探讨重庆北部地区新型冠状病毒肺炎(COVID-19)疫情前后支气管肺炎住院患儿的痰培养病原学特征和病原谱的变化。

纳入2018年1月24日至2022年1月23日于重庆市第九人民医院儿科住院的支气管肺炎患儿4 872例，年龄29 d至14岁(不包括14岁)，分析住院后首次送检的痰培养标本。以重庆市COVID-19疫情管控升级为一级响应为界点，以2018年1月24日至2020年1月23日的数据作为COVID-19疫情前，2020年1月24日至2022年1月23日的数据作为COVID-19疫情后，进行不同年龄及性别痰培养病原体检出情况比较。以2019年2月5日至2021年2月11日的数据进行疫情前后不同季节的痰培养病原体检出情况比较。

痰培养阳性(至少检出1种病原体)1 597例(32.78%)，其中肺炎链球菌占比最高(468/1 597，29.30%)，其次是流感嗜血杆菌(294/1 597，18.41%)等，混合感染(检出≥2种病原体)21例(1.31%)。在所检出病原体中，革兰氏阴性菌(833/1 597，52.16%)占比高于革兰氏阳性菌(743/1 597，46.52%)。疫情前病原体检出率为35.54%(1 065/2 997)，疫情后为28.37%(532/1 875)。在男童、女童、29 d~6月龄组、1~3岁组中，疫情前病原体检出率均高于疫情后，均差异有统计学意义(均P<0.05)。疫情前流感嗜血杆菌、金黄色葡萄球菌、大肠埃希菌的检出率均高于疫情后，在不同性别组中亦如此(P<0.05)。在男童中，肺炎链球菌疫情前的检出率高于疫情后(P<0.05)。疫情前春夏秋冬季节病原体检出率逐渐下降，疫情后冬季病原体检出率最高。不同季节疫情前后相比，肺炎链球菌、流感嗜血杆菌检出率差异有统计学意义(均P<0.05)。29 d~6月龄组病原体检出率(337/832，40.50%)高于总体检出率，且随着年龄的增长，总体检出率以及金黄色葡萄球菌检出率均逐渐降低；除29 d~6月龄组外其余各组肺炎链球菌的占比最高。

COVID-19疫情后儿童支气管肺炎痰培养病原谱排列顺序发生了部分变化，但仍以肺炎链球菌及流感嗜血杆菌为主。流感嗜血杆菌、金黄色葡萄球菌、大肠埃希菌疫情后较疫情前检出率明显下降。

To investigate the pathogenic characteristics and pathogenic spectrum changes of sputum culture in hospitalized children with bronchopneumonia before and after the COVID-19 epidemic in northern Chongqing.

A total of 4 872 children with bronchopneumonia aged from 29 days to 14 years old(excluding 14 years old) admitted to the Pediatrics Department of Chongqing Ninth People′s Hospital from January 24, 2018 to January 23, 2022 were included, and the sputum culture samples were analyzed for the first time after hospitalization. Taking the data when the COVID-19 epidemic control to the first-level response in chongqing as the critical point, the data from January 24, 2018, to January 23, 2020 (pre-COVID-19) epidemic and the data from January 24, 2020, to January 23, 2022 (post-COVID-19) epidemic were used for age and gender comparison. Data from February 5, 2019 to February 11, 2021 were used to compare the pathogenic detection of sputum culture in different seasons before and after the epidemic.

There were 1 597 cases (32.78%) with positive sputum culture (≥1 pathogen was detected), of which Streptococcus pneumoniae accounted for the highest proportion (468/1 597, 29.30%), followed by Haemophilus influenzae (294/1 597, 18.41%), and 21 cases (1.31%) of mixed infection (≥ 2 pathogens were detected). Among the pathogens detected, gram-negative bacteria (833/1 597, 52.16%) accounted for a higher proportion than gram-positive bacteria (743/1 597, 46.52%). The detection rates of pathogens before and after the epidemic were 35.54% (1 065/2 997), 28.37% (532/1 875), respectively. In male and female children groups, 29 days to 6 months age group, and 1-3 years old age group, the detection rates of pathogens before the epidemic were higher than those after the epidemic, and the differences were statistically significant (all P<0.05). The detection rates of Haemophilus influenzae, Staphylococcus aureus and Escherichia coli before the epidemic were higher than those after the epidemic, and the result was consistent in different sex groups (all P<0.05). Among male children, the detection rate of Streptococcus pneumoniae before the epidemic was higher than that after the epidemic(P<0.05). The detection rate of pathogens gradually decreased in spring, summer, autumn and winter before the epidemic, and the highest detection rate of pathogens was in the winter after the epidemic. There were significant differences in the detection rates of Streptococcus pneumoniae and Haemophilus influenzae before and after the epidemic in different seasons. The pathogen detection rate (337/832, 40.50%) in the 29 days to 6 months group was higher than the overall detection rate, and with the increase of age, the overall detection rate and the detection rate of Staphylococcus aureus gradually decreased. Except for the 29 days to 6 months age group, the proportion of Streptococcus pneumoniae was the highest in all other groups.

After the COVID-19 epidemic, the order of pathogen spectrum of bronchopneumonia sputum culture in children has changed somewhat, but Streptococcus pneumoniae and Haemophilus influenzae are still dominant. After the epidemic, the detection rates of Haemophilus influenzae, Staphylococcus aureus, and Escherichia coli decrease significantly compared with before the epidemic.