Can ultrasound probes and gels be the source for opportunistic bacterial infections?

Abstract

The aim of this study was to investigate the contaminant microorganisms on the surface of probes used in noninvasive ultrasound examination and in the gels. Culture samples were obtained from the convex abdominal probe at the beginning of the day and after use on every five patients. Cultures were taken from linear breast probe at the beginning of the day and after use one very two patients. All samples were taken after wiping with a dry tissue paper until no visible gel remained on the probes. Furthermore, the samples were taken from gels when the gel was first opened, at the end of the day and 24 hours after opening. A total of 76 samples from 25 breast probes, 33 abdominal probes and 18 gels were included. Bacteria was detected in 20 (80%) of 25 linear probe samples. Coagulase negative staphylococci (CNS) were detected in 19 (76%), Burkholderia cepacia and Staphylococcus aureus in two (8%), Cupriavidus pauculus and Stenotrophomonas maltophilia in one (%4). Bacterial growth was detected in 23 of 33 (69.7%) abdominal probes. aureus and S.maltophilia were isolated in 2 samples, most of which were CNS (n:20; 60.6%). The bacterial growth rate of all probes was 74.13% (43/58). Bacteria was detected in 2 of 18 gel samples (16.66%), two of which were CNS and one of them was S.maltophilia. Although more skin flora bacteria were detected in noninvasive probes and gels, a small number of pathogenic bacteria were also found in our study. Proper disinfection of the noninvasive probes and proper use of gels is therefore necessary. We believe that wiping with nonsterile dry tissue paper after each procedure is insufficient for disinfection of the probe surface. Disinfection and gel usage guidelines should be determined for ultrasound units both in our hospital and in our country.