Pandemic A/H1N1/2009 influenza in a paediatric haematology and oncology unit: successful management of a sudden outbreak.

Viral respiratory infections are potentially life-threatening among children treated for cancer. We report a nosocomial outbreak of six cases of pandemic influenza A/H1N1/2009 on a paediatric haematology and oncology ward. Three patients developed pneumonia and two of them sustained haemodynamic collapse. The source was probably a relative of the first infected patient. The outbreak was probably spread by cross-infection between patients during communal activities. A few days' delay in identifying the outbreak promoted spread of the influenza. Infection control measures included the use of oral oseltamivir treatment for all hospitalised patients, isolation of the infected patients, strict personal protective controls and a restriction on visitors. No new cases occurred after implementation of these containment measures. At the time when the outbreak was identified, all the patients were already isolated for other reasons. We conclude that A/H1N1/2009 influenza may spread rapidly and cause severe infection in paediatric cancer patients but can be efficiently contained. Identification of isolated or clustered cases should lead to the rapid implementation of appropriate infection control measures.