PAHO/WHO Offer Advice on Pandemic Plans

The Pan American Health Organization and the World Health Organization (PAHO/WHO) are providing their Member States and other United Nations agencies with advice on measures to prepare for and respond to a potential influenza pandemic.

WHO has issued several key documents dealing with pandemic preparedness. They include the WHO Global Influenza Preparedness Plan, the WHO Checklist for Influenza Pandemic Preparedness Planning, and the WHO Health and Medical Services Contingency Plan for an Influenza Pandemic, which is being provided to United Nations agencies. Based on that document, PAHO is developing an internal contingency plan that outlines measures the organization would take at headquarters and in its country offices in the event of an influenza pandemic.

PAHO has urged its member countries to undertake pandemic planning and has provided them with the WHO materials (which are available on the WHO website.) PAHO is currently translating WHO's pandemic planning materials into Spanish for distribution and for posting on this website.

As part of its ongoing technical cooperation, PAHO's Communicable Diseases unit has been holding workshops to train country experts in the areas of influenza epidemiology and surveillance. The most recent workshop was held in Atlanta, Georgia, in May and was cosponsored by the U.S. Centers for Disease Control and Prevention (CDC).

"There was significant interest in pandemic preparedness," says Otavio Oliva, PAHO's top expert on influenza. "There is a great deal of concern about a potential pandemic in the countries."

The new WHO Global Influenza Preparedness Plan, released in April, is an updated version of a 1999 document. WHO decided to update the original plan in response to recent developments surrounding the H5N1 avian influenza virus, including endemic animal infection in several Southeast Asian countries and continuing human cases, better understanding of the evolution of flu viruses, new techniques for diagnosis and vaccine development, improved antivirals, and the ongoing revisions of the International Health Regulations.

The new plan lays out six pandemic phases and appropriate public health responses for each one (see box at right). According to the plan, the world is currently in a Pandemic Alert Period – Phase 3, and countries should already have detailed pandemic preparedness plans in place.

The new WHO plan defines additional phases (beyond those defined in the 1999 document) during which coordinated international public health actions could be taken to gain time for developing vaccines and implementing preparedness measures planned in advance.

"Success will depend on several factors, including surveillance to provide global early warning of human infections with new influenza subtypes," notes the document.

The plan also emphasizes the importance of intersectoral planning and involving partners outside the health sector, such as agriculture, transport, trade, labor, defense, education, and the judicial branches of government, as well as partners in industry and nongovernmental organizations.

WHO Pandemic Phases and Planning Goals

NEW PHASES

OVERARCHING PUBLIC HEALTH GOALS

Interpandemic period

Phase 1. No new influenza virus subtypes have been detected in humans. An influenza virus subtype that has caused infection may be present in animals. If present in animals, the risk of human infection or disease is considered to be low.

Phase 2. No new influenza virus subtypes have been detected in humans. However, a circulating animal influenza virus subtype poses a substantial risk of human disease.

Strengthen influenza pandemic preparedness at the global, regional, national, and subnational levels.

Minimize the risk of transmission to humans; detect and report such transmission rapidly if it occurs.

Pandemic alert period

Phase 3. Human infection(s) with a new subtype, but no human-to-human spread, or at most rare instances of spread to a close contact.

Ensure rapid characterization of the new virus subtype and early detection, notification, and response to additional cases.

Phase 4. Small cluster(s) with limited human-to-human transmission but spread is highly localized, suggesting that the virus is not well adapted to humans.

Phase 5. Larger cluster(s) but human-tohuman spread still localized, suggesting that the virus is becoming increasingly better adapted to humans, but may not yet be fully transmissible (substantial pandemic risk).

Pandemic period

Phase 6. Pandemic: increased and sustained transmission in the general population.

Contain the new virus within limited foci or delay spread to gain time to implement preparedness measures, including vaccine development.

Maximize efforts to contain or delay spread, to possibly avert a pandemic and to gain time to implement pandemic response measures.

Minimize the impact of the pandemic.

WHO provides an array of information on avian influenza and pandemic preparedness at their website.

	The Pan American Health Organization Promoting Health in the Americas