Epidemiological and Clinical Features of Meningococcal Meningitis in Infants - China, 2006-2023.

INTRODUCTION

Infants have the highest incidence of meningococcal meningitis (MM) among all age groups in China. Infants receive their first and second doses of serogroup A meningococcal polysaccharide vaccine at 6 and 9 months of age.

METHODS

We extracted data on MM cases among 0-11-month-old children reported during 2006-2023 from the National Notifiable Diseases Registry System and the National Meningococcal Disease Surveillance System and conducted an epidemiological and clinical analysis.

RESULTS

During the study period, 721 infant MM cases were reported. Incidence decreased from 7.31 cases per million to 2.74 per million, while the all-age incidence declined from 1.27 cases per million to 0.06 per million. Among 210 cases with serogrouping results, five serogroups (A, B, C, W, Y) and non-groupable strains were detected. Serogroup A cases decreased from 36.36% to 1.87% during the study period, while serogroup B increased from 14.55% to 67.29%. Fever, nausea, and/or vomiting were common symptoms across all serogroups. The frequencies of petechiae and/or purpura in serogroup A (73%) and C (92%) were substantially higher than in other serogroups. Among serogroup B cases, 26.42% developed petechiae and/or purpura, 26.42% exhibited neck stiffness, and 13.21% had positive Kernig's and/or Brudzinski's signs.

CONCLUSIONS

The incidence of MM in infants has significantly decreased but remains higher than incidence across all age groups. Serogroup B cases were the most common. Atypical symptoms in infant cases challenge timely diagnosis. We suggest eligible infants receive meningococcal vaccination timely, and the development of serogroup B meningococcal vaccines should be accelerated.