Answer on Testing In Iowa

Next question? Next, ma'am.

REPORTER: Jane Zhang of the Wall Street Journal. The tests you are conducting in Iowa right now, are they going to be different from the ones you conducted in Michigan and the [inaudible]?

DR. DEHAVEN: There's a number of tests that we run on any of these samples. We have a network of over 50 laboratories, most of them state diagnostic laboratories, state veterinary diagnostic laboratories that are doing the screening test for us. They are doing what's called the PCR, polymerase chain reaction test, which looks for the genetic material of the virus. So that's a screening test that's being carried out at this laboratory at Michigan State as well as the other laboratories in our National Animal Health Laboratory network.

If any of those laboratories find an H5 or an H7 virus, again because of the potential for the H5 and H7 subtypes to mutate to a highly pathogenic virus, those samples then go to our National Reference Laboratory, which is the National Veterinary Services Laboratory in Ames, Iowa.

When samples are received there, as they were in this case, we repeat that PCR testing for H5 and H7. We also do a PCR testing to determine whether or not it's an N1 test. And so it's those two PCR tests conducted in Ames that show that we have the antigens compatible with an H5 and N1.

The additional testing that we're doing would include sequencing the genetic material. What is the sequence of the genes, and is that consistent with a North American strain or an Asian strain? The fact that this was compatible with our North American virus and not compatible with the Asian high path avian influenza virus that we are able to say that this is not the incursion of that Asian high path H5N1 virus.

There's also another test to determine pathogenicity or really two ways to determine pathogenicity. One is, looking at that sequence, that gene sequence. It's through that gene sequence testing that we're able to say that from a genetic standpoint this looks like a low pathogenic virus.

But the other test that we run involves inoculating baby chickens, eight baby chickens with this virus and then the test is that if six or more of those baby chickens die within a 10-day period then it would be characterized as a highly pathogenic virus.

So we're just starting that work. We have to grow more virus before we can inoculate it into the baby chickens. And so we're estimating it could take us upwards of two weeks before we would have that second test done that determines pathogenicity.

So two pathogenicity tests, one that looks at the gene sequence, one that looks at the impact on baby chickens. Either one or both that came back highly pathogenic, we would be bound to call this a highly pathogenic virus. The first test is done, indicates a low path virus. The results from that second test which should be forthcoming in the next two weeks.