Table 2.

Viral Infection Detected by Culture and/or Serologic Testing in Acute Exacerbations of Chronic Obstructive Pulmonary Disease (COPD) in 8 Studies Published During 1960–1980 [15]

			Percentage of total viral isolates
Variable	No. of exacerbations included	Percentage viral	Rhinovirus	Influenza	Para influenza	Respiratory syncytial virus	Coronavirus	Adenovirus
Total	1081
Mean	135	36	38	26	15	11	10	3
Range	42–522	20–61	0–78	0–45	0–39	0–40	6–18	0–10