The United Kingdom (UK) Department of Health has provided a detailed and very useful update online of their "Interim Guidelines for Smallpox Response and Management in the Post-Eradication Era (Smallpox Plan)". The 59 page core document ranges from training and planning for smallpox, to management of initial cases and their contacts, to vaccination strategies, to communication with the media and the public. The document is found on the website of the UK Department of Health at www.dh.gov.uk by entering the search term "smallpox" on the homepage.

Appendix 1-17 follows with further specific guidelines including algorithmic flow diagrams on management of initial suspected cases when they occur: at home, in the Emergency Department, in the Intensive Care Unit, on the Medical, Surgical, or Infectious Disease wards or clinics, or at a Port Health Control Unit.

In the text of the plan, pages 44-47, there are six "Alert Levels" listed, and specific preparedness measures defined for each level. The levels are:

• Level 0: No credible threat of a smallpox release.
• Level 1: At least one case of smallpox outside the UK.
• Level 2: At least one case inside the UK.
• Level 3: A smallpox outbreak in the UK.
• Level 4: A large outbreak of smallpox not controlled by "ring vaccination"
• Level 5: Outbreak controlled and no further cases.

Guidelines for these UK "alert levels" are very helpful when considering and comparing with the four general smallpox "scenarios" described for the USA by the Institute of Medicine (IOM) of the National Academies Committee on Smallpox Vaccination Program Implementation in their letter # 5 to the US Centers for Disease Control (http://books.nap.edu/catalog/10875.html)

The UK smallpox containment strategy begins with the same measures as the USA and the WHO strategy recommendations including: isolation of cases, tracing-surveillance of contacts, quarantine of contacts and "ring vaccination" of cases and cases. In the UK plan, however, there is also an Alert Level 4 defined (page 46 of 59) as when a large outbreak occurs that is not controlled by the traditional and field-proven "ring vaccination" strategy. Such hypothetical "circumstances may arise when mass vaccination may be required to raise the level of immunity to smallpox such as when:

1. A large number of cases occur simultaneously all over the country
2. Uncontrolled spread resulting from larger or multiple deliberate release
3. Many secondary cases occurring without identifiable contact with a primary case, implying that contact tracing and enhanced surveillance for cases has been ineffective".