Case Report
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Sep 26, 2019; 7(18): 2776-2786
Published online Sep 26, 2019. doi: 10.12998/wjcc.v7.i18.2776
Mycobacterium chimaera infections following cardiac surgery in Treviso Hospital, Italy, from 2016 to 2019: Cases report
Walter O Inojosa, Mario Giobbia, Giovanna Muffato, Giuseppe Minniti, Francesco Baldasso, Antonella Carniato, Francesca Farina, Gabriella Forner, Maria C Rossi, Stefano Formentini, Roberto Rigoli, Pier G Scotton
Walter O Inojosa, Mario Giobbia, Francesco Baldasso, Antonella Carniato, Francesca Farina, Gabriella Forner, Maria C Rossi, Pier G Scotton, Infectious Diseases Unit, Treviso Hospital, Treviso 31100, Italy
Giovanna Muffato, Roberto Rigoli, Microbiology Unit, Treviso Hospital, Treviso 31100, Italy
Giuseppe Minniti, Cardiac Surgery Unit, Treviso Hospital, Treviso 31100, Italy
Stefano Formentini, Health Management Unit, Treviso Hospital, Treviso 31100, Italy
Author contributions: Inojosa WO, Giobbia M, and Scotton PG designed the report; Muffato G performed the microbiological analyses; Inojosa WO, Giobbia M, Baldasso F, Carniato A, Farina F, Forner G, and Rossi MC collected the patients’ clinical data; Inojosa WO, Giobbia M, Minniti G, Formentini S, Rigoli R, and Scotton PG analyzed the data, and did the literature review and critical revision; Inojosa WO wrote the paper.
Informed consent statement: All study participants provided informed written consent prior to study enrolment for publications.
Conflict-of-interest statement: The authors declare no conflicts of interest.
CARE Checklist (2016) statement: The authors have read the CARE Checklist (2013), and the manuscript was prepared and revised according to the CARE Checklist (2016).
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Corresponding author: Walter O Inojosa, MD, Doctor, Infectious Diseases Unit, Treviso Hospital, Piazza Ospedale 1, Treviso 31100, Italy. walteromar.inojosa@aulss2.veneto.it
Telephone: +39-42-2322065 Fax: +39-42-2322069
Received: March 18, 2019
Peer-review started: March 20, 2019
First decision: May 31, 2019
Revised: August 19, 2019
Accepted: September 9, 2019
Article in press: September 9, 2019
Published online: September 26, 2019
Processing time: 191 Days and 9.6 Hours
Abstract
BACKGROUND

An epidemic of Mycobacterium chimaera (M. chimaera) infections following cardiac surgery is ongoing worldwide. The outbreak was first discovered in 2011, and it has been traced to a point source contamination of the LivaNova 3T heater-cooler unit, which is used also in Italy. International data are advocated to clarify the spectrum of clinical features of the disease as well as treatment options and outcome. We report a series of M. chimaera infections diagnosed in Treviso Hospital, including the first cases notified in Italy in 2016.

CASE SUMMARY

Since June 2016, we diagnosed a M. chimaera infection in nine patient who had undergone cardiac valve surgery between February 2011 and November 2016. The time between cardiac surgery and developing symptoms ranged from 6 to 97 mo. Unexplained fever, psychophysical decay, weight loss, and neurological symptoms were common complaints. The median duration of symptoms was 32 wk, and the longest was almost two years. A new cardiac murmur, splenomegaly, choroidoretinitis, anaemia or lymphopenia, abnormal liver function tests and hyponatremia were common findings. All the patients presented a prosthetic valve endocarditis, frequently associated to an ascending aortic pseudoneurysm or spondylodiscitis. M. chimaera was cultured from blood, bioprosthetic tissue, pericardial abscess, vertebral tissue, and bone marrow. Mortality is high in our series, reflecting the poor outcome observed in other reports. Three patients have undergone repeat cardiac surgery. Five patients are being treated with a targeted multidrug antimycobacterial regimen.

CONCLUSION

Patients who have undergone cardiac surgery in Italy and presenting with signs and symptoms of endocarditis must be tested for M. chimaera.

Keywords: Mycobacterium chimaera; Prosthetic valve endocarditis; Spondylodiscitis; Cardiac surgery infections; Case report

Core tip: A prolonged epidemic of Mycobacterium chimaera (M. chimaera) infections following cardiac surgery is ongoing worldwide. The outbreak was first discovered in Switzerland in 2011, and it has been traced to a point source contamination of the LivaNova (formerly Sorin) 3T heater-cooler unit, which is the most used device in Italy. International data are advocated in order to clarify the spectrum of clinical, laboratory, echocardiographic, and radiological features of the disease as well as treatment options and outcome. Here we report the clinical features of a case series of M. chimaera infections diagnosed in our Hospital, including the first cases notified in Italy in 2016.