Outbreak Response Unit, Division of Public Health Surveillance and Response, National Institute for Communicable Diseases, National Health Laboratory Service, Johannesburg, South Africa.
S Afr Med J. 2020 Jul 29;110(8):783-790. doi: 10.7196/SAMJ.2020.v110i8.14471.
Rates of healthcare-associated infections (HAIs) among babies born in developing countries are higher than among those born in resource-rich countries, as a result of suboptimal infection prevention and control (IPC) practices. Following two reported deaths of neonates with carbapenem-resistant Klebsiella pneumoniae bloodstream infections (BSIs), we conducted an outbreak investigation in a neonatal unit of a regional hospital in Gauteng Province, South Africa.
To confirm an outbreak of K. pneumoniae BSIs and assess the IPC programme in the neonatal unit.
We calculated total and organism-specific BSI incidence risks for culture-confirmed cases in the neonatal unit for baseline and outbreak periods. We conducted a clinical record review for a subset of cases with K. pneumoniae BSI that had been reported to the investigating team by the neonatal unit. An IPC audit was performed in different areas of the neonatal unit. We confirmed species identification and antimicrobial susceptibility, and used polymerase chain reaction for confirmation of carbapenemase genes and pulsed-field gel electrophoresis (PFGE) for typing of submitted clinical isolates.
From January 2017 to August 2018, 5 262 blood cultures were submitted, of which 11% (560/5 262) were positive. Of 560 positive blood cultures, 52% (n=292) were positive for pathogenic organisms associated with healthcare-associated BSIs. K. pneumoniae comprised the largest proportion of these cases (32%; 93/292). The total incidence risk of healthcare-associated BSI for the baseline period (January 2017 - March 2018) was 6.8 cases per 100 admissions, and that for the outbreak period (April - September 2018) was 10.1 cases per 100 admissions. The incidence risk of K. pneumoniae BSI for the baseline period was 1.6 cases per 100 admissions, compared with 5.0 cases per 100 admissions during the outbreak period. Average bed occupancy for the entire period was 118% (range 101 - 133%), that for the baseline period was 117%, and that for the outbreak period was 121%. In a subset of 12 neonates with K. pneumoniae bacteraemia, the median (interquartile range (IQR)) gestational age at birth was 27 (26 - 29) weeks, and the median (IQR) birth weight was 1 100 (880 - 1 425) g. Twelve bloodstream and 31 colonising K. pneumoniae isolates were OXA-48-positive. All isolates were genetically related by PFGE analysis (89% similarity). Inadequate IPC practices were noted, including suboptimal adherence to aseptic technique and hand hygiene (57% overall score in the neonatal intensive care unit), with poor monitoring and reporting of antimicrobial use (pharmacy score 55%).
Overcrowding and inadequate IPC and antimicrobial stewardship contributed to a large outbreak of BSIs caused by genetically related carbapenemase-producing K. pneumoniae isolates in the neonatal unit.
发展中国家出生的婴儿的医疗保健相关感染（HAI）发生率高于资源丰富国家出生的婴儿，这是由于感染预防和控制（IPC）实践不佳所致。在报告了两例新生儿耐碳青霉烯类肺炎克雷伯菌血流感染（BSI）死亡病例后，我们在南非豪登省的一家地区医院的新生儿病房进行了暴发调查。
确认耐碳青霉烯类肺炎克雷伯菌血流感染的暴发，并评估新生儿病房的 IPC 计划。
我们计算了基线期和暴发期新生儿病房培养确诊病例的总和特定病原体 BSIs 发生率风险。我们对已报告给调查小组的新生儿病房耐碳青霉烯类肺炎克雷伯菌 BSI 的病例进行了临床病历回顾。对新生儿病房的不同区域进行了 IPC 审核。我们确认了物种鉴定和抗生素敏感性，并使用聚合酶链反应（PCR）确认碳青霉烯酶基因，并进行脉冲场凝胶电泳（PFGE）对提交的临床分离株进行分型。
从 2017 年 1 月至 2018 年 8 月，共提交了 5262 份血培养物，其中 11%（560/5262）为阳性。在 560 份阳性血培养物中，52%（n=292）为与医疗保健相关 BSI 相关的致病性生物体阳性。这些病例中，肺炎克雷伯菌的比例最大（32%；93/292）。基线期（2017 年 1 月至 2018 年 3 月）医疗保健相关 BSI 的总发生率风险为每 100 例入院 6.8 例，暴发期（2018 年 4 月至 9 月）为每 100 例入院 10.1 例。基线期肺炎克雷伯菌 BSI 的发生率风险为每 100 例入院 1.6 例，而暴发期为每 100 例入院 5.0 例。整个时期的平均床位占有率为 118%（范围为 101%至 133%），基线期为 117%，暴发期为 121%。在 12 例耐碳青霉烯类肺炎克雷伯菌菌血症的亚组中，出生时的中位（四分位间距（IQR））胎龄为 27（26-29）周，中位（IQR）出生体重为 1100（880-1425）g。12 份血流和 31 份定植肺炎克雷伯菌分离株均为 OXA-48 阳性。所有分离株的 PFGE 分析结果均具有遗传相关性（89%相似性）。我们注意到 IPC 实践不足，包括无菌技术和手部卫生（新生儿重症监护病房总体评分为 57%），以及抗生素使用的监测和报告不良（药房评分为 55%）。
拥挤和 IPC 及抗生素管理不善是导致新生儿病房中耐碳青霉烯类肺炎克雷伯菌相关碳青霉烯酶产生的基因相关的血流感染暴发的主要原因。
