Clinical and epidemiological features of 18 cases of P. aeruinosa infections identified throughout the investigation.

UTI = urinary tract infection; CVC = central venous catheter; URT = upper respiratory tract; S = sensitive; I = intermediate; R = resistant; NA not applicable because the activity of the unit was moved to another hospital building.a Cases were coded by assigning to each patient a progressive number (i.e.: 1–14); subsequent cases in the same patient were identified by adding a letter (i.e.: a, b and c) to the patient's number.bPrevalent cases.cThis patient was admitted to the new located unit at the time of the look-back therefore he is previously identified as an asymptomatic case in the look-back and eventually, as a prevalent case, in the prospective surveillance.dCase identified during look back; for them time-fraction and room number is referred to their last admission.eThese samples were used for bacterial typing as shown in fig. 3.fThis represent 2 specimens taken the same day and yielding an identical molecular type to that found in the blood culture (data not shown).