An unusual form of swine flu has been detected in seven people in the last few days, but government health experts say there is no cause for alarm or undue concern.

The new flu has symptoms very much like conventional influenza, and all seven victims have recovered fully, Dr. Anne Schuchat of the Centers for Disease Control and Prevention said Thursday in a telephone news conference. It is susceptible to at least two antiviral agents, she said.

“We don’t think this is a time for major concern around the country,” she added.

It is not clear whether the virus is new or whether it has been around for a while and has simply been recognized now because of more intensive laboratory testing and disease surveillance, she said. It contains segments of human virus, avian virus from North America (not the infamous bird flu) and pig viruses from three continents.


The CDC announced this week that the virus had been found in a 10-year-old boy in San Diego County and a 9-year-old girl in Imperial County. Schuchat said researchers had now identified it in a father and his teenage daughter in San Diego County; a 41-year-old woman in Imperial County; and two 16-year-old boys in Guadalupe County, Texas, near San Antonio.

Only the Imperial County woman was hospitalized.

Authorities could find no evidence of contact between the victims in Texas and California.

None of the seven had any exposure to pigs, which is the normal way of catching swine flu. Officials thus think the virus is passed from person to person, which is unusual, but not unheard of, for swine flu.


Dr. Jonathan Fielding, Los Angeles County health officer, said no cases had been observed yet in the county, possibly partly because the symptoms are virtually indistinguishable from conventional influenza. “But now that we have these cases, we are significantly increasing our surveillance . . . and I wouldn’t be surprised if we had some cases here also,” he said.

The United States has had two previous outbreaks of swine flu, one in 1976 and one in 1988. In both, the virus was passed from person to person, but the outbreaks were limited in scope.

“Swine influenza has emerged and spread from person to person, but nothing has come of it,” Schuchat said. “It spontaneously disappeared twice without causing any problems.”

The U.S. also has a low background rate of swine flu infections, typically about one case every year or so.


From December 2005 to January of this year, however, CDC identified 12 cases. In all but one, the victims were found to have had contact with pigs.

Although CDC officials say they are not overly concerned about the new virus, they are actively monitoring the situation. “Any time there is a new influenza virus that can be spread from person to person, public health officials get concerned,” Schuchat said.

She emphasized that there was absolutely no risk of contracting the virus from eating pork products. She also said that the influenza vaccine would probably provide no protection against the swine flu virus.

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thomas.maugh@latimes.com