International Health Regulations and Influenza A | CDC EID

Volume 15, Number 8–August 2009
Perspective
Use of Revised International Health Regulations during Influenza A (H1N1) Epidemic, 2009
Rebecca Katz
Author affiliation: The George Washington University, Washington DC, USA

Suggested citation for this article

Abstract
Strong international health agreements and good planning created a structure and common procedure for nations involved in detection and evaluation of the emergence of influenza A (H1N1). This report describes a timeline of events that led to the determination of the epidemic as a public health emergency of international concern, following the agreed-upon procedures of the International Health Regulations. These events illustrate the need for sound international health agreements and should be a call to action for all nations to implement these agreements to the best of their abilities.

In March 2009, human cases of infection with a novel strain of influenza A virus (H1N1) emerged in Mexico, the United States, and Canada. As of May 26, this contagious virus has spread to 46 countries, accounting for ≈13,000 cases. To date, >90 deaths caused by this virus have occurred, most of which have been in Mexico (1). Suspected cases are even more widespread, and the number of cases will inevitably continue to increase and the virus will spread to more countries in the coming weeks and months.

Predicting the course of the epidemic is difficult, but one can state with certainty that good multilateral plans and agreements facilitated the initial notification of the disease. Good planning has also enabled communication and action around the emerging epidemic in a manner that has been rational, predictable, and productive. These plans, which only came into being in the past 5 years, enabled an unprecedented level of timely cooperation and communication for assessing and responding to the novel influenza A virus (H1N1).

Some have argued that the initial detection of the outbreaks was delayed (2), and others have opined that the international disease surveillance and reporting system is severely crippled by a lack of resources (3). Although these debates will no doubt continue, it is crucial to document how, starting with initial notification by Mexico, the systems for communication and disease mitigation worked essentially as they were designed.

Planning
The International Health Regulations (2005)
A major international agreement, a regional agreement, and a multitude of pandemic plans put into place since 2005 have set the stage for the events of the past few weeks. In response to the threat of emerging infectious diseases, and pushed into action by the events related to the emergence of severe acute respiratory syndrome (SARS), the World Health Assembly agreed to accept the revised International Health Regulations in May 2005. These regulations, known as IHR (2005), are binding to all member states of the World Health Organization (WHO) and include several major provisions aimed at facilitating global communication and cooperation for early detection and containment of events termed public health emergencies of international concern (PHEIC). Although many international efforts in health have been disease specific, IHR (2005) focuses on the larger issues of ensuring competent surveillance and detection systems in every part of the world and a global commitment to work together to mitigate the consequences of a public health emergency.

Included in the regulations are provisions that member states are required to 1) establish a National IHR Focal Point for communication with WHO, 2) meet core capacity requirements for disease surveillance, 3) inform WHO in a timely fashion of any incident that might be considered a PHEIC, and 4) respond to additional requests for information by WHO (4). The revised regulations broadened the type of events that needed to be evaluated and reported to WHO to include a list of always notifiable diseases and an algorithm for determining a potential public health emergency, regardless of source or origin (5). In addition, the regulations clearly articulate that the purpose is to "prevent, protect against, control and provide a public health response to the international spread of disease" in a manner that "avoids unnecessary interference with international traffic and trade" (6).

The IHR (2005) were implemented in the summer of 2007. Two nations submitted reservations; the United States cited federalism concerns, and India clarified how it would regard regions infected with yellow fever (7). By the terms of the regulations, all member states should currently have in place a National IHR Focal Point for communication, should complete assessments of their disease surveillance capacity by the summer of 2009, and should develop and maintain their core surveillance and response capacities by the summer of 2012.

Security and Prosperity Partnership of North America
In March 2005, the United States, Canada, and Mexico launched a trilateral agreement called the Security and Prosperity Partnership of North America (SPP). The purpose of this agreement was to enhance regional cooperation and information sharing around business competitiveness, energy, emergency management, securing of borders, and health (8). The health focus within SPP was to enhance public health cross-border coordination in infectious disease surveillance, prevention, and control. In particular, leaders of the 3 nations agreed to a set of principles that would guide collaboration in the detection and response to avian and pandemic influenza. These principles led to the formulation of the North American Plan for Avian and Pandemic Influenza (NAPAPI). This plan stresses the need for communication between nations and coordination in responding to the threat of a novel strain of influenza; it also lays out a set of actions for each nation relative to emergency coordination and communications, avian influenza, pandemic influenza, border monitoring and control measures, and critical infrastructure protection (9). A senior level coordinating body was established to facilitate planning and preparedness as well as to serve as a contact in the event of a human outbreak caused by a novel strain of influenza (10).

Pandemic Plans
Spurred by fears of avian influenza (H5N1), the United States embarked on an aggressive policy to put into place a series of plans at the federal, state, and local levels. These pandemic plans address continuity of operations, social distancing strategies, vaccine and antiviral production and distribution, hospital surge capacity, and special considerations for vulnerable populations. In addition to plans, there were accompanying implementation schedules for implementing necessary infrastructure in place to ensure the plans would be useful should a pandemic emerge (11,12).

WHO has had a pandemic planning and guidance document available since 1999. In 2005, WHO revised the document in response to the threat of avian influenza. This document was revised and rereleased in April 2009, in part to reflect advances in global pandemic planning, the IHR (2005) entry into force, and scientific advances in the development and stockpiling of countermeasures (13).

Events and IHR (2005)
I have outlined a series of events, beginning with the reporting by Mexico of an outbreak of acute respiratory illness. This event and subsequent events were linked with the corresponding article or provision in the IHR (2005), the SPP NAPAPI, or the WHO Pandemic Influenza Preparedness and Response guidance document. The events were organized according to the major goals of the IHR (2005): improving notification procedures, identifying public health emergencies of international concern, facilitating ongoing global communication during an emergency, and mitigating the consequences of the event through a coordinated response. In addition, the determination of pandemic phases as part of the IHR (2005) procedures, yet specific to this particular type of public health emergency, is discussed.

Notification
On March 18, 2009, surveillance systems in Mexico alerted authorities to an unusual number of cases of influenza-like illness (2,14). After a few days of discussion starting on April 11 between the Pan American Health Organization (PAHO) and Mexican authorities regarding unusual numbers of acute respiratory infections, the authorities notified PAHO according to recommendations in IHR Focal Points of a potential PHEIC. The event was an outbreak of acute respiratory illness in the states of Veracruz and Oaxaca, Mexico (15,16).

On April 18, the United States, through the National IHR Focal Point, notified PAHO of 2 cases of human influenza A (H1N1) in children in San Diego County and Imperial County, California. The United States assessed that these cases could be a potential PHEIC (17).

The initial notification by Mexico and the United States of a potential PHEIC within their borders aligns with the following articles of the IHR (2005):

• IHR (2005) Article 4 (Responsible Authorities). Each state is responsible for designating a National IHR Focal Point for 24 × 7 × 365 communication with WHO, including for dissemination of information from WHO to relevant sectors of the state. These National IHR Focal Points were used to officially communicate the potential PHEICs to the regional WHO office (PAHO).

• IHR (2005) Annex 2 (Decision Instrument). The decision instrument in Annex 2 helps nations determine which events should be reported to the WHO as potential PHEICs. Mexico and the United States presumably used this decision instrument to determine if the events constituted a potential PHEIC.

• IHR (2005) Article 6 (Notification). State Parties shall notify WHO (through their WHO Regional Office–PAHO in this case) by way of the National IHR Focal Point of all events that may constitute a PHEIC. This notification must occur within 24 hours of assessment of the public health information by the national authority. After a notification, the State Party and WHO shall continue to communicate in a timely fashion about the notified event.

abrir aquí para acceder al documento CDC completo (muy extenso):
International Health Regulations and Influenza A | CDC EID