Influence of Age on Serogroup Distribution of Endemic Meningococcal Disease

Abstract

The age distribution of 126 infants and children with disseminated meningococcal disease hospitalized consecutively in Houston [Texas, USA] between Jan. 1977 and June 1979, and between Jan. 1981 and June 1981 was analyzed and compared with that in the USA as a whole and to that during outbreaks of group B disease in North America and epidemics of group C disease in South America. Eighty-one (64.3%) isolates from Houston cases were serogroup B and 37 (29.4%) were serogroup C Neisseria meningitidis. Children with serogroup C disease were significantly older than those with group B disease (P = 0.017). Of the children with serogroup B infections, 33% were < 12 mo. old and 8.6% were < 3 mo. old. Of those with serogroup C disease, only 2.7% were < 3 mo. old and the majority (73%) were > 2 yr old. These age distributions are similar to those reported for the entire USA during endemic periods. Focal outbreaks of group B meningococcal infection occurred in populations that were significantly older (0.02 > P < 0.05). Epidemic disease in South America due to serogroup C strains also occurred in older children when compared with the occurrence of endemic group C disease in the USA (P = 0.02).