ARTICLES| VOLUME 4, ISSUE 5, E330-E339, MAY 2023

Infection and co-infection patterns of community-acquired pneumonia in patients of different ages in China from 2009 to 2020: a national surveillance study

Yan-Ning Liu, Yun-Fa Zhang, Qiang Xu, et al

Lancet Microbe 2023; 4: E330-E339 Published:March 28, 2023

DOI:https://doi.org/10.1016/S2666-5247(23)00031-9

Summary

Background

Severe community-acquired pneumonia (SCAP) is associated with a substantial number of hospitalisations and deaths worldwide. Infection or co-infection patterns, along with their age dependence and clinical effects are poorly understood. We aimed to explore the causal and epidemiological characteristics by age, to better describe patterns of community-acquired pneumonia (CAP) and their association with severe disease.

背景:全球范围的重症社区获得性肺炎(CAP)与大量的患者住院和死亡相关。然而，重症 社区获得性肺炎不同年龄患者的呼吸道病原体感染或复合感染状况及其临床特征尚不清 楚。本研究旨在探索不同年龄患者的病因和流行病学特征，以便更好地描述 CAP 的感染或 复合感染模式及其与重症疾病的关系。

Methods

National surveillance of CAP was conducted through a network of hospitals in 30 provinces in China from 2009–20 inclusive. Patients with CAP were included if they had evidence of acute respiratory tract, had evidence of pneumonia by chest radiography, diagnosis of pneumonia within 24 h of hospital admission, and resided in the study catchment area. For the enrolled patients with CAP, nasopharyngeal and oral swabs were taken and tested for eight viral pathogens; and blood, urine, or expectorated sputum was tested for six bacterial pathogens. Clinical outcomes, including SCAP, were investigated with respect to age and patterns of infections or co-infections by performing binary logistic regression and multivariate analysis.

方法:基于 30 个省份的哨点医院，在 2009‒2020 年期间开展了全国 CAP 患者的病原学监 测研究。本研究将有急性呼吸道感染表现、胸部摄影显示肺炎表现、入院 24 小时内诊断为 肺炎并且居住在研究区域内的 CAP 患者纳入，采集患者的鼻/咽拭子标本，用以检测八种 病毒性病原体，采集患者的血液、尿液或痰液标本用以检测六种细菌性病原体。应用多因 素二元 Logistic 回归模型，按照不同年龄组呼吸道病原体的感染状况或复合感染状况对包 括重症 CAP 在内的临床结局进行了分析。

Findings

Between January, 2009, and December, 2020, 18 807 patients with CAP (3771 [20·05%] with SCAP) were enrolled. For both children (aged ≤5 years) and older adults (aged >60 years), a higher overall rate of viral and bacterial infections, as well as viral–bacterial co-infections were seen in patients with SCAP than in patients with non-SCAP. For adults (aged 18–60 years), however, only a higher rate of bacterial–bacterial co-infection was observed. The most frequent pathogens associated with SCAP were respiratory syncytial virus (RSV; 21·30%) and Streptococcus pneumoniae (12·61%) among children, and influenza virus (10·94%) and Pseudomonas aeruginosa (15·37%) among older adults. Positive rates of detection of most of the tested pathogens decreased during 2020 compared with the 2009−19 period, except for RSV, P aeruginosa, and Klebsiella pneumoniae. Multivariate analyses showed SCAP was significantly associated with infection with human adenovirus, human rhinovirus, K pneumoniae, or co-infection of RSV and Haemophilus influenzae or RSV and Staphylococcus aureus in children and adolescents (aged <18 years), and significantly associated with infection with P aeruginosa, K pneumoniae, or S pneumoniae, or co-infection with P aeruginosa and K pneumoniaein adults (aged ≥18 years).

结果：2009年1月至2020年12月期间，本研究共纳入18807例CAP患者，其中 20.05%为重症CAP患者。在儿童组(≤5 岁)和老年组(>60 岁)患者中，重症肺炎患者的病毒感染、细菌感染以及病毒-细菌复合感染率高于非重症肺炎患者。然而，在成年组(18−60岁)患者中，仅发现重症CAP患者的细菌-细菌复合感染率高于非重症 CAP 患者。儿童重症CAP患者中最常见感染的病毒和细菌性呼吸道病原体分别是呼吸道合胞病毒(21.30%) 和肺炎链球菌(12.61%)，老年重症CAP患者中最常见的呼吸道病毒和细菌分别是流感病 毒(10.94%)和铜绿假单胞菌(15.37%)。与 2009−2019年相比，2020年CAP患者中检测的呼吸道病原体除呼吸道合胞病毒、铜绿假单胞菌和肺炎克雷伯菌外，其余病原体的阳性率均呈下降趋势。多因素模型显示:<18 岁的 CAP 患者中，重症肺炎的发生与腺病毒、鼻病毒、肺炎克雷伯菌感染，以及呼吸道合胞病毒-流感嗜血杆菌、呼吸道合胞病毒-金黄色葡萄球菌的复合感染显著相关;≥18 岁的 CAP 患者中，重症肺炎的发生与铜绿假单胞菌、肺炎克雷伯菌、肺炎链球菌的感染，以及铜绿假单胞菌-肺炎克雷伯菌的复合感染显著相关。

Interpretation

Both prevalence and infection pattern of respiratory pathogens differed between patients with SCAP and patients with non-SCAP in an age-dependent manner. These findings suggest potential advantages to age-related strategies for vaccine schedules, as well as clinical diagnosis, treatment, and therapy.

结论:研究结果显示重症肺炎和非重症肺炎患者的呼吸道病原体的感染状况与特征均与年龄相关，采取与年龄相关的疫苗接种策略、临床诊断和治疗措施具有潜在价值。

Funding

China Mega-Project on Infectious Disease Prevention and The National Natural Science Funds of China.