ACUTE BRONCHITIS IN ADULTS - HOW CLOSE DO WE COME TO ITS ETIOLOGY IN GENERAL-PRACTICE

Objective - To investigate how close we can come to the aetiology of a cute bronchitis in adults in a primary care setting. Design - Prospect ive study. Setting - General practice population in Gardabaer district , south-western Iceland. Subjects - 140 patients greater than or equal to 16 years aid who were diagnosed as having acute bronchitis during a two-year period (1992-1993). Main outcome measures - Laboratory inve stigations (twice with a minimum four-week interval), used in general practice to analyse respiratory tract infections, They included serolo gy for Chlamydia pneumoniae, Mycoplasma pneumoniae, respiratory tract viruses, and the level or C-reactive protein. Results - Of a total of 140 patients, two blood samples were taken on scheduled time in 113 pa tients, Serology confirmed recent infection in 18 (16%) of these patie nts. Only two (2%) had a bacterial infection (one C. pneumoniae, one M . pneumoniae). The others (84%) did not have a significant increase in antibody titres. Only four (4%) had C-reactive protein levels higher than 48 mg/l. Conclusions - The study indicates that it is difficult t o come close to a precise aetiology with respect to infectious agents of acute bronchitis in general practice. We conclude that the disease is rarely caused by atypical bacteria such as C. pneumoniae and M. pne umoniae, and rarely caused by bacterial infections severe enough signi ficantly to increase the level of C-reactive protein.