I emailed Lou Ann at the University of IL and inquired as to what the test standard was for adenovirus and mentioned that we were discussing this on the forum and would appreciate any information she could share regarding the fecal em testing to detect adenovirus. I also mentioned there being 4 different genus of adenovirus and what that could mean in relation to some babies having adenovirus and having die offs whereas some test positive and appear perfectly healthy without any die offs. I asked permission to post her response. Here it is:
Hi Wendy,
There are classes and families in virus just like in naming the animal kingdom. Some of the branches have been renamed in recent decades,
Virus are grouped RNA or DNA and broken down from there. Mastadenovirus is the mammalian adeno strains. Aviadenovirus is the strain in birds.
There are hundreds of strains, Dr. Jacobson told the group that there were many strains in the very beginning, so this is no surprise. More than one strain for the beardies is most probable, probably many.
Telling the strains apart, the closest you come is PCR, not all PCR is alike, what it tests for is dependent upon what the lab is set up for. How specific are they testing for. Say some lab somewhere is getting 100% positive, it could be they are testing for a marker that is something in common in all strains, say another lab tests and finds some negatives in PCR, perhaps they are testing for more specific strains, have a more purified marker they are testing for.
I'm not saying that is the case, but this is basic common sense in dealing with any laboratory testing on.... well ... anything! Especially when dealing with varying antigenistic site issues.
Control: I have positive adeno samples I look at all the time, as I have stated before this is a visual identification. When I started in Negative stain, I was tested by the virology lab by being given unmarked vials of known cultures where by how and what cell types were infected, it was known what virus was there. There are plenty of visual references, atlas' etc, and I've been looking at adeno for almost 20 years. My images are sometimes what is used for pathology board exams.
This test, as I have told many from the start, is a visual identification, and it does not tell you the strain. It is a test that has been done for many decades and is a standard in both human and veterinary medicine as a tool to assist viral identification.
If you are asking if one can tell by looking what strain, no, there are many many strains, something well known, and they all look alike, or close enough as no difference. This is an aspect of the test that just has to be accepted. The difference in the strains is at the molecular level, again no surprise. Is it easy to mix it up with another type of virus? No, it isn't, this virus, adeno, has fairly distinct crystalline arrangements that are unique to itself, and easy to tell from the artifacts and other materials in the specimen.
So if a pig has adeno and adeno is flying around an enclosure, and a dragon is in or near the enclosure, and eats something that gets contaminated by the pig adeno, will it still show up in the dragon poop. Possibly, probably not in great number if it does, it takes a certain number of particles / mm3 to be seen at all, so it would be a long shot, but if it is in great numbers, it's more likely to be not an accidental ingestion..... would be an educated speculation. Will it look like the same particle, yes, appearances are it would look like the same particle.
So that is the test limitations. As I've told others, there are some other positives to the negative stain EM test, and that is if one's beardie is passing other virus, I can see and report that as well.
Is PCR the holy grail, we don't know, it depends upon how it is set up and what it is set up for, and what quantitatively a positive means. Is it too sensitive , we don't know, there just has not been the work done out there to compare clinical history and the two testing methods over a large population or a decently long time. At least that is what I hear the experts saying. And again I must say, I'm not a Vet, not a reptile specialist, I do virology identification, but I'm not a PhD virologist, my job is to find it and
identify it, but I'm not trained to give official veterinary advice.
I have talked with one of the 2 people involved, they do PCR here, for generally $35/ sample on other things. If there was enough volume, it might be something they would consider here,but the owners and breeders WOULD have to work through a vet, not with them directly. If it would be set up, it would be no time soon, as this lab is so swamped to the gills right now.
I will tell you this, Dr. Jacobson is held in very high regard by all here, and any information he shares, or when he can, puts up his website that will include this topic, it's worth heeding what he says. If anyone has the specific species PCR well established, it's probably his lab.
Lou Ann