The main objective of this study is to investigate prevalence and risk factors for community-acquired pneumonia (CAP) and its interaction with comorbidities in an unselected group of adult patients receiving outpatient and inpatient care. In addition, information on HIV as a risk factor for CAP and on CAP in immunocompromised patients is collected.

The CAPNETZ study is a prospective, multicenter observational study investigating community-acquired pneumonia (CAP). Patients are recruited from outpatient and inpatient settings at hospitals and from primary care physicians (primarily specialists) and are followed for a period of six months. All CAP patients who meet the inclusion and exclusion criteria, consent to participate, and in whom the presence of a newly developed, community-acquired pneumonia can be verified are invited to participate. The baseline examination includes a detailed medical history, medication history, and a physical examination to record clinical and vital signs. In addition, the results of routine clinical imaging are documented, and biosamples (blood, urine, and respiratory specimens) are collected for clinical chemistry and microbiological analysis. Further in-person visits to document the course of the disease and treatment, including the collection of additional blood samples, take place 3 and 7 days after study enrollment. Twenty-eight days after enrollment, the patient's health status, treatment course, and complications are assessed by telephone. Finally, after 180 days, a telephone survey is conducted to determine the patient's whereabouts and survival status. Apart from the collection of biomaterials, no interventions are required or planned; physicians treat their patients as they normally would.

Inclusion Criteria:

• age ≥ 18
• infiltrate on chest X-ray
• further Inclusion criteria (at least one must apply): cough or purulent sputum or pathologic lung auscultation (crackles) or fever

Exclusion Criteria:

• Hospitalization lasting longer than 48 hours prior to the diagnosis of the current pneumonia
• Newly diagnosed, active pulmonary tuberculosis within the last 2 months

patients with pneumonia

All individual non-personal data and biomaterials collected as part of the study are available for use. This requires a formal request that describes a specific research project and specifies the data needed. Applications have to be submitted on https://capnetz.de/en/project-application/ .

Upon approval by the Executive Board, the relevant data and biomaterials will be provided.