Raleigh, N.C. — As the H1N1 virus continues to spread across North Carolina, the state's public health director said Tuesday that the number of confirmed cases of swine flu likely is much greater than the 14 that have been reported.

"They will definitely go unreported," Dr. Jeffrey Engel said. "We feel that our current (testing) method probably catches about one in 10 to one in 20 that are really happening here."

The first confirmed cases in the Triangle were reported over the weekend. A UNC Health Care worker and a Durham resident contracted the disease, and both were isolated to limit any spread of the disease.

Health officials said the two cases are unrelated, although both people had recently traveled to New York City, which has experienced the largest U.S. outbreak of the disease.

More than 6,500 cases of H1N1 have shown up in 48 states, and 11 people in the U.S. have died from the disease, according to the U.S. Centers for Disease Control and Prevention.

At least 42 countries have confirmed cases of the disease, which has sickened 11,168 people and caused 86 deaths, the World Health Organization reports.

The Durham case was discovered because the person was hospitalized for an unrelated illness and was tested for the virus. The person was recovering at home Tuesday, officials said.

The UNC Health Care worker, who works at University Pediatrics, on Highgate Drive in Durham, was tested because he or she is a health care worker. The clinic was operating on a normal schedule Tuesday, and officials were monitoring the situation to see if any co-workers or patients exhibit flu-like symptoms.

Engel said not all suspected cases of H1N1 are tested because the volume would overwhelm the state lab. The state is testing according to guidelines issued by the Centers for Disease Control and Prevention, he said.

"We do it by sampling. We don't do it by testing everybody," he said.

The state lab tests every case that involves hospitalization and special circumstances, such as people in schools, day care centers or health care settings.

A network of about 80 medical practices statewide also has test kits that allow them to screen for the virus and collect data for the CDC, Engel said.

"These are private practices. They are university student health clinics. Some of them are in local health departments," he said. "That (data) gives us a general idea about flu activity in the state."

Engel said he expects commercial labs to be able to test for swine flu in coming months, which would allow every potential case to be tested.

Right now, though, he said testing isn't a top priority because H1N1 is treated and prevented like seasonal flu, he said. People should wash their hands frequently, cover their faces when the cough or sneeze and stay home if they feel sick, he said.