H7N9 Causes CDC Activation of Emergency Operations Center

Recombinomics Commentary 03:00
April 10, 2013

The US Centers for Disease Control and Prevention (CDC) activated its Emergency Operations Center (EOC) in Atlanta yesterday to support the response to the H7N9 influenza outbreak in China, CDC officials said in an e-mailed statement today.

The EOC was activated at level 2, the second of three levels. Level 1, the highest, signals an agency-wide response.

The above activation of the CDC EOC is not a surprise.  Although WHO and the CDC have claimed there was no human to human (H2H) transmission of H7N9, the first confirmed case represented by A/Shanghai/1/2013 was part of a familial cluster (both sons had severe pneumonia and one, 55M, died) as well as a geographic cluster (the second confirmed case, A/Shanghai/2/2013, lived in the same area,Minghang District, and was treated at the same hospital, Fifth Peoples Hospital).  Media reports cited a significantly larger cluster.

Moreover, the birds at live markets in the area (see map) were H7N9 positive and also had a key receptor binding domain change, Q226Lraising the possibility that the birds were infected by humans.

The key change, however, was the presence of PB2 E617K in all three human sequences, and absence in all three avian sequences.  

Moreover, the case fatality rate is at 90%, although many mild cases have not been tested.

Therefore, the activation was expected.