Waiver of informed consent was obtained from the Hospital Ethics Committee due to public health care concern for information of this disease. A cross-sectional retrospective review of CXR and CT of the thorax of 166 patients with influenza symptoms who tested positive for Influenza A(H1N1) at the University of Malaya Medical Centre was done from end July 2009 to early September 2009. The majority of these patients were walk-in patients to the Accident and Emergency Unit who presented with constitutional influenza-like symptoms of fever, myalgia and headache. Laboratory confirmation of pandemic influenza A(H1N1) was carried out using a real-time polymerase chain reaction (PCR) protocol and primers from the CDC [5] , and virus isolation in Madin-Darby canine kidney cells.