title: Shift in the age-distribution of meningococcal disease as predictor of an epidemic?
abstract: Demographic data for several years before, during, and after an epidemic of meningococcal meningitis show that the age-distribution of the disease shifts considerably during an epidemic--although the highest incidence of meningococcal infections was still that among children under 5 years old, the proportion of patients aged greater than 4 years increased significantly. The ratio of the number of cases aged over 4 years to that aged up to 4 years was 0.833 and 0.775 in two non-epidemic periods, but 2.95 and 2.29 in two epidemic years. Careful demographic surveillance may reveal the approach of a meningococcal epidemic sooner than do the present surveillance methods.
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D001428:Bacterial Vaccines / Q000008:administration & dosage; D002648:Child; D002675:Child, Preschool; D002980:Climate; D004196:Disease Outbreaks / Q000453:epidemiology*; D006801:Humans; D007223:Infant; D008589:Meningococcal Infections / Q000453:epidemiology* / Q000517:prevention & control; D009345:Neisseria meningitidis / Q000276:immunology; D011379:Prognosis
chemical_list: D001428:Bacterial Vaccines