[Case study of a Legionella epidemic in a rehabilitation clinic]

A series of nosocomial Legionella infections in a rehabilitation center is reported. In a three months period a total of 10 pneumonias with 3 deaths occurred (8 patients, 1 companion, 1 staff member). Serologic analysis proved additional Legionella infections within the nursing staff. The warm-water system was proved to be the source of infection by isolating Legionella pneumophila serogroup 1 subtype Pontiac both in warm-water and patients samples. The air conditioning system could not be ruled out as another (secondary) route of exposure because of shortcomings in construction. Conclusions about prevention and the course of the disease are discussed and standards for warm-water and air conditioning systems are proposed.