Pneumocystis pneumonia (PCP) is a lung infection caused by a fungus. It's rare in healthy people, and usually affects those with a weak immune system. It's the most common infection diagnosed in people with HIV infection or AIDS. It's seen much less often now because people infected with HIV get special medicine to prevent HIV from becoming AIDS.
Symptoms of pneumocystis (new-meh-SISS-tis) pneumonia include:
Sometimes the symptoms start suddenly and are severe. Other times they may start out mild and develop slowly, over days to weeks.
A fungus called Pneumocystis jirovecii causes pneumocystis pneumonia. It can live in the lungs of healthy people without causing problems. But it can be life-threatening if it spreads to someone with a weak immune system.
People at risk for getting sick with PCP include those who:
PCP is contagious. The fungus that causes it can spread from person to person through the air. People can spread the disease even when they're healthy and have no symptoms.
Doctors might suspect PCP in patients with a fever, cough, and trouble breathing who also have a weak immune system. The doctor might order a chest X-ray or blood tests to help with the diagnosis. To confirm it, the doctor will look for the fungus in samples of fluid or tissue from the lungs.
Early treatment is key because PCP can be life-threatening. Doctors treat the infection with antibiotics, either by mouth or intravenously (into a vein), for about 3 weeks. For severe symptoms, the doctor also might give a steroid medicine. This eases inflammation in the lungs, and is different from the steroids that athletes might use.
Most kids will need treatment in a hospital. They may need IV fluids and oxygen if they have trouble breathing. Children with severe symptoms may need breathing help from a ventilator (breathing machine) until they get better.
No vaccine can prevent PCP. But people with HIV/AIDS or other conditions that weaken the immune system can take antibiotics to prevent pneumocystis infection.
Most infants born to HIV-infected mothers get antibiotic treatment to prevent PCP until doctors know if the baby also has HIV. This begins when the baby is around 1 month old. Babies found to be HIV-negative can stop taking the antibiotics. Those who are HIV-positive will continue on antibiotics until the doctor decides they're not needed. This usually is when the medicine treating the HIV or AIDS is working well, and the baby's immune system is strong enough to fight the fungus.
Some antibiotics used to treat PCP can have side effects, such as rash, diarrhea, or fever. The health care team will watch for these and manage them in the hospital. If needed, they can switch to a different medicine.
Reviewed by: Elana Pearl Ben-Joseph, MD
Date Reviewed: Jan 13, 2020
