Containment Zone WHO Strategy for Pandemic Flu Initial Emergence
The World Health Organization’s latest interim protocol for “rapid operations to contain the initial emergence of pandemic influenza” includes a “Containment Zone” and a surrounding “Buffer Zone” that have been detailed in a 20-page document on the WHO website (www.who.int).
The fundamental containment strategy is to rapidly identify the initial (“index”) cases forming a cluster of persons infected with a new pandemic flu virus while still limited to a localized geographical area and initiate routine control measures. Then, a “Containment Zone” will be drawn around this area with the index cluster of patients and both widespread antiviral drug prophylaxis and non-pharmaceutical interventions such as social distancing will be recommended.
The five (5) critical activities within the Containment Zone include (see page 12 of the WHO May 2007 document):
1. Extensive antiviral prophylaxis (20 days of antivirals would be given, not 10 days).
2. Perimeter control (“it is critical to discourage to the extent possible all non-essential movement of persons in and out of the Containment Zone” and to include “exit screening procedures”. page 13).
3. Multiple non-pharmaceutical measures (including “isolation of ill persons, voluntary quarantine of exposed persons, social distancing measures such as school closures and cancellation of mass gatherings, & other measures to minimize persons density (e.g. staggered work and market hours”. page 14).
4. Surveillance and laboratory testing
5. Detailed assessment of the novel virus
The three (3) primary activities in the “Buffer Zone” that will be drawn outside of the “containment zone” include (see page 14of 20):
1. Active and comprehensive surveillance with laboratory testing.
2. Isolation and treatment of suspect cases
3. Antiviral prophylaxis of contacts of suspect cases
Additional specific guidelines are provided in this 20-page document. At the same time, nine (9) annexes to this document “will be added shortly” (page 18) and will further help international planners anticipate and prepare better for the next human influenza pandemic.
Daniel R. Lucey, MD, MPH
Director, Center for Biological Counterterrorism & Emerging Diseases
EROne Institute Department of Emergency Medicine
Co-Director, M.S. Graduate Program in Biohazardous Threat Agents and Emerging Infectious Diseases
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