Nosocomial Burkholderia Cepacia Pseudo-Outbreak Due to Contaminated “Savlon” in the Bronchospy Unit

El Shafie S.S., Al Sattar H.A., Al Khal A.L., Al Suob H. and Estinoso W.
Departments of Laboratory and Medicine, Hamad Medical Corporation Doha, Qatar

Abstract:

Between 5th July and 22nd September 1999, forty-three patients were bronchoscoped of whom forty-one had samples sent for Microbiology i.e., eighty-two specimens (forty one broncho-alveolar lavage (BAL) and forty one bronchial wash(BW)). Of the eighty-two specimens, forty (from twenty patients) grew Burkholderia cepacia with or without other pathogens. None of the patients showed evidence of infection. Sputum cultures from all patients before bronchoscopy and during the episode of infection did not grow B. cepacia. “Savlon” (chlorhexidine and cetrimide; Schering-Plough), used for cleaning broncho-scopes was found to be contaminated with B. cepacia and acted as a source of contamination of the environment, bronchoscopes and samples of patients, leading to a pseudo-outbreak.

Key words: Burkholderia cepacia, Bronchoscopy, Savlon, Pseudo-outbreak.

Introduction:

B.cepacia is an aerobic gram-negative, non-fermenting bacillus widely distributed in the environment including water, fruit and vegetables. In 1950 Burkholder, who isolated the organism from a rotting onion, first characterized it microbiologically. In 1960 the organism was placed in the genus Pseudomonas. Subsequent characterization of the genus Pseudomonas in 1984 led to the establishment of a new genus Burkholderia with the type strain B.cepacia.

The epidemiology of B.cepacia as a nosocomial pathogen was reported in 1960, when an outbreak of urinary tract infection in children was traced to contaminated water used for bladder irrigation during cystoscopy⁽²⁾. Since that time B.cepacia has been associated with many real and pseudo-outbreaks of bloodstream, urinary tract, respiratory tract and other nosocomial infections⁽³⁾. These outbreaks have been traced to a wide variety of sources including tap, distilled or de-ionized water and intrinsically or extrinsically contaminated chlorhexidine, povidone iodine and quaternary ammonium solutions^(4-6).

Bronchoscopy is a useful procedure that can be performed safely by trained specialists when the bronchoscopes in both inpatients and ambulatory care settings are reprocessed properly to prevent transmission of infection. Although reported infection complications caused by bronchoscopy are rare⁽⁷⁾, the incidence is probably underestimated, with many episodes unrecognized or unreported. Most reported bronchoscopy-related outbreaks or pseudo-outbreaks have been associated with inadequate cleaning and disinfection procedures^(8-10).

The increased isolation of B.cepacia from BAL and BW from patients bronchoscoped in the period between July-September prompted us to investigate the source of this outbreak. This paper describes the pseudo-outbreak, the identification and elimination of the source and steps taken to prevent recurrence.

Methods:

Hamad Medical Corporation is a hospital with one thousand two hundred and fifty (1250) beds and serves as the one major hospital for the State of Qatar. About 250-300 bronchoscopies are performed in the bronchoscopy unit each year. The unit has two rooms, one for bronchoscopy procedures and the second for cleaning and disinfecting bronchoscopes. Two scopes were used for inpatients and outpatients, adults and pediatrics in the unit. After use the bronchoscopes were manually cleaned with Savlon, a process that included scrubbing internally with special brushes. Savlon was used also to flush the interior of the bronchoscopes before disinfection by immersion in 2% gluteraldehyde for 20 minutes. Then the bronchoscopes were rinsed with tap water in the same sink used for the initial cleaning, dried and covered with a sterile surgical towel until used again.

Microbiology:

As part of investigation of the outbreak, environmental specimens were taken by sampling with sterile swabs. Bronchoscopes ready for use were sampled by flushing with sterile saline. Fluid specimens, including disinfectants, were centrifuged and the deposit cultured. All specimens were plated out directly onto MacConkeys agar and incubated overnight at 37^OC in air. Colonies consistent with B.cepacia were further identified using Vitek 2 (bioMerieux, France).

Antimicrobial susceptibility testing to gentamicin, amikacin, ceftazidime, piperacillin, tazobactam, aztreonam, imipenem, ciprofloxacin and co-trimoxazole was performed on all isolates using the same machine as for identification. No typing was carried out. Interpretation of results was in accordance with the guidelines of the National Committee of Clinical Laboratories Standard (NCCLS).

Results:

B.cepacia was isolated from Savlon, surface of the Olympus cleaner, tip of the cleaning pump, sterile saline flushed through one bronchoscope and from the sink. Other organisms were also isolated from various sites as shown in Table 1.



From the susceptibility pattern, three strains of B.cepacia were isolated from the patients and the environment. However, typing would have been more accurate to define similarity of the strains.
Distilled water prepared in the Pharmacy was used to dilute disinfectants before distribution to the various units including the bronchoscopy unit. The disinfectant containers were cleaned in the pharmacy before filling but they bore no labeling indicating the expiry date of the disinfectant. However, cultures of the prepared Savlon produced no growth.
No B.cepacia was isolated from the respiratory tract of any patient or from any other site before bronchoscopy, indicating that colonization occurred during the bronchoscopy procedure.
Two per cent gluteraldehyde was used in the unit for up to 14 days after activation. Test strips were not used for quality control but cultures were negative.
The isolation of B.cepacia from the disinfected bronchoscope suggested failure of the disinfection process. Savlon was distributed in large quantities to the unit and it appears that frequent opening and using of Savlon may have led to its contamination from the environment or through staff hands.

Management of the Outbreak:

When the outbreak was recognized, the Infection Control Team visited the unit and informed the staff about the problem. General principles of Infection Control including hand washing, sterilization and disinfection policies were re-emphasized. The bronchoscopy unit nurse was instructed to discontinue the use of Savlon and replace it with hot water and detergent. The following recommendations were made also:
1. Follow the manufacturer’s recommendation for cleaning and disinfecting bronchoscopes.
2. After cleaning with hot water and detergent, disinfection with gluteraldehyde must continue for 20 – 30 minutes.
3. Rinse bronchoscopes with sterile water after disinfection.
4. Separate sinks must be used for cleaning and rinsing.
5. After rinsing bronchoscopes, dry with sterile gauze or hang in a drying cabinet.
6. Increase the number of bronchoscopes in use to allow for adequate disinfection between patients.
7. The Pharmacy must issue disinfectants in manageable quantities in sterile containers labeled with the concentration and expiration date.

Discussion:

The recognition of an unusual cluster of B.cepacia from BW and BAL by the Infection Control nurse prompted an outbreak investigation.
In all cases the organism was isolated only from the BAL and BW of bronchoscoped patients. Suspicion was then focused on the bronchoscopes and their methods of disinfection.
The problems of contamination of bronchoscopes with opportunistic and environmental organisms leading to subsequent outbreaks of infections and pseudo-infections are well recognized. These problems have continued even after the implementation of appropriate guidelines for bronchoscopes cleaning and gluteraldehyde disinfection. In most cases this had been because of failures to adhere to established protocols ^{(15, 16)}.
The result of our investigation confirmed that Savlon was contaminated by B.cepacia from the environment in the unit due to frequent accessing of bottles.
The contaminated Savlon was used to flush the interior of bronchoscope, thus resulting in contamination of the samples during suctioning of BAL and BW.
Bronchoscopes are designed with small lumens, multiple ports with obtuse angles and lining presenting obstacles to proper cleaning and disinfection. Manual cleaning with detergent followed by chemical agents such as 2% gluteraldehyde for 20 – 30 minutes is the ideal procedure. Currently automated machines recently introduced in our hospital carry out such disinfection cycles. These machines can also become colonized and cause bronchoscopy-related outbreaks and pseudo-outbreaks (5-14).
Culture of 2% gluteraldehyde was sterile although in the unit the solution was not tested with the strips as recommended by the manufacturer. However, the bronchoscopy nurse was instructed to test 2% gluteraldehyde before each use.
We conclude that intrinsic or extrinsic contamination of disinfectants remains a potential hazard to patients through contamination of equipment such as bronchoscopes. Appropriate aseptic technique, and education and training of health care workers about disinfection / sterilization and other infection control techniques can decrease the risk of contamination of disinfectants and hence outbreaks and pseudo-outbreaks.

Acknowledgment:

We would like to thank members of the Infection Control Team for their help with the investigation, the Microbiology laboratory staff for identifying the organism and for the bronchoscopy unit staff for their co-operation during the investigation of the outbreak.

References:

1. Migual W. Arbeinten ans dem Bakteriologishen. Institute of Technicschen-Hochschule zu karlaruch 1984; 1:235-238.

2. Mitchell RG, Hayward AC. Postoperative urinary tract infection caused by contaminated irrigating fluid. Lancet 1966; 1: 793-795.

3. Martone WJ. Tablan OC, Jarvis WR. Epidemiology of nosocomial epidemic Pseudomonas cepacia infection. Eur J Epidermiol 1987; 2: 222-232.

4. Reboli Ac, Koshinski R. Ariask, Austin-Marksk, Steritz D. Stull Tl. An outbreak of Burkholderia cepacia lower respiratory tract infection association with contaminated albuterol / nebulization solution. Infection Hospital Epidermiol 1996; 17: 741-743.

5. Berekelman RC, lewins, Allen JR, et al. Pseudobacteremia attributed to contamination of povidone-iodine with pseudomonas cepacia. Ann intern Med. 1981; 95: 32-36.

6. Panlilio Al, beck sugue CM Sigel JD, el al. Infections and pseudoinfections due to povidone-iodine solution contaminated with pseudomonas cepacia. Clin. Infect. Dis. 1992; 14: 1078-1083.

7. Martin MA, Reichelder for M.APIC. Guidelines for infection prevention and control in flexible endoscopy. Am J. Infection Control 1994; 22: 19-38.

8. Agerton T. Valway S, Gore B et al. Transmission of a highly drug resistant strain (strain W1) of Mycobacterium tuberculo- sis JAMA 1997; 278:1073-1077.

9. Bennett SN, Peterson DE, Johnson Dr. et al. Bronchoscopy Mycobacterium xenopi pseudoinfections. Am J Resp. Crit. Care Med. 1994; 150: 245-250.

10. Maloney S, Welbed S. Daves B et al. Mycobacterium abscesses pseudoinfection traced to an automated endoscopes washer: Utility of epidemiologic and laboratory investigation J. Infect. Dis. 1994; 169: 1166-1169.

11. Gubler JG. Salfinger M.von Graeyenitz A. Pseudoepidomics of non-tuberculosis due to contaminated bronchoscope cleaning machine : report of an outbreak and review of the literature. Chest 1992; 101: 1245-1249.

12. Faser VJ, Jones M, Murray PR et al. Contamination of flexible fiber-optic bronchoscopes with Mycobacterium chelonac linked to an automated bronchoscope disinfection machine. Am Rev Res. Dis. 1992; 145: 853-5.

13. CDC Nosocomial infection and pseudoinfection from contaminated endoscopes and bronchoscopes. Wisconsin and Missouri. MMWR 1991; 40: 675-678.

14. Kazmarek RG. Moore RM, McCorhan J. et al. Multi state investigation of the actual disinfection / sterilization of endoscopes in health care facilities. Am J Med. 1992; 92:257-261.

15. Bradley CR, Babb JR. Endoscope decontamination: Automated vs. Manual J Hosp. Inf. 1995; 30: 537-542.

16. Bradley CR, Babb JR. Endoscope decontamination: Where do we go from here? J. Hosp. Inf. 30: 543-551.

17. Garner JS. Favero MS. Guidelines for hand washing and hospital environment control, Infect. Control 1986; 7: 231-243.