Dec. 14--After peaking in October, the number of swine flu cases in Los Angeles County has plummeted, and school health officials hope Christmas break will nearly halt the spread of the disease.
The number of weekly confirmed flu cases at nine sentinel labs throughout the county peaked at 550 in late October, according to statistics from the county's Department of Public Health.
By the first week of December -- the most recent data available -- doctors confirmed only about 80 cases at the sentinel labs .
So far, the disease has been linked to 46 deaths in Los Angeles County and to 10,000 nationwide. Many of the dead were children and young adults, according to U.S. Centers for Disease Control data.
An estimated 50 million people -- one sixth of the U.S. population -- have contracted the disease, according to the CDC.
Among school children, the spread of the disease is certainly slowing, said Cathy Bray, chief school nurse for the Los Angeles County Office of Education.
"Absenteeism is down," she said. "Our data kind of runs with the data in the county. What we're really hoping now with winter break coming, we're hoping it will drop off even more."
And the number of flu cases in children ages 4 to 15 is down to normal levels for this time of year, said Dr. Elizabeth Bancroft, epidemiologist for the Los Angeles Department County Public Health.
Experts said it's possible the disease is on the wane, but they cautioned that flu outbreaks in the past have nearly disappeared only to return months later and killed millions of people.
The 1918 Spanish flu outbreak -- which killed 50 million people -- first struck in the spring, lost steam, and then came back strong in the fall, according to Dr. Paul Holtom, hospital epidemiologist at Los Angeles County-USC Medical center.
And a flu outbreak in 1957 also came in waves, experts said.
"We really don't know what's going to happen," said Holtom.
Because the H1N1 strain is new, experts have very little data for comparison, Holtom said.
It's also difficult for researches to pin down why the infection rate is declining. While hand washing and public awareness might slow the disease, no one is sure how much of a difference it makes, Holtom said.
Once a flu becomes widespread, there's no way to contain it, he said.
"With all of our modern technology, we can't stop it," Holtom said.
"These influenza outbreaks tend to ebb and flow," he said.
As the numbers decline here, nationwide studies are revealing more about the disease.
While it seems to be slightly less deadly than the normal flu, it's killing children and young adults.
The swine flu seems more deadly to obese people and American Indians. And infections tend to go deeper into the lungs than a normal flu, according to some studies.
The disease also gives people diarrhea more than the normal flu, Holtom said.
There's a possibility the swine flu could get nastier.
It has genetic information from pigs, birds and humans, and it's possible it could mix with other strains of influenza and form a new, more potent disease, Holtom said.
"They certainly can mutate and exchange information," Holtom said.
Meanwhile, experts are still waiting for seasonal flu to strike. Last year it didn't come until January, Bancroft said.
In addition, the strong respiratory syncytial virus, RSV, is going around. It's dangerous to infants, toddlers and people with bad lungs.
"All of this activity so far predates normal flu season," Bancroft said.
ben.baeder@sgvn.com
(626) 962-8811, Ext. 2230
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