Table 1.
Characteristics of included studies.
| First author | Study setting | Study design | Patient characteristics | Total number of patients with CAP | Number of viruses tested for | Male% | Diagnostic methods | Principal study focus | Specimen sites* |
|---|---|---|---|---|---|---|---|---|---|
| Le Bel [26] | France, inpatients | Prospective cohort | Patients aged >18 years presented to Emergency dept. | 319 | 8 | 101 (31.7%) | PCR | Inflammatory biomarkers in CAP patients | UR |
| Capelastegui [27] | Spain, inpatients and outpatients | Prospective cohort | Patients aged >18 years in the community and hospital | 700 | 5 | Incomplete: 239 of 390 (61.3%) | Blood cultures, urinary antigen tests, serology, direct immunofluorescence antibody assay | Aetiology of CAP | S |
| Cilloniz [28] | Spain, inpatients and outpatients | Prospective cohort | Patients aged >16 years admitted to the Emergency wards and outpatients. | 568 | 5 | 301 (53.0%) | Serology, blood culture, antigen tests. | Aetiology of CAP | UR |
| Clark [29] | UK, inpatients | Prospective cohort | Patients aged >18 years admitted to hospital with acute respiratory infection but subset with CAP patients | 166 | 9 | 87(52.4%) | Blood and Sputum culture, PCR | Aetiology of ARI in adults | S |
| Das [30] | France, inpatients | Prospective cohort | Patients aged >18 years admitted to the Emergency dept. | 125 | 7 | Not reported | PCR | Aetiology of CAP | UR |
| de Roux [31] | Spain, inpatients | Prospective cohort | Patients aged >18 years admitted to hospital | 1356 | 5 | 893(65.8%) | Serology, complement fixation kit tests for viruses. | Viral CAP in non-immunocompromised adults | LR, S |
| Diederen [32] | Netherlands, Inpatients | Prospective cohort | Patients aged >18 years admitted to the hospital | 242 | 8 | 7(2.9%) | PCR, serology, ELISA | Detection of respiratory pathogens using PCR | LR, S |
| Guiterrez [33] | Spain, inpatients and outpatients | Prospective cohort | Patients aged >15 years admitted to the hospital | 493 | 5 | 308(62.5%) | Blood and sputum cultures, complement fixation tests. | Investigating the influence of age and gender on the incidence of CAP | LR, S |
| Holm [34] | Denmark, outpatients | Prospective cohort | Patients aged >18 years with CAP presenting to the GP | 48 | 6 | 28(58.3%) | PCR | Aetiology of CAP | LR |
| Holter [35] | Norway, inpatients | Prospective cohort | Patients aged >18 years admitted to the hospital | 267 | 8 | 140(52.4%) | Culture, serology, PCR | Aetiology of CAP in Norway | UR |
| Howard-a [25] | UK, inpatients | Prospective cohort | Patients aged >15 years | 69 | Uncertain | 6(8.7%) | Complement fixation tests, blood culture | Not reported | LR, S |
| Howard-b [25] | UK, inpatients | Prospective cohort | Patients aged >16 years | 99 | Uncertain | 6(6.1%) | Complement fixation tests, blood culture | Aetiology of CAP | LR,S |
| Johansson [36] | Sweden, inpatients | Prospective cohort | Patients aged >18 years admitted to the hospital | 184 | 9 | 94(51.1%) | Culture, PCR, Serology | Aetiology of CAP | UR |
| Joikinen [37] | Finland, inpatients and outpatients | Prospective cohort | Patients aged >15 years admitted to the hospital and patients in the community | 345 | 7 | 176(51.0%) | Serology | Aetiology of CAP in adults in Eastern Finland | S |
| Koksal [38] | Turkey, outpatients | Cross −sectional | Patients aged >17 years with CAP in outpatient settings | 292 | 6 | 147(50.3%) | Culture, direct immunofluorescence, serology | Aetiology of CAP in adults in Turkey | UR, LR |
| Liberman [39] | Israel, inpatients | Prospective cohort | Patients aged >18 years admitted to the hospital | 183 | 8 | 105(57.4%) | PCR | Evaluate the role of respiratory viruses in adult CAP | UR |
| Lim [40] | UK, inpatients | Prospective cohort | Patients aged >16 years admitted to the hospital | 267 | 5 | 135(50.6%) | Other conventional methods | Investigate the aetiology of CAP and implication for CAP management | S |
| Sangil [41] | Spain, inpatients | Prospective cohort | Patients aged >18 years admitted to the hospital | 169 | 9 | Not reported | PCR, serology | Aetiology of CAP using PCR and other conventional methods. | UR |
| Shibli [42] | Israel, inpatients | Prospective cohort | Patients aged >18 years admitted to the hospital | 127 | 6 | 73(57.5%) | PCR, DNA & RNA extraction, Serology | Investigate the aetiology of CAP in hospitalised patients . | UR, LR |
| van Gageldonk-Lafeber [43] | Netherland, inpatients | Prospective cohort | Patients aged >18 years presented to the Emergency dept. | 339 | 9 | 212(62.5%) | Culture, serology, antigen tests, PCR | Aetiology of CAP | UR, LR |
| Viasus [44] | Spain, inpatients | Prospective cohort | Adult patients admitted to the hospital | 747 | 8 | 423(56.8%) | PCR, Serology | Aetiology of CAP | UR |
| Templeton [45] | Netherlands, inpatients and outpatients | Prospective cohort | Patients aged >18 years admitted to the hospital | 136 | 7 | 75(55.1%) | Culture, PCR, Serology | Aetiology of CAP | LR, S |
| Bochud [46] | Switzerland, outpatients | Prospective cohort | Patients aged >15 years | 184 | 4 | 82(44.6%) | Serology | Aetiology of CAP in outpatients | UR, LR, S |
| Marcos [47] | Spain, inpatients | Prospective cohort | Patients aged >14 years admitted to the hospital | 198 | 7 | 115(58.1%) | PCR, immunofluorescence and culture | Aetiology of CAP | LR |
| Hohenthal [48] | Finland, inpatients | Prospective cohort | Patients aged >18 years admitted to the hospital | 71 | 7 | 48(67.6%) | Culture | Diagnostic value of BAL | LR |
| Huijskens [49] | Netherland, inpatients | Prospective | Patients aged >18 years presented to the emergency dept. | 408 | 11 | 250(61.3%) | PCR, Culture and serology | to differentiate pure bacterial, pure viral and mixed viral and bacterial aetiologies based on clinical signs admission | UR, LR, S |
| Cilloniz [50] | Spain, Inpatients | Prospective cohort | >18 years with CAP admitted to ICU within 24 h | 362 | 5 | 232(64.1%) | Immunofluorescence, PCR | polymicrobial pneumonia | UR, LR, S |
| Almirall [51] | Spain, inpatients and outpatients | Prospective cohorts | >14 years, 216 patients were managed at home and 280 patients were admitted to hosp. | 496 | 7 | 302(60.9%) | Culture, serology, Immunofluorescence | Differences in aetiology of CAP | LR, S |
Specimen sites: UR = upper respiratory tract; LR = lower respiratory tract; S = serological assessment (using paired sera). *In studies which sampled from >1 site, not all patients will have undergone sampling at all sites.