People wearing surgical masks enter the General Hospital in Mexico City on Friday. At least 16 people have died and more than 900 others fell ill from what health officials suspect is a strain of swine flu.
MEXICO CITY — A unique strain of swine flu is the suspected killer of dozens of people in Mexico, where authorities closed schools, museums, libraries and theaters in the capital on Friday to try to contain an outbreak that has spurred concerns of a global flu epidemic.
The worrisome new virus – which combines genetic material from pigs, birds and humans in a way researchers have not seen before – also sickened at least eight people in Texas and California, though there have been no deaths in the U.S.
“We are very, very concerned,” World Health Organization spokesman Thomas Abraham said. “We have what appears to be a novel virus and it has spread from human to human. . . . It’s all hands on deck at the moment.”
Pima County health officials said no cases have been reported here.
“We have sent a communication to our infection control practitioners at area hospitals asking them to be aware of patients that may arrive at their emergency departments presenting with the identified symptoms and recent travel history to the San Diego or Imperial counties of California, southern Texas to San Antonio, or central Mexico,” said Michelle McDonald, chief medical officer for the county Health Department.
The WHO was convening an expert panel to consider whether to raise the pandemic alert level or issue travel advisories.
There is no vaccine that specifically protects against swine flu, and it was unclear how much protection current human flu vaccines might offer. A “seed stock” genetically matched to the new swine flu virus has been created by the U.S. Centers for Disease Control, said Dr. Richard Besser, the agency’s acting director. If the government decides vaccine production is necessary, manufacturers would need that stock to get started.
Epidemiologists are particularly concerned because the only fatalities so far were in young people and adults. It’s possible that more vulnerable populations – infants and the aged – had been vaccinated against other strains, providing some protection.
The eight U.S. victims recovered from symptoms that were like those of the regular flu, mostly fever, cough and sore throat, though some also experienced vomiting and diarrhea.
U.S. health officials announced an outbreak notice to travelers, urging caution and frequent hand washing, but stopping short of telling Americans to avoid Mexico.
Scientists have long been concerned that a new flu virus could launch a worldwide pandemic of a killer disease. A new virus could evolve when different flu viruses infect a pig, a person or a bird, mingling their genetic material. The resulting hybrid could spread quickly because people would have no natural defenses against it.
Still, flu experts were concerned but not alarmed about the latest outbreak.