Objective The study aimed to compare the epidemiology of bacterial meningitis (BM) before and after vaccination, and identify possible risk factors associated with mortality.

Methods The medical and microbiologic records of children (1 month–18 years) with a discharge diagnosis of BM in a third level children's hospital in Mexico from 1990 to 2018 were reviewed. The epidemiology, pathogens, and outcomes were compared before and after introducing Haemophilus influenzae type b (Hib) and pneumococcal conjugate vaccines to the Mexican immunization schedule. Risk factors associated with mortality were determined.

Results In the 28-year period, 226 cases with BM were included 55.8% (1990–1999), 27.4% (2000–2008), and 16.8% (2009–2018) (p = 0.0001). The most frequent pathogen was Hib, documented in 39% of cases. There was a reduction in neurological complications after introducing the Hib conjugate vaccine (59 vs. 39%; p = 0.003) and sequelae after the Streptococcus pneumoniae conjugate vaccine (43 vs. 35%; p = 0.05). Independent risk factors associated with mortality were coma (odds ratio [OR]: 15 [2.9–78]), intracerebral bleeding (OR: 3.5 [1.4–12]), and pneumococcal meningitis (OR: 9.4 [2.2–39]).

Conclusion Since the introduction of Hib and pneumococcal conjugate vaccines to the national immunization schedule, there was a reduction in BM cases, mainly associated with the Hib vaccine, with the consequent reduction of neurological complications and sequelae.

目的 本研究旨在比较疫苗接种前后细菌性脑膜炎（BM）的流行病学，并确定与死亡率相关的可能危险因素。

方法 回顾性分析1990年至2018年墨西哥某三级儿童医院出院诊断为BM的儿童（1个月～18岁）的医疗和微生物学记录。在将b 型流感嗜血杆菌(Hib) 和肺炎球菌结合疫苗引入墨西哥免疫计划之前和之后，比较了流行病学、病原体和结果。确定了与死亡率相关的危险因素。

结果 在 28 年期间，226 例 BM 包括 55.8% (1990-1999)、27.4% (2000-2008) 和 16.8% (2009-2018) ( p  = 0.0001)。最常见的病原体是 Hib，记录在 39% 的病例中。引入 Hib 结合疫苗后神经系统并发症（59 对 39%；p  = 0.003）和肺炎链球菌结合疫苗后后遗症（43 对 35%；p  = 0.05）有所减少。与死亡率相关的独立危险因素是昏迷（比值比 [OR]：15 [2.9-78]）、脑内出血（OR：3.5 [1.4-12]）和肺炎球菌脑膜炎（OR：9.4 [2.2-39]）。

结论 自从将 Hib 和肺炎球菌结合疫苗引入国家免疫计划以来，BM 病例有所减少，主要与 Hib 疫苗有关，从而减少了神经系统并发症和后遗症。