text-nocardia

Subacute pnumonia --> lung abcess (Page 2/2)

Prepared by...
Virat Sirisanthana, M.D. *

* Department of Pediatrics, Chiang Mai University

Copy from: 1997 Red Book (Report of the Committee on Infectious Diseases, 24th ed.).
Page 372-3.

CLINICAL MANIFESTATIONS: A common presentation in nonimmunocompro-mised children is
cutaneous or lymphocutaneous disease after contamination of an abrasion. Usually in these cases
the lesions remain localized. Invasive disease occurs most commonly in immunocompromised
patients, particularly those with chronic granulomatous disease or HIV infection. Infection
characteristically begins in the lung, with hematogenous spread to the liver, brain, kidneys, and
other organs. Pulmonary disease resembles that of tuberculosis and systemic fungal infection.

ETIOLOGY: Nocardia species are funguslike bacteria. Disease is caused most commonly by
Nocardia asteroides, less frequently by Nocardia braziliensis, and occasionally by other Nocardia
species.

EPIDEMIOLOGY: Nocardia species are free living in nature, soil, and compost,and are found
worldwide. Infectious particles are airborne, and the lung is the probable portal of entry. Direct skin
inoculation occurs, often as the result of minortrauma and/or soil contamination. Person-to-person
transmission does not occur.The incubation period is unknown.

DIAGNOSTIC TESTS: Stained smears of sputum, cerebrospinal fluid, or pus can demonstrate
beaded, branched, weakly Gram-positive rods that are variably acid fast. The Brown and Brenn and
the methenamine silver stains are recommended for demonstrating microorganisms in tissue.
Growth of typical colonies occurs on Sabouraud's dextrose agar without added antibiotics. Blood
specimens should be cultured on brain-heart infusion media. These organisms are slow growing;
therefore, cultures should be maintained for 7 to 10 days.

TREATMENT: Trimethoprim-sulfamethoxazole or a sulfonamide (eg, sulfadiazine, sulfisoxazole,
or triple sulfonamide combinations) is the drug of choice. Blood concentrations of the sulfonamide
should be maintained at 15 to 20 mg/dL. Immunocompetent patients with lymphocutaneous
disease usually respond after 6 to 12 weeks of therapy. Immunocompromised patients and those
with invasive disease should be treated for 6 to 12 months and for at least 3 months after apparent
cure because of the tendency for relapse or the appearance of metastatic abscesses that can
recur months or years after therapy. Patients with AIDS may need even longer therapy. Patients
with meningitis or brain abscess should be monitored with serial imaging studies of the brain. If
response to trimethoprim-sulfamethoxazole or sulfadiazine drugs does not occur, gentamicin,
amikacin, minocycline, cycloserine, ampicillin, imipenem, amoxicillin/clavulanate, or an extended-
spectrum cephalo-sporin may be of benefit. Tetracycline antibiotics generally are not recommended
for children younger than 8 years of age (see Antimicrobials and Related Therapy, p 606). Incision
and drainage of abscesses are beneficial.

CONTROL MEASURES: None.

DX: Nocardiosis
Copy from: 1997 Red Book (Report of the Committee on Infectious Diseases, 24th ed.). Page 372-3.

Nocardiosis
CLINICAL MANIFESTATIONS: A common presentation in nonimmunocompro-mised children is cutaneous or lymphocutaneous disease after contamination of an abrasion. Usually in these cases the lesions remain localized. Invasive disease occurs most commonly in immunocompromised patients, particularly those with chronic granulomatous disease or HIV infection. Infection characteristically begins in the lung, with hematogenous spread to the liver, brain, kidneys, and other organs. Pulmonary disease resembles that of tuberculosis and systemic fungal infection.