Topic: Culture results of distal endocavitary ultrasound probes after disinfection
I gathered the below while putting together an experiment protocol on the above
topic. The protocol has come to a halt as I think there is already enough information
out there to suggest HLD should be universally employed for endocavitary
probes if not being done so. Perhaps this is common knowledge or perhaps even
still debatable to some of you. I was not previously fully aware.
This free brief non-peer-reviewed review is brought to you by the journal of Clark.
-Clark Rosenberry, MD FACEP
Rational and Background information:
Concerns have been raised about the effectiveness of emergency department
disinfection of endocavitary ultrasound probes.1,2 Disinfection techniques vary
between institutions and do not uniformly meet high-level disinfection (HLD).3
Condoms as probe covers have been determined to be effective barriers to disease
transmission but are imperfect with a failure rate approximately 1-5%.4-6
Perforation rate has been reported as high as 9% during ultrasound guided
procedures such as transrectal prostate biopsies.7 Low-level disinfection (LLD)
techniques such as antiseptic wipes, cleaning with towels, and hot water to clean
ultrasound probes have been shown to significantly reduce residual bacterial
contamination but are to substantially varying degrees imperfect.8-10 Alcohol wipes
have been particularly effective at disinfecting probes bacteriologically but it causes
probe deterioration over time.11 LLD also does not eliminate viruses such as HSV or
cancer-causing HPV.12-14 Rates of persistent detectable viral presence are 1 to
several percent. One study estimates that dozens of HIV transmissions and
thousands of other viral infections each year may be attributable to vaginal or rectal
ultrasound studies if only LLD is used.15 Ultraviolet C (UVC) appears to provide
additional antiseptic benefit when used in combination with chemical
disinfectants.16-18 HLD techniques such as protocoled saturation in an antiseptic
solution in a timed automated device have been recommended to successfully
improve decontamination and reduce variability.19 It has also been recommended
the handles be included in HLD practices.20 Specifically, the hydrogen peroxidebased Trophon system appears to be superior to the glutaraldehyde-based Cidex
system on various metrics.21
References:
1. Ejtehadi F, Ejtehadi F, Teb JC, et al. A safe and practical decontamination method
to reduce the risk of bacterial colonization of ultrasound transducers. J Clin
Ultrasound. 2014;42:395-8.
2. Savasci U, Oren NC, Akpak YK, et al. Comparison of probe disinfection procedures
in routine ultrasonography: hot water versus antiseptic wiping. Intern Med.
2014;53:2201-4.
3. Gray RA, Williams PL, Dubbins PA, et al. Decontamination of transvaginal
ultrasound probes: review of national practice and need for national guidelines. Clin
Radiol. 2012;67:1069-77.
4. Amis S, RuddyM, Kibbler CC, et al. Assessment of condoms as probe covers for
transvaginal sonography. J Clin Ultrasound. 2000;28:295-8.
5. Storment JM, Monga M, Blanco JD. Ineffectiveness of latex condoms in preventing
contamination of the transvaginal ultrasound transducer head. South Med J.
1997;90:206-8.
6. Milki AA, Fisch JD. Vaginal ultrasound probe cover leakage: implications for
patient care. Fertil Steril. 1998;69:409-11.
7. Masood J, Voulgaris S, Awogu O, et al. Condom perforation during transrectal
ultrasound (TRUS) prostate biopsies: a potential infection risk. Int Urol Nephrol.
2007;39:1121-4.
8. Mirza WA, Imam SH, Kharaj, et al. Cleaing methods for ultrasound probes. J Coll
Physicians Surg Pak. 2008;18:286-9.
9. Frazee BW, Fahimi J, Lambert L, et al. Emergency Department ultrasonographic
probe contamination and experimental model of probe disinfection. Ann Emerg Med.
2011;58:56-63.
10. M’Zail F, Bounizra C, Leroy S, et al. Persistence of microbial contamination on
transvaginal ultrasound probes depite low-level disinfection procedure. PLOS one.
2014;9:e93368.
11. Koibuchi H, Kotani K, Taniguchi N. Ultrasound probes as a possible vector of
bacterial transmission. Med Ultrason. 2013;15:41-44.
12. Leroy S. Infectious risk of endovaginal and transrectal ultrasonography:
systematic review and meta-analysis. J Hosp Infect. 2013;83:99-106.
13. Casalegno JC, Carval KLB, Eibach D, et al. High Risk HPV contamination of
endocavitary vaginal ultrasound probes: an underestimated route of nosocomial
infection. PLOS one. 2012;7:e4813714. Ma ST, Yeung AC, Chan PK, et al. Transvaginal ultrasound probe contamination
by the human papillomavirus in the emergency department. Emerg Med J.
2013;30:472-5.
15. Leroy S, M’Zail F, Kann M, et al. Impact of vaginal-rectal ulstrasound
examinations with covered and low-level disinfected transducers on infectious
transmissions in france. Infect Control Hosp Epidemiol. 2014;35:1497-504.
16. Kac G, Gueneret M, Rodi A, et al. Evaluation of a new disinfection procedure for
ultrasound probes using ultraviolet light. J Hosp Infect. 2007;65:163-8.
17. Bloc S, Mercada L, Garnier T, et al. Evaluation of a new disinfection method for
ultrasound probes used for regional anesthesia: ultraviolet C light. J Ultrasound Med.
2011;30:785-8.
18. Kac G, Podglaien I, Si-Mohamed A, et al. Evaluation of ultraviolet C for
disinfection of endocavitary ultrasound transducers persistently contaminated
despite probe covers. Infect Control Hosp Epidemiol. 2010;31:165-70.
19. Vickery K, Gorgis VZ, Burdach J, et al. Evaluation of an automated high-level
disinfection for ultrasound transducers. J infect Public health. 2014;7:153-60.
20. Ngu A, McNally G, Patel D, et al. Reducing transmission risk through high-level
disinfection of transvaginal ultrasound ransducer handles. Infect Control Hops
Epidemiol. 2015;36:581-4.
21. Johnson S, Proctor M, Bluth E, et al. Evaluation of a hydrogen peroxide-based
system for high-level disinfection of vaginal ultrasound probes. J ultrasound Med.
2013;32:1799-804.