WHO Issues H1N1 Pandemic Alert Recombinomics Commentary

April 26, 2011
Since the beginning of 2011, in the region of the Americas, there have been significant outbreaks of influenza A (H1N1) 2009 that, while
geographically limited, have generated a significant demand on health
services.

There have been outbreaks in Ecuador (January 2011), Mexico and
Venezuela (March 2011). In the past 3 weeks, the Dominican Republic's
National Influenza Centre has detected an increase in the positive
samples of influenza A(H1N1) 2009. In the last month, other sporadic
detections have occurred in Cuba, Colombia, Honduras, Jamaica and El
Salvador.

It is recommended that all of the countries activate their National Preparedness Plans for the pandemic and follow the WHO and
PAHO recommendations.

The above comments come from the April 20 alert issued by the WHO Pan America Health Organization, which recommends activation of Pandemic Preparedness Plans due to the “significant demand on health services" in marked contrast to announcements two weeks ago claim no such demands.

This alert follows the rapid spread of H1N1 in Mexico and Venezuela. Sequences from Mexico have been released which have a high frequency of D225N, raising concerns that the number of severe and fatal cases will be higher than previous outbreaks.

Moreover, the precursor to this Chihuahua sub-clade was identified in Air Force dependents who had been vaccinated with California/07/2009 raising serious concerns regarding the effectiveness of this vaccine against the Chihuahua sub-clade, which has a new glycosylation site, S165N, as well as receptor binding domain changes, A189T, D225N, and D225G.

Anecdotal reports indicate this sub-clade is rapidly spreading in North and South America, including the countries listed in the alert and may also be responosble for the high level of pneumonia and influenza deaths in El Paso.

Release of sequences from sever and fatal cases in the countries listed above would be useful