The organism Pneumocystis jirovecii was known formerly as Pneumocystis carinii.
Suspicion for Pneumocystis pneumonia (PCP) is based on clinical signs or symptoms of pneumonia in a person with immune suppression, especially when due to HIV infection.
Diagnosis is made by detection of the organism in either induced sputum or bronchoalveolar lavage.
The treatment of choice is trimethoprim/sulfamethoxazole (TMP/SMX).
The incidence of PCP is declining with the use of combination antiretroviral therapy and PCP prophylaxis.
Pneumocystis pneumonia (PCP) is an infection of the lung caused by the fungal organism Pneumocystis jirovecii (formerly known as Pneumocystis carinii). Typically, it causes clinical disease in severely immunocompromised patients, such as HIV-positive patients with CD4 cell counts <200 cells/microlitre, haematopoietic cell transplant patients, solid-organ transplant patients, or patients on chronic immunosuppressive therapy.
History and exam
Key diagnostic factors
Other diagnostic factors
- oropharyngeal candidiasis
- recurrent bacterial pneumonia
- weight loss
- longer duration of symptoms (HIV-positive patients)
- rapid onset of symptoms (HIV-negative patients)
- dry cough
- normal chest examination
- tachypnoea or respiratory distress
- extrapulmonary manifestations
- pleuritic chest pain
- unilateral diminished breath sounds
- CD4 cell count below 200 cells/microlitre
- immunocompromised state
- chronic corticosteroid therapy
- prior Pneumocystis pneumonia
1st investigations to order
- chest x-ray
- arterial blood gas
- serum LDH level
- induced sputum
Investigations to consider
- high-resolution computed tomography (HRCT) chest
- pulmonary function testing
- bronchoscopy and bronchoalveolar lavage (BAL)
- polymerase chain reaction (PCR)
- plasma S-adenosylmethionine level
- serum (1,3)-beta-D-glucan level
high-risk for Pneumocystis pneumonia (PCP) infection
adults or adolescents: HIV-positive
children: HIV-positive or at risk for HIV
immunocompromised adults or adolescents: HIV-negative and not solid-organ transplant recipients
immunocompromised adults or adolescents or children: HIV-negative and solid-organ transplant recipients
completed successful treatment of PCP infection
- Coronavirus disease 2019 (COVID-19)
- Bacterial pneumonia
- Guidelines for the prevention and treatment of opportunistic infections in adults and adolescents with HIV
- Pneumocystis jiroveci in solid organ transplantation
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