Respiratory Viral Infections in Hospital Patients with Chronic Bronchitis: Observations during Periods of Exacerbation and Quiescence

Abstract

All patients admitted to the pneumology department with chronic bronchitis between November, 1968, and July, 1969, were included in the survey. During periods of exacerbation diagnosis of viral infection was based on virus isolation, associated or not with seroconversion. Outside the periods of exacerbation the survey was confined to determining seroconversion on serum samples taken every month. Forty-nine exacerbations were observed. A diagnosis of viral infection was made in 31 cases (63.3 percent) by virus isolation and/or seroconversion. Seroconversion alone detected 21 of 37 cases (56.8 percent). Isolation alone detected a virus in 15 of 29 cases (51.7 percent). In 10 of these 29 cases (34.4 percent), moreover, viruses were isolated in urine during the first few days of the exacerbation. The viruses most frequently involved were influenza and parainfluenza. The ratio of association between viral infections and exacerbations is high; the seroconversion study during exacerbations and at other times revealed a great difference, 58.3 percent to 3.7 percent.