By SHILANDA WOOLRIDGE

Mission Neighborhood Health Clinic has seen 20 to 30 percent more patients coming in and some general panic around swine flu, according to its medical director Dr. Jamie Ruiz.

There is, he tries to reassure them,  little reason for concern.

“We’re not worried because in the states the swine flu isn’t worse than any other flu,” said Ruiz, who is also a pediatrician. “The people most susceptible are people with decreased immunity—small children, elderly or people with asthma, heart or lung disease.”

So far in the U.S. only a two-year-old toddler from Mexico has died of swine flu. That number is dwarfed by the average number of flu deaths in a regular season, Ruiz said.

The Center for Disease Control estimates that 5 to 20 percent of U.S. residents get flu every year. Of those, some 200,000 are hospitalized with complications and about 36,000 die.

San Francisco had its first reported swine flu case on Friday—a child who recently traveled to Mexico. While the overall impact is likely to be minimal it doesn’t stop people from taking precautions and 11 schools—none in San Francisco—have closed in the last week. The San Francisco Chronicle reports, however, that some are rethinking that decision.

Earlier last week the testing for swine flu was only performed at the Centers for Disease Control in Atlanta, and local clinics had to send in specimens. By late last week the center had made kits and testing available to local public health officials.

To test for swine flu, a long cotton swab is inserted into the patient’s nasal cavity to take a mucus sample. The sample is sent to the San Francisco Department of Public Health and results are known in about 36 hours.

A polymerase chain reaction (PCR) test is run to find out if influenza virus type A is present. Avian, swine and human flu viruses are all type A.

Next the scientists establish whether the type A flu is H1 or H3, which are common seasonal human forms of the flu virus. In this particular outbreak, the swine strain comes up negative on the H1 and H3 tests. When that happens, the specimen is listed as probable.

“It takes about four and a half hours of lab work from the moment a sample is in hand to the completion of the H1/H3 test,” said Mark Pandori, chief microbiologist at the San Francisco Department of Public Health.

Next the sample is sent to the department’s state lab in Richmond. Once it arrives scientists perform a H1N1-specific PCR test. If the sample comes up positive, it’s declared a confirmed case of swine flu.

Mission Neighborhood Health Center has an office to screen for swine flu at the front of the clinic. If a patient appears to have flu-like symptoms, particularly high fever and respiratory infection, or has recently been to Mexico or had contact with someone who just came from Mexico, the doctor may opt to perform the test.

The clinic has screened many people, but only one person has been tested for swine flu. The results came back negative.

Care Practice at 508 14th St. also screens for swine flu. Like Dr. Ruiz, Dr. Tatiana Granik is not concerned about swine flu.

“We’ve received lots of calls, mostly people coming from or going to Mexico. We try to calm them down,” she said.

The single patient they’ve tested for swine flu also proved free of the virus.