Mexican and US officials on Friday took emergency measures to contain outbreaks of a new multi-strain swine flu blamed for scores of deaths in Mexico and seven infections in the United States.
The World Health Organization in Geneva said 60 people had died from suspected swine flu in Mexico, while Mexican Health Minister Jose Angel Cordova confirmed 16 deaths and said authorities were probing 50 more possible fatalities.
Mexican officials warned people to avoid crowds or using the subway as they launched a massive vaccination campaign in the country’s sprawling, densely populated capital.
“The confirmed (deaths) from the virus are 16. They’re studying the cases of 50 more patients who died,” Cordova said on Milenio television.
Authorities were probing 943 possible infections.
“It’s a virus which mutated from pigs and transmitted to some humans,” Cordova said on Televisa television.
US medical authorities expressed strong concern as seven known cases were reported in the southern United States, and underlined that the virus included strains from different types of flu.
President Barack Obama was being fully briefed on an outbreak, said a White House spokesman.
The US cases included five in California and two in Texas, in three clusters, WHO spokeswoman Fadela Chaib told journalists in Geneva.
The WHO, which has identified swine influenza as a potential source of a human flu pandemic, activated its global epidemic operations center.
Mexican authorities closed schools in the capital and the center of the country and Mexico City launched a massive vaccination campaign for “all people who haven’t been vaccinated” against the usual winter flu, local Health Minister Armando Ahued said at a news conference.
“This new virus is susceptible to a specific antiviral, and the cases that are detected and determined as flu will be perfectly treated,” Ahued said.
The US Centers for Disease Control and Prevention (CDC) says on its website that there is no vaccine to specifically protect humans from swine flu, only to protect pigs.
“The seasonal influenza vaccine will likely help provide partial protection against swine H3N2, but not swine H1N1 viruses,” the website says.
It was yet unclear which strains had been identified in Mexico, but the European Centre for Disease Prevention and Control said the “novel” A/H1N1 influenza identified in at least two of the recent cases by US counterparts might have a risk of developing into a pandemic-type virus.
“It’s very obvious that we are very concerned. We’ve set up emergency operation centers,” CDC spokesman Dave Daigle told AFP.
Mexico’s Health Minister Cordova urged people to avoid large crowds, shaking hands, kissing people as a greeting, or using the subway.
Medical teams were on stand-by at the capital’s international airport, passengers with flu symptoms were advised not to fly, and all passengers had to fill out a health questionnaire, said Victor Mejia, a spokesman at the capital’s international airport.
There had been some 800 suspected cases with flu-like illness in Mexico, with 57 deaths in the Mexico City area, WHO spokeswoman Fadela Chaib said.
Twenty four suspected cases and three deaths were also recorded in San Luis Potosi in central Mexico, Chaib added.
Most of the Mexican cases were found in healthy young adults with no known record of prior illness.
The WHO said it was in constant contact with health authorities in the United States and in Mexico.
Human outbreaks of H1N1 swine influenza virus were recorded in the United States in 1976 and 1988, when two deaths were recorded, and in 1986. In 1988 a pregnant woman died after contact with sick pigs, according to the WHO.
In recent years the global focus for a pandemic has shifted to the H5N1 bird flu virus, which has spread from poultry to humans and killed 257 of the 421 people infected by the virus since 2003.
WHO experts have pointed out that pigs have been implicated in the emergence of new influenza viruses responsible for two of the previous century’s influenza pandemics.
If a pig is simultaneously infected with a human and an avian influenza virus, it can serve as a “mixing vessel” for the two viruses that could combine to create a new more virulent strain.