Figure 1: An example of the equipment that may be used to take a nasopharyngeal aspirate (NPA) in a patient with suspected avian H5N1 influenza. Note the large suction tube (on the patient's right) designed to remove any infectious aerosols generated by the procedure in order to protect the healthcare worker (wearing full personal protective equipment, PPE) taking the sample (on the patient's left). (Photograph used here, by the courtesy of the Infection Control Team, Prince of Wales Hospital)