Wednesday, February 24, 2010

WHO Statement On Pandemic Status

 

 

# 4376

 

 

Trying to second guess the course of a pandemic, particularly when our understanding of how the influenza virus works is (to put it kindly) incomplete, is a quick way to get egg on your face.  

 

While levels of novel H1N1 influenza in North America and Europe have declined dramatically over the past couple of months, and it looks like the pandemic of 2009 may have run its course, we’ve been fooled before.

 

image

NEJM 2009

 

The 1957 pandemic, for example, appeared to have run out of steam by the spring the following year - but roared back to life two years later, and then again 3 years after that.

Influenza is often full of surprises.

 

So one can understand why the WHO (World Health Organization) isn’t particularly anxious to declare the pandemic of 2009 as being over.  

 

With rising levels of immunity in the developed world (from exposure and/or vaccination), it would be a bit surprising to see another major wave of illness in North America or Europe.   

 

Surprising, but not impossible.

 

And many parts of the world have no access to vaccine, and immunity levels remain relatively low. 

 

There also remains the possibility that the virus will pick up antigenic changes that would allow it to evade existing immunity – something that could spark a new round of illness.

 

So one can understand the reluctance of scientists to declare that this pandemic has peaked.

 

Although the WHO telegraphed their intentions not to roll back the pandemic phase last night, this morning they’ve released an official statement.     

 

They will revisit the issue again in a few weeks.

 

 

24 February 2010

Director-General statement following the seventh meeting of the Emergency Committee

The Emergency Committee held its seventh meeting by teleconference on 23 February 2010. The Director-General sought the Committee's views on the determination of the pandemic status.

 

A detailed update was provided to the Committee on the global pandemic situation. After asking additional questions and reviewing the evidence and holding extensive discussion, the Committee was of the view that there was mixed evidence showing declining or low pandemic activity in many countries, but new community level transmission activity in West Africa. Moreover, they expressed concern that the winter months of the Southern Hemisphere had not yet started and there was uncertainty whether additional generalized waves of activity might occur and the need to not undermine preparations. The Committee advised that it was premature to conclude that all parts of the world have experienced peak transmission of the H1N1 pandemic influenza and that additional time and information was needed to provide expert advice on the status of the pandemic. The Committee accordingly suggested that the Committee be re-convened in a few weeks to review intervening developments and related epidemiological information.

 

Having considered these views, the current epidemiological evidence and other relevant information, the Director-General determined that there had been no change in the pandemic phase, and decided to continue to monitor the situation and developments closely and to convene the Committee again within the next several weeks.

 

The WHO Director-General asked the Committee for their views on continuance of the three current temporary IHR recommendations issued for the public health emergency of international concern. The consensus view of the Committee was in favor of continuation but to update the second recommendation by replacing "Intensify" with "Maintain" in recognition of the increased pandemic surveillance already implemented by countries and the need to maintain this activity. Having considered the views of the Emergency Committee, and the ongoing pandemic situation, the Director-General determined to continue the three temporary recommendations, as modified, namely:

  • countries should not close borders or restrict international traffic and trade;
  • maintain surveillance of unusual flu-like illness & severe pneumonia;
  • if ill, it is prudent to delay travel.