Division Epidemiological criteria

At least one of the following three in the seven days before disease onset:

• a person who was a close contact to a confirmed case of novel influenza A(H1N1) virus infection while the case was ill

• a person who has travelled to an area where sustained human-to-human transmission of novel influenza A(H1N1) is documented

• a person working in a laboratory where samples of the novel influenza A(H1N1) virus are tested