RT Journal Article SR Electronic T1 H1N1 influenza – A second wave? The experience from a large teaching hospital in the UK JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP p4342 VO 38 IS Suppl 55 A1 Dhruv Parekh A1 Judith Brebner A1 Chirag Dave YR 2011 UL http://erj.ersjournals.com/content/38/Suppl_55/p4342.abstract AB Introduction: The new H1N1 influenza (pH1N1) virus largely ran its course by August 2010 as the WHO declared the pandemic to be over, fortunately without causing as much devastation as provisionally predicted. However the impact of the outbreak on our healthcare system was considerable. In the post -pandemic period, although the rates of pH1N1 have been reported to be lower the risk of severe illness caused by pH1N1 remains. This epidemiological study reflects our experience in a large teaching hospital of the significant morbidity and mortality associated with admission to hospital with H1N1 infection during the recent flu season.Methods: We retrospectively analysed the electronic records for all patients admitted with H1N1 infection between 1st November 2010 and 31st January 2011 to identify patient demographics, length of stay, co-morbidity and outcome.Results: 280 patients were identified (mean age 39.5) with an average length of stay of 6.35 days; mortality 4%. A third had no co-morbidities. Overall 37 (13.2%) of patients required respiratory support (18 intubated, 19 NIV/CPAP). This is comparable to the pandemic of 2009 when 10–30% of laboratory confirmed hospitalised patients required critical care. 11 patients died (mean age 55; time to death 8.3 days) of those 18% had no previous medical history; the rest had co-morbidities respiratory 45%, cardiovascular 18%, haematological malignancy 9%, obesity 9% and pregnancy 9%.Conclusions: Although the virus seems to be taking on the behaviour of the seasonal flu our data suggests the threat of H1N1 continues and has a predilection for severe rapid disease in the young, healthy and same high risk groups as previously identified.