A medical locum service as a site for sentinel influenza surveillance.

Surveillance of influenza in the countries of the European Union includes a sentinel network of general practitioners reporting cases of influenza-like illness (ILI), the collection of specimens for virological testing, and laboratory reporting of influenza diagnoses. In Victoria, Australia we have a similar sentinel surveillance system, with ILI defined by fever, cough and fatigue, and influenza seasons described by thresholds. The coordination of sentinel general practices can, however, be time consuming and expensive. For the last two influenza seasons we have used a deputising medical locum service as a sentinel site for influenza surveillance. We are not aware of such a service being used as a sentinel site elsewhere in the world. In both retrospective and prospective comparisons, we have shown that ILI surveillance patterns from sentinel general practices are very similar to those from the locum service. Because of its timeliness, flexibility, patient mix and geographic spread, locum service surveillance is able to supplement sentinel ILI surveillance and may also have a role in the recognition of emerging disease patterns. This is likely to be true not only in Australia but also in countries of the European Union.