This figure shows the seasonal pattern of legionellosis, by month of diagnosis and species from 2009 to 2014.  In 2014, the diagnosis of Legionella pneumophila peaked in autumn with 24 cases diagnosed in both April and May, and Legionella longbeachae peaked in spring with 22 cases diagnosed in October.  From 2009 to 2014, the diagnosis of Legionella pneumophila commonly occurred in the autumn and summer months, except for 2013 when diagnoses peaked at the end of winter.  In the same period, the diagnosis of Legionella longbeachae more commonly occurred in winter and spring. End of description.