Headlines
As reported by the Danbury News-Times, April 27, 2009.
Swine Flu Virus Is a Mutation
By Robert Miller
People, pigs and poultry. Their living in close quarters can trigger epidemics that end up traveling around the globe.
The three, in combination, provide a fertile place for viruses to mutate. The 1918 flu epidemic -- the worst epidemic since the Black Plague -- may have come from such a combination.
That's apparently what's happening now with the swine flu outbreak that's spreading through North America to Europe, and possibly New Zealand.
The new swine flu apparently cropped up in Mexico, where poultry and pigs live in close proximity with their human keepers on small farms. DNA analysis shows it is a novel combination of viruses from birds, humans and pigs.
"We have not seen this,'' said Dr. Richard Garibaldi, epidemiologist at John Dempsey Hospital at the University of Connecticut School of Medicine in Farmington and a specialist in infectious diseases.
Garibaldi said many viruses start in birds. They can then move to pigs, and from pigs to humans.
Dr. Louise-Marie Dembry, associate professor of medicine at Yale School of Medicine in New Haven and director of the epidemiology laboratory at Yale-New Haven Hospital, said pigs are considered the chief viral mixing vessels.
"They get flu viruses from birds and from humans,'' she said.
Humans who work close to pigs or poultry are at risk of getting influenza viruses from them. Thanks to genetic mutations, the new swine flu can spread from human to human.
"Is it transmissible?" Garibaldi asked. "It appears it is.''
But it is not avian flu. There have been 400 cases of that disease worldwide. The mortality rate is high -- about 60 percent in humans -- but it does not appear to readily move to other humans.
Garibaldi said no one knows how deadly the swine flu will prove to be. It's killed about 150 people in Mexico as of Monday night, but no one knows how many cases of the disease there have been in Mexico. So far it is proving to be mostly a mild illness in the United States.
"There are too few cases right now to know,'' Garibaldi said of the American illnesses. "When we get 100 or 150, we'll have a better idea.''