overview The revised Regulations define an emergency as an"extraordinary event that could spread internationally or might require a coordinated international response. Events that may constitute a public health emergency of intemational concern are assessed by State Parties using a decision instrument and, if particular criteria are met, WHO must be notified. Mandatory notification is called for in a single case of a disease that could threaten global public health security: human influenza caused by a new virus ubtype, poliomyelitis caused by a wild-type poliovirus, SARS and smallpox. The broad definitions of"public health emergency of international concern"and disease"allow for the inclusion in IHR (2005)of threats beyond infectious diseases, including those caused by the accidental or intentional release of pathogens, or chemi cal or radionuclear materials. This extends the scope of the Regulations to protect global public health security in a comprehensive way The IHR (2005) redirect the focus from an almost exclusive concentration on mea- sures at airports and seaports aimed at blocking the importation of cases, as required in IHR (1969), towards a rapid response at the source of an outbreak. They introduce a set of "core capacity requirements"that all countries must meet in order to detect, assess notify and report the events covered by IHR(2005)and aim to strengthen collaboration on a global scale by seeking to improve capacity and demonstrate to countries that compliance is in their best interests. Thus, compliance has three compelling incentives to reduce the disruptive consequences of an outbreak, to speed its containment, and to maintain good standing in the eyes of the international community A revolutionary departure from previous international conventions and regulations is the fact that IHR(2005)explicitly acknowledges that non-state sources of informa- tion about outbreaks will often pre-empt official notifications. This includes situations where countries may be reluctant to reveal an event in their territories. WHO is now authorized through IHR (2005 )to take into account information sources other than official notifications. WHO will always seek official verification of such information from the country involved before taking any action based on the information received his reflects a new reality in a world of instant communications: the concealment of disease outbreaks is no longer a viable option for governments.The revised Regulations define an emergency as an “extraordinary event” that could spread internationally or might require a coordinated international response. Events that may constitute a public health emergency of international concern are assessed by State Parties using a decision instrument and, if particular criteria are met, WHO must be notified. Mandatory notification is called for in a single case of a disease that could threaten global public health security: human influenza caused by a new virus subtype, poliomyelitis caused by a wild-type poliovirus, SARS and smallpox. The broad definitions of “public health emergency of international concern” and “disease” allow for the inclusion in IHR (2005) of threats beyond infectious diseases, including those caused by the accidental or intentional release of pathogens, or chemi￾cal or radionuclear materials. This extends the scope of the Regulations to protect global public health security in a comprehensive way. The IHR (2005) redirect the focus from an almost exclusive concentration on mea￾sures at airports and seaports aimed at blocking the importation of cases, as required in IHR (1969), towards a rapid response at the source of an outbreak. They introduce a set of “core capacity requirements” that all countries must meet in order to detect, assess, notify and report the events covered by IHR (2005) and aim to strengthen collaboration on a global scale by seeking to improve capacity and demonstrate to countries that compliance is in their best interests. Thus, compliance has three compelling incentives: to reduce the disruptive consequences of an outbreak, to speed its containment, and to maintain good standing in the eyes of the international community. A revolutionary departure from previous international conventions and regulations is the fact that IHR (2005) explicitly acknowledges that non-state sources of informa￾tion about outbreaks will often pre-empt official notifications. This includes situations where countries may be reluctant to reveal an event in their territories. WHO is now authorized through IHR (2005) to take into account information sources other than official notifications. WHO will always seek official verification of such information from the country involved before taking any action based on the information received. This reflects a new reality in a world of instant communications: the concealment of disease outbreaks is no longer a viable option for governments. overview xv