11 June 2009

Phase 6 Declared by WHO for Novel Influenza A (H1N1) Based on International Sprea= d at the Community Level

This afternoon, Dr. Margaret Chan, the Director-General of the World Health Organization (WHO) declared = the novel influenza A (H1N1) to have triggered a pandemic (“Phase 6”= ; in the 6 phase WHO classification system) based solely on community-level person-to-person transmission in at least two WHO regions.

WHO reported that as of tod= ay 74 nations have reported a total of 28, 774 cases, and 144 deaths. In addition to the well-known outbreaks in North America, Chile has reported 1,694 cases (2 deaths),= Australia 1,307 cases (0 deaths), the UK 822 = cases (0 deaths), and Japan 518 cases (0 deaths).&n= bsp; Notably, on the continent of Africa only Egypt has reported confirmed cases (10, with 0 deaths), most of whom are American students in Cairo<= /st1:City>.

Dr. Chan emphasized that we= are witnessing and monitoring in real-time the longitudinal unfolding of an influenza pandemic, and noted that its “moderate” severity could change over time, including in less-developed nations:

“Globally, we have go= od reason to believe that this pandemic, at least in its early days, will be of moderate severity. As we know from experience, severity can vary, depending= on many factors, from one country to another”…Finally, and perhaps= of greatest concern, we do not know how this virus will behave under conditions typically found in the developing world. To date, the vast majority of cases have been detected and investigated in comparatively well-off countriesR= 21;.

Dr. Chan also already advis= ed anticipation and preparation for a second pandemic wave:<= /p>

“Countries should pre= pare to see cases, or the further spread of cases, in the near future. Countries where outbreaks appear to have peaked should prepare for a second wave of infection”.

In addition, the WHO posted= on their H1N1 influenza website http://www.who.int/csr/disease/swinefl= u/frequently_asked_questions/levels_pandemic_alert/en/index.html a document that was titled “What is Pha= se 6?”

This document explicitly addressed the recurring issue of the “severity” assessment of t= his virus and the pandemic it has started:

&= #8220;What about severity?

At this time, WHO considers= the overall severity of the influenza pandemic to be modera= te. This assessment is based on scientific evidence available to WHO, as well as input from its Member States on the pandemic's impact on their health systems, and their social and economic functioning.

The moderate assessment reflects that:

= &nbs= p; Most people recover = from infection without the need for hospitalization or medical care.<= /span>

= &nbs= p; Overall, national le= vels of severe illness from influenza A (H1N1) appear similar to levels seen dur= ing local seasonal influenza periods, although high levels of disease have occu= rred in some local areas and institutions.

= &nbs= p; Overall, hospitals a= nd health care systems in most countries have been able to cope with the numbe= rs of people seeking care, although some facilities and systems have been stre= ssed in some localities.

WHO is concerned about curr= ent patterns of serious cases and deaths that are occurring primarily among you= ng persons, including the previously healthy and those with pre-existing medic= al conditions or pregnancy.

Large outbreaks of disease = have not yet been reported in many countries, and the full clinical spectrum of disease is not yet known”.

No mention was made = by WHO today, however, of whether persons who recovered f= rom infection with this virus were immune to re-infection with this same virus,= a concept discussed in this space several times since 2006.

Daniel R. Lucey, MD, MPH

EROne Institutes, Department of Emergency Medicine

Washington<= /st1:PlaceName> Hospital Center

Adjunct Professor of Microbiology and Immunology=

Georgetown University Medical Center, Washington, D.C.

Website for this posting: www.BePast.org