金黄色葡萄球菌血流感染住院患儿临床特征及危险因素

Clinical characteristics and risk factors of Staphylococcus aureus bloodstream infection in hospitalized children

目的了解儿童金黄色葡萄球菌(SA)血流感染的临床特点以及菌株的药敏特征,探讨耐甲氧西林金黄色葡萄球菌(MRSA)血流感染和SA血流医院感染(HA)的易感因素。方法回顾性分析2014年1月—2019年12月某儿童医院血培养检出SA住院患儿的病历资料,根据其药敏试验结果及来源分为MRSA组与甲氧西林敏感金黄色葡萄球菌(MSSA)组、HA组与社区感染(CA)组,应用卡方检验和logistic回归分析MRSA血流感染及HA血流感染的危险因素。结果共纳入143例病例,男女比例为1.8∶1,<1岁71例(49.6%),病灶性血流感染90例(62.9%)。MARS组50例(35.0%),MSSA组93例(65.0%);HA组73例(51.0%),CA组70例(49.0%)。机械通气[OR=17.320,95%CI(1.576~190.399)]、抗菌药物联合使用[OR=0.580,95%CI(0.359~0.938)]是MRSA血流感染的独立危险因素(均P<0.05)。机械通气[OR=31.466,95%CI(1.434~690.538)]、入院前使用抗菌药物[OR=24.524,95%CI(1.699~353.915)]、住院时间>7 d[OR=1.090,95%CI(1.010~1.176)]、抗菌药物使用时间>7 d[OR=0.910,95%CI(0.842~0.984)]是HA血流感染的独立危险因素(均P<0.05)。MRSA对红霉素、克林霉素、利福平的耐药率分别为82.0%、76.0%、32.0%,均高于MSSA(均P<0.05)。HA血流感染组死亡/未愈6例(8.2%),CA血流感染组死亡/未愈4例(5.7%),两组比较差异无统计学意义(P>0.05)。静脉置管、机械通气及入住ICU为SA血流感染患儿预后不良的危险因素(均P<0.05)。结论SA血流感染患儿中男性居多,主要见于<1岁年龄,病灶性血流感染更为多见。机械通气及抗菌药物联合使用是MRSA感染的危险因素。HA多发生于有机械通气、入院前使用抗菌药物、住院时间>7 d、抗菌药物使用时间>7 d的患者。临床应根据药敏结果及感染类型采用针对性治疗方法及防控措施。

Objective To understand the clinical characteristics of bloodstream infection(BSI)of Staphylococcus aureus(SA)in children and antimicrobial susceptibility characteristics of the pathogenic strains,and explore the susceptibility factors of methicillin-resistant SA(MRSA)BSI and SA healthcare-associated infection(HAI).Methods Medical records of hospitalized children with SA isolated from blood culture in a children’s hospital from January 2014 to December 2019 were retrospectively analyzed.According to antimicrobial susceptibility test results and sources of SA,patients were divided into MRSA group,methicillin-sensitive SA(MSSA)group,as well as healthcare-associated BSI group(HA group)and community-associated BSI group(CA group).Chi-quare test and logistic regression were used to analyze the risk factors for MRSA BSI and HA-BSI.Results A total of 143 cases were included,the ratio of male to female was 1.8∶1,71 cases(49.6%)were<1 year old,and 90 cases(62.9%)were with focal BSI.50 cases(35.0%)were in MARS group and 93 cases(65.0%)in MSSA group;73 cases(51.0%)were in HA group and 70 cases(49.0%)in CA group.Mechanical ventilation(OR=17.320,95%CI[1.576-190.399])and combined use of antimicrobials(OR=0.580,95%CI[0.359-0.938])were independent risk factors for MRSA BSI(both P<0.05).Mechanical ventilation(OR=31.466,95%CI[1.434-690.538]),use of antimicrobials before admission(OR=24.524,95%CI[1.699-353.915]),length of hospital stay>7 days(OR=1.090,95%CI[1.010-1.176]),use of antimicrobials>7 days(OR=0.910,95%CI[0.842-0.984])were independent risk factors for HA BSI(all P<0.05).Resistance rates of MRSA to erythromycin,clindamycin and rifampicin were 82.0%,76.0%and 32.0%respectively,all were higher than those of MSSA(all P<0.05).6 cases(8.2%)in HA group and 4 cases(5.7%)in CA group died/not cured,with no statistically significant diffe-rence between two groups(P>0.05).Intravenous catheterization,mechanical ventilation and admission to ICU were risk factors for poor prognosis of children with SA BSI(all P<0.05).Conclusion The majority of children with SA BSI are male,mainly at the age of<1 year old,and focal BSI is more common.Mechanical ventilation and combined use of antimicrobials are risk factor for MRSA infection.HA BSI often occurs in patients with mechanical ventilation,use of antimicrobials before admission,length of hospital stay>7 days,and use of antimicrobials>7 days.Targeted treatment as well as prevention and control measures should be taken according to antimicrobial susceptibility test results and infection types.