Texas health officials on Sunday were asking hospitals and doctors to take samples from flu patients so they could aggressively survey for a new strain of swine flu that has killed dozens of people in Mexico and sparked fears of a global pandemic.
Dallas County health officials said Sunday three possible cases of swine flu are under investigation. Health officials said the patients are not related to each other, nor are they linked to a California boy who visited Dallas and was diagnosed with swine flu last week.
The 10-year-old boy from San Diego came to Dallas for a visit two weeks ago, but recovered before returning to California.
It will likely take several days to determine if the three cases are swine flu, health officials said. The patients are 3 months, 7 years and 24 years old.
Gov. Rick Perry has also asked the Centers for Disease Control for close to 40,000 courses of antiviral medicine in case more cases surface in Texas.
Two cases have been confirmed near San Antonio, and Texas health officials are awaiting lab results on a third person.
State health department spokeswoman Emily Palmer said Sunday that officials are aggressively seeking other cases and expect to find more.
The illnesses have caused concern because of the outbreak in Mexico, where health officials say a strain of swine flu has killed up to 86 people and sickened more than 1,000.
Dr. Sandra Guerra, the health official leading the Texas investigation, asked residents of Guadalupe County to avoid public gatherings and to stay home if they or a family member are ill.
Palmer said the state was asking hospitals and doctors to do preliminary onsite tests to determine if patients with flu-like symptoms have the virus and to forward the samples of flu patients to a state lab. From there, any samples of unidentifiable flu viruses will be sent to the CDC, she said.
Because of the aggressive survey, officials expect more cases to be identified in Texas. Typically, mild cases of the flu might otherwise go unnoticed.
"We expect we probably will find more cases because we are into actively looking for cases," Palmer said.
Palmer said neither of the two confirmed Texas cases -- two high school students in Cibolo -- had traveled to Mexico or had contact with people who did, according to them and their families.
The World Health Organization chief said Saturday that the strain has "pandemic potential," and it might be too late to contain a sudden outbreak.
Doctors say people should seek medical attention if they come down with flu symptoms. Public health officials along the border were carefully monitoring reports and asking health care providers to take respiratory samples from patients who appear to have the flu.
Swine flu is a respiratory disease of pigs caused by type A flu viruses, the CDC's Web site says. Human cases are uncommon but can occur in people who are around pigs. It also can be spread from person to person. Symptoms include a high fever, body aches, coughing, sore throat and respiratory congestion.
Health officials are concerned because people appear to have no immunity to the virus, a combination of bird, swine and human influenzas. The virus also presents itself like other swine flus, but none of the U.S. cases appear to involve direct contact with pigs, a Kansas health official said.