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Nocardiosis
Nocardiosis is a rare and often fatal infectious condition that begins in the lungs and can spread to the brain. It is caused by a fungus-like bacterium that is found in the soil. Humans can become infected by inhaling contaminated dust or, less commonly, by wounds or cuts becoming contaminated. It cannot be passed from person to person.
Nocardiosis occurs worldwide in people of all ages. However, it occurs more commonly in older adults and in people with weakened immune systems. Men are affected more often than women.
Signs and Symptoms
The first sign of nocardiosis is a cough that produces thick phlegm, which is sometimes bloodstained. The cough is similar to that experienced with pneumonia or tuberculosis.
Other symptoms can include:
- Chills
- Night sweats
- Chest pain
- Fatigue and weakness
- Lack of appetite
- Weight loss
In about 30% of cases the infection enters the bloodstream and spreads to the brain, where it causes abscesses. When this occurs symptoms experienced can include:
- Severe headaches
- Confusion
- Dizziness
- Nausea
- Seizures
If the abscesses in the brain rupture, meningitis can occur.
Approximately 30% of patients will develop abscesses on, or just under, the skin. They may also develop abscesses in other organs such as the kidneys or liver.
Diagnosis
The bacterium that causes nocardiosis is difficult to identify. Diagnosis can be made by analysis of the phlegm and by taking a thorough medical history. X-rays and lung biopsies may also be taken.
It is important that nocardiosis is diagnosed and treated as early as possible. Early treatment, before it has spread to the brain, provides the best chance of recovery.
Treatment
Bed rest and high doses of antibiotics are the usual treatment for nocardiosis. The bacterium that causes nocardiosis is usually resistant to penicillin so other antibiotics may be prescribed. These include trimethoprim and erythromycin. Antibiotic treatment usually needs to be continued for between 12 to 18 months.
Surgery to drain and/or remove abscesses may also be required.
Prognosis
Nocardiosis is a serious condition that is fatal in up to 50% of cases – even when appropriate treatment has been given. The fatality rate is higher if the infection has spread to the brain.
References
Centre for Disease Control and Prevention (2005) Nocardiosis. Division of Bacterial and Mycotic Diseases; Centre for Disease Control and Prevention, Atlanta, GA. http://www.cdc.gov/ncidod/dbmd/diseaseinfo/nocardiosis_t.htm
Turkington, C. A. (2006) Nocardiosis. The Gale Encyclopedia of Medicine, Third Edition. Jacqueline L. Longe, Editor. Farmington Hills, MI. Thompson Gale.
Last Reviewed - 09/10/07