Ventilator temperature sensors: an unusual source of Pseudomonas cepacia in nosocomial infection

Single-Center Experience of Control of Ventilator-Circuit-Transmitted Burkholderia cepacia Outbreak in an Intensive Care Unit

Burkholderia cepacia is an emerging nosocomial pathogen frequently associated with outbreaks, but the exact transmission route of this pathogen can at times be elusive in spite of extensive environmental investigative cultures. Active surveillance for sputum cultures was performed for all patients from September 2008 to September 2009 in an intensive care unit (ICU) with B. cepacia outbreak. With evidence of persistent positive conversion of sputum cultures (colonization) and infections among patients, discontinuing re-usable ventilator circuits was introduced. A total of 689 patients were admitted to this unit for a mean duration of 8.7 ± 7.5 days. There were 489 patients (71.0%) with a stay for one to ten days; 161 (23.4%) patients for 11 to 20 days; and 39 (5.7%) with over 20 days. In the first group, 13.5% of patients had cultures converting from negative to positive, in contrast to 66.7% in the last group (p < 0.01). With intervention of using disposable ventilator circuits since June 2009, the incidence of isolated B. cepacia decreased gradually. The estimated 30-day isolation-free probabilities of the groups before, during, one month (August 2009) after, and two months (September 2009) after this intervention were 38.5%, 47.3%, 66.5%, and 96.0%, respectively (p < 0.01). Furthermore, the effect of discontinuing reusable ventilator circuit persisted in the following 6 years; both total isolates of B. cepacia and the infection caused by it were much lower compared to the outbreak period. In summary, this six-year outbreak in a medical ICU persisted until reusable ventilator circuits were discontinued in 2009. The effect of disposable circuits on the decreased incidence of B. cepacia infection maintained in the following years.

Global burden, point sources, and outbreak management of healthcare-associated Burkholderia cepacia infections: An integrative review

OBJECTIVE

To examine the global burden, associated point sources, and successful prevention and control measures for documented outbreaks of Burkholderia cepacia healthcare-associated infections (HAIs).

DESIGN

Integrative review.

METHODS

A review of all outbreaks of Burkholderia cepacia HAIs published in the peer-reviewed literature between January 1970 and October 2019 was conducted to identify the global burden, associated point sources, and successful prevention and control measures using the Guidelines for Outbreak Reports and Intervention Studies of Nosocomial Infections (ORION).

RESULTS

In total, we reviewed 125 documented outbreaks of Burkholderia cepacia-related HAIs worldwide. The reported B. cepacia HAIs for this period involved 3,287 patients. The point sources were identified in most outbreaks of B. cepacia HAIs (n = 93; 74.4%); they included medication vials, disinfectants, and antiseptics. Moreover, 95 of the outbreak reports (76%) described effective prevention and control measures, but only 33 reports indicated the use of a combination of environment-, patient- and staff-related measures. None of the outbreak reports used the ORION guidelines.

CONCLUSIONS

Outbreaks of Burkholderia cepacia HAIs are an ongoing challenge. They are often associated with immunocompromised patients who acquire the infection from exposure to contaminated medications, products, and equipment. These outbreaks are not infrequent, and a range of infection prevention and control measures have been effective in arresting spread. The use of ORION guidelines for outbreak reporting would improve the quality of information and data to generate evidence for translation into practice.

Pseudobrote por Burkholderia cepacia en dos unidades de cuidados intensivos de un Hospital Universitario en Bogotá – Colombia

Introducción: Burkholderia cepacia es causante de brotes cuyo origen frecuentemente son fuentes ambientales.Materiales y métodos: Ante la sospecha de brote por B. cepacia en hemocultivos. Se realizó toma de cultivos ambientales y de insumos. Los aislamientos microbiológicos fueron sometidos a análisis molecular.Resultados: Se identificaron 8 pacientes con hemocultivos para B. cepacia en la UCI Adultos y UCI Pediátrica, edades entre 3 meses y 88 años, Los hemocultivos fueron tomados a través de catéter venoso central. Ningún paciente presentó infección por este microorganismo. Se documentó crecimiento de B. cepacia en lote de bolsitas (“sachet”) jabón de clorhexidina al 4% y en lavamanos que se correlacionaron con el clon identificado en los pacientes. Con el retiro del lote de jabón de clorhexidina, optimización de los procesos de limpieza y desinfección, lavado de manos y medidas de aislamiento se controló el pseudobrote .Conclusiones: Se presenta un pseudobrote por B. cepacia causado por la contaminación de un lote de clorhexidina jabón y de los lavamanos, llamando la atención acerca de la posibilidad de contaminación de antisépticos con este microorganismo.

Infection Prevention and Control Guideline for Cystic Fibrosis: 2013 Update

The 2013 Infection Prevention and Control (IP&C) Guideline for Cystic Fibrosis (CF) was commissioned by the CF Foundation as an update of the 2003 Infection Control Guideline for CF. During the past decade, new knowledge and new challenges provided the following rationale to develop updated IP&C strategies for this unique population:

1.The need to integrate relevant recommendations from evidence-based guidelines published since 2003 into IP&C practices for CF. These included guidelines from the Centers for Disease Control and Prevention (CDC)/Healthcare Infection Control Practices Advisory Committee (HICPAC), the World Health Organization (WHO), and key professional societies, including the Infectious Diseases Society of America (IDSA) and the Society for Healthcare Epidemiology of America (SHEA). During the past decade, new evidence has led to a renewed emphasis on source containment of potential pathogens and the role played by the contaminated healthcare environment in the transmission of infectious agents. Furthermore, an increased understanding of the importance of the application of implementation science, monitoring adherence, and feedback principles has been shown to increase the effectiveness of IP&C guideline recommendations.

2.Experience with emerging pathogens in the non-CF population has expanded our understanding of droplet transmission of respiratory pathogens and can inform IP&C strategies for CF. These pathogens include severe acute respiratory syndrome coronavirus and the 2009 influenza A H1N1. Lessons learned about preventing transmission of methicillin-resistantStaphylococcus aureus(MRSA) and multidrug-resistant gram-negative pathogens in non-CF patient populations also can inform IP&C strategies for CF.

Outbreak of Burkholderia cepacia complex among ventilated pediatric patients linked to hospital sinks

We investigated a cluster of Burkholderia cepacia complex colonization in ventilated pediatric patients. Isolates from 15 patients, 2 sink drains, and several ventilator components were found to belong to a single B cenocepacia clone. Hospital tap water used during oral and tracheostomy care was identified as the most likely mechanism for transmission.

The changing microbial epidemiology in cystic fibrosis

Infection of the airways remains the primary cause of morbidity and mortality in persons with cystic fibrosis (CF). This review describes salient features of the epidemiologies of microbial species that are involved in respiratory tract infection in CF. The apparently expanding spectrum of species causing infection in CF and recent changes in the incidences and prevalences of infection due to specific bacterial, fungal, and viral species are described. The challenges inherent in tracking and interpreting rates of infection in this patient population are discussed.

Therapeutic options for Burkholderia cepacia infections beyond co-trimoxazole: a systematic review of the clinical evidence

Burkholderia cepacia complex (BCC) is an important group of pathogens affecting patients with cystic fibrosis and chronic granulomatous disease as well as immunocompromised and hospitalised patients. Therapeutic options are limited owing to high levels of resistance of the organism, either intrinsic or acquired, to many antimicrobial agents. Co-trimoxazole (trimethoprim/sulfamethoxazole) has been a drug of choice. However, in some cases it cannot be administered because of allergic or hypersensitivity reactions, intolerance or resistance. We systematically searched for relevant publications including clinical data in PubMed and Scopus. The search identified 48 relevant case reports (57 cases) and 8 cohort studies or trials. Nineteen (33.3%) of 57 patients included in the case reports received ceftazidime-based regimens, 14 (73.7%) of whom were cured. Meropenem was administered in seven patients (12.3%), one (14.3%) of whom improved and five (71.4%) were cured. Seven (12.3%) of 57 cases were treated with penicillins, four of which were piperacillin (all had a favourable outcome). Based on the data reported in the eight relevant cohort studies or trials identified, favourable outcomes were observed in 68.4% (26/38) to 100% (16/16) of cases treated with ceftazidime and 66.7% (6/9) of cases treated with meropenem. Also, 9/12 (75%) of patients receiving penicillins improved. Thus, Ceftazidime, meropenem and penicillins, mainly piperacillin, either alone or in combination with other antimicrobial agents, may be considered as alternative options for BCC infections, according to the in vitro antimicrobial susceptibility patterns and clinical results. However, the available clinical data are not sufficient and further clinical experience is required to clarify the appropriateness of these antibiotics for BCC infections.

Moisturizing body milk as a reservoir of Burkholderia cepacia: outbreak of nosocomial infection in a multidisciplinary intensive care unit

Background

An outbreak of severe nosocomial Burkholderia cepacia infections in patients admitted to intensive care unit (ICU), including investigation of the reservoir, is described.

Methods

Over a period of 18 days, isolates of Burkholderia cepacia were recovered from different biological samples from five patients who were admitted to a multidisciplinary 18-bed intensive care unit. Isolation of B. cepacia was associated with bacteraemia in three cases, lower respiratory tract infection in one and urinary tract infection in one. Contact isolation measures were instituted; new samples from the index patients and adjacent patients were collected; and samples of antiseptics, eau de Cologne and moisturizing body milk available in treatment carts at that time were collected and cultured.

Results

B. cepacia was isolated from three samples of the moisturizing body milk that had been applied to the patients. Three new hermetically closed units, from three different batches, were sent for culture; two of these were positive as well. All strains recovered from environmental and biological samples were identified as belonging to the same clone by pulsed-field gel electrophoresis. The cream was withdrawn from all hospitalization units and no new cases of B. cepacia infection developed.

Conclusion

Moisturizing body milk is a potential source of infection. In severely ill patients, the presence of bacteria in cosmetic products, even within accepted limits, may lead to severe life-threatening infections.

An Outbreak of Burkholderia cepacia Associated With Contamination of Albuterol and Nasal Spray

BACKGROUND

Species within the Burkholderia cepacia complex (Bcc) can contaminate medications and disinfectants and cause severe pneumonia in critically ill patients or persons with cystic fibrosis. In March 2004, we investigated a hospital outbreak of Bcc possibly associated with a contaminated nasal spray.

METHODS

We conducted a matched case-control study, environmental sampling, and observations of infection control practices. Case patients had infection or colonization with Bcc, and control patients had sputum culture not yielding Bcc. Isolates from patients and environmental samples were compared by pulsed-field gel electrophoresis (PFGE).

RESULTS

Bcc was recovered from sputum in 18 patients. Compared with matched control patients (n = 18), case patients were more likely to be receiving mechanical ventilation (p = 0.01), to have been hospitalized > 6 days (p = 0.01), and to have received antimicrobial treatment within 7 days before sputum collection (p = 0.03). Bcc was cultured from opened, but not unopened, multidose albuterol bottles, a nebulizer attached to a ventilator, and opened and unopened nasal spray bottles from contaminated lots. PFGE showed that isolates from albuterol samples and from patients were indistinguishable but unrelated to the nasal spray strain. Observations revealed improper aseptic techniques during respiratory therapy procedures and inadequate nebulizer cleaning.

CONCLUSIONS

Despite a temporal association with use of a contaminated nasal spray, this outbreak was caused by extrinsic contamination of multidose albuterol used for nebulization treatments and lack of adherence to infection control precautions. Implementation and re-enforcement of infection control measures successfully terminated the outbreak.

[Epidemiology of nosocomial infections due to Pseudomonas aeruginosa, Burkholderia cepacia and Stenotrophomonas maltophilia]

Non-fermentative Gram negative rods are opportunistic pathogens responsible for nosocomial infections. Using phenotypic markers (serotypes for Pseudomonas aeruginosa and antibiotic susceptibility) allows a preliminary screening of epidemiologically-related strains. However, genotypic markers are necessary to better characterize nosocomial strains for the investigation of outbreaks or cross-transmissions in the hospital setting. Infections due to P. aeruginosa, Burkholderia. cepacia or Stenotrophomonas. maltophilia are usually hospital-acquired and responsible for a high mortality rate as illustrated by the lethality of nosocomial pneumonia due to P. aeruginosa. The severity of these infections is due to the virulence factors of the bacteria and to their occurrence in debilitated patients in whom invasives devices are used. The hospital environment can act as a reservoir with a rate of exogeneous transmission of these bacteria as high as 50% in some studies. To better prevent nosocomial infections related to Gram negative non fermentative rods, the control of the aqueous hospital environment, the strict application of hand disinfection and the investigation of potential cross-transmission in the hospital setting are needed.

Épidémie nosocomiale à Burkholderia cepacia dans une unité de réanimation infantile

BACKGROUND

We report an outbreak of Burkholderia cepacia respiratory tract infection and colonization in an intensive pediatric care unit.P PATIENTS AND METHODS: Between February and December 1999, B. cepacia was isolated from five children hospitalized in this unit. We reviewed the charts of the patients, evaluated the antiseptics use and the disinfection practices for reusable patient care equipment. An environmental study was conducted and comparison of B. cepacia was performed with genotypic method (RAPD).

RESULTS

All patients were mechanically ventilated and had received large spectrum antibiotics. The disinfection procedure for reusable equipment was not respected and some single-dose of antiseptics solutions were used for several patients. B. cepacia was not found in 34 environmental samples. The RAPD assay revealed that all five isolates had identical DNA profiles.

CONCLUSION

Despite the investigation the source of the B. cepacia clone in this nosocomial outbreak remained unknown, but antiseptics use and disinfection practices were revised. No new B. cepacia infections were identified after control measures were implemented.

Electronic ventilator temperature sensors as a potential source of respiratory tract colonization with Stenotrophomonas maltophilia

Stenotrophomonas maltophilia (S. maltophilia) is an important cause of nosocomial infection among ventilated and immunocompromised patients, and among patients receiving broad-spectrum antimicrobials. We report a cluster of patients in a surgical intensive care unit who were colonized or infected with S. maltophilia. An epidemiological investigation was initiated after surveillance data revealed that eight patients were culture-positive from sputum for S. maltophilia in the preceding month. Review of respiratory care procedures revealed that when mechanical ventilators were serviced between patients, the electronic temperature probes used with servo-controlled humidifiers were wiped with inadequate disinfection. We collected cultures of case-patient room surfaces, sinks and ventilator equipment. S. maltophilia was recovered from room surfaces, ventilator expiratory circuits and a temperature sensor which had been kept in ambient air after disinfection. Patients and environmental isolates were examined by RAPD-PCR. Three clinical isolates and one environmental isolate had the same profile, which suggests cross-contamination or common source exposure. The outbreak was controlled by adequate disinfection of the temperature sensors. No single epidemic strain was identified but several observations support the conclusion that the temperature probes contributed to the outbreak.

Burkholderia cepacia lower respiratory tract infection associated with exposure to a respiratory therapist

OBJECTIVE

To investigate and control a nosocomial outbreak of Burkholderia cepacia lower respiratory tract infection.

DESIGN

Outbreak investigation and case-control study.

SETTING

A 260-bed community hospital.

PATIENTS

Participants were mechanically ventilated intensive care patients without cystic fibrosis. A case was defined as a hospitalized patient with a sputum culture positive for B. cepacia between January 1 and November 6, 1998.

METHODS

Respiratory therapy infection control policies and practices were reviewed; laboratory and environmental studies and a retrospective case-control study were conducted. Case-patients were matched with control-patients on age, gender, diagnosis, and type of intensive care unit.

RESULTS

Nine case-patients were identified; B. cepacia likely caused pneumonia in seven and colonization in two. Two respiratory therapy practices probably contributed to the transmission of B. cepacia: multidose albuterol vials were used among several patients, and nebulizer assemblies often were not dried between uses. B. cepacia was grown from cultures of three previously opened multidose vials; pulsed-field gel electrophoresis patterns of B. cepacia from seven case-patients and two multidose vials were indistinguishable. Case-patients had longer durations of heated humidified mechanical ventilation (mean, 9.8 days vs 4.4 days; P=.03) and were more likely to have exposure to one particular respiratory therapist than controls (odds ratio, undefined; 95% confidence interval, 4.7-infinity; P=.001). The association with the respiratory therapist, a temporary employee, persisted after controlling for duration of heated humidified ventilation. No new B. cepacia infections were identified after control measures were implemented.

CONCLUSIONS

B. cepacia probably was transmitted among patients through use of extrinsically contaminated multidose albuterol vials. Respiratory therapy departments must pay close attention to infection control practices, particularly among new or temporary staff.

Validation of use of whole-cell repetitive extragenic palindromic sequence-based PCR (REP-PCR) for typing strains belonging to the Acinetobacter calcoaceticus-Acinetobacter baumannii complex and application of the method to the investigation of a hospital outbreak

Acinetobacter spp. are being reported with increasing frequency as causes of nosocomial infection. In order to identify reservoirs of infection as quickly as possible, a rapid typing method that can differentiate epidemic strains from environmental and nonepidemic strains is needed. In 1993, a cluster of Acinetobacter baumannii isolates from five patients in the adult intensive therapy unit of our tertiary-care teaching hospital led us to develop and optimize a rapid repetitive extragenic palindromic sequence-based PCR (REP-PCR) typing protocol for members of the Acinetobacter calcoaceticus-A. baumannii complex that uses boiled colonies and consensus primers aimed at repetitive extragenic palindromic sequences. Four of the five patient isolates gave the same REP-PCR typing pattern as isolates of A. baumannii obtained from the temperature probe of a Bennett humidifier; the fifth isolate had a unique profile. Disinfection of the probe with 70% ethanol, as recommended by the manufacturer, proved ineffective, as A. baumannii with the same REP-PCR pattern was isolated from it 10 days after cleaning, necessitating a change in our decontamination procedure. Results obtained with REP-PCR were subsequently confirmed by ribotyping. To evaluate the discriminatory power (D) of REP-PCR for typing members of the A. calcoaceticus-A. baumannii complex, compared with that of ribotyping, we have applied both methods to a collection of 85 strains that included representatives of six DNA groups within the complex. Ribotyping using EcoRI digests yielded 53 patterns (D = 0.98), whereas 68 different REP-PCR patterns were observed (D = 0.99). By computer-assisted analysis of gel images, 74 patterns were observed with REP-PCR (D = 1.0). Overall, REP-PCR typing proved to be slightly more discriminatory than ribotyping. Our results indicate that REP-PCR typing used boiled colonies is a simple, rapid, and effective means of typing members of the A. calcoaceticus-A. baumannii complex.

Tracheal colonization with Sphingomonas paucimobilis in mechanically ventilated neonates due to contaminated ventilator temperature probes

Sphingomonas paucimobilis was isolated from tracheal secretions of a total of 85 mechanically ventilated babies in a neonatal intensive-care unit (NICU) during a two-year-period. None of the neonates developed pneumonia or sepsis. After each increase in the fluctuating number of S. paucimobilis isolates, extra attention was paid to hand hygiene and to the maintenance of the ventilation equipment. This resulted in a reduction of the frequency of isolation each time. Cultures of all liquids in use and of the ventilation equipment were negative on several occasions. Fifteen months after the start of the outbreak, the NICU was moved to another building, and some older ventilation equipment was abandoned. After a period of six weeks without problems, S. paucimobilis was isolated in association with at least four ventilators. A new investigation showed that the ventilator temperature probes were the source of contamination. Once effective sterilization procedures for the temperature probes were introduced no new cases appeared, until a spare ventilator with an unautoclaved temperature probe was accidentally used and this caused contamination of one child. After correction, no further cases have occurred to date. The clonal relatedness of the outbreak isolates from patients and from ventilator temperature probes was documented by fingerprinting with the arbitrarily primed polymerase chain reaction.

The emergence of epidemic, multiple-antibiotic-resistant Stenotrophomonas (Xanthomonas) maltophilia and Burkholderia (Pseudomonas) cepacia

Stenotrophomonas (Xanthomonas) maltophilia has recently emerged as an important nosocomial pathogen in immunocompromised cancer patients and transplant recipients. S. maltophilia has been documented as a cause of bacteraemia, infections of the respiratory and urinary tracts, meningitis, serious wound infections, mastoiditis, epididymitis, conjunctivitis and endocarditis. The reservoir of S. maltophilia and the mechanisms by which it is transmitted, remain largely unknown. Risk analysis has shown that mechanically ventilated intensive care unit patients, receiving antibiotics especially carbapenems, are at increased risk of colonization/infection. Because of the in vitro resistance to many commonly used agents, it is essential that S. maltophilia is isolated and identified correctly. Over the last decade Burkholderia (Pseudomonas) cepacia has become a major threat to the management of patients with cystic fibrosis (CF). The spread of B. cepacia through previously stable CF clinic populations, is an increasing cause for concern. Anxiety has arisen following the observation that some patients with previously mild disease, experience an accelerated and fatal deterioration in pulmonary function with fever, necrotizing pneumonia, and in some cases septicaemia. Early UK surveillance studies suggested a maximum prevalence of 7%, though this has risen in recent reports to approach the 40% described in the US. Mounting evidence of person-to-person transmission has led the Cystic Fibrosis Trust to issue guidelines for the management of colonized patients. In an attempt to monitor and understand the spread of B. cepacia, typing techniques such as ribotyping have been employed. Because of these problems, together with multiple-antibiotic resistance, there is an urgent need to identify the major routes of transmission, colonizing, pathophysiological and immunological factors.

Arbitrarily primed PCR, ribotyping, and plasmid pattern analysis applied to investigation of a nosocomial outbreak due to Enterobacter cloacae in a neonatal intensive care unit

In December 1992, Enterobacter cloacae was isolated from the oropharynx and respiratory tract of six ventilated neonates hospitalized in the intensive care unit (ICU) of our hospital. To establish the spread of the outbreak, 41 strains of E. cloacae were analyzed for genotypic markers by three methods: plasmid profile analysis, ribotyping with EcoRI or PvuII endonuclease, and arbitrarily primed (AP) PCR. The tested strains included 12 isolates from the 6 epidemic cases, 4 isolates from the respiratory tract of 4 children hospitalized in other wards during the same period, 13 isolates from 12 children hospitalized in pediatric units before or after the outbreak, and 12 epidemiologically unrelated isolates. Ribotyping and AP PCR demonstrated that each of the last 12 strains exhibited distinct genomic patterns, as did each of the strains isolated from neonates hospitalized before or after the epidemic peak. Conversely, two clones of strains were found among the isolates recovered in December, with concordant results being obtained by the three typing methods: the first clone included seven strains from five ventilated children in the ICU and two children from another ward; another clone was shared by one neonate in the ICU and an infant from another ward. These results indicate that ribotyping and AP PCR-the latter applied, to our knowledge, for the first time to the genotypic analysis of E. cloacae--represent very discriminatory tools for the investigation of nosocomial outbreaks caused by this species.