Epidemiological characteristics of meningococcal meningitis and Neisseria meningitidis carriage in healthy population in southern Xinjiang 2011 to 2022

Objective To understand the epidemiological characteristics of meningococcal meningitis and the carrying status of Neisseria meningitidis in healthy population in southern Xinjiang and provide evidence for the prevention and treatment of meningococcal meningitis.

Methods Descriptive epidemiological methods were used to analyze the incidence data of meningococcal meningitis in southern Xinjiang from 2011 to 2022. Based on the incidence and geographical distribution of meningococcal meningitis in southern Xinjiang, N. meningitidis carriage surveys in healthy population were conducted in three prefectures of southern Xinjiang in 2016, 2018 and 2019. Slide agglutination test and real-time polymerase chain reaction were used to detect the serum group of the strain of N. meningitidis. The carriage rates of N. meningitidis of 2 tests were compared with χ² test.

Results From 2011 to 2022, a total of 219 cases of meningococcal meningitis, including 13 deaths, were reported in four prefectures in southern Xinjiang, with annual incidence rate ranging from 0.08/100 000 to 2.81/100 000. The incidence rate was the highest in 2014 (2.81/100 000). The top two prefectures reporting high case counts were Kashi (111 cases) and Hotan (63 cases). In 1 374 throat swabs from healthy population, 293 strains of N. meningitidis were isolated, with a carriage rate of 21.32%. Serum group B was predominant; There were significant differences in the carriage rate of N. meningitidis among different age groups (χ²=91.552, P<0.001), the carriage rate was highest in age group 16-20 years (33.33%) and lowest in age group ＜3 years (9.79%); There were significant differences in the carriage rates among different areas (χ²=74.514, P<0.001), the highest carriage rate (33.65%) was detected in Hotan, and the serum groups of the N. meningitidis strains were mainly unspecified. There was gender specific significant difference in the carriage rate in healthy population (χ²=10.286, P<0.001); There was significant difference in the carriage rate among healthy individuals with different vaccination status（χ²=40.943, P<0.001). The healthy population with unknown vaccination history had the highest carriage rate (28.13%).

Conclusion The incidence of meningococcal meningitis in southern Xinjiang was mainly sporadic during 2011–2022 instead of the epidemic occurring from time to time. However, the carriage rate of N. meningitidis in healthy population was high, and the serum group of strains varied. It is necessary to strengthen the surveillance for meningococcal meningitis in key populations and places to prevent and control the outbreak of the disease.