key: cord-0875873-fm8c6zgo authors: Amarsy, Rishma; de Ponfilly, Gauthier Pean; Benmansour, Hanaa; Jacquier, Hervé; Cambau, Emmanuelle; Mégarbane, Bruno title: Serratia marcescens outbreak in the intensive care unit during the COVID-19 pandemic: a paradoxical risk? date: 2020-05-21 journal: Med Mal Infect DOI: 10.1016/j.medmal.2020.05.004 sha: ae044c8137eb15e2b962ccbfc58401810ee73a68 doc_id: 875873 cord_uid: fm8c6zgo nan 2 cultures positive for Serratia marcescens, resistant to amoxicillin, amoxiclav, 1 st and 2 nd generation cephalosporins (inducible AmpC β-lactamase) and with low-level resistance to amikacin (chromosomeborne aac(6')-Ic). Isolates were clonal based on whole genome sequencing using Illumina™ procedures. Noteworthy, S. marcescens, a saprophytic environmental Enterobacteriaceae transitory found in human microbiota [1] , was commonly implicated in nosocomial infections, especially in neonatal ICUs [2] . After the Infection Prevention and Control Team (IPCT) investigation, an environmental reservoir was suspected as the five patients stayed for at least one day in the same double room (Figure 1 ). The source patient had been admitted to this room for septic shock due to community-acquired S. marcescens infection from his dialysis catheter, a few days before the COVID-19 outbreak started. Thereafter, S. marcescens acquisition by the COVID-19 patients was likely promoted from the environment due to invasive procedures, high antimicrobial selective pressure and immunomodulatory therapy administration [1] [2] [3] . Additionally, difficulties in applying optimal biocleaning procedures during the COVID-19 outbreak may have contributed to facilitating the bacterial reservoir [3]. Transmission between caregivers and patients was facilitated by increased patient density and severity, enhanced workload, and reduced space (e.g., two mechanically ventilated patients managed in rooms routinely dedicated to single patients). Due to the severity of COVID-19 pneumonia, our patients extensively received cefotaxime (82%) to treat a possible bacterial coinfection. They also extensively received azithromycin (93%) as empirical antibiotic treatment in addition to its alleged antiviral and immunomodulatory properties, especially combined with hydroxychloroquine [4] . However, despite these almost systematic antibiotic prescriptions in our COVID-19 patients, we suspected an additional condition that had promoted the S. marcescens outbreak, by contrast to the multidrug-resistant bacteria outbreaks usually attributed to the density of antimicrobial prescriptions in the ICU. as recommended [5] . Caregivers were encouraged to wear gloves during patient care if contact with blood or other body fluids could be reasonably anticipated. They were advised to systematically carry out hand hygiene with alcohol-based hand rub after removing gloves. However, inappropriate excessive glove use, especially in additional staff not trained to manage ICU patients, resulted in poor compliance with hand hygiene, as reported [6] . Unexpectedly, strengthening PPE combined to the fear of self-contamination by SARS-CoV-2 pushed caregivers to wear gloves systematically, even when not required, as soon as entering the patient room. The IPCT observed that several caregivers did not change their gloves between the cares of two patients. This malpractice likely contributed to the room contamination and S. marcescens cross-transmission between patients. Interestingly, crosstransmission due to continuous glove and gown wearing had been responsible for increase in methicillin-resistant Staphylococcus aureus acquisition rate and change in pathogen pattern during an outbreak of severe acute respiratory syndrome in a Hong Kong ICU [7] . Here, once the S. marcescens epidemic was identified, intensive bio-cleaning of the room was performed and recommendations to improve hand hygiene were provided to caregivers. No further cases occurred. During the COVID-19 outbreak, implementation of additional infection control procedures was expected to be associated with a decrease in healthcare-associated infections. Our experience suggests that extra procedures could, by contrast, lead to counterproductive effects if not adequately applied. Serratia infections: from military experiments to current practice Serratia marcescens Infections in Neonatal Intensive Care Units (NICUs) Intensive care unit design and environmental factors in the acquisition of infection Hydroxychloroquine and Azithromycin to Treat Patients With COVID-19: Both Friends and Foes? Guidance for wearing and removing personal protective equipment in healthcare settings for the care of patients with suspected or confirmed COVID-19 The dirty hand in the latex glove": a study of hand hygiene compliance when gloves are worn Increase in methicillin-resistant Staphylococcus aureus acquisition rate and change in pathogen pattern associated with an outbreak of severe acute respiratory syndrome