Lessons learned across all Australian and New Zealand Intensive Care Units (ICUs) from the impact of the H1N1 2009 influenza (swine flu) virus have been published in the New England Journal of Medicine. This is the first comprehensive study to reveal the impact of the virus on the health of the general public. It was carried out over the peak three months of the 2009 pandemic, and showed 722 patients were admitted to 109 Australian and New Zealand ICUs, (96 patients in New Zealand) and at its peak up to 20% of ICU beds were occupied by swine flu patients. The study was co-coordinated by the Monash University-based Australian and New Zealand Intensive Care Research Centre. Dr Colin McArthur, from the Department of Critical Care Medicine at Auckland City Hospital said the impact on ICUs was dramatic, “The surge of patients with H1N1 influenza placed substantial strain on staff and resources. The most severely affected patients had pneumonia affecting both lungs that was caused by the virus.” Study leader Clinical Associate Professor Steve Webb from the Intensive Care Unit at Royal Perth Hospital said, “Unlike previous ‘seasonal’ influenza strains, which impact heavily on elderly people and people with severe coexisting medical conditions, the H1N1 virus affected a different profile. Critical illness due to swine flu was commonest in infants and middle-aged people; with pregnant patients, the obese, and Pacific Island, Maori and Aboriginal patients being particularly affected.” About one in three patients admitted to an ICU with swine flu had no underlying health problem.