Serial culture of ultrasound gels in relation to CDC/FDA alert: A transversal prevalence study of contamination in an anesthesia center.

BACKGROUND AND

OBJECTIVE

Ultrasound is essential in anaesthesiology, non-sterile multidose gels can cause nosocomial infection. Following the CDC/FDA safety alert published on 13 May 2025 regarding outbreaks of Paraburkholderia fungorum linked to contaminated gels, we determined the prevalence of microbial contamination in the ultrasound gels regularly used in our anaesthesia department.

MATERIALS AND

METHODS

Cross-sectional prevalence study based on the analysis of 37 ultrasound gel samples. Using convenience sampling, we collected 33 samples of gels in active use in various areas (operating rooms, resuscitation, interventional radiology room, and delivery room) together with 4 control samples (2 unopened multidose gels and 2 sterile single-dose gels). Infusion broth was inoculated with the samples and incubated at 37 °C for 10 days, after which they were tested for colonisation using the MALDI-TOF technique.

RESULTS

Microorganisms were isolated in 6.1% (2/33) of the samples of multidose gels in active use, specifically, Streptococcus parasanguinis and Staphylococcus pasteuri, which were isolated in different batches of TransonicGel. No bacterial growth was found in samples from gel warmers (n = 3), electrode gels, or controls. None of the microorganisms isolated matched those listed in the hospital's infection database.

CONCLUSIONS

The finding of 6.1% contamination shows the latent risk involved in using multidose gels. These results reinforce the importance of adhering to the CDC, ACEP, and ASRA guidelines, which recommend protecting patients by using only sterile single-dose gels and validated probe covers in all invasive ultrasound-guided procedures.