[Epidemiological characteristics of adenovirus infection in hospitalized children with acute respiratory tract infection in Kunming during 2019].

Objective: To investigate the epidemiology and clinical characteristics of adenovirus (ADV)-caused acute respiratory tract infection among hospitalized children in Kunming, China. Methods: Clinical and laboratory data were collected from 467 children with adenovirus infection who were hospitalized from January 1, 2019 to December 31, 2019 in 6 grade A class Ⅲ hospitals in Kunming area. The basic characteristics, epidemiology, mixed infection and adenovirus genotypes of the patients were retrospectively analyzed. The patients diagnosed with adenovirus pneumonia (AP) were divided into two groups, severe AP (SAP) group and general AP(GAP) group according to the severity of illness. Mann-Whitney U test or χ2 test was used for comparison between groups, while multivariate regression was applied to analyze the risk factors of SAP. Results: Among 15 635 hospitalized children with respiratory tract infection, 467 cases were adenovirus positive, with a detection rate of 2.99%. Of the 467 patients with adenovirus infection, 284 were male and 183 female, the age was 2.4 (1.1,3.9) years, including 44 cases (9.4%) < 0.5 years, 59 cases (12.6%) of 0.5 to<1.0 years, 176 cases (37.7%) of 1.0 to <3.0 years, 150 cases (32.1%) of 3.0 to <7.0 years, and 38 cases (8.1%) of 7.0 to 14.0 years. Adenovirus infection was common in autumn and winter, and the high incidence months were October to December, which accounted for 51.6% (241/467) of the whole year cases. Co-infection was detected in 226 cases (48.4%) out of 467 patients, in which one pathogen co-infection was the most frequent form (172 cases, 76.1%). Of the 262 pathogen detected 108 (41.2%) were Mycoplasma pneumoniae. In 144 of ADV-positve cases (30.8%) were taken geno-typing was done by PCR amplification, the results showed that 74 cases (51.4%) were ADV 3, 7 subtypes and 65 cases (45.1%) of ADV 1, 2,6 subtypes. Of the 467 cases of ADV infection, 320 (68.5%) were diagnosed with pneumonia, 82 (17.6%) with upper respiratory tract infection and pharyngeal tonsillitis, and 65 (13.9%) with bronchitis, laryngeal bronchitis, and asthmatic bronchitis. Among the 320 patients with AP, 56 cases were severe and 264 cases were general. Two cases (3.6%) in severe group died. Compared with the GAP group, the age was young [17 (11,42) months vs. 24 (14,44) months, Z=2.222, P=0.026], the fever duration was long [8 (5,14) days vs. 6 (3,9) days, Z=3.380, P<0.01], and the proportions of preterm birth and having underlying diseases were high [respectively 19.6% (11/56) vs. 6.1% (16/264), 26.8% (15/56) vs. 10.2% (27/264), χ2=8.965,11.109, P<0.05] in SAP group. Referring to laboratory markers, white blood cell count, C-reactive protein, creatine kinase-MB and lactate dehydrogenase were significantly increased in SAP group as compared to GAP group(all P<0.05). Multivariate Logistic regression analysis showed that preterm birth (OR=3.284, 95%CI 1.079-9.993, P=0.036), underlying disease (OR=3.284, 95%CI 1.079-9.993, P=0.036), fever duration ≥10 d (OR=2.523,95%CI 1.195-5.328, P=0.015) and C-reactive protein ≥50 mg/L (OR=3.156, 95%CI 1.324-7.524, P=0.010) were positively correlated with the risk of SAP. Conclusions: The incidence of adenovirus infection among hospitalized children in Kunming was lower than the national level, and no outbreak occurred in 2019. Subtype 3 and 7 of ADV are the predominant strains for infection, which usually occurs in autumn and winter and mainly causes pneumonia. Premature birth, underlining diseases, long fever duration and markedly increased C-reactive protein are the risk factors for developing into severe pneumonia. This paper presents the prevalence and clinical characteristics of adenovirus infection in children at high altitude area.目的： 了解昆明地区住院儿童呼吸道腺病毒流行情况及临床特点。 方法： 回顾性收集2019年全年在昆明市6家三甲医院儿科住院的467例腺病毒感染患儿的临床和实验室资料，分析患儿的基本特征、流行病学特点、混合感染情况和腺病毒基因型别。根据病情轻重将诊断为肺炎的患儿分为重症腺病毒肺炎（SAP）组和普通腺病毒肺炎（GAP）组，采用Mann-Whitney U检验或χ2检验进行组间比较，采用多因素回归分析SAP组的高危因素。 结果： 共有15 635例患儿因呼吸道感染住院，检出腺病毒阳性患儿467例，检出率2.99%。其中男284例、女183例，年龄2.4（1.1，3.9）岁，其中<0.5岁44例（9.4%），0.5~<1.0岁59例（12.6%），1.0~<3.0岁176例（37.7%），3.0~<7.0岁150例（32.1%），7.0~14.0岁38例（8.1%）。腺病毒感染高发月份为10—12月份，占全年总检出的51.6%（241/467）。226例（48.4%）检出合并其他病原体感染，其中172例（76.1%）以混合单一病原体感染，检出的262株病原体中，肺炎支原体108株（41.2%）。144例（30.8%）患儿行PCR基因分型，检出腺病毒3、7亚型74例（51.4%），腺病毒1、2、6亚型65例（45.1%）。467例腺病毒感染病例中，320例（68.5%）诊断为肺炎，82例（17.6%）为上呼吸道感染及咽扁桃体炎，65例（13.9%）支气管炎、喉支气管炎、喘息性支气管炎。320例腺病毒肺炎中，SAP组 56例，死亡2例（3.6%），GAP组 264例。SAP比GAP组患儿年龄更小［17（11，42）比24（14，44）月龄，Z=2.222，P=0.026］，热程更长［8（5，14）比6（3，9）d，Z=3.380，P<0.01］，有早产史及基础疾病的比例更高［19.6%（11/56）比6.1%（16/264）、26.8%（15/56）比10.2%（27/264），χ2 =8.965、11.109，均P<0.05］，且SAP组实验室指标白细胞计数、C反应蛋白、肌酸激酶-MB、乳酸脱氢酶均高于GAP组（均P＜0.05）。多因素Logistic回归分析显示早产（OR=3.284，95%CI 1.079~9.993，P=0.036）、有基础疾病（OR=3.284，95%CI 1.079~9.993，P=0.036）、热程≥10 d（OR=2.523，95%CI 1.195~5.328，P=0.015）、C反应蛋白≥50 mg/L（OR=3.156，95%CI 1.324~7.524，P=0.010）与SAP发生风险呈正相关。 结论： 昆明地区住院儿童腺病毒的感染率低于全国水平，2019年度未出现爆发流行现象。腺病毒感染以3、7亚型为主，秋冬季好发，主要引起肺炎，早产、基础疾病，热程长及C反应蛋白明显升高是重症肺炎的高危因素。.