Testing for chytridiomycosis

[TJ]

Ed, Frank, Ralf, or somebody else who might know, how would one go about having their animals tested for chytridiomycosis? (hopefully without having to sacrifice any animals!)

I have several dozen seemingly healthy Hynobius tokyoensis juveniles that I've raised from a couple of egg sacs. They were taken by a naturalist acquaintance from an area where this species is locally threatened. They've been kept in isolation from all other newts and sals, and various other precautions have been taken. I raised them for the specific purpose of releasing them, but the more I hear about chytridiomycosis, the more concerned I am.

I wouldn't want to sacrifice any of them, but I suppose that if one were to die for some reason, I could have it tested by my vet.

What's the situation for testing for this in zoos, for instance? What is the test method and is it widely availablee? Any more particularly alarming pathogens that one should be made aware of? How is this danger dealt with by the officially sanctioned breeding-for-release programs for amphibians, if any?

(Message edited by TJ on September 20, 2005)

 

[TJ]

I didn't until now realize that there was a somewhat related post today:

http://www.caudata.org/forum/messages/13/43299.html?1127219640

...with a link to an interesting article "Successful Treatment of Chytridiomycosis":

http://www.open.ac.uk/daptf/froglog/FROGLOG-46-1.html

...but it doesn't concern detection of Chytridiomycosis.

I did, however, partially find what I was looking for here in an Australian government document:

<font color="0000ff">Diagnosis of Chytridiomycosis

The clinical signs of chytridiomycosis can be similar to those of other amphibian diseases, such as iridoviral infection and bacterial septicaemia (red leg) ... so that laboratory tests are required to make a diagnosis.
Also, healthy frogs may carry infections. The development of accurate tests that do not harm the amphibian is important for increasing the efficacy of quarantine measures.

The following diagnostic tests are available:
�EMicroscopy
o Direct examination of skin scrapings
o Histology - haematoxylin and eosin (H&E) or silver stain
o Immunoperoxidase
�EEnzyme Linked Immunosorbent Assay (ELISA)
�EPolymerase Chain Reaction (PCR) �Enormal or real-time Taqman
�ECulture</font>

Source:

Threat Abatement Plan for Infection of amphibians with chytrid fungus resulting in chytridiomycosis
(DRAFT FOR PUBLIC CONSULTATION)

http://www.deh.gov.au/biodiversity/threatened/publications/tap/amphibians/pubs/amphibians.pdf

I don't suppose this testing can be easily be accessed by hobbyists at reasonable prices...

(Message edited by TJ on September 20, 2005)

 

[edward]

Hi Tim,

This is what you want to look at
http://www.open.ac.uk/daptf/declines/decl2.htm
I do not know if anyone is performing the tests near where you live but given that chytrid was recently documented in Asia, I would hope so.

The pcr test here in the USA supposedly costs about $20 to run so with markup, it should still be pretty inexpensive and is much more accurate than looking for chytrid under a microscope...
Supposedly this will work to detect chytrid with a swab or a sample of the water in which it has been living.

Chytrid is not the end, supposedly there are at least two more unidentified fungal species that are not chytrid killing amphibians in Northern South America.....
Ed

 

[TJ]

Thanks for that link, Ed.

At the Amphibian Diseases Home Page
http://www.jcu.edu.au/school/phtm/PHTM/frogs/ampdis.htm

...I found this one:

Diagnosis of chytridiomycosis in amphibians by histologic examination
http://www.jcu.edu.au/school/phtm/PHTM/frogs/histo/chhisto.htm

That and more can be found here:
http://www.jcu.edu.au/school/phtm/PHTM/frogs/batrachochytrium.htm

The H. tokyoensis I'm raising seem to be good candidates for release (if disease-free!) as the local decline seems to be mainly due to the eggs and adults being collected by humans and preyed upon by raccoons (an invasive species here), as well as occasional breeding site disruption by wild boar (which can cause significant damage!).

(Message edited by TJ on September 21, 2005)

 

[frank]

Hi Tim,

I would be very careful when releasing animals to the wild, especially when they have had contact with other, non native species. The problem is that you can have them checked for Iridoviruses or chytrids (if you find a lab willing to do this) but that these tests are specific and do not detect other pathogens.

 

[TJ]

Hi Frank,

Seems the risks could outweigh the benefits here, especially if it's not done as part of an organized, well-thought-out effort, with proper safeguards in place.

Well, my other option is to have them brought to Europe or the United States next time I get a visitor from there or find a cheap, legal and safe way to send them. My monthly cricket bill is high enough even without having so many H. tokyoensis mouths to feed! These all came from only just 2 egg sacs (one female hynobiid lays 2 egg sacs).

Wouldn't it be nice if there was some kind of "dip" that could be used to disinfect one's animals

I don't suppose a simple salt bath would do the job...