The incidence of scarlet fever.

This study attempted to find the incidence of scarlet fever in the Oxford region, including the proportion of patients from whom Streptococcus pyogenes could be isolated. General practitioners collected throat swabs from patients with suspected scarlet fever. The swabs were examined for viral and bacterial pathogens. Children admitted to hospital were used as controls. Twenty-five of 105 patients with suspected scarlet fever grew Str. pyogenes; M type 4 was the commonest type. The clinical diagnosis of scarlet fever was not always confirmed by throat culture. The annual incidence of scarlet fever was estimated to be 0.3 cases per 1000 per year.