Laboratory-confirmed human cases of H5N1 avian influenza, January 2004 to present

Last updated March 9, 2005

Note: The cases reported below fall into two phases and are thus presented in two separate tables, with a cumulative table following. The first wave of cases occurred from early 2004 through late October 2004. After a 2-month lull, a new wave began occurring in late December 2004 and is ongoing.

The first table (mid-December 2004–present) shows both official World Health Organization (WHO) numbers and unofficial numbers compiled by CIDRAP staff that include the WHO cases plus cases reported as laboratory-confirmed by media sources we consider reliable (CIDRAP monitors numerous US and international news services, newspapers, and Web sites and includes cases only if they are reported by multiple sources). The second table (Jan 28–Oct 25, 2004) gives official WHO numbers reported at the end of the first wave.