Institut de Recerca Sant Joan de Deu, Hospital Sant Joan de Deu, Barcelona, Spain.
CIBER de Epidemiologia y Salud Publica (CIBERESP), Instituto de Salud Carlos III, Madrid, Spain.
PLoS One. 2020 Feb 6;15(2):e0228612. doi: 10.1371/journal.pone.0228612. eCollection 2020.
The objective of this study is to describe incidence and shifts of serotype and clonal distribution of invasive Streptococcus pneumoniae strains in four different age groups (<5 years, 5-17 years, 18-64 years and >65 years) during a period of intermediate PCV13 vaccination coverage (2011-2016) in Catalonia, Spain.
We included all pneumococcal strains systematically sent to the Catalan support laboratory for molecular surveillance of invasive pneumococcal disease (IPD) located at Hospital Sant Joan de Deu, Barcelona. Two study periods were considered: 2011-13, early PCV13 vaccination period (EVP) and 2014-2016, late vaccination period (LVP).
A total of 2142 strains were included in the study. Five years after intermediate introduction of PCV13 in our population, a significant decrease of overall incidence of IPD in children <5 years was observed (incidence rate ratio 0.5, 95% confidence interval 0.4-0.8). However, in seniors older than 65 years, a significant increase of overall incidence of IPD was observed (IRR 1.4, 95% CI 1.1-1.7). The contribution of PCV13 vaccine serotypes to IPD declined significantly in all age groups: from 59% to 38.1% in <5 years; 82.7% to 59% in 5-17 years, 47.8% to 34.1% in 18-64 years and 48.2% to 37% in >65 years. Results found when comparing both periods were consistent with IRRs observed year by year. In children <5 years, the three major serotypes detected were 1, 24F and 19A in EVP vs 24F, 14 and 10A in LVP. Among patients 5-17 years the first three serotypes were 1, 12F and 14 both in EVP and LVP. Among adults 18-64, the three major serotypes detected were 1, 12F and 8 vs 8, 12F and 3, respectively. Finally, in patients >65 years the most frequently isolated serotypes were 3, 19A and 7F vs 3, 14 and 12F, respectively. Regarding clonal complexes (CCs) expressing mainly PCV13 serotypes, significant decreases of the proportions of CC306, CC191 and CC320 were observed, while CC156 showed a significant increase. As for CCs expressing mostly non-PCV13 serotypes, significant increases in ST989, CC53 and CC404 were showed.
Despite low vaccine coverage in our setting a significant decrease of incidence of IPD was observed in children younger than 5 years. The modest indirect protection against vaccine serotypes causing IPD in elderly indicate the need for the inclusion of more serotypes in future high-valent PCV and vaccinating old adults should be considered.
本研究的目的是描述在西班牙加泰罗尼亚地区，在 PCV13 疫苗接种覆盖率处于中等水平（2011-2016 年）的情况下，4 个不同年龄组（<5 岁、5-17 岁、18-64 岁和>65 岁）侵袭性肺炎链球菌（Streptococcus pneumoniae）菌株的血清型和克隆分布的发生率和变化。
我们纳入了所有系统送往位于巴塞罗那圣若翰保禄医院的加泰罗尼亚支持实验室进行侵袭性肺炎球菌病（IPD）分子监测的肺炎球菌菌株。考虑了两个研究期：2011-13 年为 PCV13 早期接种期（EVP），2014-2016 年为晚期接种期（LVP）。
共纳入 2142 株菌株。在我们的人群中 PCV13 中度引入 5 年后，观察到<5 岁儿童的总体 IPD 发生率显著下降（发病率比 0.5，95%置信区间 0.4-0.8）。然而，在 65 岁以上的老年人中，总的 IPD 发生率显著增加（IRR 1.4，95%CI 1.1-1.7）。所有年龄组中，PCV13 疫苗血清型对 IPD 的贡献显著下降：<5 岁时从 59%降至 38.1%；5-17 岁时从 82.7%降至 59%，18-64 岁时从 47.8%降至 34.1%，>65 岁时从 48.2%降至 37%。比较两个时期时发现的结果与逐年观察到的 IRR 一致。<5 岁的儿童中，EVP 中检测到的三种主要血清型为 1、24F 和 19A，而 LVP 中为 24F、14 和 10A。在 5-17 岁的患者中，EVP 和 LVP 中前三种血清型均为 1、12F 和 14。在 18-64 岁的成年人中，EVP 和 LVP 中检测到的三种主要血清型均为 1、12F 和 8。最后，在>65 岁的患者中，最常分离到的血清型分别为 3、19A 和 7F，而 3、14 和 12F 分别为 3、14 和 12F。关于主要表达 PCV13 血清型的克隆复合物（CCs），观察到 CC306、CC191 和 CC320 的比例显著下降，而 CC156 则显著增加。对于主要表达非 PCV13 血清型的 CCs，ST989、CC53 和 CC404 的比例显著增加。
尽管我们的设置中疫苗覆盖率较低，但<5 岁的儿童 IPD 发生率显著下降。疫苗血清型对老年人 IPD 的间接保护作用较低，表明需要在未来的高价 PCV 中纳入更多的血清型，并考虑为老年人接种疫苗。
