Epidemiological Study on Community Acquired Pneumonia

Overview

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.

Detailed description

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.

Primary outcome measures

• diagnosis [Time frame: 2 weeks]
• therapy [Time frame: 2 weeks]
• hospitalization [Time frame: 2 weeks]

Eligibility criteria

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

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: No

Study design

Observational model

Cohort

Study locations

Germany · 1 center

• Medical School Hannover — Hanover

Publications

• Welte T, Suttorp N, Marre R. CAPNETZ-community-acquired pneumonia competence network. Infection. 2004 Aug;32(4):234-8. doi: 10.1007/s15010-004-3107-z. No abstract available. PMID 15293080
• Welte T, Marre R, Suttorp N. [CAPNet--network of competence for community acquired pneumonia: structures and aims]. Pneumologie. 2003 Jan;57(1):34-41. doi: 10.1055/s-2003-36635. German. PMID 12528066
• Weckler BC, Wu Q, Bertrams W, Kutzinski M, Reiter R, Khan SA, Ahnert P, Suttorp N, Witzenrath M, Wildberg C, Pletz MW, Rupp J, Zissler UM, Greulich T, Brenner T, Alter P, Rohde G, Vogelmeier CF, Mayr A, Schmeck B. Association Between Admission Eosinophil Count and Hospital Resource Use in Community-Acquired Pneumonia: A Prospective Multicenter Study. Chest. 2026 Mar 31:S0012-3692(26)00427-7. doi: PMID 41933608
• Mendez R, Gonzalez-Jimenez P, Latorre A, Piqueras M, Mengot N, Hervas D, Knox D, Carr J, Barten-Neiner G, Rohde G, Pletz MW, Rupp J, Witzenrath M, Dean NC, Menendez R. The Long-term Pneumonia Mortality Index: an international multicenter derivation and validation study for patients with community-acquired pneumonia. Am J Respir Crit Care Med. 2026 Jun 1;212(6):1305-1314. doi: 10.1093/ajrccm/aamag0 PMID 41738235
• Millet Pascual-Leone B, Fiocca Vernengo F, Hillus D, Wernicke C, Krishnamoorthy G, Rupp J, Rohde G, Pletz MW, Witzenrath M; CAPNETZ-study group; Suttorp N, Sander LE, Vestergaard Jensen A, Opitz B, Thibeault C. Community-acquired pneumonia in diabetic patients is characterised by a distinct pathogen spectrum and enhanced inflammation: results from CAPNETZ, a prospective observational cohort study. PMID 41077620
• Pott H, Gaffron S, Martin R, Maier D, Kutzinski M, Weckler B, Bertrams W, Jung AL, Laakmann K, Heider D, Vogelmeier CF, Rohde G; CAPNETZ Study Group; Schmeck B. Self-organising map clustering identifies high-risk clusters of post-acute mortality in a prospective multicentre study of community-acquired pneumonia. ERJ Open Res. 2026 Jan 19;12(1):00374-2025. doi: 10.1183/23120541.00374-2025. eCollect PMID 41561102
• Waldeck F, Lemmel S, Panning M, Kading N, Essig A, Rohde G, Pletz MW, Witzenrath M, Boutin S, Rupp J; Members of the CAPNETZ study group. Comparing viral, bacterial, and coinfections in community-acquired pneumonia, a retrospective cohort study. Int J Infect Dis. 2025 May;154:107841. doi: 10.1016/j.ijid.2025.107841. Epub 2025 Feb 21. PMID 39988242
• Rischke S, Gurke R, Zielbauer AS, Ziegler N, Hahnefeld L, Kohm M, Kannt A, Vehreschild MJ, Geisslinger G, Rohde G, Bellinghausen C, Behrens F, Study Group C. Proteomic, metabolomic and lipidomic profiles in community acquired pneumonia for differentiating viral and bacterial infections. Sci Rep. 2025 Jan 14;15(1):1922. doi: 10.1038/s41598-025-85229-2. PMID 39809876

Identifiers

NCT: NCT02139163 · U1111-1147-8393

Primary sources (government registries)

• ClinicalTrials.gov (US NIH)

View this study on ClinicalTrials.gov ↗