CRITICAL-EVALUATION OF 4-WEEK INCUBATION FOR FUNGAL CULTURES - IS THE4TH WEEK USEFUL

To determine the benefit of a 4-week incubation for mycology cultures, we evaluated all positive cultures during the fourth week of incubati on in a I-year period. Of 3,855 positive mycology cultures (yeast, 82% ; molds, 18%), 62 (1.6%) were positive during the fourth week (yeast, 42%; molds, 58%). Only 15 of the 62 cultures (24%) were considered cli nically relevant (2 isolates from invasive fungal infection and 13 iso lates from cutaneous mycosis). With the exception of those from skin s amples, isolates recovered during the fourth week are rarely important for patient care.