National Neisseria and Streptococcus Reference Center, Department of Bacteriology, Mycology, and Parasitology, Statens Serum Institut, Copenhagen, Denmark.
Clin Infect Dis. 2010 Feb 1;50(3):329-37. doi: 10.1086/649872.
Pneumococcal infections have historically played a major role in terms of morbidity and mortality. We explored historical trends of invasive pneumococcal disease (IPD) and pneumococcal serotypes in a population exposed to limited antibiotic selective pressure and conjugate pneumococcal vaccination (PCV).
Retrospective cohort study based on nationwide laboratory surveillance data on IPD collected uninterruptedly in Denmark during 1938-2007. Changes in the reported incidence and trends of pneumococcal serotypes were explored using nonlinear regression analysis.
There were 25,502 IPD cases included in our study. The median incidence of IPD increased from 2.8 cases per 100,000 population (interquartile range [IQR], 1.5-2.6) during the first 4 decades to 15.7 cases per 100,000 population (IQR, 7-20.4) during the 1980s and 1990s, mainly attributed to an increase in the number of bacteremia cases. The incidence of meningitis remained relatively stable, with a median of 1.3 cases per 100,000 population (IQR, 0.9-1.6). The proportions of serotypes/groups 4 and 9 increased; the proportion of serotype 18C decreased; the proportions of serotypes 6, 7F, 14, and 23F remained stable; and serotype 2 nearly disappeared. Before the 1960s, serotypes 1, 2, 3, and 5 presented peaks every 2-3 years, becoming less frequent during the 1970s with peaks every 7-10 years. Between 20% and 90% of IPD in children <5 years were caused by PCV serotypes during the last 4 decades. Cases of IPD caused by serotype 19A increased before introduction of PCV. Between 1993 and 2007, the level of resistance to macrolides and beta-lactams was 6%.
The epidemiology of IPD and single serotypes has constantly changed over the past 7 decades. PCV serotypes appeared to dominate the pneumococcal population.
肺炎球菌感染在发病率和死亡率方面一直起着重要作用。我们探索了在接触有限抗生素选择压力和结合型肺炎球菌疫苗（PCV）的人群中，侵袭性肺炎球菌病（IPD）和肺炎球菌血清型的历史趋势。
这是一项基于丹麦在 1938-2007 年期间不间断收集的全国性 IPD 实验室监测数据的回顾性队列研究。使用非线性回归分析来探讨报告的发病率变化和肺炎球菌血清型趋势。
我们的研究共纳入 25502 例 IPD 病例。IPD 的中位发病率从最初 4 个 10 年的每 100000 人 2.8 例（四分位距 [IQR]，1.5-2.6）增加到 20 世纪 80 年代和 90 年代的每 100000 人 15.7 例（IQR，7-20.4），主要归因于菌血症病例数的增加。脑膜炎的发病率保持相对稳定，中位数为每 100000 人 1.3 例（IQR，0.9-1.6）。血清型 4 和 9 的比例增加；血清型 18C 的比例减少；血清型 6、7F、14 和 23F 的比例保持稳定；血清型 2 几乎消失。在 20 世纪 60 年代之前，血清型 1、2、3 和 5 每隔 2-3 年出现一次高峰，在 20 世纪 70 年代每 7-10 年出现一次高峰，频率降低。在过去的 40 年里，0-5 岁儿童中 20%至 90%的 IPD 是由 PCV 血清型引起的。在引入 PCV 之前，血清型 19A 引起的 IPD 病例有所增加。1993 年至 2007 年，大环内酯类和β-内酰胺类的耐药率为 6%。
在过去的 70 年中，IPD 和单一血清型的流行病学一直在不断变化。PCV 血清型似乎主导了肺炎球菌群体。
