity after the shot.

Another health system, UPMC, which includes UPMC Passavant Cranberry, has yet to impose any gown or masking requirements on employees, said Clare Collins, manager of UPMC Public Relations. She also said the health system is not requiring workers to get the vaccine when it becomes available.

National health care organizations are warning people shouldn't expect to get the vaccine through workplace clinics.

The vaccine initially will be distributed to doctors and clinics as well as schools for those most at risk of contracting the virus or developing complications — children and young adults, pregnant women, health care workers and the chronically ill. People caring for infants also will receive priority.

Businesses may have to wait months to offer shots, if they get them at all.

At least 195 million doses are expected through winter.

Meanwhile, health care professionals continue to remind people to wash their hands frequently, to cover their mouths and noses when sneezing and coughing, and to stay home if they are sick.

"We're just trying everything to stop the virus from spreading," McGill added.

The Associated Press contributed to this article.