Seasonality of biofilm-related hospitalizations by geographic region.

Average monthly Legionnaires’ disease hospitalizations per 10,000 discharges peaked in New England and Mid-Atlantic states earlier in the year (July–August) compared to Midwestern and Mountain states (September–October). The other respiratory biofilm-forming pathogens exhibited no discernible seasonality. Intestinal pseudomonas hospitalizations peaked between October and February in some regions but there were few hospitals in the intestinal Pseudomonas-specific dataset. (ZIP)