Extrapolating the real number of H1N1 cases in the US

[hongkonger]

Re: Extrapolating the real number of H1N1 cases in the US

Thanks for the welcomes!

I should clarify the assumptions I'm making. I'm actually thinking that 25,000 might be the figure from 15 or 16 days ago, if the figure is now 400,000 and the doubling rate is 3 or 4 days. If the number now is 200,000 and the doubling rate is 5 days, the result is the same. Of course if the doubling rate is 5-6 days and the current number is 800,000-1,000,000, the situation is better than I suggested (higher denominator, lower fatality rate).

Also, one reason I think that the current number may be around 400,000 is that Hong Kong has identified 2 or 3 people with flu flying in from the U.S. or Canada every day recently, out of about 10,000 visitors a day from the U.S. or Canada. If they are catching only one out of five people sick with flu, that would indicate that around 1/1000 people from the U.S. or Canada have flu. However, people with flu or people whose family have flu are less likely than average to fly to Hong Kong. But on the other hand, people who fly to Hong Kong are more likely than average to be from California or New York, places hit relatively hard by flu. So, I just estimate on the basis of all these vague figures, that 1/1000 of Americans have flu, or about 300,000. Since the trend is rising rapidly, I use 400,000 for my calculations. It's not very precise, I admit, but I find it unlikely that the Hong Kong authorities have missed many more than 5 times as many cases as they have caught, since there hasn't been any identified in-country transmission in Hong Kong yet.

 

[gsgs]

Re: Extrapolating the real number of H1N1 cases in the US

thanks a lot for your estimate.

I hope, that pflu in the other threat will also give an estimate


the polling institutes should ask 1000 randomly selected New Yorkers,
whether they had ILI in the last 2 weeks



when Olsen and Schuchat don't give their actual estimates then we must stick to those from
hongkonger,gsgs and pflu and ...


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I wrote earlier by looking at the CDC updates:

estimating the number of new Mexflu infected people in USA
by comparing with seasonal flu:

week 16:13403
week 17:71090
week 18:85781
week 19:255067
week 20:522359

assuming 30M cases of seasonal flu and all are in weeks 40-20
assuming cases are proportional to positive samples per week
assuming seasonal flu and M**flu don't disturb each other

 

[Whatabout]

Re: Extrapolating the real number of H1N1 cases in the US

I've wondered about the CDC's count for the past few weeks. I know they are at least 2 days behind on Illinois counts. Its not just the CDC that is behind the curve on the actual numbers, WHO also is not giving us an actual accounting. I'm sure they have a "real" model of the amount of victims somewhere with real extrapolation as we move forward. We?ve seen that in too many movies not to be so (laughing).

Because it is apparently a mild bug, why scare people. The weak economy couldn't handle the majority of its population staying home from work. Such a thing may set the whole world back into the dark ages.

As long as there aren't people keeling over dying in the streets, they figure we can get through this without all the alarms. Besides that I believe they are hoping that exposure now will better prepare us for a mutated more virulent H1N1 in the near or far flung future. Containment proved impossible, therefore, I hope they are right.

 

[Possibilities]

Re: Extrapolating the real number of H1N1 cases in the US

Now they're claiming 200,000 in the US.


http://www.heraldnet.com/article/20090607/NEWS01/706079828&news01ad=1

Snohomish County readies for fall swine flu

By Sharon Salyer
Herald Writer

With the number of people in the U.S. sickened by swine flu now estimated at 200,000, plans are now under way in Snohomish County to respond to a potential "second wave" outbreak this fall.

Step one of the plan doesn't involve swine flu, however, but the more typical seasonal flu, said Dr. Gary Goldbaum, health officer for the Snohomish Health District.

The public health agency is talking with clinics, pharmacies, hospitals and other groups that provide annual flu shots, or could provide them, so that they're ready for the expected increase in public demand for that shot in the fall.

"We want to make it really easy to do the right thing, which, to my mind, is to get the vaccine," Goldbaum said.

By talking now, the groups may be able to come up with new and more convenient ways to provide the shot to children and adults, he said.

These preparations also could be used if federal officials decide to go ahead with developing a swine flu vaccine, he said.

Although swine flu is not getting the near-nonstop attention it received when the first handful of cases were discovered in the U.S. in April, it has spread widely across the U.S.

More than 13,000 people have become ill and 770 people have been hospitalized, according to Dr. Anne Schuchat, interim deputy director at the Centers for Disease Control in Atlanta.

Nationally, 28 people have died, including two people in Washington, a 39-year-old man from Snohomish and a woman in her 20s from Pierce County.

Cases have now been reported in all 50 states, including 577 in Washington.

Even though more than 13,000 people are known to have been infected nationally, that represents only a fraction of those who have become ill, Schuchat said. "Really, we think the disease is much more common than that."

In fact, an estimated 200,000 people could have been sickened by swine flu nationally, said Joe Quimby, a spokesman for the federal health agency.

So far, about 7.8 percent of patients with known cases of swine flu have been hospitalized, Schuchat said.

In recent weeks, public health officials have abandoned trying to count every swine flu case. Now, they're focusing on testing those who were most at risk of having serious health complications from it, such as people 18 and younger.

They're also tracking both the number and the ages of those who are hospitalized.

One thing that distinguishes swine flu from its more common seasonal flu cousin is that it is hitting young people far harder than seniors.

Sixty percent of all swine flu cases and 42 percent of people hospitalized due to the virus are between the ages of 5 and 24, Schuchat said.

Dr. Anthony Marfin, a state Department of Health epidemiologist, said he doesn't think swine flu will be going away anytime soon.

"From what we're seeing right now, we have no reason to believe it will disappear before fall," he said.

Most of the current cases of influenza are swine flu, he said.

And although swine flu seems to be declining in some areas of the country, federal health officials say it's still circulating widely in Alaska, Idaho, Oregon and Washington.

"What is surprising is there is still as much of it around in the middle of the summer," said Dr. Yuan Po-Tu, who tracks influenza issues at The Everett Clinic.

State, federal and international health officials are watching how the virus spreads in the Southern Hemisphere, which is now entering its influenza season. They want to see if the virus changes -- for example, if it makes people sicker or if spreads more readily.

Meanwhile, health officials in Washington also will continue to closely monitor the virus, watching for signs of outbreaks at camps and other student summer gatherings, said James Apa, a spokesman for Public Health -- Seattle and King County.

"We're not out of the woods by any means," he said.

The federal government's decision on whether to approve production of a swine flu vaccine will be key in developing public health planning for swine flu response in the fall, Apa said.

Even if a vaccine is produced, it may be in limited supply, and health officials would have to decide how to ration it.

The priority list would likely include children, who have been shown to spread the virus to others at high rates.

Unlike the seasonal flu vaccine, anyone who gets the swine flu shot will probably have to get it in two doses.

"The first one is like a priming dose and then you follow up with the second dose," Marfin said.

Tu, The Everett Clinic physician, said it's anybody's guess on how swine flu will act in the fall.

"My educated guess is we'll see a large number of cases and it probably will come in waves," he said.

Goldbaum said he is surprised to hear critics say that the medical community "got all worked up" with the first brush with swine flu and that "it was just Chicken Little."

Since swine flu is a never-before-seen combination of influenza viruses, "we couldn't assume that anything new would be mild," he said.

Public health agencies must begin preparing now in case swine flu erupts again this fall, he said.

"It's like watching a car coming down the highway in your lane and assuming that it will return to the right lane," Goldbaum said. "I'm not confident I can predict that."

Reporter Sharon Salyer: 425-339-3486, salyer@heraldnet.com.

 

[Farmer]

Re: Extrapolating the real number of H1N1 cases in the US

Thanks for posting Possibilities.

I am impressed by how much the reporter, Ms. Salyer, got right.

IMO it is rare for reporters to include so many relevant points in a story about the H1N1 epidemic - a challenging and multidimensional topic.