EFHSS Questions and Answers - Answer to Question Q01094

what detergent we can use in our hospital's CSSD to sterile and will gaurantee that it kills Prion.

Lumen

Currently there is no validated method to decontaminate prions, although few methods have been studied. This issue has been dealt with in this forum. Please search this website for answers to questions article and resources about this issue.
Regards,
Yaffa Raz

Hi,

see answer to question Q01087

Hello,

We would like t know the sterilizers which can sterilizer the prion.
Which sterilzier can sterilize the prion regardless sterilization type?
We know, the Sterrad system (J&J) possible but want to know the rest of ther sterilizer which can sterili prion?

Thanks and best regards,

Grace Lee

Hi,

presciption about sterilising prion say that you have to do 6 times a normal sterilisation fase of 134° for 3 minuts, in total 18 minuts ...

so you can sterilise prions in any steriliser, or, ask your steriliser factory to put a prionprogram in your steriliser.
then you have a program of 134° at 18 minuts in one program.
its very time saving, it last an hour, and six separated programs last 300 minuts (depending an your steriliser)
I have such a program in my Getinge sterilisers, but other factory vcan also provide such a program.

you also need special prion indicators.

jef

Dear
Don't miss to look at the presentation "Parametric control of cleaning processes in the age of vCJD" held on the Decontamination Sciences Congress 2005 London by Klaus Roth.
You find it under Education; Conference Lectures and Presentations on our site.
Best regards
Josy Holdener

Dear Grace,
I want to confirm what Yaffa wrote: At the moment there is NO method (nor cleaning, nor disinfection, nor sterilization) that "kills" prions with absolute certainty. Even when using a sterilisation time of 18 minutes at 134 - 137° C for steam sterilisation, a certain proportion of the prions can continue to be infectious (J. Bertram, Zentral Sterilization, suppl. 1, 2004 April Vol. 12). Also a normal Sterrad 100S process doesn't inactivate prions completely.

Abstracts of interesting publications, in this regard, can be found on "pubmed". Enter "pubmed" in Google.
Then search for:

1. Klaus Roth prions.
   You will find the abstract of: "Infectivity of prion protein bound to stainless steel wires: a model for testing decontamination procedures for transmissible spongiloform encephalopathies" (Infect Control Epidemiol. 2004 April, 25(4) 276-9;
2. Guillaume Fichet prion-contaminated medical devices.
   You find the abstract of: "Novel methods for disinfection of prion-contaminated medical devices" (Lancet 2004; 364: 521-26).

Good luck,
Wim Renders

Reaction to Wim,

your comment is very at the point.
I only wanted to indicate the (commercially) best offered way to sterilise prion.

thanks anyway for your correction when you say that there always will be some not sterilised part after such a cycle.
I saw a documentary that was showing that prions even survived a burning acetylenic welding torch.... so ... it's difficult stuff to treath...

jef

Dear,
Interesting to read is the WIP guideline: "Infection prevention with regard to prion diseases". You find it on the English pages of: www.wip.nl , follow: Documentation, Subjects, Hospital, Prion diseases.
Good luck,
Wim Renders

This is always a difficult issue, but from work that we and others have done there are a number of new conclusions based on the published papers that Wim mentioned above:

• some cleaners can increase and some can decrease the risk. Two enzymatic based products were compared: one made the prion more resistant to steam and the other worked well, itself giving a 4 log reduction and then greater activity following steam
• some alkaline cleaners have shown great effects but they also range in efficacy. There is only one cleaner I know of which actually has a regulated claim (under the medical devices directive, as an accessory) which is Hamo100. It is claimed to to 'remove and inactivate (TSE) prion proteins and reduce the risk of prion infectivity on medical devicesurfaces'.
• immersion in water during the specified steam sterilization cycle was actually more effetcive than subjecting to steam itself. This is in line with other publications that higher steam sterilization temperature may actually be less effective than low.

• Ask for data on any product/sales person that makes a claim; there is a lot of speculation in this area but a growing body of real data.
  
  Gerry