Hemophilus influenzae type b disease. An epidemiologic study with special reference to day-care centers.

Day-care centers are a relatively new phenomena of American society that bring together large numbers of young children susceptible to contagious disease. This study examines the incidence and risk factors of endemic Hemophilus influenzae type b disease both in the general population and in day-care attendees in Monroe County, New York, for 1982 and 1983. The attack rate in the general population (excluding day-care attendees) was highest in children younger than 1 year (131.9 cases per 100,000 per year) and in those 1 to 2 years old (75.7 cases per 100,000 per year) compared with older children. The relative risk for day-care attendees was much greater than that of the general population. It was 12.3 times greater for children younger than 1 year, 7.2 times greater for those 1 to 2 years old, and 3.8 times greater for those 2 to 3 years old. We conclude that children attending day-care facilities face a substantial increased risk of contracting invasive H influenzae type b disease. Efforts to prevent susceptibility and contagious spread of this disease in this population seem necessary.