December 22 21:23 2019 Print This Article

Pulmonary nocardiosis is an infection of the lung that is caused by the fungus-like bacteria Nocardia asteroides. Nocardia may also infect the skin through a cut or scratch that occurs while working outdoors or gardening. Nocardia are weakly gram-positive, filamentous bacteria found worldwide in soils. It occurs as sporadic cases worldwide. Some 70 cases, with about 20 deaths, occur per year in the USA.

The risk is greatly increased by immune suppression. If inhaled, the bacteria may cause pneumonia, which can lead to blood poisoning (sepsis) and the spread of nocardiosis to other organs of the body. This is called disseminated nocardiosis. majority (about 80%) of cases of nocardiosis involves lung infection, brain abscess, or disseminated (widespread) disease from Nocardia. Nocardiosis can be distinguished from actinomycosis by a lesser proclivity for sinus tract formation and a greater tendency for hematogenous dissemination specially to the brain.

Nocardiosis is found throughout the world among people of all ages, although it is most common in older people and males. Bronchopulmonary or disseminated nocardiosis can occure in various rheumatologic disease, including SLE, temporal arteritis, polyarthritis nodosa, intermittent hydarthrosis, vasculitis or uveitis. Nocardia brasiliensis is a common cause of localized chronic mycetoma.

Members of the genus Nocardia are aerobic actinomycetes that are ubiquitous saprophytes in soil, decaying organic matter, and water. Respiratory tract colonisation with Nocardia has been reported in patients with tuberculosis, asthma, bronchitis, aspergillosis and cancer. Nocardiosis is rare in AIDS patients. It is not transmitted by person-to-person contact. The diagnosis of Nocardia may be difficult. Newer molecular diagnostic and subtyping methods can assist in earlier diagnosis.

Causes of Nocardiosis

The comman causes of Nocardiosis include the following:

  • Chronic pulmonary disease: Although nocardial pulmonary disease has been described in a variety of chronic pulmonary diseases, patients with pulmonary alveolar proteinosis are at particular risk.
  • Nosocomial cases have been reported. In some cases, N asteroides were detected in the dust and air of the hospital unit.
  • Alcoholism.
  • Bone marrow or stem cell transplantation.
  • Chronic corticosteroid use or Cushing syndrome.
  • Nocardia infection develops when you inhale the bacteria. The infection causes pneumonia-like symptoms but is often not limited to the lungs.
  • It can be contracted by inhaling contaminated dust or via contamination of a wound with soil containing nocardia.

Symptoms of Nocardiosis

Some sign and symptoms related to Nocardiosis are as follows:

  • Chest pain not due to heart problems.
  • Shortness of breath.
  • Breathing gets harder and harder (pulmonary insufficiency).
  • Pain in affected area (eg chest pain).
  • Weakness, lethargy.
  • Suppurative pneumonia.
  • Pleural effusions.
  • Change in mental state (occurs with brain lesions).
  • Confusion.
  • General discomfort, uneasiness, or ill feeling ( malaise ).
  • Unintentional weight loss.
  • Night sweats.
  • Ulcers and/or nodules with infection sometimes tracking along lymph node chains.

Treatment of Nocardiosis

Here is list of the methods for treating Nocardiosis:

  • Sulfa-based therapy is recommended. Trimethoprim-sulfamethoxazole (Bactrim) or a sulfonamide (sulfadiazine), given intravenously in high doses, is the treatment of choice.
  • Protracted specific antimicrobial therapy is the mainstay of medical care for nocardiosis. Therapy generally is recommended for at least 6 months.
  • Antibiotics are used, but the response to treatment may be slow and the medications must be continued for at least 6 months
  • Surgery may be needed to remove or drain infected areas.
  • Individuals with nocardiosis, either disseminated or cutaneous, require long-term antibiotic treatment for the infection.
  • Additional concurrent therapy with an aminoglycoside (amikacin, gentamicin) benefits patients with fulminant disease.