To evaluate the sensitivity and specificity of the combined detection system for the diagnosis of pneumocystis infection in immunocompromised population in Southern China.

Pneumocystis jirovecii pneumonia (PJP) is a serious opportunistic infection in immunocompromised patients, with a difficult diagnosis, rapid progression and high mortality rate. The PJP mortality rate is high among patients with delayed diagnosis and treatment, and death is due to severe respiratory failure. Up to now, data regarding Pneumocystis jirovecii infection in immunocompromised patients is limited. In the present prospective study, the investigators aimed to evaluate the sensitivity and specificity of the combined detection system for the diagnosis of pneumocystis infection in immunocompromised population in Southern China.

Inclusion Criteria:

1. Patients with immunocompromised conditions, including but not limited to HIV infection, long-term systemic use of corticosteroids, use of immunosuppressive agents, hematologic malignancies, solid tumors, hematopoietic stem cell transplantation, solid organ transplantation, radiotherapy and/or chemotherapy for malignancies,primary immunodeficiency disease.
2. Patients with typical clinical manifestations of PJP such as fever,nonproductive cough, shortness of breath, and progressive hypoxemia.
3. Patients with radiological abnormalities suggestive to PJP in bilateral lungs revealed by chest computed tomography (CT).
4. Respiratory tract samples were collected for qPCR and/or mNGS detection.

Exclusion Criteria:

1. Patients who were unable to obtain a respiratory specimen.
2. Medical record was incomplete.

Immunocompromised patients who have fever, respiratory symptoms or pulmonary imaging changes were recruited into group.Respiratory tract specimens such as alveolar lavage fluid, sputum and throat swabs were collected from enrolled patients and detected for pneumocystis by the combined detection system including qPCR and/or mNGS.