Investigation of Neisseria meningitidis in healthy population in Kashgar, Xinjiang, 2019

  Objective   To investigate the carriage of Neisseria meningitidis in the healthy population of Kashgar, Xinjiang.

  Methods   In four counties in Kashgar prefecture, a total of 703 throat swabs were collected from healthy people in different age group selected by cluster random sampling. N. meningitidis was isolated and identified by culture and real-time PCR. The serogroup of N. meningitidis strain was determined by slide agglutination and real-time PCR. The laboratory results and epidemiological survey data were analyzed.

  Results   In this study, a total of 91 N. meningitidis strains were isolated with a carriage rate of 12.94%. The proportion of serogroup B, C, W, Y, E and non-groupable (NG) strains were 32.97% (30/91), 13.18% (12/91), 16.48% (15/91), 12.09% (11/91), 1.10% (1/91) and 24.17%(22/91), respectively. The N. meningitidis carriage rate in healthy population were 27.27% (27/99) in age group 15–19 years, 15.00% (21/140) in age group ≥20 years, 14.20% (23/162) in age group 7–14 years, 9.18% (9/98) in age group 5–6 years, 4.90% (5/102) in age 3–4 years and 5.88% (6/102) in age group 0–2 years, respectively, the differences were significant ( χ²=45.725, P<0.05). A total of 185 throat swabs were positive in real-time PCR, and the difference in detection rates between culture and real-time PCR was significant ( χ²=153.589, P<0.05).

  Conclusion   The N. meningitidis carriage rate in healthy population in Kashgar was relatively high with age group 15–19 years having the highest carriage rate. The serogroups of N. meningitidis strains isolated from the healthy population were complex. The application of real-time PCR in the carriage survey of N. meningitidis in healthy population can increase the positive rate of the detection.