Each year since 2003 the number of human H5N1 cases have increased.
30 cases have already been confirmed in the first two months of 2006.
If this trend continues there will be much more cases in 2006 then
previously seen.
Case-specific mortality in confirmed cases have fluctuated, perhaps due to:

variation of medical support/assistance of availability and accessibility of the countries
experience dealing with this illness.
decrease in virulence

Vietnam had 100% (3/3) deaths in 2003 and 69% (20/29) deaths in 2004. In 2005 the largest number of confirmed cases (61) were identified in Vietnam with only 19 deaths (31%).