Influence of Indoor Heating on Carrier State of Beta-Hemolytic Streptococci among School Children

A total of 124 school children in Sapporo, Hokkaido, Japan were followed for beta-hemolytic streptococci for 29 months with serial monthly throat cultures. Information on the carrier state, host factors (degree of tonsillar hypertrophy, ABO blood type, HLA serotype, past histories of scarlet fever, measles, rheumatic fever, etc.) and environmental factors (number of siblings, indoor heating system, use of a humidifier, duration of humidifying, etc.) were successfully obtained from 93 of these .124 subjects. Risk factors increasing the probability that a child will become a carrier were examined epidemiologically. A child from a household without a humidifier tended to be a streptococcal carrier (p<0.05).