Etude n°6

• 6. SELECTION AND USE OF DISINFECTANTS FOR TRANSVAGINAL ULTRASOUND PROBES

Cette étude est in vitro uniquement. Elle démontre que les sondes d'échographie vaginale recouvertes de deux gaines sont tout de même contaminées par Mycobacterium bovis. Cette étude teste en laboratoire l'efficacité de sept produits de trempage chimique permettant d’atteindre une Désinfection de Niveau Intermédiaire sur les sondes d'échographie vaginale. Tous les produits sont efficaces sur les micro-organismes testés au bout de 20 minutes, mais seulement deux sont efficaces au bout d’une minute l’acide phénolique et l’acide per-acétique additionné avec du peroxyde d'hydrogène.

BACKGROUND: Routine surveillance of high level disinfection practices for TransVaginal Ultrasound Probes (TVUPs) identify dissimilar disinfection standards of practice and disparate assumptions among departments within the National Naval Medical Center (NNMC). Infection Control identifies that TVUP disinfection recommendations are divergent in the fields of infection control and infertility literature.

METHODS: Procedures include an attempt to adapt the Best et al study published in 1994 to test efficacy of eradi- cating expected vaginal flora on TVUPs that have been protected by sheaths. TVUPs are cultured directly after being exposed in vitro through double sheaths to likely vaginal flora and known pathogens by type : bacteria, mycobacteria, bacterial spores, viruses, and fungi. Efficacy tests of germicides against study organisms are performed by exposing to germicides individually and by mixture of the five organisms for periods of 1 to 20 minutes.

RESULTS: There is no growth of any single or mixture of control organisms on double-sheathed TVUPs except for Mycobacterium boris, growing one colony in each of the individual and mixed challenges. Controls for all organisms are positive in both individual and mixed challenges on unsheathed control TVUPs: _>108 or too numerous to count (TNTC) for all organisms. Effectiveness of germicides varies with different organisms in all but two germicides. Seven of 7 germicides eradicated study organisms at 20 minutes, but only 2 of 7 germicides (p-tertiary amylphenol 7.4% & 2-phenylphenol 7.3% & phosphoric acid 15% & isopropopanol 7.0% and paracetic acid 0.06% & hydrogen per-oxide 0.8%) were effective against all tested organisms at 1 minute.

CONCLUSIONS: Bacteria are able to penetrate 2 sheaths despite careful attempts to protect the TVUPs. Sheaths are very fragile and the researchers report that applying them can cause tears. Growth of organisms occurred following disinfection in >10 minute time period by all but the specified phenolic and paracetic acid germicides tested. Literature recommendations for high-level disinfection for 20 minutes for devices contaminated by mucous membranes of vaginal mucosa are confirmed by this study; however, these preliminary data demonstrate the desirability of further studies of sheathed TVUPs to be treated for periods of 1 minute with selective germicides. The views expressed in this article are those of the author(s) and do not reflect the official policy or position of the Department of the Navy, Department of Defense, nor the U.S. Government. The Chief, Navy Bureau of Medicine and Surgery, Washington, D.C., Clinical Investigation Program sponsored this study #B95-075.