None was isolated in 162 cases.There was a tendency of decreasing in meningococcal and unknown pathogenic meningitis and increasing of gram-negative bacterial meningitis during the 11 years.

• 在11年间的观察中，我们发现脑膜炎双球菌及未明病菌脑膜炎病例有渐减，而格兰氏阴性菌脑膜炎病例渐增的趋势，其他则不变。