As a never-before-seen flu captures the world's attention, South Carolina braces to be next on the virus' map.

Twenty-two residents have been tested for the virus. Results are expected today, according to officials at the S.C. Department of Health and Environmental Control. There are no confirmed cases in the state.

A private school in Newberry closed Monday after some students returned from Mexico with flu-like symptoms. Schools also are closed in New York City, Texas, California and Ohio.

Of the cases confirmed worldwide, 50 are in the United States. On Monday afternoon, the World Health Organization raised its pandemic alert to Phase 4 - sustained human-to-human transmission - the stage preceding pandemic.

Is it time to stock pantry shelves and cancel public events, or stay tuned to breaking news? The answer is somewhere in between, said Dr. Robert Ball, an epidemiologist with DHEC and co-chairman of the S.C. Pandemic Influenza Ethics Task Force.

"While we're concerned, we're prepared," said Dr. Michael Schmidt, professor of microbiology at Medical University of South Carolina and task force member.

The task force held a meeting Monday night in North Charleston, an event planned before swine flu erupted. A coalition of state agencies and health care providers sought input for a response plan that will be submitted to the Legislature in the summer.

But the state's response may be tested before then.

Although dubbed "swine flu," the virus is technically a hybrid virus containing genetic material from pigs, birds and humans. Since this virus is new, the annual flu shot does not provide protection. A new vaccine is months away, Ball said.

Droplets from coughing and sneezing transmit the virus up to 6 feet away. Symptoms begin within one to two days of exposure, and people are infectious before they are symptomatic.

Symptoms of swine flu are similar to regular flu and include fever, sore throat, cough, stuffy nose, chills, fatigue, headache and body ache.

The virulence of the virus is difficult to estimate this early. The Spanish influenza pandemic of 1918-19 infected about a third of the world's population and killed about 50 million people worldwide with a death rate of about 3 percent.

As of Monday night, about 2,000 cases of swine flu were suspected in Mexico, and about 150 believed dead. That would give this new strain a death rate more than double the Spanish flu.

The cases in the United States, however, have so far been mild. Ultimately, scientists are expecting a death rate that may still approximate Spanish flu, Ball said. Experts are hoping for a much larger denominator. In other words, if many more cases of swine flu exist than are suspected, the death rate would fall.

Antiviral drugs such as Tamiflu seem to work for swine flu when taken shortly after symptoms begin. South Carolina has a small stockpile of these drugs and will be getting more within the next few days from the federal government, which mobilized roughly 12 million doses.

DHEC estimates it can treat about 150,000 cases of influenza, should private health care providers run low on supplies. Whether the antivirals should be used as a preventive for health care workers or as treatment for patients was one point debated Monday night.

Charleston County hospitals are on heightened alert for patients with influenza-like symptoms and are placing masks on patients with symptoms.

Some area travel agencies reported they had received calls from customers about planned vacations in Mexico.

"They seemingly are concerned about whether to go or not," said Cecil Wilson, owner of Charleston Travel & Cruise Center.

"People are calling examining their options for rescheduling. We have spent a large part of our morning looking at options," Wilson said. He said that he had received less than 10 calls from concerned clients.

U.S. officials on Monday urged against "non-essential" travel to Mexico. The Pandemic Influenza Ethics Task Force tackled tough questions about medical care. People should expect a shift from traditional care, where the sickest get first claim to medical resources, to a model where patients with the best chance of recovery get priority.

All will get care, but, for some, care may be limited to palliative efforts. Ventilator decisions and triage teams also were discussed.

"The goal will be to reduce the number of infections and the number of deaths," Ball said.

Prentiss Findlay and the The Associated Press contributed to this report.

Glossary

Epidemic: An outbreak that affects more than the expected number of people in a community or region.

Pandemic: An epidemic that has gone worldwide.

Pandemic flu: A virulent human flu that causes a global outbreak, or pandemic, of serious illness. Because there is little natural immunity, the disease can spread easily from person to person. Currently, there is no pandemic flu.

Seasonal (common) flu: A respiratory illness that can be transmitted person to person. Most people have some immunity, and a vaccine is available.