HomeHealth TopicsLungs BreathingPneumocystis Infections
Back to Lungs Breathing
Pneumocystis Infections
Reviewed by Medicinsk Expert•Last updated: 2026-10-22•Lungs Breathing

Pneumocystis Infections

Pneumocystis jirovecii is a fungus that can cause a serious lung infection called pneumocystis pneumonia (PCP) in individuals with weakened immune systems.

What is Pneumocystis jirovecii?

Pneumocystis jirovecii is a fungus that is common throughout the world. Many people have been exposed to it as children. If you are healthy, it usually will not make you sick. But it can make you sick if you have a weakened immune system, for example if you:

  • Have HIV
  • Have an autoimmune disease
  • Have cancer
  • Have a chronic (long-lasting) lung disease
  • Had an organ or bone marrow transplant
  • Take medicines which weaken your immune system, such as chemotherapy and steroids

How does Pneumocystis jirovecii spread?

Pneumocystis jirovecii can spread from person to person through the air. You can spread it to others even if it isn't making you sick.

What is pneumocystis pneumonia (PCP)?

The most common type of infection that Pneumocystis jirovecii causes is pneumocystis pneumonia (PCP). Pneumonia is an infection in one or both of the lungs, causing the air sacs to fill up with fluid or pus.

What are the symptoms of PCP?

The symptoms of PCP can develop over several days or weeks and may include:

  • Fever
  • Cough
  • Trouble breathing
  • Chest pain
  • Chills
  • Fatigue

How is PCP diagnosed?

To find out if you have PCP, your provider will take a sample of fluid or tissue from your lungs—such as sputum, fluid collected during a bronchoalveolar lavage, or tissue taken with a biopsy—to check for Pneumocystis in the lab.

What are the treatments for PCP?

The treatment for PCP is with antibiotics, either by mouth or intravenously (by IV), typically for about 3 weeks. Severe cases may require hospitalization.

Can PCP be prevented?

There is no vaccine to prevent PCP. Some people who are at high risk of getting PCP may need to take antibiotics to prevent it.

Frequently Asked Questions

The best prevention is to keep my CD4 count above 200 cells/µL by taking antiretroviral therapy consistently, and to take a daily prophylactic dose of trimethoprim‑sulfamethoxazole (TMP‑SMX) if my CD4 is below 200 or if I have a history of PCP. Avoiding high‑dose steroids or reducing them to the lowest effective dose also helps.
Treatment usually lasts 21–28 days of TMP‑SMX, sometimes with a steroid taper for severe cases. Common side effects include nausea, rash, and low blood counts; severe reactions like Stevens‑Johnson syndrome or agranulocytosis are rare but require immediate medical attention. Keep a symptom diary and report any new rash, fever, or dizziness.
Recurrence is possible, especially if the underlying immune suppression persists. After finishing therapy, I should have a follow‑up chest X‑ray or CT within 4–6 weeks, and my provider may repeat a sputum test. If I remain immunocompromised, ongoing PCP prophylaxis with TMP‑SMX is usually continued until my immune status improves.
If I develop a dry cough that worsens over days, new or worsening shortness of breath, fever, chills, or chest pain that does not improve with over‑the‑counter meds, I should call my provider or go to the emergency department immediately, as these can signal PCP or other serious infections.
Source: MedlinePlus, National Library of Medicine

MedlinePlus brings together authoritative health information from the National Library of Medicine (NLM), the National Institutes of Health (NIH), and other government agencies and health-related organizations.

kontakt@hittavard.se

Ⓒ 2024. Alla rättigheter förbehålls av juxt ab

Sök
Om ossVillkor och policyVanliga frågorKontakta oss