Epidemiology and Infection Prevention, University of California Irvine Health, Orange, California.
Department of Immunology and Infectious Diseases, Harvard T. H. Chan School of Public Health, Boston, Massachusetts.
Infect Control Hosp Epidemiol. 2023 Apr;44(4):589-596. doi: 10.1017/ice.2022.133. Epub 2022 Jun 16.
To describe the genomic analysis and epidemiologic response related to a slow and prolonged methicillin-resistant (MRSA) outbreak.
Prospective observational study.
Neonatal intensive care unit (NICU).
We conducted an epidemiologic investigation of a NICU MRSA outbreak involving serial baby and staff screening to identify opportunities for decolonization. Whole-genome sequencing was performed on MRSA isolates.
A NICU with excellent hand hygiene compliance and longstanding minimal healthcare-associated infections experienced an MRSA outbreak involving 15 babies and 6 healthcare personnel (HCP). In total, 12 cases occurred slowly over a 1-year period (mean, 30.7 days apart) followed by 3 additional cases 7 months later. Multiple progressive infection prevention interventions were implemented, including contact precautions and cohorting of MRSA-positive babies, hand hygiene observers, enhanced environmental cleaning, screening of babies and staff, and decolonization of carriers. Only decolonization of HCP found to be persistent carriers of MRSA was successful in stopping transmission and ending the outbreak. Genomic analyses identified bidirectional transmission between babies and HCP during the outbreak.
In comparison to fast outbreaks, outbreaks that are "slow and sustained" may be more common to units with strong existing infection prevention practices such that a series of breaches have to align to result in a case. We identified a slow outbreak that persisted among staff and babies and was only stopped by identifying and decolonizing persistent MRSA carriage among staff. A repeated decolonization regimen was successful in allowing previously persistent carriers to safely continue work duties.
描述与缓慢和持续的耐甲氧西林金黄色葡萄球菌（MRSA）爆发相关的基因组分析和流行病学应对措施。
前瞻性观察性研究。
新生儿重症监护病房（NICU）。
我们对涉及对婴儿和员工进行连续筛查以确定去定植机会的 NICU MRSA 爆发进行了流行病学调查。对 MRSA 分离株进行全基因组测序。
一个具有出色手部卫生依从性和长期最低限度医疗保健相关感染的 NICU 发生了涉及 15 名婴儿和 6 名医护人员（HCP）的 MRSA 爆发。总共，12 例病例在 1 年内缓慢发生（平均间隔 30.7 天），随后又有 3 例病例在 7 个月后发生。实施了多项渐进性感染预防干预措施，包括接触预防措施和对 MRSA 阳性婴儿进行分组、手部卫生观察员、加强环境清洁、对婴儿和员工进行筛查以及对携带者进行去定植。只有对被发现持续携带 MRSA 的 HCP 进行去定植才能成功阻止传播并结束爆发。基因组分析在爆发期间发现了婴儿和 HCP 之间的双向传播。
与快速爆发相比，在感染预防实践较强的单位中，“缓慢和持续”的爆发可能更为常见，以至于一系列的突破必须同时发生才能导致病例发生。我们发现了一种在员工和婴儿中持续存在的缓慢爆发，只有通过识别和去定植员工中持续存在的 MRSA 携带才能阻止爆发。重复的去定植方案成功地使以前持续携带的携带者能够安全地继续工作。
