Bacterial Contamination of Ultrasound and Stethoscope Surfaces in Low- and High-Resource Settings

Abstract

Point-of-care ultrasound is an accurate diagnostic and monitoring tool. Its increasing affordability, portability, and versatility make it an excellent component of standard clinical evaluation alongside the stethoscope. However, like the stethoscope, ultrasound carries risks of surface contamination and potential cross-infection. In this international observational study, we compared the surface contamination of ultrasound equipment to stethoscopes in two medical centers: a tropical low-resource hospital and academic high-resource hospital. Ultrasound equipment and coupling gel had similar prevalence of microbial surface contamination compared with observed stethoscopes. Most microbes were commensal Gram-positive, but some were opportunistic and pathogenic microbes (such as Escherichia coli and Staphylococcus aureus). In conclusion, it is crucial to appreciate and reduce the risk of ultrasound device contaminations. When ultrasound is used bedside, similar to stethoscopes, conscientious hygiene measures are equally fundamental.

Figure 1.

Distribution of microbial contamination type across different settings. If multiple microbes were cultured, the most commonly pathogenic was reported in the figure. Percentages in figure were rounded to integers. CNS refers to coagulase-negative staphylococci. Other Gram-positive refers to commensal Gram-positive flora. This figure appears in color at www.ajtmh.org.