Sunday, May 03, 2009

Even On Sundays

 


# 3122

 

 

Dr. Anne Schuchat, M.D., Interim Deputy Director for Science and Public Health Program and Dr. Nancy Cox, who is director of CDC's influenza division held another tele-briefing for the media today, and after issuing a short statement answered a number of reporter’s questions.

 

As the CDC likes to remind us, this is a rapidly evolving situation, and there are gaps in their knowledge and lag times involved in getting, analyzing, and distributing information.   

 

Today’s (and yesterday’s) press briefings should eventually be added to the CDC’s  H1N1 Flu (Swine Flu) Press Briefings page.

 

The new numbers for today indicate 226 confirmed cases in the United States – in 30 states – with 1 confirmed fatality.    We are also told that – out of those 226 cases30 are hospitalizedsome in serious condition.

 

Of course, the real numbers are almost certainly quite a bit higher.   There is a huge backlog of testing, and the CDC is no longer recommending that everyone who gets sick with flu-like symptoms be tested for the virus.

 

There are just too many `suspect’ cases. 

 

Dr.  Schuchat stated that the virus was `widespread’ and in `virtually every community’ by now.   There are probable or confirmed cases in `nearly every state’.

 

 

Dr Schuchat said, “In most of the country, this virus is there" and that we should, “Expect numbers to jump quite a bit in the coming days.

 

 

The median age of those confirmed with the virus is a relatively young 17, with most of the cases under 21.   Very few cases have been confirmed in people over the age of 50.

 

 

It is unknown whether this indicates some pre-existing immunity in those born before 1957, or simply that the number of confirmed cases doesn’t really represent the spectrum of ages affected.

 

 

The subject of concerns over reassortment in pigs was addressed by Dr. Cox.  

 


She prefaced her remarks by stating, “We are concerned about this virus as it is.   This is a new virus, is transmitting Human to human, and can cause severe illness.”

 

Dr. Cox called reassortment a common & complex process.

 

  • Influenza viruses have segmented genomes. Genes essentially in 8 different pieces.

  • If a host (and that can be human, bird, pig, or other)  is infected by 2 viruses, the 2 viruses can swap genes, and the virus that emerges is a hybrid of the two.

  • What happens with pigs is that pigs can get swine, human, and avian influenza viruses.  Which makes them wonderful mixing vessels.

  • Now that we've had transmission to pigs, if pigs are infected with this virus and other viruses, there could be additional reassortments. 

  • Likewise if a human is infected with seasonal flu and the new flu, we could get a hybrid.

 

She stated that worries over additional reassortments is `always a concern  . . .  but this new strain as it is now is a major concern.’

 

While Dr. Schuchat said the CDC was seeing some encouraging signs and is monitoring reports out of Mexico, it remained cautious. 

 

It is too soon to know how this will play out.