Installations like cooling towers are frequently associated with epidemic outbreaks of Legionnaire’s disease, a type of pneumonia with a death rate of 12-15%. Bacteria are contracted by inhaling the aerosols generated in such installations, and the infectious load of these microdrops, which spread through air, depends on the level that Legionella is present in water. Therefore, its rapid determination is absolutely critical.

The rapid quantification of Legionella bacteria in waters by means of an automated and independent plated culture process is a huge scientific-technological leap forward. This work describes automated bionsensor equipment that reliably quantifies in situ the level of Legionella spp in waters. It combines the immunocapture of intact Legionella cells with colorimetry techniques.

It is based on a validated AOAC-RI-certified method to quantitatively determine Legionella spp in waters by considering a cell to be a minimum unit of infection. This system, used as an Early Warning System, includes automatic processing for preconcentrations, analyses and reporting the result in the area where samples are taken; that is, in the installation in question. It comes in an “all-in-one” format and takes only 1 hour as opposed to the 7-14 days that a conventional culture method takes. Its novel feature is that it is the first automated rapid test validated by an international certification organisation for quantifying Legionella.