Abstract
The results found and the laboratory methods used for the isolation of viruses and β haemolytic streptococci in two MRC/PHLS surveys of respiratory disease in patients in hospital and general practice are described. 717 viruses and 82 β haemolytic streptococci were isolated from 2418 children in hospital and 835 viruses and 435 strains of β haemolytic streptococci from patients seen in general practice. Virus isolation rates in the two surveys were 28·9% and 21·0% respectively. Rates by age, sex, time and by clinical categories are given and discussed in relation to isolations from control subjects, the cause of deaths in twenty-two of the children tested, and the incidence of convulsions and meningism found in those examined in these surveys.