Antigermix – disinfection of endocavitary ultrasonography probes



The CEDIT assessed the value of ultraviolet rays UV-C (the Antigermix device) used for disinfection of endocavitary ultrasonography probes (endorectal and endovaginal), potential carriers for microbiological contaminations accross patients.

Technical aspects: The Antigermix disinfection unit manufactured by Germitec uses ultraviolet rays with a wavelength of 254 nm generated by six low-pressure mercury gas-discharge lamps. The cylinder-shaped enclosure has a diameter of 55 cm and height of 100 cm, for a total weight of 60 kg. The system includes a traceability functionality allowing print out of paper receipts. Each probe is identified by an RFID chip attached to the cable enabling recording of device history for individual follow-up. The Antigermix unit is a class IIb medical device (CE marked since 2007). The time spent by the probe in the disinfecting chamber is about 2 minutes. Alternative disinfection methods are (disinfectant) soaking including the GUS® system (about 10 min), and the Trophon® system (7 min).

Clinical aspects: This assessment highlights the question of the relevance of a systematic use of high level means of disinfection between patients, and in that case whether preference should be given to the UV-C technology or to its alternatives, including the historical alternative which is soaking.
Despite studies and modeling conducted until recently, the infectious risk associated with the use of endocavitary probes remains difficult to assess.
The National Academy of Medicine confirmed in 2008 the recommendations issued by the High Council of Public Health (HCSP) the same year. The HCSP recommendations are currently under review following a request from the Ministry of Health in July 2013. The 2008 recommendations of the HCSP do not specify the benefit of UV-C, object of our assessment, as a means of disinfection of endocavitary ultrasound probes.
Antigermix is an alternative means of disinfection to the soaking techniques and the Trophon® system. The performance of UV-C disinfection (bactericidal, virucidal, fungicidal, sporicidal roles) is established by in vitro microbiological studies. The National Medicines Safety Agency (ANSM) confirmed in 2009 that the Antigermix AS1 unit complies with the essential requirements of the 93/42/EC Directive.
The three published studies on the use of UV-C in clinical practice, of which two were funded by Germitec, showed that Antigermix, used in combination with other methods (eg, wipes soaked with disinfectant), is a good way to disinfect ultrasonography probes. However none of these studies allowed to isolate and quantify the own contribution of UV-C throughout the disinfection process. In addition, one study is not relevant for our assessment because performed for transcutaneous ultrasonography, with a prototype of the Antigermix unit. Therefore, these studies do not allow to establish the effectiveness in real conditions of Antigermix device as a means of disinfection endocavitary probes.

Economic aspects: no available data allow comparison of the efficacy and the costs of different disinfection methods. Costs to be considered are linked to the device, its maintenance, downtime of sonography equipment and possible need for additional probes (for soaking, two or more probes could be used according to an alternating schedule, disinfection of one during use of the other), and in some cases the need for a dedicated room. If the systematic use of a high-level disinfection between patients would have clinical interest and should be recommended by the HCSP, a more developed economic evaluation should then be considered.

Organizational aspects: disinfection practices may impact the organization in several ways: 1) need for space to perform the disinfection procedures, close to the room where the ultrasonography probes are used; 2) non-availability of probes during disinfection; 3) need for ventilation for certain disinfectants.
To minimize the time-loss associated with the disinfecting process, it is preferable to place the disinfecting unit at the point of sonography examination.
It is the task of hospital hygiene teams, in collaboration with concerned users, to evaluate the correct implementation of recommendations regarding disinfection of endocavitary sonography probes. The use Antigermix does not exempt users from vigilance regarding disinfection, which should be performed under general protocols including a cleaning phase and precautions against recontamination of probes after disinfection.
Seven Antigermix units are currently used (March 2015) in different AP-HP hospitals.

Recommendations of CEDIT:
Considering the available data, the CEDIT makes the following recommandnations:

  • Awaiting the opinion from the HCSP, unchanged practice in user departments that are already equipped with Antigermix, but no purchase. This position is justified by the uncertainty linked with the future recommendations and their associated cost.
  • If the opinion of the HCSP is favorable to the widespread use of UV-C or more generally to the systematic use of high level disinfection between two exams, Antigermix or one of its alternatives (including soaking), should be used in accordance with the organization of user departments.
  • In this case, and since the current level of evidence supporting the clinical effectiveness of Antigermix remains low (see clinical aspects above), the CEDIT considers that a prospective comparative study evaluating the efficacy of this equipment and its appropriateness for the prevention of nosocomial infections has to be put in place.
  • If the opinion of the HCSP confirms the current recommendations, the CEDIT considers that it is not necessary to systematically acquire Antigermix systems for endocavitary (endorectal and endovaginal) sonography purposes.