Objective: To determine whether disinfection protocols currently used for gastroscopes are effective against cultures of Tropheryma whipplei.
Design: The bactericidal activity of 2% glutaraldehyde and two peracetic acids on the Twist-Marseille strain of T. whipplei grown in cell monolayers was determined.
Patients: Two patients who were diagnosed as having Whipple's disease 3 years after they had had intestinal biopsies.
Results: The disinfectants reduced bacteria by approximately 2 log to 3 log10 after 5 to 60 minutes of contact.
Conclusion: The bactericidal activity of a disinfectant is usually considered significant if it causes a 5 log10 or greater reduction in viable bacterial titers. Disinfecting gastroscopes with 2% glutaraldehyde or peracetic acids for 20 minutes may be insufficient to prevent transmission of T. whipplei on the instruments or stop false-positive results on polymerase chain reaction.