Nocardiosis

Last reviewed: April 2018

Last updated: January 2018

Summary

A localized or disseminated infection caused by the actinomycete Nocardia species.

Typically occurs in immunocompromised patients with subacute or chronic pulmonary disease. More prevalent in patients with deficient cell-mediated immunity (e.g., post-transplant, with AIDS, on corticosteroid therapy, or with malignancies).

Disseminated forms (lungs, skin, subcutaneous tissues, and CNS) frequently occur.

Treatment of immunocompromised patients with disseminated or severe disease consists of intravenous therapy with 2 or more antibiotics.

High tendency to recur. Maintenance therapy should be continued until the immunocompromised state can be reversed or improved.

Surgical treatment may be needed in some cases (e.g., CNS abscesses with poor response to antimicrobial treatment).

Definition

Nocardiosis is a localized or disseminated infection caused by the actinomycete Nocardia species that usually affects immunocompromised patients. It has been reported more frequently in patients with deficient cell-mediated immunity, such as organ transplant recipients and AIDS patients. Clinical presentation can be acute, subacute, or, more frequently, chronic. Nocardiosis has a high mortality rate and a tendency to recur. Immunocompetent patients usually develop localized cutaneous lesions, cellulitis, abscesses, or sporotrichoid forms.

History and exam

Key diagnostic factors

cough with purulent sputum
fever

Full details

Other diagnostic factors

male gender
headache
nausea and vomiting
confusion
depressed consciousness
cutaneous ulcers or abscesses

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Risk factors

solid organ and hematopoietic stem cell transplant recipients
HIV-positive and low CD4 T-cell count (<100 cells/mm^3)
immunosuppression
structural pulmonary disease
malignancy and chemotherapy
male gender
agricultural work

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Diagnostic investigations

1st investigations to order

Gram and acid-fast stains
culture
CXR

Full details

Investigations to consider

biochemical species typing
thoracic CT scan
CT head
MRI head

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Emerging tests

16S rRNA sequencing
identification and typing according to gyrB and rpoB genes
matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS)

Full details

Treatment algorithm

ACUTE

severe nocardiosis: disseminated disease, CNS involvement, cavitary pulmonary lesions, or immunocompromise

nonsevere nocardiosis: immunocompetent, nondisseminated, no CNS involvement, no pulmonary cavitary lesions

Contributors

Authors VIEW ALL 

Jorge Garbino, MD, MPD

Division of Infectious Disease

Geneva University Hospital

Geneva

Switzerland

Disclosures

JG declares that he has no competing interests.

Juan Ambrosioni, MD, PhD

Division of Infectious Diseases

Hospital Clinic-IDIBAPS

Barcelona

Spain

Disclosures

JA declares that he has no competing interests.

Peer reviewers VIEW ALL 

Ali Hassoun, MD, FACP, FIDSA, AAHIVS

Infectious Disease Specialist

Alabama Infectious Diseases Center

Huntsville

Disclosures

AH declares that he has no competing interests.

M. Narita, MD

Associate Professor of Medicine

Division of Pulmonary and Critical Care

Harborview Medical Center

University of Washington

Seattle

Disclosures

MN declares that he has no competing interests.

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Nocardiosis

Summary

Definition

History and exam

Key diagnostic factors

Other diagnostic factors

Risk factors

Diagnostic investigations

1st investigations to order

Investigations to consider

Emerging tests

Treatment algorithm

severe nocardiosis: disseminated disease, CNS involvement, cavitary pulmonary lesions, or immunocompromise

nonsevere nocardiosis: immunocompetent, nondisseminated, no CNS involvement, no pulmonary cavitary lesions

Contributors

Authors VIEW ALL 

Jorge Garbino, MD, MPD

Disclosures

Juan Ambrosioni, MD, PhD

Disclosures

Peer reviewers VIEW ALL 

Ali Hassoun, MD, FACP, FIDSA, AAHIVS

Disclosures

M. Narita, MD

Disclosures

Differentials

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