TABLE 3.

Baseline characteristics and serological results of the 72 patients with empyema and 78 controls

	Empyema	SPPE	Cardiac effusions
Patients	72	29	49
Age years	59 (43–72)	68 (53–80)	75 (67–82)
Male/female %	49/23	16/13	34/15
Right/left %	40/32	17/12	38/11
Symptom duration days	10 (4–16)	4 (2–6)	35 (10–78)
Serum complement fixation testing
Influenza all	17 (24)	2 (7)	2 (4)
Influenza A	14 (20)	1 (3)	2 (4)
Influenza B	3 (4)	1 (3)	0 (0)
RSV	2 (3)	2 (7)	6 (12)
Age range of serology-positive patients years	38–90	41–85	49–87

Data are presented as n, median (interquartile range) or n (%). SPPE: simple parapneumonic effusions; RSV: respiratory syncytial virus.