Thursday, August 09, 2012

Today’s CDC H3N2v Briefing



Credit Wikipedia


# 6486


The CDC held a press briefing earlier this afternoon to address the recent increase in H3N2v cases detected across Indiana, Ohio, and today . . . Illinois.  Dr. Joseph Bresee, of the CDC’s Influenza Division, gave a short statement and then took reporter’s questions.


The transcript will be posted on the CDC’s media site (HERE) later today.  But for now, a few highlights.


As has been widely reported, the number of confirmed H3N2v cases over the past week in the Midwest have increased sharply, from 16 reported last Friday to 145 reported today.



The lone case in Utah occurred in March, and is not part of this current outbreak.

These numbers are likely to increase over the coming days, as more cases get tested.  Individual states are now doing their own lab confirmation, and releasing results, and so the CDC’s numbers will only be updated once a week (Fridays).


While a five-fold increase in cases may look alarming, the CDC believes most of these cases come as the result of direct contact with pigs, not from human-to-human transmission.

While they concede that some `limited’ human-to-human transmission may have occurred in this outbreak, the vast majority of cases so far have had some sort of direct contact with pigs, or their environment.


As Dr. Bresee emphasized, “This is not a pandemic situation”.


All of the recent cases are genetically similar, meaning they are all swine H3N2 with the M (matrix) gene from the 2009 H1N1 virus.


It is thought that this M gene may help increase transmissibility of swine viruses among humans, but that this virus has not adapted sufficiently well to humans to be easily spread.


This virus remains sensitive to antivirals (oseltamivir and Zanamivir).

At this time, the CDC does not see the need to ask fairs to cancel or restrict the showing of pigs. Instead they are advising those who are in contact with pigs follow these recommendations:


  • Wash your hands frequently with soap and running water before and after exposure to animals.
  • Never eat, drink or put things in your mouth in animal areas.
  • Children younger than 5 years, people 65 years and older, pregnant women, and people with certain chronic medical conditions (like asthma, diabetes, heart disease, weakened immune systems, and neurological or neurodevelopmental conditions) are at high risk from serious complications if they get influenza. These people should consider avoiding exposure to pigs and swine barns this summer, especially if sick pigs have been identified.
  • If you have animals – including swine – watch them for signs of illness and call a veterinarian if you suspect they might be sick.
  • Avoid close contact with animals that look or act ill, when possible, and
  • Avoid contact with pigs if you are experiencing flu-like symptoms.



While there is obviously a lot of concern in the press and among the public, the bottom line is that unless and until this virus adapts sufficiently to spread easily among humans – it doesn’t represent a major public health threat.


The hallmark of influenza viruses, of course, is that they are constantly changing.  What we can say was true about a virus yesterday, may not hold true tomorrow.


And so public health officials will watch this emerging flu strain carefully for any signs that the situation is changing. 


Regardless of how this swine virus plays out, the CDC’s advice to practice good `flu hygiene’ (hand washing, covering coughs & sneezes, staying home if sick) - and to get the flu shot each fall - remain your best strategies against the multiple strains of influenza that circulate each year.