Nocardia
OVERVIEW
- gram positive bacilli that form weakly acid-fast beaded branching filaments
- found worldwide in soil and some form part of healthy oral flora
- usually transmitted by inhalation or traumatic inoculation
- disease of the immunocompromised – esp T-cell mediated immunity (AIDS, SCID, immunosuppressant therapy)
CLINICAL FEATURES
- pneumonia + brain abscess
- meningitis
- spinal cord
- granulomatous disease
INVESTIGATIONS
- sample graunloma
- gram stain
- culture
- BAL
- lung biopsy
MANAGEMENT
In general
- co-trimoxazole (first line agent)
- ceftriaxone (second line agent)
Brain abscess
- Expert advice recommended.
- Empiric therapy:
trimethoprim-sulfamethoxazole 320+1600 mg (child more than 2 months: 8+40 mg/kg up to 320+1600 mg) IV or orally, 12-hourly
PLUS EITHER
imipenem 500 mg (child: 12.5 mg/kg up to 500 mg) IV, 6-hourly
OR
meropenem 2 g (child: 40 mg/kg up to 2 g) IV, 8-hourly (meropenem has a lower risk of seizures than imipenem, but there is less published data to support its use)
OR
amikacin (adult and child) 15 mg/kg IV, daily or amikacin (adult and child) 7.5 mg/kg IV, 12-hourly - Subsequent therapy should be guided by species identification and susceptibility results.
— Ceftriaxone 4 g (child: 100 mg/kg up to 4 g) IV, once daily (or in 2 divided doses) can replace the carbapenem and/or amikacin if the organism is susceptible.
— trimethoprim-sulfamethoxazole up to 320+1600 mg (child more than 2 months: 8+40 mg/kg up to 320+1600 mg) orally, 12-hourly for up to a further 12 months.
— amoxycillin+clavulanate, minocycline, linezolid and moxifloxacin have also been successful in small numbers of cases, particularly for some of the more unusual species. - Duration:
— Initial parenteral therapy should be continued for 3 to 6 weeks.
— Oral therapy is continued for up to a further 12 months.
Prophylaxis in lung transplant patients
- low-dose trimethoprim/sulfamethoxazole prophylaxis to protect against Pneumocystis jiroveci pneumonia, toxoplasmosis and nocardial infection.
References and Links
- Brown-Elliott BA, Brown JM, Conville PS, Wallace RJ Jr. Clinical and laboratory features of the Nocardia spp. based on current molecular taxonomy. Clin Microbiol Rev. 2006 Apr;19(2):259-82. PMC1471991
- Kanne JP, Yandow DR, Mohammed TL, Meyer CA. CT findings of pulmonary nocardiosis. AJR Am J Roentgenol. 2011 Aug;197(2):W266-72. PMID: 21785052
- Leis JA, Bunce PE, Lee TC, Gold WL. Brain and lung lesions in an immunocompromised man. CMAJ. 2011 Mar 22;183(5):573-6. PMC3060186
- Saubolle MA, Sussland D. Nocardiosis: review of clinical and laboratory experience. J Clin Microbiol. 2003 Oct;41(10):4497-501. PMC254378
Critical Care
Compendium
Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also a Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.
After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.
He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE. He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.
His one great achievement is being the father of three amazing children.
On Twitter, he is @precordialthump.
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