[Human influenza--recent outbreak of avian influenza A/H5N1 among human in Asian countries--].

Since late 2003, avian influenza A/H5N1 virus has infected 100 adults and children in Vietnam, Thailand, Cambodia resulting in 54 deaths (54.0%). The avian H5N1 is becoming more infectious for people and capable of human-to-human transmission. Experts have warned that the widespread occurrence of the H5N1 could ignite a pandemic capable of killing millions of people around the world. However, calculating with any precision the risk or when it will strike is impossible, and yet the consequences of failing to respond to this uncertain threat could be dire. At this stage, time-series epidemiological and virological analysis on the shift of avian to human influenza viruses are quite important for control of the H5N1 outbreak and the pandemic.