[Prevention of infection in sonography]

The instruments and surroundings of five ultrasound diagnostic departments were tested for bacteria, antimicrobic characteristics, and prevalence of Hbs Ag in commercial contact medium (cellulose) and were also analysed after contamination in vitro. Facultative pathogenic bacteria as well as normal skin bacteria were found on the ultrasound equipment. It was established that cellulose and oils taken from wide- mouthed containers and applied manually or with a brush, were often contaminated. However, no contamination was evident in contact medium that was still in its original packing or stored in small containers and subsequently refilled daily. No antimicrobic activity on the part of preservative agents in the cellulose could be demonstrated after artificially contaminating some contact medium with Staph. aureus and E. coli. Elimination of artificially added Hbs Ag in the contaminated contact medium could not be proven. It is postulated that transfer of bacteria or Hepatitis B infection during an ultrasound diagnosis is possible. It is therefore recommended that appropriate prophylactic hygienic measures be taken, especially with patients susceptible to infection.