Nocardiosis

Nocardiosis
Nocardiosis
Classification and external resources
ICD-10 A43
ICD-9 039.9
DiseasesDB 9058
eMedicine med/1644 derm/297 ped/1610
MeSH D009617

Nocardiosis is an infectious disease affecting either the lungs (pulmonary nocardiosis) or the whole body (systemic nocardiosis). It is due to infection by bacterium of the genus Nocardia, most commonly Nocardia asteroides or Nocardia brasiliensis.

It is most common in men, especially those with a compromised immune system. In patients with brain infection, mortality exceeds 80%; in other forms, mortality is 50%, even with appropriate therapy.[1]

It is one of several conditions that has been called the great imitator.[2]

Cutaneous nocardiosis commonly occurs in immunocompetent hosts.[3]

Contents

Causes

Normally found in soil, these organisms cause occasional sporadic disease in humans and animals throughout the world. Another well publicized find is that of Nocardia as an oral microflora. Nocardia spp. have been reported in the normal gingiva and periodontal pockets along with other species such as Actinomyces, Arthromyces and Streptomyces spp.[4]

The usual mode of transmission is inhalation of organisms suspended in dust. Another very common method is that by traumatic introduction, especially in the jaw. This leads to the entrance of Nocardia into the blood stream and the propagation of its pathogenic effects. Transmission by direct inoculation through puncture wounds or abrasions is less common.[1] Generally, nocardial infection requires some degree of immune suppression.

Symptoms

Pulmonary Infection

  • Produces a virulent form of pneumonia (progressive)
  • night sweats, fever, cough, chest pain
  • Pulmonary nocardiosis is subacute in onset and refractory to standard antibiotherapy
  • symptoms are more severe in immunocompromised individuals
  • radiologic studies show multiple pulmonary infiltrates with tendency to central necrosis

Neurological Infection

  • Headache, lethargy, confusion, seizures, sudden onset of neurological deficit
  • CT scan shows cerebral abscess
  • Nocardial meningitis is difficult to diagnose

[5] [6] Cardiac Conditions

  • Nocardia has been highly linked to endocarditis as a main symptom
  • In recorded cases, it has caused damage to heart valves whether natural or prosthetic

[1] Lymphocutaneous disease

  • Nocardial cellulitis is akin to erysipela but is less acute
  • Nodular lymphangeitis mimics sporotrichosis with multiple nodules alongside a lymphatic pathway
  • Mycetoma is a rare complication and osteitis may ensue

Ocular disease

  • Very rarely nocardiae cause keratitis
  • Generally there is a history of ocular trauma

Disseminated nocardiosis

  • Dissemination occurs through the spreading enzymes possessed by the bacteria
  • Disseminated infection can occur in very immunocompromised patients
  • It generally involves both lungs and brain
  • Fever, moderate or very high can be seen
  • Multiple cavitating pulmonary infiltrates develop
  • Cerebral abscesses arise later
  • Cutaneous lesions are very rarely seen
  • If untreated, the prognosis is poor for this form of disease

Diagnosis

Diagnosis may be difficult. Nocardiae are weakly acid-fast organisms and can be visualized by a modified Ziehl-Neelsen stain like Fite-Faraco method In the clinical laboratory, routine cultures may be held for insufficient time to grow nocardiae, and referral to a reference laboratory may be needed for species identification.[7] Infiltration and pleural effusion are usually seen via x-ray.

Treatment

Nocardiosis requires at least 6 months of treatment, preferably with co-trimoxazole or high doses of sulfonamides. In patients who don’t respond to sulfonamide treatment, other drugs, such as ampicillin, erythromycin, or minocycline, may be added.

Treatment also includes surgical drainage of abscesses and excision of necrotic tissue. The acute phase requires complete bed rest; as the patient improves, activity can increase.[1]

A new combination drug therapy (sulfonamide, ceftriaxone, and amikacin) has also shown promise.[7]

References


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Look at other dictionaries:

  • nocardiosis — infección causada por gérmenes del género Nocardia, ampliamente distribuidos por la naturaleza. En general la lesión primaria asienta en el pulmón en forma de neumonía de evolución subaguda o crónica, que cursa con fiebre, tos, expectoración, a… …   Diccionario médico

  • nocardiosis — ▪ pathology       chronic systemic bacterial disease of humans and many other animals originating in the respiratory tract and disseminated by way of the blood to other organs, especially the brain. It is caused either by introduction into the… …   Universalium

  • nocardiosis — a chronic systemic bacterial disease caused by Nocardia asteroides. Lesions are formed internally and externally and additionally fish show popeye and anorexia. Some fish, such as salmonids, may show no external symptoms although the disease is… …   Dictionary of ichthyology

  • nocardiosis — A generalized disease in humans and other animals caused by Nocardia asteroides, N. otitidiscaviarum, N. transvalensis, and N. brasiliensis and characterized by primary pulmonary lesions that may be subclinical or chronic with hematogenous spread …   Medical dictionary

  • nocardiosis — noun An infectious disease affecting either the lungs or the whole body, caused by infection by bacteria of the genus Nocardia …   Wiktionary

  • nocardiosis — no·car·di·o·sis …   English syllables

  • nocardiosis — n. a disease caused by bacteria of the genus Nocardia, primarily affecting the lungs, skin, and brain, resulting in the formation of abscesses. Treatment involves antibiotics and sulphonamides …   The new mediacal dictionary

  • nocardiosis — …   Useful english dictionary

  • Нокардиоз (Nocardiosis) — заболевание, вызываемое бактериями рода Nocardia; поражает легкие, кожу и головной мозг чело века, вызывая образование в них абсцессов. Для лечения заболевания применяются антибиотики и сульфамиды. Источник: Медицинский словарь …   Медицинские термины

  • bovine nocardiosis — infection of cattle with species of Nocardia; see bovine farcy and nocardial mastitis …   Medical dictionary

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