CJD-sodium hydroxide
From: | LuAnn Anderson <ander093@gold.tc.umn.edu> |
Hi Bob and histonetters,
Just to elaborate...I really do not wish to get into a heated discussion on this
subject. There have been documented cases of pathologists and even a histotech
or two who have contracted CJD. Due to the latency period, it is difficult to
say whether it was contracted through working with infected materials or
sporadic, however, there are very strong documentation of persons contracting
the disease after corneal transplants, after use of contaminated electrodes and
after growth hormone injections. This provides argument for transmissability of
the prions and we feel it is better to err on the safe side and take the extra
precautions .
As for the sodium hydroxide...I do not have "large quanities slopped around the
lab". We get between 1-3 suspected cases per year. I make up the sodium
hydroxide as needed, when needed. As for the formic acid treatment, again it has
been shown to be the most effective means of deactivation (still not 100%
however..don't be fooled) and therefore we use it, cautiously of course. It is
the recommended method today.
Typically, we see "brain only" autopsys being performed for the purpose of
diagnosing CJD. As you point out, decontamination is always a problem, and for
this reason, I hand process all suspected cases. Our Neuropathologist does all
the grossing and usually takes just the necessary sections to provide
diagnosis.I handle all the cases alone at a biosafety two level and no one else
in the lab has contact with any of the material after it is grossed. This cuts
down on the possibility of exposure and the risk of accidents occurring.
Therefore, I hand process 5-6 cassette at a time.If the result is negative, more
sections are taken for routine processing. We have a very specific autopsy
protocol set up here and I would be happy to share if anyone is interested.
This is simply the way these specimens are handled at our facility. It is by no
means the only way to handle them, each institution should develop their own
protocols based on their own needs.
There is tons of info on this available on the web, as well as from NIH, CAP,CDC
etc. There have been numerous previous discussions on the histonet as well. The
mere mention of CJD still causes panic.
Hope this adds some clarification..it will continue to be a controversial
subject, I am sure.
LuAnn Anderson HT(ASCP)
Division of Neuropathology
University of Minnesota>
Sodium hydroxide solution slopped around in large quantities to combat
> prions?
>
> Obviously we're in a situation where satisfying the demands of bureaucrats is
>
> more important than the safety of laboratory people - but strong solutions of
>
> sodium hydroxide, handled in large quantities in crowded laboratories by
> numerous people of varying degrees of consciousness - are a significantly
> hazardous material, particularly for eye injuries. (The same arguments apply
> to formic acid.)
>
> Obviously prions are a laboratory hazard, but they're one we've lived with
> for a long time, and as far as I know there is still no known case of
> Creutzfeldt-Jakob disease resulting from exposure to pathology specimens. I
> think it remains to be shown that we need any change in our methods. (For one
>
> thing, we'd have to return to open-bucket tissue processing, since a modern
> tissue processor cannot be cleared of prions.)
>
> One thing I would caution against is doing an autopsy on a body with a prion
> disease - this undertaking clearly requires more containment than is possible
>
> in an ordinary autopsy facility. (Somehow bureaucrats have always managed to
> make the assumption that an autopsy could not be an infection hazard.)
>
> Bob Richmond
> Samurai Pathologist
> Knoxville TN
>
>
> .
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