RESUMO
The occurrence of transient culture positivity for Mycobacterium tuberculosis (MTB), known as mirage de tuberculose, poses significant challenges in understanding its spectrum and implications. Here, we report a case of transient culture positivity, oscillating between detectable and non-detectable MTB cultures with minimal radiological features and review the literature on this phenomenon. The scarcity of scientific literature on this subject stems from the inherent impossibility of systematically studying mirage de tuberculose. Ethical and public health concerns prevent withholding treatment to monitor spontaneous reversion to negative cultures. Based on the literature, we estimate that mirage de tuberculose occurs in approximately one-third of individuals infected with MTB who exhibit no symptoms. Despite the inherently limited nature of these findings, they suggest that the significance of mirage de tuberculose may be greater than currently perceived. Managing cases of mirage de tuberculose presents formidable challenges from a public health perspective. Striking a balance between prompt treatment initiation to prevent transmission and the risk of unnecessary treatment requires careful consideration. In conclusion, mirage de tuberculose remains a poorly understood clinical entity with very limited literature available. Advancing research and interdisciplinary collaborations are essential to unravel the intricacies of this phenomenon and develop effective strategies to address its public health challenges.
L'apparition d'une culture transitoire positive pour Mycobacterium tuberculosis (MTB), connue sous le nom de mirage de tuberculose, pose des défis importants dans la compréhension de son spectre et de ses implications. Nous rapportons ici un cas de positivité transitoire des cultures, oscillant entre des cultures MTB détectables et non détectables avec des caractéristiques radiologiques minimales et passons en revue la littérature sur ce phénomène. La rareté de la littérature scientifique sur ce sujet provient de l'impossibilité inhérente d'étudier systématiquement le mirage de tuberculose. Des préoccupations éthiques et de santé publique empêchent l'interruption du traitement pour surveiller le retour spontané à des cultures négatives. Sur la base de la littérature, nous estimons que le mirage de tuberculose survient chez environ un tiers des personnes infectées par le MTB qui ne présentent aucun symptôme. Malgré la nature intrinsèquement limitée de ces résultats, ils suggèrent que l'importance du mirage de tuberculose pourrait être plus grande que ce que l'on perçoit actuellement. La prise en charge des mirages de tuberculose présente des défis considérables du point de vue de la santé publique. Il faut trouver un équilibre entre l'instauration rapide du traitement pour prévenir la transmission et le risque d'un traitement inutile. En conclusion, le mirage de tuberculose reste une entité clinique mal comprise et la littérature disponible est très limitée. L'avancement de la recherche et les collaborations interdisciplinaires sont essentiels pour démêler les subtilités de ce phénomène et élaborer des stratégies efficaces pour relever ses défis en matière de santé publique.
RESUMO
OBJECTIVE: The international outbreak of cardiac surgery-associated Mycobacterium chimaera infections was traced back to infectious aerosols originating from contaminated water reservoirs of heater-cooler devices (HCD). In general, nontuberculous mycobacteria (NTM) frequently colonize water systems and can contaminate medical devices. Data on detection of NTM other than M. chimaera in samples gathered from HCDs are scarce. The present study summarizes prospective mycobacterial surveillance of five HCDs over more than four years. METHODS: A cohort of five, in 2014 factory-new acquired, LivaNova 3T (London, UK) HCDs were prospectively followed. Until mid-April 2014 HCDs were maintained according to the manufacturer's recommendations, subsequently according to an intensified in-house protocol including exhaust air evacuation. Mycobacterial surveillance cultures consisted of monthly water samples gathered from patient and cardioplegia circuits, as well as airflow samples. RESULTS: Out of 441 water samples, 170 (38.6%) revealed NTM growth. The most frequently detected NTM were Mycobacterium chimaera (n=120 (67.4%)), Mycobacterium gordonae (n=35 (19.7 %)), and Mycobacterium paragordonae (n=17 (9.6%)). Growth of NTM, M. chimaera and M. paragordonae was significantly more common in water samples derived from the patient than the cardioplegia circuit of the HCD. Three (2.0%) out of 150 air samples grew NTM. CONCLUSION: Growth of NTM in HCD water samples was frequent. Diverse NTM species were detected, with M. chimaera being most common. The majority of air samples remained negative. The relevance of NTM other than M. chimaera contaminating HCDs is poorly defined, but a recent report on a HCD-associated outbreak with Mycobacterium abscessus confirms a potential threat.
