The days are long and the years are short

Now, don't panic yet about the increased number of deaths. That doesn't always mean that the flu is more deadly. It can mean that hospitalized people finally died.

Confirmed cases (in the US) 17,855 and 45 deaths. That is a bigger % increase in deaths than in cases. Locations include New York, Massachusetts, Wisconsin (largest number of confirmed cases), Illinois, Washington (state), California and Texas. Substantial increases in deaths in New York.

Attempts to determine prevalence of non-tested cases in New York City resulted in an estimate of 6.9% of the population having a flu-like illness between May 1 and May 20.

H1N1 is still spreading in Canada and has begun to spread in Australia (and probably the U.K.).

MD is concerned about the probable return in the fall.

There are still new cases being reported in the US and Canada. Illinois has suddenly had 3 deaths. But the numbers of new cases are small compared to the numbers that have already been reported. The big increases in cases are occurring in the tropics (?) like Panama, and the Southern Hemisphere, especially Latin America.

I wonder about the seasonality of it. All flu is supposed to be seasonal, due to the way it reproduces. It can be spread 6 or more feet by a sneeze in cold, dry weather. Much less distance in warm humid weather. Hmmm.

CDC has gone to Mon-Wed-Fri reporting. They expect to go to weekly reporting soon. It makes sense. School will soon be out (those disease vectors with legs will soon be separated). The warmer average temperatures will result in less effective spread. There is a need to analyze smaller data sets to figure out risk of death/hospitalization and transmission rates in different environments.

I would have done one more daily update to clear the backlog from the three-day weekend, but maybe tomorrow will be the first time that they can actually clear that backlog. The state of Wisconsin (for example) has a much higher number on its public health webpage than CDC is reporting for it.

Rift Valley fever predicted by satellite. The transmission (from mosquitoes) is so weather-dependent that satellites can observe and protect people from the disease (if they follow the advice).

"Richard Knox: Yes, thank you.  I'm wondering why, if you have any information or hypotheses, that we would see so many more cases in Wisconsin and Illinois than in, you know, in California and New York, Arizona, and other places where you might expect it to be the hotspots?  Is there some factor there? 

Daniel Jernigan: That's right.  I think what we're seeing now, because we're looking very closely, is probably what happens each year with influenza in certain parts of the country have disease before other parts.  There may be certain factors or events where there are a number of people that are exposed, and so I believe what we're seeing now is a reflection of those factors and not necessarily a geographic or regional difference based on humidity or temperature or whatever.  "

Knox is a reporter and Jernigan is deputy director for influenza at CDC.
 

Illinois and Wisconsin are marked (on the CDC map) as having a regional outbreak of H1N1. The Illinois Department of Health reports 707 confirmed cases, of which 519 are in Chicago or Cook County (If you don't already know, Cook County takes in most of the close-in suburbs of Chicago). DuPage, Kane, Lake and Will have double-digits numbers of cases (and account for most of the far-out suburbs of Chicago). Actually, I'm not 100% sure of the location of Will county, but I think it appears on my maps near Kane county. ETA: Will is near the border with Indiana in the north, but not right along the lake. I would still guess that it is a commuter suburb of Chicago.

Wisconsin has large numbers of cases in Milwaukee, Waukesha, and Dane counties. Primarily, Milwaukee with 508 out of Wisconsin's total of 765.

However, when I drill down on CDC's site, IL and WI are reported as having "normal" incidences of flu-like illness for this time of year. I wonder if these cities are also "normal", or if the cities are being drowned out by the non-city areas.

ETA: Why is this interesting? If the disease is widespread in many or all areas of the USA this spring and it comes back in the fall, the USA will need a lot less of the vaccine to protect it. People with prior exposure will be dead-ends for this virus. Of course, the risk from continued transmission in the USA this spring is that there is NO vaccine to protect the at-risk populations and that recombination risk increases with every case. On the other hand, the load of seasonal flu is lower and decreasing as the weather turns summery.

Why are the numbers of H1N1 cases so high in Illinois (466) and Wisconsin (357)?

Weather stayed cool/cold longer?

More time spent indoors/ in groups?

More testing?

I am listening to the press conference about the school closing. One of the big issues is that the SATs were scheduled for this school on Saturday.
Another issue is that student privacy is being probed pretty hard, since the media would like to report the epidemiology to give an idea of the risk.

Dr. Weast just stood up and gave a strong, strong defense of student privacy. Good man. He compared it to some of the reactions in the early 80s to AIDS cases.

The medical officer explained the difference between suspect, probable and confirmed cases. She also mentioned that Atlanta is still the only place that MD can get probable cases turned into confirmed cases. The CDC was aiming to have test kits to the states on Friday, but MD doesn't have one yet and is assuming a delay at the CDC in confirming the accuracy of the test kits.

CDC is going to finish preparing for the seasonal flu, and develop the seed strain for the H1N1 strain. Then they will decide if they are going to ask for it to be made for the fall. They are, of course, hoping that transmission is stopped soon.