Bacterial contamination of ultrasound probes and coupling gels in a university hospital in Turkey

Abstract

Objectives: Nosocomial outbreaks of infection originating from ultrasound probes and contaminated coupling gels have been reported. It was reported that the ultrasound probe, if cultured after routine scanning of intact skin, may become colonized with skin flora.

Methods: Culture swabs from 22 probes of the 9 ultrasound machines and from the gels in the 10 gel folders were taken. All swabs taken from probe head, probe holder and the coupling gel in the folder at the beginning of the day were cultured. After fifth scanning and after wiping off the gel with a dry, nonsterile paper towel, cultures were again obtained from probe head and probe holder.

Results: A total of 98 culture results were included of which 42.8% were positive for bacterial growth. The rate of bacterial contamination from probes at morning before the start of examination and after scanning were 34.1% and 56.8%, respectively and this difference was statistically significant (p = 0.023).

Conclusions: We think that using nonsterile, dry, soft and absorbent paper towel after each procedure, could be inadequate for disinfection of probe head. Especially, good hand hygiene could decrease the rate of growth of bacterial colony at probe handle. 

Keywords

• Bacterial contamination,ultrasound,coupling gel,nosocomial infections

References

1. [1] Ducell G, Fabry J, Nıcoll L. Prévention des infections nosocomiales, Guide pratique, 2nd ed., Organisation mondiale de la Santé. WHO. 2008.
2. [2] Brachman PS. Epidemiology infections. In: Bennett JV, Brachmann PS, eds. Hospital infections, 3rd ed. Boston: Little, Brown, 1993:3-20.
3. [3] Tikhomirov E. WHO Programme for the Control of Hospital Infections. Chemiotherapia 1987;3:148-51.
4. [4] Bures S, Fishbain JT, Uyehara CF, Parker JM, Berg BW. Computer keyboards and faucet handles as reservoirs of nosocomial pathogens in the intensive care unit. Am J Infect Control 2000;28:465-71.
5. [5] Spach DH, Silverstein FE, Stamm WE. Transmission of infection by gastrointestinal endoscopy and bronchoscopy. Ann Intern Med 1993;118:117-28.
6. [6] Steinberg PJ, de Hoop D. [The stethoscope as a vehicle of pathogenic microorganisms in the hospital]. Ned Tijdschr Geneeskd 1978;122:303-5. [Article in Dutch]
7. [7] Livornese LL Jr, Dias S, Samel C, Romanowski B, Taylor S, May P, et al. Hospital-acquired infection with vancomycin-resistant Enterococcus faecium transmitted by electronic thermometers. Ann Intern Med 1992;117:112-6.
8. [8] Gaillot O, Maruéjouls C, Abachin E, Lecuru F, Arlet G, Simonet M, et al. Nosocomial outbreak of Klebsiella pneumoniae producing SHV-5 extended-spectrum beta-lactamase, originating from a contaminated ultrasonography coupling gel. J Clin Microbiol 1998;36:1357-60.

9. [9] Weist K, Wendt C, Ptersen LR, Versmold H, Rüden H. An outbreak of pyodermas among neonates caused by ultrasound gel contaminated with methicillin-susceptible Staphylococcus aureus. Infect Control Hosp Epidemiol 2002;21:761-4.
10. [10] Hutchinson J, Runge W, Mulvey M, Norris G, Yetman M, Valkova N, et al. Burkholderia cepacia infections associated with intrinsically contaminated ultrasound gel: the role of microbial degradation of parabens. Infect Control Hosp Epidemiol 2004;25:291-6.
11. [11] Ohara T, Itoh Y, Itoh K. Contaminated ultrasound probes: a source of nosocomial infections. J Hosp Infect 1999;43:73.
12. [12] Kibria SM, Kerr KG, Dave J, Gough MJ, Homer-Vanniasinkam S, Mavor AI. Bacterial colonization of Doppler probes on vascular surgical wards. Eur J Vasc Endovasc Surg 2002;23:241-3.
13. [13] Bello TO, Taiwo SS, Oparinde DP, Hassan WO, Amure JO. Risk of nosocomial bacteria transmission: evaluation of cleaning methods of probes used for routine ultrasonography. West Afr J Med 2005;24:167-70.
14. [14] Spencer P, Spencer RC. Ultrasound scanning of post-operative wounds--the risks of cross-infection. Clin Radiol 1988;39:245-6.
15. [15] Burke J. Infection control: a problem for patient safety. N Engl J Med 2003;348:651-6.
16. [16] Marroni M, Fiorio M, Cao P, Parlani G, Morosi S, Stagni G. [Nosocomial infections in vascular surgery: 1-year surveillance]. Recenti Prog Med 2003;94:430-3. [Article in Italian]
17. [17] Valero LF, Sáenz MC. [The etiology of nosocomial infection in surgery: comparison of 2 years (1988 and 1996)]. Enferm Infecc Microbiol Clin 1998;16:79-82. [Article in Spanish]
18. [18] Sykes A, Appleby M, Perry J, Gould K. An investigation of the microbiological contamination of ultrasound equipment. J Infect Prevent 2006;7:16-20.
19. [19] Ohara T, Itoh Y, Itoh K. Ultrasound instruments as possible vectors of staphylococcal infection. J Hosp Infect 1998;40:73-7.
20. [20] Patterson SL, Monga M, Silva JB, Bishop KD, Blanco JD. Microbiologic assessment of the transabdominal ultrasound transducer head. South Med J 1996;89:503-4.
21. [21] Muradali D, Gold WL, Phillips A, Wilson S. Can ultrasound probes and coupling gel be a source of nosocomial infection in patients undergoing sonography? An in vivo and in vitro study. AJR Am J Roentgenol 1995;164:1521-4.
22. [22] Grouden MC, Keogh E, Colgan MP, Moore DJ, Shanik DG. Results of an infection control survey in ultrasound departments and recommended guidelines. BMUS Bulletin 1999;7:15-18.
23. [23] Aylirffe G, Babb J, Taylor L. Cleaning, disinfection or sterilization? Hospital acquired infection. 3rd ed. London: Arnold; 2001;1448.
24. [24] Tesch C, Froschle G. Sonography machines as a source of infection. Am J Roentgenol 1997;168:567-8.
25. [25] Karadeniz YM, Kiliç D, Kara Altan S, Altinok D, Güney S. Evaluation of the role of ultrasound machines as a source of nosocomial and cross-infection. Invest Radiol 2001;36:554-8.
26. [26] Kac G, Gueneret M, Rodi A, Abergel E, Grataloup C, Denaire N, et al. Evaluation of a new disinfection procedure for ultrasound probes using ultraviolet light. J Hosp Infect 2007;65:163-8.
27. [27] Tarzmani MK, Eshraghi N, Asghari PB, Estakhri R, Eshraghi A. Role of ultrasound probes in transmission of hospital infections. Casp J Intern Med 2010;1:134-6.
28. [28] Fowler C, McCracken D. US probes: risk of cross-infection and ways to reduce it-comparison of cleaning methods. Radiology 1999;213:299-300.
29. [29] Mirza WA, Imam SH, Kharal MS, Aslam M, Ali SA, Masroor I, et al. Cleaning methods for ultrasound probes. J Coll Phys Surg Pak 2008;18:286-9.