Surface probes are frequently used in semi-critical procedures
but often inadequately disinfected1,2
The evidence is clear
Multiple guidelines advise that all semi-critical instruments should undergo high level disinfection (HLD) between patient exposures, including surface probes used in semi-critical procedures.
A surface probe can contact a patient’s broken skin and bodily fluids and could become contaminated with blood and microorganisms.
Often there is no visible evidence of blood or microbe contamination on the probe after surface use, so a visual inspection is not a reliable way of concluding lack of contamination.
In addition, there may be a lack of awareness about the risk of infection potential if surface probes are contaminated with blood. This is due to the assumption that because the probe is in contact with skin only (and not intracavity), there is no blood contamination risk.
All of these factors can lead to the contamination of probes in clinical practice, resulting in cross infection between the next patient and staff.
That’s why it’s essential to HLD every probe before it is used on the next patient.
A recent study detected the prevalence of blood contamination and microbial contamination on ultrasound equipment used in emergency and ICU departments: these departments commonly use surface probes in semi-critical and critical applications.1
Results showed that 57% of probes tested positive for blood contamination, and 46% for microbial contamination. Only 51% of the blood-contaminated probes were visibly stained.
Ultrasound probes that could come into contact with blood and sterile tissue should undergo a HLD process as a minimum and be used with a sterile sheath.
A separate survey of emergency departments in the United States recently demonstrated the variability in surface probe disinfection protocols. 2
It was also recently shown that 21% of ultrasound probe bodies are still contaminated after disinfection with low-level disinfectant wipes.3
Another study showed that the use of wipes/sprays left probes still contaminated with bacteria (12.9%) and virus (1%). Prevalence of infected patients after contact was estimated to be 3.1%.4
- Keys, M., et al. Efforts to Attenuate the Spread of Infection (EASI):, a prospective, observational multicentre survey of ultrasound equipment in Australian emergency departments and intensive care units. Critical Care and Resuscitation. Volume 17 Number 1, March 2015
- Hoyer R, Adhikari S, Amini R. Ultrasound transducer disinfection in emergency medicine practice. Antimicrob Resist Infect Control. 2016;5:12.
- BüscherDL, MöllersM, FalkenbergMK, AmlerS, Burdach J, KlockenbuschW, Schmitz, R. Disinfection of transvaginal ultrasound probes in a clinical setting -comparative performance of automated and manual reprocessing methods. Ultrasound ObstetGynecol. 2016;47(5):646-51.
- Leroy S. Infectious risk of endovaginal and transrectal ultrasonography: systematic review and meta-analysis. J Hosp Infect. 2013;83(2):99-106.
- Assesses and compares microbial contamination of TA and TV transducers used in the obstetrics and gynecology setting.
Ohara T, Itoh Y, Itoh K. Ultrasound instruments as possible vectors of staphylococcal infection. J Hosp Infect. 1998;40(1):73-7.
- Evaluates role of ultrasound instruments in the spread of nosocomial staphylococcal infections.
O’Doherty AJ, Murphy PG, Curran RA. Risk of Staphylococcus aureus Transmission during Ultrasound Investigation. J Ultrasound Med. 1989;8:619-20.
- Investigates staphyloccocal transmission between patients undergoing TA ultrasound to assess cross-infection risk.