The global spread of (highly pathogenic) H5N1 in birds is considered a significant pandemic threat. While prior H5N1 strains have been known, they were significantly different from the 2006 strain of H5N1 on a genetic level, making the global spread of this new strain unprecedented. The 2006 strain of H5N1 is a fast-mutating, highly pathogenic avian influenza virus (HPAI) found in multiple bird species. It is both epizootic (an epidemic in non-humans) and panzootic (a disease affecting animals of many species especially over a wide area). Unless otherwise indicated, "H5N1" in this article refers to the highly pathogenic 2006 strain of H5N1. In the first two months of 2006 H5N1 spread to Africa and Europe in wild bird populations possibly signaling the beginning of H5N1 being endemic in wild migratory bird populations on multiple continents for decades, permanently changing the way poultry are farmed. In addition, the spread of highly pathogenic H5N1 to wild birds, birds in zoos and even sometimes to mammals (example: pet cats) raises many unanswered questions concerning best practices for threat mitigation, trying to balance reducing risks of human and nonhuman deaths from the current nonpandemic strain with reducing possible pandemic deaths by limiting its chances of mutating into a pandemic strain. By April 2006, scientists had concluded that containment had failed due to the role of wild birds in transmitting the virus and were now emphasizing far more comprehensive risk mitigation and management measures. In June 2006 the World Health Organization predicted an upsurge in human deaths due to H5N1 during late 2006 or early 2007. In July and August 2006, significantly increased numbers of bird deaths due to H5N1 were recorded in Cambodia, China, Laos, Nigeria, and Thailand while continuing unabated a rate unparalleled in Indonesia. In September, Egypt and Sudan joined the list of nations seeing a resurgence of bird deaths due to H5N1; followed by Vietnam and South Korea in December. In 2006, the World Organization for Animal Health started requiring reporting H5 and H7 avian influenza fearing pathogenic mutants. The USDA started tracking wild birds, backyard flocks, commercial flocks and live bird markets.

January

January 5, 2006 January 7, 2006 January 8, 2006 January 10, 2006 January 16, 2006 January 18, 2006 January 21, 2006 January 29, 2006 January 30, 2006

February

February 4, 2006 February 6, 2006 February 7, 2006 February 8, 2006 February 9, 2006 February 10, 2006 February 11, 2006 February 12, 2006 February 13, 2006 February 14, 2006 February 15, 2006 February 17, 2006 February 18, 2006 February 19, 2006 February 20, 2006 February 21, 2006 February 23, 2006 February 25, 2006 February 27, 2006 February 28, 2006

March

March 1, 2006 March 2, 2006 March 3, 2006 March 4, 2006 March 5, 2006 March 6, 2006 March 8, 2006 March 9, 2006 March 10, 2006 March 12, 2006 March 14, 2006 March 15, 2006 March 16, 2006 March 17, 2006 March 18, 2006 March 19, 2006 March 20, 2006 March 21, 2006 March 24, 2006 March 26, 2006 March 29, 2006 March 30, 2006 March 31, 2006

April

April 3, 2006 April 4, 2006 April 5, 2006 April 6, 2006 April 10, 2006 April 11, 2006 April 12, 2006 April 18, 2006

May

May 5, 2006 May 11, 2006 May 13, 2006 May 15, 2006 May 16, 2006 May 21, 2006 May 24, 2006 May 25, 2006 May 30, 2006

June

June 2, 2006 June 17, 2006 June 23, 2006 June 30, 2006

July

July 5, 2006 July 7, 2006 July 22, 2006 July 26, 2006 July 28, 2006

August

August 5, 2006 August 10, 2006 August 12, 2006 August 18, 2006 August 25, 2006

September

September 7, 2006 September 13, 2006 September 25, 2006 September 27, 2006

October

October 4, 2006 October 11, 2006 October 16, 2006 October 31, 2006

November

November 2, 2006 November 13, 2006

December

December 12, 2006 December 18, 2006 December 19, 2006 December 24, 2006