[Analysis of epidemic characteristics for meningococcal meningitis in China during 2015-2017].

Objective

To analyze the characteristics of epidemiology and neisseria meningitidis (Nm) serogroups distribution for meningococcal meningitis (MM) cases in China from 2015 to 2017.

Methods

The data of MM cases were collected from National Notifiable Diseases Registry System (NNDRS) and case-based MM surveillance system (MMSS) from 2015 to 2017; Demographic data are from the National Bureau of statistics. Inclusion criteria: the date of onset was January 1, 2015 to December 31, 2017, the status of infectious disease report card was "final examination card", the cases are classified as "laboratory confirmed cases" and "clinical diagnostic cases", and the card data information of disease name was "Meningococcal meningitis". According to the Diagnostic Criteria for Meningococcal meningitis (WS295-2008), laboratory confirm was made for reported cases or clinically diagnosed cases of meningococcal meningitis.

Results

From 2015 to 2017, a total of 325 MM cases were reported in China, with an average annual incidence of 0.007 9 per 100 000 population. And 148 cases were laboratory confirmed. There were 3, 15, 12, 5, 2 and 18 provinces which were reported serogroup A, B, C, W, Y, Others and NG MM Cases, respectively. Except for Tibet and Hainan, other provinces have reported group A cases; The provinces reporting group B, C, W and Y cases increased by 9, 11, 13 and 2 provinces in 2007, respectively compared with 2005. Serogroup B was the primary reason causing the cases of <1 year old and 1-6 years old children; and in this age group, 51.43% (18 cases) and 68.18% (15 cases) of group B were accounted for in laboratory confirmed, respectively; Serogroup C, others and NG was the major reason in the cases of 7-12 and >12 years old students and adults: 33.33% (5 cases) and 26.32% (20 cases) of group C were accounted for in laboratory confirmed respectively, then 26.67% (4 cases) and 34.21% (26 cases) of group others and NG were accounted for respectively; 2 cases of serogroup Y were all >12 years old.

Conclusion

The epidemic serogroup of Nm caused MM cases showed a diversifying trend. To develop and provide new vaccines for serogroup B and other bacteria groups should be one of the important tasks for MM control and prevention in the future.