Outbreak in Mexico, U.S. tied to new swine flu
Source of unique virus a mystery; CDC expects more cases
Video
Swine flu reported in Calif., Texas
April 23: Federal health officials are reporting seven cases of a strange new kind of swine flu found in California and Texas. Chief Science Correspondent Robert Bazell reports.
WHO calls emergency meeting on swine flu
White House closely following U.S. swine flu outbreak
Swine flu not as serious as SARS: Ontario
WHO concerned over 800 Mexican flu cases
msnbc.com news services
updated 4 minutes ago
The unique strain of swine flu found in seven people in California and Texas has been connected to the deadly flu that has broken out in Mexico, killing as many as 60 people, NBC News has confirmed.
The strain has never been seen before and is raising fears of a possible pandemic across North America.
The World Health Organization said it was concerned at what it called hundreds of "influenza-like" cases in Mexico, and also about the confirmed outbreak of the new strain of swine flu in the United States.
The agency said Friday that 12 of the samples from Mexico had a genetic structure identical to the virus found in the U.S.
"It is a virus that mutated from pigs and then at some point was transmitted to humans," Mexico's Health Minister Jose Angel Cordova told the Televisa network.
He said 44 additional suspected cases were still being tested. Mexico's Public Health Department put the total number of people sickened at around 943 nationwide.
Cordova said in Mexico the virus has killed only people among the normally less-vulnerable young and mid-adult age range. One possibility is that the most vulnerable segments of the population — infants and the aged — had been vaccinated against other strains, and that those vaccines may be providing some protection.
Mexico canceled classes for millions of children in its sprawling capital city and surrounding area on Friday.
The White House is closely following the outbreak and President Barack Obama has been informed, an administration official said on Friday.
U.S. health officials said they expect to find more cases of the swine flu as they check people who had contact with the California and Texas patients. All of the seven U.S. victims recovered from the flu.
The swine flu's symptoms are like those of the regular flu, mostly involving fever, cough and sore throat, though some of the seven also experienced vomiting and diarrhea.
"We are very, very concerned," WHO spokesman Thomas Abraham said. "We have what appears to be a novel virus and it has spread from human to human." If international spread is confirmed, that meets WHO's criteria for raising the pandemic alert level, he added.
Growing mystery
The U.S. cases are a growing medical mystery because it's unclear how they caught the virus. The Centers for Disease Control and Prevention said none of the seven people were in contact with pigs, which is how people usually catch swine flu. And only a few were in contact with each other.
Dr. Anne Schuchat, director of the CDC's National Center for Immunization and Respiratory Diseases, said they believe it can spread human-to-human, which is unusual for a swine flu virus.
Still, health officials said it's not a cause for public alarm. Worldwide, seasonal flu kills between 250,000 and 500,000 people in an average year. Plus, testing indicates some mainstream antiviral medications seem to work against the new swine virus.
CDC officials detected a virus with a unique combination of gene segments that have not been seen in people or pigs before. The bug contains human virus, avian virus from North America and pig viruses from North America, Europe and Asia.
Health officials have seen mixes of bird, pig and human virus before, but never such an intercontinental combination with more than one pig virus in the mix.
Scientists keep a close eye on flu viruses that emerge from pigs. The animals are considered particularly susceptible to both avian and human viruses and a likely place where the kind of genetic reassortment can take place that might lead to a new form of pandemic flu, said Dr. John Treanor, an infectious disease specialist at the University of Rochester Medical Center.
The virus may be something completely new, or it may have been around for a while but was only detected now because of improved lab testing and disease surveillance, CDC officials said.
The virus was first detected in two children in southern California — a 10-year-old boy in San Diego County and a 9-year-old girl in neighboring Imperial County.
The cases were detected under unusual circumstances. One was seen at a Navy clinic that participates in a specialized disease detection network, and the other was caught through a specialized surveillance system set up in border communities, CDC officials said.
On Thursday, investigators said they had discovered five more cases. That includes a father and his teenage daughter in San Diego County, a 41-year-old woman in Imperial County who was the only person hospitalized, and two 16-year-old boys who are friends and live in Guadalupe County, Texas, near San Antonio.
Puzzling cases
The Texas cases are especially puzzling. One of the California cases — the 10-year-old boy — traveled to Texas early this month, but that was to Dallas, about 270 miles northeast of San Antonio. He did not travel to the San Antonio area, Schuchat said.
The two 16-year-olds had not traveled recently, Texas health officials said.
CLICK FOR RELATED CONTENT
7 swine flu cases found in U.S.
Resistance to flu drug widespread in U.S.
New drugs needed to fight flu pandemic
CDC are not calling it an outbreak, a term that suggests ongoing illnesses. It's not known if anyone is getting sick from the virus right now, CDC officials said.
It's also not known if the seasonal flu vaccine that Americans got last fall and early this year protects against this type of virus. People should wash their hands and take other customary precautions, CDC officials said.
The Mexican government warned people not to shake hands or kiss when greeting or share food, glasses or cutlery for fear of contracting the flu.
Mexico City, one of the world's biggest cities and home to some 20 million people, was quieter than usual on Friday morning. Normally choking traffic was less chaotic in the absence of school buses and parents driving kids to school.
Many people waiting to enter subway stations had their faces covered with surgical masks.
http://www.msnbc.msn.com/id/30386163/
