095 Managing mycobacteria chimaera risk linked to heater cooler units. (December 2018)

• Record Type: Journal Article
• Authors: Yongblah, FG; Nakrani, M; Asadi, F; Cloutman-Green, EA; Hartley, JC
• Is Part Of: Archives of disease in childhood. Volume 103:Supplement 2(2018)
• Page Start: A38
• Page End: A38
• Publication Date: 2018-12
• Subjects: Infants -- Diseases -- Periodicals; Newborn infants -- Diseases -- Periodicals; Fetus -- Diseases -- Periodicals; 618.920105
• DOI: 10.1136/goshabs.95
• Languages: English
• ISSNs: 1359-2998

Abstract

Abstract : In Zurich in 2012, 2 cases of Mycobacterium chimaera endocarditis/vascular graft infection were identified. This led to an investigation where six patients (in total) were found to have M. chimaera infection, detected up to 3.6 years post-surgery. M. chimaera was cultured from both the air surrounding and the water from the heater-cooler units used during surgery and therefore was thought to be the source. Aim: To investigate levels of heater-cooler unit colonisation and aerosolisation risk over time within a single UK centre Methods: In 2015, guidance was released that required the surveillance of both waters from heater cooler unit's post-use and air samples taken from during use. Mycobacterial culture of the water samples was undertaken using a modified BacTalert TB protocol (Biomerieux). Air sampling was undertaken as per the guidelines using Middlebrook 7 H11 agar, as well as standard microbiological culture. Results: 66 water samples from three heater cooler units (cardioplegia and patient circuits) were taken between September 2015 and February 2017. 12 samples were positive for M. chimaera across all three units, no single unit, however, has been continuously detected as positive. Air samples were taken for monitoring both within the theatre environment and within the setup environment isolated M.mucogenicum. This then grew in a theatre mock-up when the machine was covered. All other air samples remained negative. Other Mycobacteria were isolated from 10 water samples and sequencing was required for identification. Conclusions: Despite sporadic detection of M. chimaera within all three-heater cooler units utilised no M. chimaera has been detected within the air surrounding the units, thus indicating a low risk of transmission to patients undergoing surgery. Air was sampled in rooms that had between 10 and 25 air changes per hour and this may be the source of the decreased detection levels.