Department of Clinical Epidemiology, Office of Clinical Epidemiology, Analytics, and Knowledge, Tan Tock Seng Hospital, 11 Jalan Tan Tock Seng, Singapore, 308433, Singapore.
Preventive Medicine Residency Programme, National University Health System, Singapore, Singapore.
BMC Infect Dis. 2020 Jun 17;20(1):423. doi: 10.1186/s12879-020-05140-1.
Streptococcus pneumoniae infections can lead to severe morbidity and mortality, especially in patients with invasive pneumococcal disease (IPD). This study evaluated factors associated with pneumococcal disease, pneumococcal vaccine effectiveness, and risk factors for all-cause mortality in hospitalised adults with pneumococcal disease in Singapore.
Retrospective case-control study of patients tested for pneumococcal disease with streptococcal urinary antigen testing and at least one sterile site culture, during their admission to a tertiary hospital in Singapore from 2015 to 2017. Patients were defined as cases of IPD or non-IPD, or as controls, based on laboratory results and clinical diagnoses. Multivariable models were constructed to determine factors associated with IPD/non-IPD, and risk factors for mortality from pneumococcal disease. Vaccine effectiveness against IPD/non-IPD was estimated using a variation of the test-negative design.
We identified 496 pneumococcal disease cases, of whom 92 (18.5%) had IPD. The mean age of cases was 69.1 ± 15.4 years, and 65.5% were male. Compared with controls (N = 9181), IPD patients were younger (mean age 61.5 ± 16.3 years, vs 72.2 ± 16.1 years in controls; p < 0.001) and with less co-morbidities [median Charlson's score 1 (IQR 0-4), vs 3 (1-5) in controls; p < 0.001]. IPD patients also had the highest proportions with intensive care unit (ICU) admission (20.7%), inpatient mortality (26.1%) and longest median length of stay [9 (IQR 8-17) days]. On multivariable analysis, IPD was negatively associated with prior pneumococcal vaccination (adjusted relative risk ratio = 0.20, 95%CI 0.06-0.69; p = 0.011). Risk factors for mortality among pneumococcal disease patients were ICU admission, diagnosis of IPD, age ≥ 85 years and Charlson's score > 3.
Patients with pneumococcal disease (especially IPD) were younger and had less co-morbidities than controls, but had higher risk of severe clinical outcomes and mortality. Pneumococcal vaccination effectiveness against IPD was estimated to be about 80%, and should be encouraged among high-risk patients.
肺炎链球菌感染可导致严重的发病率和死亡率，尤其是在侵袭性肺炎球菌病（IPD）患者中。本研究评估了与肺炎球菌病相关的因素、肺炎球菌疫苗的有效性以及新加坡住院肺炎球菌病患者全因死亡率的危险因素。
对 2015 年至 2017 年在新加坡一家三级医院住院的患者进行了肺炎球菌病的回顾性病例对照研究，这些患者通过链球菌尿抗原检测和至少一个无菌部位培养进行了肺炎球菌病检测。根据实验室结果和临床诊断，将患者定义为 IPD 或非 IPD 病例或对照。构建多变量模型以确定与 IPD/非 IPD 相关的因素，以及肺炎球菌病死亡率的危险因素。使用测试阴性设计的变体估计疫苗对 IPD/非 IPD 的有效性。
我们共确定了 496 例肺炎球菌病病例，其中 92 例（18.5%）为 IPD。病例的平均年龄为 69.1±15.4 岁，65.5%为男性。与对照组（N=9181）相比，IPD 患者更年轻（平均年龄 61.5±16.3 岁，而对照组为 72.2±16.1 岁；p<0.001），合并症较少[中位 Charlson 评分 1（IQR 0-4），而对照组为 3（1-5）；p<0.001]。IPD 患者还具有 ICU 入住率（20.7%）、住院死亡率（26.1%）和最长中位住院时间[9（IQR 8-17）天]最高的比例。多变量分析显示，IPD 与既往肺炎球菌疫苗接种呈负相关（调整后的相对风险比=0.20，95%CI 0.06-0.69；p=0.011）。肺炎球菌病患者死亡的危险因素包括 ICU 入住、IPD 诊断、年龄≥85 岁和 Charlson 评分>3。
肺炎球菌病患者（尤其是 IPD 患者）比对照组更年轻，合并症更少，但严重临床结局和死亡率的风险更高。肺炎球菌疫苗对 IPD 的有效性估计约为 80%，应鼓励高危患者接种疫苗。
