An outbreak of Serratia marcescens associated with the anesthetic agent propofol

Outbreak of Invasive Serratia marcescens among Persons Incarcerated in a State Prison, California, USA, March 2020-December 2022

Serratia marcescens is an environmental gram-negative bacterium that causes invasive disease in rare cases. During 2020-2022, an outbreak of 21 invasive Serratia infections occurred in a prison in California, USA. Most (95%) patients had a history of recent injection drug use (IDU). We performed whole-genome sequencing and found isolates from 8 patients and 2 pieces of IDU equipment were closely related. We also identified social interactions among patients. We recovered S. marcescens from multiple environmental samples throughout the prison, including personal containers storing Cell Block 64 (CB64), a quaternary ammonium disinfectant solution. CB64 preparation and storage conditions were suboptimal for S. marcescens disinfection. The outbreak was likely caused by contaminated CB64 and propagated by shared IDU equipment and social connections. Ensuring appropriate preparation, storage, and availability of disinfectants and enacting interventions to counteract disease spread through IDU can reduce risks for invasive Serratia infections in California prisons.

Mechanisms of Action of the Detrimental Effects of Propofol on Survival

Due to its favorable pharmacologic features, propofol is the most commonly used hypnotic agent in perioperative and intensive care settings. However, it also has adverse effects like propofol infusion syndrome and an increased risk of infection. Growing evidence suggests that propofol may worsen clinical outcomes by inhibiting the organ-protective properties of other interventions, such as volatile anesthetics or remote ischemic preconditioning. This editorial describes possible mechanisms underlying the detrimental effects of propofol, and provides an overview of the results of clinical trials evaluating the effects of propofol in various settings.

[Sepsis outbreak associated with use of contaminated propofol: A new case series and literature review]

INTRODUCTION

Propofol is the most commonly used hypnotic agent for the induction and maintenance of general anesthesia. Due to its lipid-based composition, propofol requires a strict handling protocol to avoid an increased risk of extrinsic contamination.

METHODS

On September 09, 2021, 05 patients with post-anaesthetic Enterobacter cloacae infections were identified in the pediatric exploration department of the Hassan II University Hospital of Fez in Morocco. We describe the investigation into this outbreak. All patient medical records were reviewed to determine patient characteristics and potential risk factors. For the literature review, we identified relevant articles by searching PubMed, Medline, Embase and Science Direct.

RESULTS

Our study included five patients, 80% were boys. The average age was 4.6 years (1-7 years), with no medical history. All five patients underwent exploratory procedures. Immediately after the procedures, all 5 patients presented with chills, tachycardia and fever in the same order of admission. They were all admitted to hospital and blood samples were taken. Blood cultures were positive for E. cloacae. All patients had elevated levels of C-reactive protein (CRP) and an elevated white blood cell count. Bacteriological investigation revealed that the infection was caused by extrinsic contamination of the intravenous anesthetic propofol by E. cloacae.

CONCLUSION

Fatal infections due to contaminated drugs, including propofol, have been reported worldwide. Propofol is a potential source of infections due to its lipophilic nature which promotes microbial growth. This probably remains an underestimated problem that deserves awareness for early recognition.

Genomic characterisation of an entomopathogenic strain of Serratia ureilytica in the critically endangered phasmid Dryococelus australis

Between 2014 and 2019, unexpected mortalities were observed in a colony of Dryococelus australis, an endangered stick-insect kept at the Melbourne Zoo for a breeding and conservation program. Pure cultures of Serratia spp. were obtained from the haemolymph of moribund and recently deceased individuals. The combined bacteriological and histopathological observations suggested an infectious cause of these mortalities. Genotyping of Serratia sp. isolated from the insects and their environment revealed a predominant strain profile. A representative isolate, AM923, was entirely sequenced and compared to 616 publicly available Serratia spp. genomes, including 37 associated with insects. The genomes were distributed into 3 distinct groups, with 63% of the insect-associated isolates within a single clade (clade A) containing AM923, separated from most environmental/plant-associated strains (clade B) and human isolates (clade C). Average nucleotide identity and phylogenetic analyses identified AM923 as S. ureilytica and revealed similarities with putatively entomopathogenic strains. An experimental infection model in honey bees (Apis mellifera) confirmed the pathogenic potential of AM923. A urease operon was found in most insect isolates and a PCR assay, based on the ureB gene sequence, was used to confirm the presence of AM923 in experimentally infected bees. This species-specific PCR could be applied to detect entomopathogenic Serratia spp. in infected insects or their environment.

Intravenous Drug Use: a Significant Risk Factor for Serratia Bacteremia

Background:

Serratia is an opportunistic pathogen known to cause an array of infectious presentations. Aside from case reports, intravenous (IV) drug use has not been adequately quantified as a major risk factor for Serratia infection.

Methods:

A retrospective cohort study of 103 adult patients admitted to four community hospitals in Ohio from January 2014 to December 2018 with a positive blood culture for Serratia species. A complete data set of 103 patients was analyzed for demographics, comorbidities, initial diagnosis, treatment, and outcomes. Outcomes were recurrence of infection, in hospital mortality, 90-day mortality, length of hospital stay (LOS), complications (endocarditis, osteomyelitis, abscess), and evaluation for resistance to third-generation cephalosporins and extended-spectrum beta-lactamase (ESBL) activity. Descriptive statistics were performed using frequencies for discrete variables and median [interquartile range (IQR)] for continuous variables.

Results:

Serratia marcescens was the predominate species 94 (91%). Demographics were White 88 (85%) and male 63 (62%); 42 (42%) were IV drug users. IV drug users were younger than non-IV drug users with a median (IQR) age of 40 [33–50] versus 71 years [41–72] and likely to have hepatitis C virus (HCV) infection 37 (88%) versus 3 (5%), p < 0.0001. Culture and susceptibility analysis revealed 36% of isolates with possible or confirmed ESBL production. The most common complications were endocarditis (12%) and osteomyelitis (10%). In-hospital mortality was 2%, 90-day mortality (2%), with 90-day readmission (21%). The median (IQR) LOS is 7 [3.25–14.75].

Conclusion:

This is the largest study to our knowledge evaluating non-nosocomial Serratia bacteremia. Our study shows that a high proportion of patients hospitalized with a positive Serratia culture are IV drug users and have HCV co-infection. There is significant ceftriaxone resistance and ESBL activity noted in our population. Based on this, we suggest empiric treatment with cefepime or consider carbapenem therapy for Serratia bloodstream isolates pending full susceptibility data. Focus should be on proper antibiotic treatment as the readmission rate and LOS are high.

Serratia marcescens sepsis outbreak caused by contaminated propofol

We presented a sepsis outbreak caused by Serratia marcescens from contaminated propofol to raise awareness. Three patients had sepsis syndrome after chest surgery. Isolation of S marcescens from patients' respiratory and blood samples alerted us to a possible outbreak. Four syringes filled with propofol and 1 saline solution yielded S marcescens. Nine of 10 isolates from samples of patients and environment genotyped by pulsed-field gel electrophoresis were the same. Disobeying aseptic injection rules of propofol is still causing outbreaks.

Outbreak of bacterial endocarditis associated with an oral surgery practice: New Jersey public health surveillance, 2013 to 2014

BACKGROUND

In October and November 2014, the New Jersey Department of Health received reports of 3 patients who developed Enterococcus faecalis endocarditis after undergoing surgical procedures at the same oral surgery practice in New Jersey. Bacterial endocarditis is an uncommon but life-threatening condition; 3 patients with enterococcal endocarditis associated with a single oral surgery practice is unusual. An investigation was initiated because of the potential ongoing public health risk.

METHODS

Public health officials conducted retrospective surveillance to identify additional patients with endocarditis associated with the practice. They interviewed patients using a standardized questionnaire. An investigative public health team inspected the office environment, interviewed staff, and reviewed medical records.

RESULTS

Public health officials identified 15 confirmed patients with enterococcal endocarditis of those patients who underwent procedures from December 2012 through August 2014. Among these patients, 12 (80%) underwent cardiac surgery. One (7%) patient died from complications of endocarditis and subsequent cardiac surgery. Breaches of recommended infection prevention practices were identified that might have resulted in transmission of enterococci during the administration of intravenous sedation, including failure to perform hand hygiene and failure to maintain aseptic technique when performing procedures and handling medications.

CONCLUSIONS

This investigation highlights the importance of adhering to infection prevention recommendations in dental care settings. No additional patients with endocarditis were identified after infection prevention and control recommendations were implemented.

PRACTICAL IMPLICATIONS

Infection prevention training should be emphasized at all levels of professional dental training. All dental health care personnel establishing intravenous treatment and administering intravenous medications should be trained in safe injection practices.

Infectious Disease Risk Associated with Contaminated Propofol Anesthesia, 1989-2014(1)

Transmission of illness to 144 patients, resulting in 10 deaths, has been linked to extrinsic contamination.

Administration of propofol, the most frequently used intravenous anesthetic worldwide, has been associated with several iatrogenic infections despite its relative safety. Little is known regarding the global epidemiology of propofol-related outbreaks and the effectiveness of existing preventive strategies. In this overview of the evidence of propofol as a source of infection and appraisal of preventive strategies, we identified 58 studies through a literature search in PubMed, Embase, and Lilacs for propofol-related infections during 1989–2014. Twenty propofol-related outbreaks have been reported, affecting 144 patients and resulting in 10 deaths. Related factors included reuse of syringes for multiple patients and prolonged exposure to the environment when vials were left open. The addition of antimicrobial drugs to the emulsion has been instituted in some countries, but outbreaks have still occurred. There remains a lack of comprehensive information on the effectiveness of measures to prevent future outbreaks.

An Outbreak of Serratia marcescens in a Moroccan Neonatal Intensive Care Unit

Serratia marcescens (S. marcescens) is an Enterobacteriaceae microorganism that is widespread in the environment, which may be the source of nosocomial infections, rare in the newborn but severe, and often in the form of outbreaks. The aim of our study is to report our experience, during an outbreak of S. marcescens, to show the severity of this germ, with review of the literature. Our study was retrospective, including 8 newborns with S. marcescens nosocomial infection, collected in the neonatal intensive care unit of Mohammed VI University Medical Hospital, during the epidemic period, over a period of 2 months (July and August 2016). The mean gestational age of the cases was 36 weeks of amenorrhea. Boys accounted for 75% of the cases. The average weight was 1853 grams. All the patients were initially placed under empiric antibiotic therapy based on ceftriaxone and gentamicin. The mean duration of nosocomial infection, diagnosed in all cases by blood cultures, was 7 days. The strains of S. marcescens were in 75% of the cases sensitive to the cephalosporins, intermediate sensitivity in 12.5% of cases and resistant in 12.5% of cases. The outcome was fatal in 62.5% of cases. S. marcescens nosocomial infections are often reported on epidemic series, and their eradication is not always easy.

Bacterial contamination of propofol vials used in operating rooms of a third-level hospital

We found a 6.1% bacterial contamination rate among 198 propofol vials collected after clinical use in 12 operating rooms of a high-complexity hospital in Cali, Colombia. Some propofol vials were used for extended periods (up to 72 hours), and only 26.1% of vials were punctured once. Median time of use, although not statistically significant, was higher in positive samples (7.2 vs 3.5 hours, P = .08). Education on the topic should stress that vials are single-patient use and must be immediately discarded after use.

Severe Osteomyelitis and Septic Arthritis due to Serratia marcescens in an Immunocompetent Patient

Septic arthritis and osteomyelitis due to Serratia marcescens in immunocompetent patients without risk factors are extremely rare. Here, we report a case of septic arthritis and severe adjacent osteomyelitis of the tibia due to Serratia marcescens in a diabetic community-dweller patient. The patient had no contact with healthcare workers or facilities and had no chronic disease except for poorly controlled diabetes. Without predisposing risk factors, this type of infection is extremely rare, even in diabetics.

In vitro evaluation of antimicrobial features of sugammadex

BACKGROUND

Drugs administered by intravenous routes may be contaminated during several stages of production or preparation. Sugammadex is a modified gamma cyclodextrin. While research into the antibacterial effects of varieties of cyclodextrin is available, there are no studies focusing on the antibacterial effects of sugammadex. This study investigates the in vitro antimicrobial activity of sugammadex.

MATERIALS AND METHODS

The in vitro antimicrobial activity of sugammadex was investigated using the broth microdilution method. The pH of the test solution was determined using a pH meter. The test microorganisms included Staphylococcus aureus ATCC 29213, Enterococcus fecalis ATCC 29212, Escherichia coli ATCC 25922 and Pseudomonas aeruginosa ATCC 27853. In the second phase of the study 100mg/mL sugammadex (50μg) was contaminated with test microorganisms (50μg), including S. aureus ATCC 29213, E. fecalis ATCC 29212, E. coli ATCC 25922 and P. aeruginosa ATCC 27853, left to incubate for 24h and then the bacterial production in sugammadex was evaluated.

RESULTS

The pH of the test solutions ranged between 7.25 and 6.97. Using the microdilution method, sugammadex had no antibacterial effect on S. aureus, E. fecalis, E. coli and P. aeruginosa at any concentration. In the second phase of the study bacterial production was observed after 24h in 100mg/mL sugammadex contaminated with the test microorganisms S. aureus, E. fecalis, E. coli and P. aeruginosa.

CONCLUSIONS

Sugammadex had no antimicrobial effect on the test microorganisms, S. aureus, E. fecalis, E. coli and P. aeruginosa. Care should be taken that sterile conditions are maintained in the preparation of sugammadex; that the same sugammadex preparation not be used for more than one patient; and that storage conditions are adhered to after sugammadex is put into the injector.

Critical evaluation of the off-label indication and of the risks associated to the use of multi-dose vials on the treatment of age-related macular degeneration

Age-related macular degeneration (AMD) is an ocular inflammatory diseases treated mainly by means of a bevacizumab (Avastin®) or ranibizumab (Lucentis®) intravitreal injection. Among these drugs, only ranibizumab has a specific therapeutic indication for AMD. Considering that, the off-label use on ophthalmic therapy seems to become a rule when it should be an exception. Furthermore, bevacizumab presentation consists of multi-dose vials although it does not contain preservatives in its formula. The current literature review aimed at assessing the risks for the patient related to the use of off-label indication and multi-dose vials on AMD treatment. Considering this, the proposal related to the Brazilian Public Consultation no.10, dated September 12, 2012, which proposes the Clinical Protocol and Therapeutic Guidelines for AMD treatment, was evaluated. This systematic review allowed to conclude that the bevacizumab off-label indication results in increased risks for the patient when compared to the product with specific therapeutic indication for AMD treatment (ranibizumab), especially referring to the significant raise in the adverse events. The risks for the patient related to the multi-dose vial use, referring to the microbiological stability and dose precision, were also made clear.

The antimicrobial effects of ketamine combined with propofol: An in vitro study

BACKGROUND AND OBJECTIVES

Ketamine and propofol are the general anesthetics that also have antimicrobial and microbial growth-promoting effects, respectively. Although these agents are frequently applied together during clinical use, there is no data about their total effect on microbial growth when combined. In this study, we investigated some organisms' growth in a ketamine and propofol mixture.

METHOD

We used standard strains including Escherichia coli, Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans in this study. Time-growth analysis was performed to assess microbial growth rates in 1% propofol. Antimicrobial activity of ketamine, alone and in propofol was studied with microdilution method.

RESULTS

In propofol, studied strains grew from 10(3)-10(4) cfu/mL to ≥10(5) cfu/mL concentrations within 8-16 hours depending on the type of organism. Minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) (for candida, minimal fungicidal concentration) of ketamine were determined as follows (MIC, MBC): E.coli 312.5, 312.5 μg/mL; S.aureus 19.5, 156 μg/mL; P.aeruginosa 312.5, 625 μg/mL; and C.albicans 156, 156 μg/ml. In ketamine+propofol mixture, ketamine exhibited antimicrobial activity to E.coli, P.aeruginosa and C.albicans as MBCs at 1250, 625 and 625 μg/mL, respectively. Growth of S. aureus was not inhibited in this mixture (ketamine concentration=1250 μg/mL).

CONCLUSION

Ketamine has sustained its antimicrobial activity in a dose-dependent manner against some organisms in propofol, which is a strong microbial growth-promoting solution. Combined use of ketamine and propofol in routine clinical application may reduce the risk of infection caused by accidental contamination. However, one must keep in mind that ketamine cannot reduce all pathogenic threats in propofol mixture.

Infection prevention in anesthesia practice: a tool to assess risk and compliance

Transmission of bacterial and viral infections to patients from improper anesthesia infection prevention and control practices continues to be reported. "Recommendations for Infection Control for the Practice of Anesthesiology" were recently revised. The process used to develop an anesthesia infection prevention assessment tool is described. The tool is intended to encourage collaboration between infection preventionists and anesthesia providers in an effort to assess infection prevention and control practices in various health care anesthesia settings.

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.

Analytic reviews: managing the agitated patient in the ICU: sedation, analgesia, and neuromuscular blockade

Physical and psychological distress is exceedingly common among critically ill patients and manifests generically as agitation. The dangers of over- and undertreatment of agitation have been well described, and the intensive care unit (ICU) physician must strike a balance in the fast-paced, dynamic ICU environment. Identification of common reversible etiologies for distress may obviate the need for pharmacologic therapy, but most patients receive some combination of sedative, analgesic, and neuroleptic medications during the course of their critical illness. As such, understanding key pharmacologic features of commonly used agents is critical. Structured protocols and objective assessment tools can optimize drug delivery and may ultimately improve patient outcomes by reducing ventilator days, ICU length of stay, and by reducing cognitive dysfunction.

Association of preservative-free propofol use and outcome in critically ill patients

BACKGROUND

Propofol is widely used to provide sedation to patients in the intensive care unit (ICU). This study examined whether preservative-free propofol infusion independently influences outcome in critically ill patients.

METHODS

This was a nested cohort study within a randomized controlled trial. ICU patients who received preservative-free propofol and those who did not were compared. The following data were collected: demographic information, APACHE II score, admission category, chronic severe illnesses, nutritional data, and blood glucose level and insulin dose. The main exposure was the use of preservative-free propofol infusion. The main outcomes were the occurrence of ICU-acquired infections, ICU-acquired sepsis, and ICU and hospital mortality.

RESULTS

A total of 523 patients were included (no propofol group, n = 399; propofol group, n = 124). After adjustment for differences in baseline characteristics, preservative-free propofol use was associated with increased risk of ICU-acquired infections (adjusted odds ratio [aOR], 1.89, 95% confidence interval [CI], 1.17-3.06; P = .009) and ICU-acquired severe sepsis and septic shock (aOR, 1.91; 95% CI, 1.12-3.28; P = .02), but not with ICU or hospital mortality.

CONCLUSION

Preservative-free propofol infusion in critically ill patients may be associated with increased risk of ICU-acquired infections and ICU-acquired sepsis, with no significant difference in ICU or hospital mortality. This association might have been related to the use of preservative-free preparations.

Outbreak of severe sepsis due to contaminated propofol: lessons to learn

Nosocomial infections are a frequent concern in healthcare. Despite the available knowledge on nosocomial infections and preventive measures, outbreaks of infections continue to occur. An outbreak of severe sepsis in patients who underwent minor procedures in an operating theatre during two consecutive days is described and analysed in this study. We performed a retrospective cohort study using epidemiological data in order to investigate the source of infection together with microbiological and on-site investigations and interviews. Seven patients met the case definition of postoperative systemic inflammatory response syndrome (SIRS). All other patients operated on over the same period served as controls. Of the risk factors investigated, general anaesthesia and propofol were statistically significant (P=0.003). Klebsiella pneumoniae and Serratia marcescens were cultured from opened vials of propofol, propofol-related devices and from blood cultures from two of the patients. These strains were genotypically indistinguishable. Lapses in aseptic preparation, handling and storage of the propofol were observed, and were the most probable cause of the extrinsic contamination. The daily procedure of handling propofol was not performed according to the manufacturer's recommendations, the main departure being the use of a single-use vial for multiple patients. This study documents the risk of infection due to contaminated propofol and the importance of having written guidelines for its handling.

Serratia marcescens sepsis outbreak in a neonatal intensive care unit

BACKGROUND

Contaminated parenteral nutrition (PN) is an important source of infection in neonates. Many organisms have been reported to cause contamination resulting in outbreaks in intensive care units. The aim of the present study was to investigate an outbreak caused by Serratia marcescens in a neonatal intensive care unit (NICU).

METHODS

This was a descriptive study of an outbreak of sepsis in an NICU of a university teaching hospital. The outbreak was detected in seven patients from 10 to 12 December 2005 following the administration of PN. Extensive environmental samplings for culture were performed. The clonal relationship among isolates was tested using pulsed-field gel electrophoresis, random amplification of polymorphic DNA-polymerase chain reaction and plasmid DNA typing.

RESULTS

Serratia marcescens was found in blood cultures from infected newborns and from in-use PN solutions. Gestational age of the seven babies ranged from 28 to 34 weeks (median, 32 weeks), birthweight ranged from 1000 g to 2190 g (median, 1469 g), and postnatal age ranged from 8 to 22 days. The mortality rate was 14.3%. All these strains of S. marcescens had the same antibiotic susceptibility pattern and the same genomic DNA profile. Plasmid typing, as well as RAPD-PCR showed that all isolates had the same profile.

CONCLUSION

The source of the nosocomial sepsis in seven neonates was the PN solution. Contamination may occur during storage or repeated handling during PN preparation.

The prevalence of multidose vial contamination by aerobic bacteria in a major teaching hospital, Shiraz, Iran, 2006

BACKGROUND

Parenteral medications are usually given out in multidose vials (MDVs) and can be used for a prolonged period for 1 or more patients. The risk of extrinsic contamination of MDVs and its consequences may be serious and may lead to an outbreak, especially in hospitals. Therefore, bacterial contamination of multiple-dose medication vials in Namazi Hospital, the major referral teaching hospital, in Shiraz, southwestern Iran, was evaluated.

METHODS

In a period of 4 months, all used MDVs in Namazi Hospital were collected by the infection control nurses. Information was recorded about the medication, labeling of vials, storing temperature, wards, and dates of opening. Remained contents of each vial were also tested for aerobic bacteria. Microbial contamination was confirmed by microbiologic methods.

RESULTS

Bacterial contamination was identified in 36 of 637 (5.6%) of vials, with no difference in contamination among different wards in the hospital or the medication type. Most commonly identified organisms were part of the normal commensally flora. Gram-positive bacteria (88.9%) were more significantly involved than gram-negative ones (11.1%), with the highest frequency for Staphylococcus epidermidis (44.4%) and the lowest for Actinomyces viscosus (2.8%).

CONCLUSION

Although the clinical significance is not resolved at this point, infection control practices should be emphasized considering this potential source of nosocomial infection.

Self-limited febrile syndromes temporally associated with the use of propofol for sedation in gastrointestinal endoscopic procedures

PURPOSE

To investigate cases of febrile illnesses in patients who received propofol for sedation during gastrointestinal endoscopy.

METHODS

Active case finding for patients who underwent endoscopy between 1 April and 30 May 2007 and suffered unexplained fever, chills, or myalgia within 48 hour after the procedure. We reviewed medications and clinical practices to find factors associated with the reactions.

RESULTS

Seventy-four cases at eight facilities in five states were identified yielding a rate of 36 reactions per 1000 procedures, compared with a baseline rate of 0.6 per 1000. The majority of patients experienced self-limited fever (89.2%), chills (73.0%), or myalgia (63.5%). Blood samples from five patients were collected for culture; no organisms grew. All health care facilities that reported cases and fully participated in the investigation (n = 7) had received a common lot of propofol just before recognition of the first case. Bacterial endotoxin and sterility testing on unopened vials from this lot of propofol showed no abnormalities. Cases terminated after facilities stopped using the associated lot of propofol.

CONCLUSIONS

We found a temporal association between a particular lot of propofol and an outbreak of febrile illnesses at several healthcare facilities performing endoscopy. When propofol is used to sedate patients for endoscopy, fever is a rare outcome and healthcare professionals should investigate clusters of these reactions. Post-procedure surveillance is important to identify possible medication reactions.

Outbreak of Serratia marcescens bloodstream and central nervous system infections after interventional pain management procedures

OBJECTIVES

To determine the cause of an outbreak of Serratia marcescens infections in patients after interventional pain management procedures at an outpatient pain clinic.

METHODS

We conducted a case-control study and collected clinical and environmental samples.

RESULTS

We identified 5 culture-confirmed case-patients and 2 presumptive case-patients who had no bacteria recovered from cultures. The 7 case-patients were compared with 28 controls who underwent procedures at the same clinic but did not develop symptoms of infection. All confirmed case-patients had S. marcescens bloodstream infections; 2 had concurrent S. marcescens central nervous system infections. Case-patients were more likely than controls to have procedures that used contrast solution or entered the epidural or intervertebral disc space (P< or =0.01 for each). All S. marcescens clinical isolates were indistinguishable by pulsed-field gel electrophoresis. We did not isolate S. marcescens from medications or environmental samples; however, S. marcescens was shown to survive and grow in contrast solution that was experimentally contaminated for up to 30 days. Single-dose vials of medication, including contrast solution, were used for multiple procedures; multiple medications were accessed with a common needle and syringe.

DISCUSSION

The findings of this investigation suggest contamination of a common medication, likely contrast solution, as the source of the outbreak. Practices, such as reusing single-dose medication vials and using a common needle and syringe to access multiple medications, could have led to contamination and propagation of S. marcescens and should be avoided in interventional pain management procedures.

Multifactorial origin of high incidence of Serratia marcescens in a cardio-thoracic ICU: analysis of risk factors and epidemiological characteristics

OBJECTIVE

A four-fold increase in the incidence of Serratia marcescens occurred in a cardio-thoracic ICU within a 13-month period. Clinical, epidemiological and molecular characteristics were analysed to elucidate the outbreak's origin.

METHODS

Epidemiological data were analysed by mapping clustered cases; isolates were genotyped by AFLP analysis. A case-control study was performed to identify risk factors for the acquisition of S. marcescens. Data were obtained from files and electronic databases of the ICU and Department of Medical Microbiology. The adherence to hygiene protocols on the ICU was reviewed by a medical audit.

RESULTS

Genotyping showed 16 distinct S. marcescens strains. Twenty-one cases and 39 controls were enrolled in the case-control study. Significant differences found by univariate analysis included the duration of surgery, APACHE-II-score on ICU admission, length of ICU stay, duration of mechanical ventilation, tube feeding and the sum of the number of days per invasive device. In a multivariate logistic regression model, the length of ICU stay and tube feeding were independent risk factors. Outbreak strains were not more frequently resistant to gentamicin, ciprofloxacin, meropenem or trimethoprim-sulfamethoxazole as compared to a reference group. Hygiene protocols, including hand washing, were insufficiently practiced by the ICU's medical staff.

CONCLUSIONS

The heterogeneity of the strains points to transmission from various sources. This outbreak of S. marcescens was most probably caused by reduced hand washing and other breaks in infection prevention protocols in combination with the presence of the identified risk factors, which act by affecting the number and intensity of potential transmission events.

Antibacterial activity of remifentanil and mixtures of remifentanil and propofol

STUDY OBJECTIVE

To investigate the antibacterial activity of glycine, which is contained in remifentanil, when combined with propofol.

DESIGN

Prospective study.

SETTING

Departments of anesthesiology and microbiology of a university hospital.

MEASUREMENTS

Growth of the microorganisms Staphylococcus epidermidis, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans in propofol 1%; saline dilutions of remifentanil at one-, 10-, and 100-microg/mL concentrations; and 1:1 mixtures of propofol with remifentanil solutions was determined.

MAIN RESULTS

Remifentanil inhibits bacterial growth in a concentration-dependent manner. The antibacterial effects were more pronounced with Staphylococcus aureus and Pseudomonas aeruginosa at cultures obtained at the fifth hour. The inhibition of bacterial growth was less influenced with Escherichia coli and Candida albicans.

CONCLUSIONS

Propofol and remifentanil mixtures decreased bacterial growth, and combinations may reduce the infectious complications from accidentally contaminated propofol.

Hospital-acquired infections related to contaminated substances

Drug-related outbreaks are frequently reported from various medical departments. A systematic review was performed to describe characteristics of these outbreaks and to determine the most frequent occasions in which contamination of substances for patient care take place. Articles were assessed by a search of the outbreak database, a search of PubMed, and hand search of reference lists from relevant articles. Articles published before 1990 were excluded. Data on affected patients, hospital-acquired infections, substances, pathogens and graded information about the location of the contamination incidence were extracted. A total of 2250 patients in 128 articles were included, mostly from intensive care units or haematological departments. Septicaemia was the most frequent hospital-acquired infection. Most often articles report contamination of blood products and heparin-sodium chloride solutions. The most frequent pathogens were hepatitis A virus, Yersinia enterocolitica, and Serratia spp. for blood products and Burkholderia cepacia and Enterobacter spp. for substances other than blood products. Mortality was highest if red blood cells or total parenteral nutrition formulas were contaminated. In 64 of the outbreaks multi-dose vials had been used against the manufacturers' recommendations. Thus, drug-related outbreaks are likely to occur particularly when basic hygiene measures are disobeyed. A large proportion of drug-related nosocomial infections could have been prevented, for example, by avoiding the use of multi-dose vials.

Propofol EDTA and reduced incidence of infection

Propofol formulated in a lipid vehicle supports the growth of microorganisms. There have been worldwide reports of extrinsic microbial contamination of propofol leading to outbreaks of serious postoperative nosocomial infections. Therefore it is essential that medical professionals follow strict aseptic precautions when handling propofol, as recommended by manufacturers of propofol and the Centers for Disease Control and Prevention. Non-adherence to these recommendations increases the risk of nosocomial postoperative infections, which impose a heavy burden of morbidity and mortality and have serious economic consequences. It has also been recommended that the use of EDTA-containing formulations of propofol be considered. In vitro studies have confirmed that EDTA added to propofol retards microbial growth. Data on the incidence of nosocomial infections before and after the introduction of propofol with EDTA indicates that there have been no further cluster outbreaks and individual nosocomial infections appear to have been reduced. The addition of EDTA is an additional safety precaution to good aseptic practice.

Acquisition of multidrug-resistant Serratia marcescens by critically ill patients who consumed tap water during receipt of oral medication

We describe an outbreak of multidrug-resistant Serratia marcescens infection and colonization involving adults admitted to a surgical intensive care unit. Examination of the outbreak revealed epidemiological evidence that consumption of tap water from a contaminated faucet during receipt of oral medication was the mechanism of S. marcescens acquisition.

Propofol for sedation in neuro-intensive care

Interventions in the intensive care unit often require that the patient be sedated. Propofol is a widely used, potent sedative agent that is popular in critical care and operating room settings. In addition to its sedative qualities, propofol has neurovascular, neuroprotective, and electroencephalographical effects that are salutory in the patient in neurocritical care. However, the 15-year experience with this agent has not been entirely unbesmirched by controversy: propofol also has important adverse effects that must be carefully considered. This article discusses and reviews the pharmacology of propofol, with specific emphasis on its use as a sedative in the neuro-intensive care unit. A detailed explanation of central nervous system and cardiovascular mechanisms is presented. Additionally, the article reviews the literature specifically pertaining to neurocritical care use of propofol.

Experimental confirmation of Serratia marcescens contamination in multiple-dose vials of heparin-saline solution

The initial contamination of heparin-saline solution (HS) in multiple-dose vials (MDVs) by Serratia marcescens was experimentally investigated using various isolates. Isolates I2 and S1 were from blood specimens from patients with a hospital-acquired infection (HAI). Isolates I13 and FHSM9043 were from urine and blood specimens, respectively, from patients without HAI. Isolate I124, with a pulsed-field get electrophoresis pattern identical to that of isolate I2, was from the hospital environment. Viable cells of isolate I2 were carried over into the HS of MDVs when the contaminated rubber septum was pierced with a syringe needle. When the outside surface of the septum was contaminated by inoculating it with wet-cell suspensions in HS or Müller-Hinton broth, the viable cells carried over were detected at a minimum inoculum size (MIS) of 10(3) s cfu/ml. However, when the surface was contaminated by inoculating it with dry-cell suspensions, the viable cells carried over were detected at an MIS of 10(7) s cfu/ml. The viable cells in the internal lumen of the needle much more than those on its outside surface spread to the HS of MDVs. For exposures of 24 h and 72 h at 4 degrees C to HS with 1% benzyl alcohol as a preservative in MDVs, viable cells of all isolates tested were detected at MIS values of 1 s and 10 s cfu/ml, respectively, increases three orders of magnitude smaller than those of reference strain IFO3736. These results suggest that S. marcescens isolates are readily carried over into the HS of MDVs by piercing a wet, contaminated rubber septum with a syringe needle. Also, despite the sterilization action of 1% benzyl alcohol, the organism persistently survived at 4 degrees C, even when initial contamination was with a small amount of inoculum.

Clustering of Serratia marcescens infections in a neonatal intensive care unit

OBJECTIVES

To study clusters of infections caused by Serratia marcescens in a neonatal intensive care unit (NICU) and to determine risk factors for S. marcescens infection or colonization.

DESIGN

Genotyping of S. marcescens isolates was performed by pulsed-field gel electrophoresis (PFGE). A retrospective case-control study was conducted.

SETTING

A tertiary-care pediatric hospital with a 16-bed NICU.

PATIENTS

All neonates with at least one culture positive for S. marcescens in the NICU during December 1999 to July 2002. Case-patients (n = 11) treated in the NICU during December 1999 to February 2000 were included in the case-control study. Neonates treated in the NICU for at least 72 hours during the same period with cultures negative for S. marcescens were used as control-patients (n = 27).

RESULTS

S. marcescens was cultured from 19 neonates; 9 were infected and 10 were colonized. PFGE analysis identified three epidemic strains; each cluster consisted of identical isolates, except one isolate in the first cluster that was different. The risk factors identified were low birth weight, prematurity, prolonged respiratory therapy, prolonged use of antibiotics, and maternal infection prior to delivery. Overcrowding and understaffing were recorded simultaneously with the clusters.

CONCLUSIONS

PFGE analysis showed three independent clusters. Several factors contributed to spread of the epidemic strains: (1) there were many severely premature and susceptible neonates, (2) the NICU was overcrowded during the clusters, and (3) transmission was likely to occur via the hands of staff. Cohorting and improvement of routine infection control measures led to the cessation of each cluster.

Étude cas-témoins d’une épidémie à Serratia marcescens dans un service de réanimation pédiatrique

OBJECTIVES

To identify patient-related risk factors of infection and ways of transmission of extended-spectrum betalactamase (ESBL) producing Serratia marcescens in the paediatric intensive care unit (PICU) of Amiens university hospital (France) between June and July 2002.

METHODS

Five cases (four pulmonary infected and one stool contaminated symptom-free neonates) and 35 controls, admitted in the PICU, are included. S. marcescens ESBL analysed are isolated from respiratory tract and faecal samples for cases and urine and pus samples from two non-paediatric other patients. Univariate and multivariate analysis are performed on EPI INFO 6.04 dFr and SPSS 11.0.1.

RESULTS

S. marcescens ESBL infections or colonisations rate is 12.5% [4.7-27.6]. The incidence is 8.8 [6.7-11.6] per 1000 hospital-stay days. By univariate analysis, cases and controls don't differ with respect of age, sex, and weight at admission or preterm delivery. Cases don't have more often invasive nursing care than controls. But, they were intubated (P <0.03) and hospitalised (P <0.03) for a longer time than controls. Linear regression analysis showed that duration of intubation was independent predictor of acquisition of S. marcescens ESBL (P <0.008). S. marcescens ESBL strains implicated in pulmonary infections, showed the same pattern of multidrug resistant and ERIC-PCR profile. This clone differs from others isolated from stool or other samples from other hospital wards.

CONCLUSION

As S. marcescens cross-colonization appears to be due to lake of hand hygiene and asepsis during invasive nursing care, reinforcing hygiene measures permit to contain the outbreak.

Infection control and its application to the administration of intravenous medications during gastrointestinal endoscopy

Several infection control practices and procedures crucial to the prevention of disease transmission in the health care setting are reviewed and discussed. Emphasis is placed on the importance of infection control to gastrointestinal endoscopy. Recommendations that minimize the risk of nosocomial infection during the preparation, handling, and administration of intravenous medications, particularly propofol, are provided. These recommendations include the labeling of predrawn syringes; use of sterile single-use syringes, needles, and administration sets for each patient; and, whenever feasible, administration of intravenous medications promptly after opening their prefilled syringes or after opening their ampoules or vials and filling the sterile syringes.

Outbreak of joint and soft-tissue infections associated with injections from a multiple-dose medication vial

An outbreak of Staphylococcus aureus joint and soft-tissue infections occurred after therapeutic injections in an outpatient setting. A physician performed intra-articular or soft-tissue injections on 17 patients in August 2001, and 5 (29%) were subsequently hospitalized for infections at the site. S. aureus was isolated from 4 patients, and all 4 isolates were indistinguishable by pulsed-field gel electrophoresis. Of 10 patients injected with lidocaine and triamcinolone, 5 (50%) developed infections, compared with 0 of 7 patients injected with triamcinolone only (P=.04). A multiple-dose vial (MDV) of lidocaine was likely contaminated with S. aureus. A possible contributing factor was refrigeration after the use of MDVs of lidocaine; the manufacturer recommends storage at room temperature. An in vitro study of S. aureus in MDVs of lidocaine revealed prolonged survival at refrigerator temperatures. This outbreak highlights the importance of strict attention to aseptic procedures and carefully following manufacturers' instructions when using MDVs.