Demographic factors in the epidemiology of hemophilus influenzae meningitis in young children.

To determine the effect of various demographic factors on the incidence of Hemophilus influenzae, type b meningitis, Rhode Island residents with H. influenzae in 1970-1974 were identified by review of data from the State Department of Health, a private health care research organization, death certificates, and hospital bacteriology laboratories. Of the 108 cases of H. influenzae, 99 (92%) occurred in children under five years of age. The disease incidence among black children under five (103.6/100,000/annum) was significantly (P less than 0.0005) higher than that among white children (23.9/100,000/annum). By eliminating the 29 of 185 census tracts in which the total population was greater than 5% black, disease incidence was studied in a virtually monoracial population. In these white census tracts, in which the population was 99.2% white, the occurrence of H. influenzae was not related to family income, education, number of household members, population density, or rate of hospitalization. These findings confirm the increased incidence of H. influenzae in blacks and indicate that socioeconomic factors do not affect the incidence of the disease in white children.