An outbreak of Serratia marcescens bacteremia after general anesthesia

Effectiveness of healthcare worker screening in hospital outbreaks with gram-negative pathogens: a systematic review

Background

Identifying the source of an outbreak is the most crucial aspect of any outbreak investigation. In this review, we address the frequently discussed question of whether (rectal) screening of health care workers (HCWs) should be carried out when dealing with outbreaks caused by gram negative bacteria (GNB).

A systematic search of the medical literature was performed, including the Worldwide Outbreak Database and PubMed. Outbreaks got included if a HCW was the source of the outbreak and the causative pathogen was an Escherichia coli, Klebsiella spp., Enterobacter spp., Serratia spp., Pseudomonas aeruginosa, or Acinetobacter baumannii.

This was true for 25 articles in which there were 1196 (2.1%) outbreaks due to GNB, thereof 14 HCWs who were permanently colonized by the outbreak strain. Rectal screening of HCWs was helpful in only 2 of the 1196 (0.2%) outbreaks. Instead, the hands of HCWs served as a reservoir for the outbreak strain in at least 7 articles – especially when they suffered from onychomycosis or used artificial fingernails or rings.

Conclusion

Due to very weak evidence, we do not recommend rectal screening of HCWs in an outbreak situation with GNB. However, besides a critical review of hand hygiene habits, it might be useful to examine the hands of staff carefully. This measure is cheap, quick to perform, and seems to be quite effective.

Electronic supplementary material

The online version of this article (10.1186/s13756-018-0330-4) contains supplementary material, which is available to authorized users.

Serratia marcescensBacteremia: Nosocomial Cluster Following Narcotic Diversion

OBJECTIVE

To describe the investigation and control of a cluster ofSerratia marcescensbacteremia in a 505-bed tertiary-care center.

METHODS

Cluster cases were defined as all patients withS. marcescensbacteremia between March 2 and April 7, 2014, who were found to have identical or related blood isolates determined by molecular typing with pulsed-field gel electrophoresis. Cases were compared using bivariate analysis with controls admitted at the same time and to the same service as the cases, in a 4:1 ratio.

RESULTS

In total, 6 patients developedS. marcescensbacteremia within 48 hours after admission within the above period. Of these, 5 patients had identicalSerratiaisolates determined by molecular typing, and were included in a case-control study. Exposure to the post-anesthesia care unit was a risk factor identified in bivariate analysis. Evidence of tampered opioid-containing syringes on several hospital units was discovered soon after the initial cluster case presented, and a full narcotic diversion investigation was conducted. A nurse working in the post-anesthesia care unit was identified as the employee responsible for the drug diversion and was epidemiologically linked to all 5 patients in the cluster. No further cases were identified once the implicated employee’s job was terminated.

CONCLUSION

Illicit drug use by healthcare workers remains an important mechanism for the development of bloodstream infections in hospitalized patients. Active mechanisms and systems should remain in place to prevent, detect, and control narcotic drug diversions and associated patient harm in the healthcare setting.

Infect Control Hosp Epidemiol2017;38:1027–1031

Serratia infections: from military experiments to current practice

Serratia species, in particular Serratia marcescens, are significant human pathogens. S. marcescens has a long and interesting taxonomic, medical experimentation, military experimentation, and human clinical infection history. The organisms in this genus, particularly S. marcescens, were long thought to be nonpathogenic. Because S. marcescens was thought to be a nonpathogen and is usually red pigmented, the U.S. military conducted experiments that attempted to ascertain the spread of this organism released over large areas. In the process, members of both the public and the military were exposed to S. marcescens, and this was uncovered by the press in the 1970s, leading to U.S. congressional hearings. S. marcescens was found to be a certain human pathogen by the mid-1960s. S. marcescens and S. liquefaciens have been isolated as causative agents of numerous outbreaks and opportunistic infections, and the association of these organisms with point sources such as medical devices and various solutions given to hospitalized patients is striking. Serratia species appear to be common environmental organisms, and this helps to explain the large number of nosocomial infections due to these bacteria. Since many nosocomial infections are caused by multiply antibiotic-resistant strains of S. marcescens, this increases the danger to hospitalized patients, and hospital personnel should be vigilant in preventing nosocomial outbreaks due to this organism. S. marcescens, and probably other species in the genus, carries several antibiotic resistance determinants and is also capable of acquiring resistance genes. S. marcescens and S. liquefaciens are usually identified well in the clinical laboratory, but the other species are rare enough that laboratory technologists may not recognize them. 16S rRNA gene sequencing may enable better identification of some of the less common Serratia species.

Outbreak of bloodstream infections because of Serratia marcescens in a pediatric department

BACKGROUND

Serratia marcescens can cause health care-associated infections. We herewith report the investigation and control of an outbreak of S marcescens bloodstream infections (BSI) in a general pediatric department.

METHODS

From April to May 2009, temporally related cases of S marcescens BSI occurred in a 40-bed general pediatric department of a tertiary care hospital. An outbreak investigation including case identification, review of medical records, environmental cultures, patients' surveillance cultures, personnel hand cultures, pulsed-field gel electrophoresis, and a case-control study were conducted. Controls were patients without S marcescens BSI but hospitalized in the department for at least 48 hours during the outbreak. Enhanced infection control measures were immediately implemented by the Infection Control Committee.

RESULTS

During the study period, 4 patients developed BSI because of a S marcescens strain demonstrating the same antimicrobial susceptibility pattern as well as the same molecular profile. Patients' surveillance cultures and personnel hand cultures were negative. In 1 case-patient, S marcescens grew from cultures of intravenous infusion systems. In the case-control study performed, there were no differences in demographics, intravenously administered medications, or place of hospital stay. Case patients had changes in vascular access significantly more frequently than controls. No S marcescens infections occurred in the department during the 18 months following implementation of the enhanced infection control measures.

CONCLUSION

Prompt recognition and strict adherence to infection control measures are of paramount importance in combating an outbreak of S marcescens bloodstream infection.

Clinical practice guidelines for the diagnosis and management of intravascular catheter-related infection: 2009 Update by the Infectious Diseases Society of America

These updated guidelines replace the previous management guidelines published in 2001. The guidelines are intended for use by health care providers who care for patients who either have these infections or may be at risk for them.