If you are working with ultrasound probes, have you ever wondered just how safe they really are, especially if you (or yourreprocessing department) are using low level disinfection wipes or an ineffective high level disinfection solution.
Now there is a compelling answer to the question of ultrasound probe safety, thanks to a new population-level study that reveals an increased risk of infection and antibiotic prescriptions following semi-invasive ultrasound probe procedures.
Released in October 2017, the study is important because it is the first of its kind. It also reinforces a positive message – the importance of maintaining proper high level disinfection processes for endocavitary procedures to avoid increased risk of infection.
It was carried out by Health Protection Scotland and NHS National Services Scotland and is entitled NHS Scotland Risk Based Recommendations for the Decontamination of Semi-Invasive Ultrasound Probes: Risk of infection following semi-invasive ultrasound procedures in Scotland, 2010 to 2016.
The findings demonstrated a greater risk of positive microbiological reports and antibiotic prescriptions (within 30 days) for adults who had undergone semi‑invasive ultrasound procedures (SIUP) when high level disinfection was not used as standard of care.1
During the study period from 2010 to 2016, low level disinfection was the primary method used for the disinfection of endocavitary probes.
- In relation to transvaginal ultrasound scans, the study found that in the 30 days after a scan, patients were 41% (HR=1.41) more likely to have positive bacterial cultures and 26% (HR=1.26) more likely to be prescribed antibiotics than similar patients who underwent gynaecological procedures without ultrasound (p<0.001).
- For transrectal scans, patients were 3.4 (HR=3.4) times more likely to have positive bacterial cultures and 75% (HR=1.75) more likely to be prescribed antibiotics (p<0.001).
As a result, the study authors strongly recommend adherence to the current NHS Scotland guidance calls for high level disinfection of endocavitary ultrasound probes.2 This guidance came into effect in 2016 before the results of the new study were known.
In conclusion, the new study stated: “Analysis of linked national datasets demonstrated a greater risk of positive microbiological reports and community antibiotic prescriptions within 30 days for Scottish adults who had undergone SIUP procedures in Scotland. This indicates that, prior to the publication NHS Scotland guidance advocating high level disinfection, the re-use of semi-invasive ultrasound probes without high level disinfection posed an increased risk of infection.”
“… failure to comply with guidance recommending high level disinfection of semi-invasive ultrasound probes will continue to result in an unacceptable risk of harm to patients.”
Official guidance and standards are paving the way to reduce infection risk and increase compliance
There is good news in the fight against the risk of cross-contamination. In line with growing international concerns, official guidance and standards are being released around the world to help prevent the risk of ultrasound infections caused by cross-contamination.
The Spaulding Classification forms the basis for multiple Ultrasound guidelines and standards in Australia and New Zealand (ANZ).
In Australia, semi-critical ultrasound probes must undergo HLD according to the ACIPC-ASUM guidelines.3 This includes ultrasound probes that are used in interventional procedures such as ultrasound guided vascular access, biospies, nerve blocks and drainages as well as probes that contact mucous membranes or non-intact skin.
Semi-critical reusable medical devices must minimally undergo HLD :
Therapeutic Goods Administration (TGA), states that “These devices (semi-critical medical devices), when disinfected, must be subjected to at least a high level disinfection process with an ‘instrument grade high level disinfectant’. TGA Order No. 54, 2009.”4
ASN ZS 4187-2014 The Standards Australia/Standards New Zealand (ASNZS) 4187-2014 guidelines advise that “HLD as the minimum reprocessing standard for ultrasound probes used in semi-critical procedures.”5
The National Health and Medical Research Council (NHMRC), state that “Semi-critical Reusable medical devices (RMDs) require cleaning followed by high-level disinfection at a minimum.”6
This study highlights an already known risk in the US in women’s health…
That transvaginal ultrasound patients face risk of infection due to improperly reprocessed ultrasound probes is not a new concern for US obstetricians and gynecologists. A well known Call to Action in the American Journal of Obstetrics & Gynecology addresses this very issue (in the context of the potential for human papilloma virus transmission). It recommends that “Sonicated H202 should be used to disinfect the probe and handle after every transvaginal ultrasound examination”.7
trophon® EPR is an effective high level disinfection solution for ultrasound probes that can reduce infection risks and increase compliance
trophon is a safe, versatile and simple solution that supports healthcare facilities in their fight against ultrasound probe cross-contamination. When it comes to efficacy, trophon EPR inactivates drug resistant pathogens, spores and pathogens that cause sexually transmitted infections (STIs). trophon EPR also inactivates the mandated subset of microorganisms, as required by US guidelines and is proven to also eliminate an extended range of infectious pathogens, including high-risk cancer causing human papillomavirus (HPV).
- Health Protection Scotland, NHS National Services Scotland. NHSScotland Risk Based Recommendations for the Decontamination of Semi-Invasive Ultrasound Probes: Risk of infection following semi-invasive ultrasound procedures in Scotland, 2010 to 2016. Version 1.0. October 2017. Accessible at: http://www.hps.scot.nhs.uk/pubs/detail.aspx?id=3366.
- Health Facilities Scotland, NHS National Services Scotland, Health Protection Scotland. Scotland, March 2016. NHSScotland Guidance for Decontamination of Semi-Critical Ultrasound Probes; Semi-invasive and Non-invasive Ultrasound Probes. Document: HPS/HFS Version 1.0.
- ACIPC-ASUM. Guidelines for Reprocessing Ultrasound Transducers. Australasian Journal of Ultrasound in Medicine. 2017;20(1):30-40.
- Therapeutic Goods Order No. 54B. Standard for Disinfectants and Sterilants (Amendment to Therapeutic Goods Order No. 54). Therapeutic Goods Act 1989; 2009 (https://www.legislation.gov. au/Details/F2009C00327).
- Standards Australia/Standards New Zealand. AS/NZS 4187:2014 Reprocessing of reusable medical devices in health service organizations (superseding AS/NZS 4187:2003). Standards Australia; 2014.
- Australian Government/ National Health and Medical Research Council (NHMRC) Australian Guidelines for the Prevention and Control of Infection in Healthcare (2010). NHMRC; 2010 (https://www.nhmrc.gov.au/guidelines-publications/cd33).
- Combs CA, Fishman A. A proposal to reduce the risk of transmission of human papilloma virus via transvaginal ultrasound. American Journal of Obstetrics & Gynecology. 2016;215(1):63-7.