Flu Season Is Off to Slow Start, But for Va.
Monday, February 2, 2009
Virginia is the first state in the nation to report a widespread outbreak of the flu, and the federal Centers for Disease Control and Prevention says the chronic winter illness might spread rapidly after a relatively slow start this season.
"We could really get slammed in two weeks," Anthony Fiore, a CDC epidemiologist, responded when asked whether much of the nation might be spared this year. "Oh, no, it'll get here."
The weekly survey conducted by the CDC during flu season found localized outbreaks of the illness in Maryland and sporadic cases in the District, but Virginia was the only state so far where the flu was widespread.
"We can expect to see high incidence for the next six to eight weeks," said Laura Ann Nicolai, an epidemiologist for the Virginia Department of Health. "You can see the illness into March, April, even May."
Although the flu season generally begins with the onset of colder weather in October and November, in some years it peaks later. People who get sick during that period often mistake one of the scores of other winter viruses for the flu, whose symptoms include fever, aching muscles, headache, a dry cough, sore throat and lack of energy.
Although it doesn't keep track of the others as meticulously, the federal government carefully monitors influenza because severe strains can result in death. The 1918 worldwide flu epidemic killed an estimated 20 million to 40 million people, including 675,000 Americans.
Flu vaccination grew out of that pandemic, when desperate doctors discovered that blood transfusions from recovered flu patients to new patients had a positive effect. The first vaccines were approved for use by the military in the 1940s, and a decade later researchers developed the current production methods, which grow the virus in chicken embryos.
The illness presents itself in a mix of strains, some more powerful than others, so, as they formulate the vaccine each year, researchers make an educated guess as to which strains the vaccine should protect against.
"The years when we tend to have more illness tend to be the years when there's not a good match," said David Blythe, an epidemiologist with the Maryland Department of Health. "This year, there's a good match with the two A strains, and some of the B strains don't match quite as well."
The fact that the vaccine matches up well with this year's version of the flu is one explanation for the somewhat slow advance of the illness outside Virginia.
"It's out there, but no question, it's breaking late," said Susan Fay, coordinator of the communicable disease program in Fairfax County. "That's happened the last few seasons."
The fact that the District and Maryland are next door to Virginia doesn't necessarily mean that they will be next to cross the threshold into the "widespread" flu designation that every state in the nation achieved last year.