Investigation of antibody level against Neisseria meningitidis W135 and Y in healthy population in Tianjin, 2016

Objective To understand the antibody level against Neisseria meningitidis W135 and Y in healthy population in Tianjin and provide scientific evidence for the prevention and control of meningococcal meningitis.

Methods In 2016, a total of 811 healthy people were selected in urban, suburb and outer suburb areas in Tianjin through age-stratified random sampling. Blood samples were taken from them to detect IgG against N. meningitidis W135 and Y with enzyme-linked immunosorbent assay(ELISA).

Results The positive rate of antibody against N. meningitidis W135 and Y were 26.51% and 29.96% respectively, the median of antibody titers were all ＜0.01 μg/ml. The positive rate of IgG against N. meningitidis W135 was 21.07% in males and 31.20% in females, the difference was significant (χ²＝10.610, P＝0.001). The positive rate of IgG against N. meningitidis Y was 26.93% in males and 32.57% in females, the difference was not significant (χ²＝3.051, P＝0.081). The positive rates of IgG were highest in urban area (44.00% for W135 and 49.50% for Y), followed by those in suburb area (27.49% for W135, 31.87% for Y) and in outer suburb area (7.00% for W135, 6.50% for Y), the differences were significant (χ²＝7.682, P＝0.001; χ²＝89.559, P＝0.001). In different age group, the positive rates of IgG against W135 and Y were highest in age group ＞50 years (52.50% for W135, 40.00% for Y), the differences had significance (χ²＝81.434, P＝0.001; χ²＝34.391, P＝0.001).

Conclusion Infections with N. meningitidis W135 and Y were detected in Tianjin, and general population is susceptible to the infection. It is necessary to strengthen the surveillance for meningococcal meningitis and take strict measures to prevent the outbreaks ofN. meningitidis W135 and Y.