GRAND CANYON, Ariz. - Though it's been relatively mild, public health officials are urging a cautious view of the H1N1 flu outbreak.
"We're watching it but it doesn't even reach the level of our normal flu season," said National Park Service Public Health Consultant Matt Walburger, who led a public meeting here last week to discuss concerns and answer questions. "We should have concern. I like the phrase measured caution."
None of the information presented at the meeting on Tuesday, May 5, was new. Rather it was presented as a way to bring some perspective.
"One of the most difficult parts of any disease outbreak is to properly communicate the risk that exists at any point in time," he said. "It's a difficult thing to do because you don't want to overstate but you don't want to understate."
He noted that the 1918 flu epidemic is driving some of the concern. That was an avian flu that showed up in a mild form in the spring and came back stronger in the fall, eventually killing 40 million people worldwide.
"I think an experience like that causes the current concern when you have a flu that's new," Walburger said. "You don't really know what it's going to do until it does its thing."
In most cases, fatalities are linked to complicating factors. What concerned health officials about the 25 deaths in Mexico was how they seemed to occur in otherwise healthy people.
"We don't have a lot of information why that is, why there are some severe cases versus in the U.S. where all we've seen are mild cases," said Walburger. "There could very well be something else, those who die have other issues in complication with the flu."
As of last week, worldwide cases numbered a little over 1,100 in 21 countries, 286 in the United States.
Though referred to as swine flu, Walburger said this strain contains components of avian, swine and seasonal-type viruses. So far its effects have been mild and officials are treating it as they do the regular, seasonal flu. They urge traditional preventive behavior - frequent handwashing, disinfecting surfaces and door knobs more often as usual, keeping hands away from your face and avoiding close contact with people out in public.
"It's nothing glamorous," said Walburg. "There isn't much beyond that, that can be done at a local park or operations level."
In gauging the severity, Walburger said it's hard at this point to come up with numbers. Though in Mexico hey had 25 deaths out of 590 lab-confirmed cases, he said huge numbers could have been ill but not enough to see a doctor.
"The problem with the flu is that to get accurate numbers in real time is extremely difficult," he said. "If you have a mild case, you probably don't check into a hospital."
The 1918 outbreak had a 2.5 percent fatality rate. If this had a fatality rate of even half that, it could point to as many as quarter of a million unconfirmed cases. Walburger said health officials will only order lab tests for severe cases.
"The point is that you look at standard numbers for outbreak," he said. "Even compared to the most severe, cases would be in the many thousands, hundreds of thousands."
He said to prepare for the possibility that the virus could come back stronger in the fall, the government is boosting the national stockpile of anti-viral medication. Researchers are also working to create a vaccine for the H1N1 virus to be included in this year's flu shot with three other strains.
What's kept some of the most virulent avian flu out of the mainstream has been how poorly it passes from human to human. The seasonal flu is highly transmissible but not often deadly. Health officials are prepared for a virus that combines the strengths of both.