Mycobacterium chimaera: Difference between revisions

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Mycobacterium chimaera
m (Text replacement - "Clinical Presentation" to "Clinical Manifestations")
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==Clinical Manifestations==
 
==Clinical Manifestations==
* Median incubation period was 14.5 months (range 6 weeks to 5 years), with 80% of patients becoming unwell during the first two years
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* Median incubation period was [[Usual incubation period::14.5 months]] (range [[Incubation period range::6 weeks to 5 years]]), with 80% of patients becoming unwell during the first two years
 
* Duration of symptoms median 7 weeks but up to 1 year
 
* Duration of symptoms median 7 weeks but up to 1 year
 
* Most commonly presented with unexplained fever
 
* Most commonly presented with unexplained fever

Revision as of 09:51, 5 August 2020

Background

Microbiology

Epidemiology

  • A global outbreak of Mycobacterium chimaera infections was associated with point-source contamination of Stöckert 3T-HCD heater-cooler units (HCUs) used in cardiac bypass
  • Higher rates in mainland Europe, followed by UK, followed by North America

Pathophysiology

  • The HCUs aerosolized mycobacteria into the surgical field

Clinical Manifestations

  • Median incubation period was 14.5 months (range 6 weeks to 5 years), with 80% of patients becoming unwell during the first two years
  • Duration of symptoms median 7 weeks but up to 1 year
  • Most commonly presented with unexplained fever
  • Constitutional symptoms are common
  • Caused prosthetic valve endocarditis, aortic graft infection, surgical site infections, and disseminated disease affecting liver, spleen, bone marrow, spine, skin, and bone
  • Lymphopenia and thrombocytopenia are common, as is elevated ALP

Diagnosis

  • Culture in general has sensitivity of 68% but increases to essentially 100% with two cultures
    • Blood, urine, sputum, tissue, et cetera
  • Two blood cultures are about 76% sensitive

Management

  • No specific guidelines exist for treatment
  • Typically use a MAC regimen with azithromycin, ethambutol, and rifampin
  • May need additional aminoglycoside such as amikacin for severe disease
  • Duration unclear, but at least several months

Prognosis

  • Poor prognosis, with median survival of30 months from initial surgery and 9 months from start of therapy

Further Reading

  • Mycobacterium chimaera infection following cardiac surgery in the United Kingdom: clinical features and outcome of the first 30 cases. Clin Microbiol Infect. 2018. doi: 10.1016/j.cmi.2018.04.027