The first survey was conducted from January 2009 to March 2009. The WHO influenza pandemic alert level assigned to H5N1 during that period was phase 3. Phase 3 signifies an animal or human-animal influenza reassortant virus that has caused sporadic cases or small clusters of disease in people but has not resulted in human to human transmission sufficient to sustain community level outbreaks. Limited human to human transmission may occur under some circumstances, such as when there is close contact between an infected person and an unprotected carer. However, limited transmission under such restricted circumstances does not indicate that the virus has gained the level of transmissibility among humans necessary to cause a pandemic.