. 2003 Nov 6;22(12):720–725. doi: 10.1007/s10096-003-1042-z

Table 3.

Etiologic diagnoses

Pathogen	Total diagnoses	Diagnostic accuracy		Timing of diagnosis after admission		Delay LRTI onset – admission^f
		Definite^a	Probable^b	Early^c diagnosis	Late^d diagnosis	≤3 days (n=70)	4–7 days (n=24)	>7 days (n=30)
		diagnosis	diagnosis	Early^c diagnosis	Late^d diagnosis	≤3 days (n=70)	4–7 days (n=24)	>7 days (n=30)
Influenza	43	43 (100%)	0	22 (51.2%)	21 (48.8%)	20 (46.5%)	7 (16.3%)	9 (20.9%)
RSV	6	6 (100%)	0	1 (16.6%)	5 (83.4%)	1 (16.6%)	0	1 (16.6%)
Parainfluenza	2	2 (100%)	0	0	2 (100%)	2 (100%)	0	0
S. pneumoniae	6	6 (100%)	0	6 (100%)	0	2 (33.3%)	2 (33.3%)	2 (33.4%)
S. aureus	2	1 (50%)	1 (50%)	2 (100%)	0	0	1 (50%)	0
Gram negative^e	7	1 (14%)	6 (86%)	7 (100%)	0	3 (42.9%)	1 (14.3%)	2 (28.5%)
M. pneumoniae	1	1 (100%)	0	0	1 (100%)	0	1 (100%)	0
Total (n=165)	67 (40.1%)	60 (36.4%)	7 (4.2%)	38 (23%)	29 (17.6%)	28 (17%)	12 (7.3%)	14 (8.5%)

RSV, respiratory syncytial virus

^aDefinite diagnosis: positive hemoculture, positive viral culture, fourfold rise in serological titres

^bProbable diagnosis: good-quality sputum (i.e. more polymorphonuclear than squamous epithelial cells) and a sputum culture with 1 pathogen

^cEarly diagnosis: established ≤72 h after admission

^dLate diagnosis: established >72 h after admission (i.e. fourfold rise in serological titres)

^eGram-negative: A. lwoffi 1 positive blood culture; H. influenzae 2, E. coli 3, E. cloacae 1 positive sputum cultures

^fFor 41 patients, exact onset was indefinable