The following is an excerpt from the May 15 briefing by Dr. Dan Jernigan.

“The H1N1 virus continues to circulate in the United States and people continue to be ill and to be hospitalized. Today we had our fourth death reported from Maricopa county in Arizona. There are 22 U.S. states that are reporting widespread or regional influenza activity, which is something that we would not expect at this time. There are, again, more deaths and hospitalizations that we’re monitoring. There is increased amount of flu-like illness in New York City, in schools and in Houston in schools as a result of many children becoming sick with influenza-like illness that we presume will be the H1N1 virus. There are at least, in terms of our case counts, over 4,700 probable and confirmed cases in the United States.

That number is one that we’re continuing to follow. We will continue to get those numbers from the states that report to us, but the numbers are becoming less important as we move through the increasing numbers of cases. And so we are monitoring the influenza through other surveillance systems that the CDC and state health departments maintain. What we’re seeing is there is geographic variation in H1N1 flu activity, and that is the activity appears to be highest in the Pacific Northwest and in southwest and in other areas of the country. So we expect, just as with seasonal flu, that the flu will appear in different places. It will come, it will go, so we’re trying to monitor that. But overall, we’re seeing increased activity.

There are four known fatalities, like I mentioned. There are 173 hospitalizations that have been reported to CDC so far. Most of the cases that we have, again, remain among younger people in the ages of 5 to 24 years old. But unlike seasonal flu, we’re still seeing relatively few cases in older individuals, and that may be just a matter of time until the virus is capable of getting to those populations, or maybe that it is a reflection of a different that this particular virus has in the populations that are affected.

The estimates of the number of confirmed and probable cases in the United States are probably not the best indicator of transmission at this point because of the effect of testing, that is early on, a lot of tests were done but now the amount of testing is more targeted. And so they likely are underestimates of the actual number of people infected. And so we do know that in some places there are reporting thousands of suspect cases, and so as we know more, especially as we know more from the field teams that are doing household surveys and so forth, we will be able to have better estimates of the numbers of cases that we estimate are actually caused by influenza, the outpatient kind of illness.

There has been some discussion about the virus mutating. We’re working very closely with W.H.O., with other countries and academics and other collaborating centers around the globe to look at these viruses, to look at the gene sequences in them. And so far, we’re not seeing significant evidence of any mutation towards more virulence in the U.S. However, we’re continuing to look at these things, trying to see whether or not there are different kinds of illness that is caused by them. But at this point, nothing that we are able to say about any change that has occurred in the virus.

At this point, we’re not seeing the seriousness of illness that was initially reported in Mexico in the United States, but this certainly does not mean that the outbreak is over. The H1N1 virus is not going away. We know that the outbreak is not localized but is spreading and appears to be expanding throughout the United States.

Later on in the interview he was asked about how many ill are there…his reply…”if we had to make an estimate, I would say that the amount of activity we’re seeing with our influenza-like illness network is probably upwards of maybe 100,000, but that’s something we will have a much better estimate of once we get the information back from the field teams that are collecting that data.”

We are a long way from being done with this so don’t relax now…get ready.