In outbreaks with potential international implications

All travel-associated (TALD) and all community-acquired outbreaks should be considered as having potential international implications, i.e. involving cases of Legionnaires' disease in other countries. For TALD, an established procedure for sharing information within ELDSNet exists (see http://ecdc.europa.eu/en/activities/surveillance/ELDSNet/Pages/Index.aspx). For community-acquired outbreaks, past experience has shown that additional cases with matching outbreak strains can be found in international travellers living in other countries. Sharing information on community outbreaks allows for active case finding and cases identified are to be considered outliers with potential interesting information for source identification. EPIS ELDSNet allows for sharing information on community-acquired outbreaks with the network of relevant public health authorities.

Information sharing and collaboration:

• Consider using EPIS - for sharing information on risk assessment and outbreak investigation.
• Consider issuing a EWRS [1] message to Member States focussing on risk management and the control measures taken in the country of origin and other countries.
• IHR [WHO, 2005, http] are designed to provide security against the international spread of infectious diseases. Although Legionellosis is not incorporated into the lists of diseases in the IHR (WHO, 2005), any disease event that meets the criteria described in the Regulations (serious public health impact, unexpected, likely to spread internationally or likely to result in travel or trade restrictions) must be notified to WHO following the inception of the IHR (2005) in June 2007.
• Consider publishing a preliminary report (e.g. Eurosurveillance)

Further considerations:

• Consider performing an analytical study
• Investigations might need to be managed from an incident room within a national public health institution.

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