In a Legionella outbreak, it is important to try to identify the source of exposure in order to control the outbreak and prevent outbreaks in the future, by matching environmental samples with clinical ones. A thorough investigation may provide evidence to link the source of exposure with cases. In some outbreaks, the source of exposure may be obvious from the outset, whilst in others the source may only become apparent after extensive investigations. In addition, there may be the issue of establishing liability, in which case it will be necessary to collect and document evidence in such a way that would stand up to judicial scrutiny.
It is also important to note that, in some outbreaks, the source of exposure may never be established or proven.
This section will thus consider:
Why attempt to match source with cases?