Socio-economic factors and rheumatic fever occurrence. Differences between patients with and without frequent sore throat.

One hundred and fourty-eight rheumatic fever patients and 444 controls matched by age, sex and place of residence, were interviewed about socio-economic and some other variables. Socio-economic factors recognized as risk factors for rheumatic fever (flat dampness, more than 2 persons per room, sleeping in bed with other person, low education of mother and undernourishment) were of lesser importance for persons with frequent sore throat in comparison to persons without frequent sore throat. According to the results obtained it seems that there is positive connection between host's propensity to clinical manifestation of throat infection and manifestation of rheumatic fever. The lesser susceptibility the more additional factors are needed for Rheumatic Fever to occur. The relative importance of socio-economic factors in rheumatic fever occurrence depends on host's susceptibility to infection.