[A-DROP system might result in underestimation of severity of cases with Legionnaires' disease].

Fifteen cases of legionella pneumonia experienced in our department or associated hospital were included in this study. Each case was classified with the A-DROP system of the Japanese Respiratory Society Guidelines, and guidelines from the Infectious Diseases Society of America (IDSA) (1998) and then we compared the severity of the cases of pneumonia. Although 10 cases were classified as intermediate, 3 as severe, and 2 as extremely severe with the A-DROP system, most cases were classified as severe according to the IDSA guidelines. Among 5 fatal cases, three were ranked as intermediate with the A-DROP system. However all the fatal cases were ranked as severe in the IDSA guidelines. This study suggested that the A-DROP system might underestimate the severity of pneumonia in cases with legionella pneumonia.