OKLAHOMA CITY (AP) A woman who began showing flu-like symptoms after a trip to Mexico has become the first person in Oklahoma to have a confirmed case of swine flu, state health officials said Tuesday.

The woman, who lives in Pontotoc County in southeast Oklahoma, did not require hospitalization and has recovered, State Epidemiologist Dr. Kristy Bradley said.

The woman stayed home from work while ill, and it is thought that she did not transmit the disease to others in the community, Bradley said. She began showing symptoms on April 25 after a trip to Puerto Vallarta. She was given antiviral treatment.

"This announcement should not cause any interruption in the day-to-day activity of Oklahomans," Bradley said. "There is no reason for anybody to have an unnecessary anxiety level."

She said the experience with swine flu in the United States is that it has been no more severe than seasonal flu.

Oklahoma joins 38 other states with cases of swine flu confirmed through the Centers for Disease Control and Prevention. More than 400 cases have been reported nationally, and one death, a toddler from Mexico who died in Texas.

Oklahoma doctors are routinely sending in samples from patients with flu-like symptoms, and several of those have been sent on to the Centers for Disease Control and Prevention for further testing.

Bradley said four other probable positive samples for swine flu from Oklahoma have also been sent to the CDC, and state health officials are awaiting confirmation.

She declined to release further details about the woman.

State health officials have been predicting Oklahoma would join the many other states in which swine flu cases have been confirmed, and have been urging residents to wash hands frequently and stay home from work or school if sick.

"The confirmation of a case in the state means citizens should be cautious, but not fearful," Gov. Brad Henry said in a statement. "It simply means that Oklahomans should continue to take commonsense measures to avoid getting the virus, and to see a doctor if they experience flu-like symptoms."