Pneumocystis pneumonia is a potentially severe fungal infection of the lungs and respiratory tract. It is caused by the Pneumocystis jiroveci fungus, a very common, widespread pathogen that is usually harmless to healthy individuals. Infants and people with immune system disorders, such as AIDS, are at the highest risk of experiencing active infections. Pneumocystis pneumonia can cause coughing and shortness of breath that can become life threatening without prompt treatment. A two- to three-week course of antibiotics is usually sufficient to cure the condition.
Pneumocystis jiroveci is found worldwide, and most people are exposed to it by early childhood. The immune system is usually strong enough to suppress the fungus, and it never causes adverse health problems. Infants younger than six months, chronically ill children, and people who have compromised immune systems are the most likely to experience symptoms. When infection does occur, the airborne fungus attaches to the linings of air sacs called alveoli in the lungs. The fungus is capable of quickly replicating itself and spreading throughout the respiratory tract if the immune system is not strong enough to combat it.
Early symptoms of Pneumocystis pneumonia include a dry cough, a sore throat, and a mild fever. Over the course of a few weeks, coughing tends to worsen and an individual may have shortness of breath following physical activity. Severe breathing difficulties, throat swelling, fatigue, and chest pain are common in advanced cases of Pneumocystis pneumonia.
A doctor can diagnose Pneumocystis pneumonia and rule out other possible causes of symptoms by taking a thorough medical history, performing a physical exam, and taking x-rays of the chest. Blood and mucus samples are usually collected and tested in a laboratory to check for the presence of pathogens. If other tests are inconclusive, the doctor may decide to examine the interior of the lungs and extract a sample of tissue using a bronchoscope.
Pneumocystis pneumonia does not typically respond to standard antifungal medications, but some antibiotics have proven effective against the disease. Oral and intravenous dosages of trimethoprim sulfamethoxazole, leucovorin, or another antibiotic may be administered. Patients with relatively minor symptoms need to take medications for about two weeks, while people with serious breathing troubles may need to be hospitalized and receive at least three weeks of treatment. The prognosis is generally good, even for patients with advanced forms of the disease, as long as the proper precautions are taken against acute respiratory failure.
