Yume Koi Has Been Hit With Khv

[Regenmeneer]

JR, you're right. I shou;d have been more clear.

When mentioning the heat cycle, what I meant was that shipments of koi when arriving, be subjected to KHV permissive watertemperatures for a period of time to find out if the new koi were infected/carriers of the KHV.

I have never heard that koi can only get KHV twice. But this could well be the reason why in Israel they advise to put a infected koi through two cycles of heat above 30C to be sure.

[johnsmith]

Morning Reg. I just wanted to restate the different ways heat is referenced when talking about KHV because we have this wacky thing started over here by a Vet who misunderstood the Israeli experiments and thought it would be clever and humane to use the heat on already diseased fish- a kinda 'vampire effect' in which you take 'bitten' fish and turn them into live carriers.

It's true that the Israeli have been 'through the looking glass' on this one. Probably due to their complete involvement with the disease. In that thinking they have actually come one possible scenario- if all fish are exposed and survive twice, they are all immune- and even if they are carriers- they are all immune- IN THEORY..
In other words, KHV loses it's power to kill two time survivors and is no longer a lethal disease- or even relevant, unless of course, there are naive fish around.

[PapaBear]

It has been my understanding that KHV lies dormant at lower temperatures, becomes active and infectious at warm temperatures, and is KILLED at higher (90deg range) temperatures.
IF that is correct, at lower temperatures infected Koi are neither symptomatic nor infectious as the virus is lying dormant within the infected carriers cells.
At warmer temperatures (75-80deg range) the virus becomes active, reproduces, overwhelmes the Koi immune system, and the Koi spreads the disease and dies before its immune system can produce antibodies against KHV.
If the Koi is warmed to the 90deg temp range the virus dies, but the Koi produces antibodies to kill off any surviving KHV remnants, rendering it immune to further infection. It is no longer a carrier of "live" KHV and should be immune from future infection. If exposed a second time to the virus its immunity should not only protect it from infection, but kill off any KHV entering its system thereby preventing it from being an immune carrier.
If I am incorrect in ANY of this please point me in the right direction.

[MikeM]

Papa: When the temperature is raised to 90F the virus is not killed. The koi is able to recover, but the virus remains. In most instances it is believed the koi develops immunity, but becomes a carrier. But there may be instances where even such a koi becomes ill again. This is why I have reached the view that all KHV exposed fish should be euthanized, without regard to whether the individual fish recovered. Those who keep infected koi that survive, whether survival is due to high heat treatment or naturally developed immunities, are simply asking to be ostracized from the rest of the hobby. So much has been learned, but it amounts to so little. IMO it should be assumed that all the fish, ponds, equipment, nets etc. of the keeper of KHV survivors are instruments of death.

[johnsmith]

Unfortunately the devil is in the details and you have some things right Larry and some things in your post not so right. Reread what I wrote about heat conversations and see if you can fill in the blanks. Remember this is a virus and not bacteria so adjust your thinking about the immune system and the cycle of the invader.
I'd suggest you get a Microbiology text book on the college or post grad level and read up on viruses- then read up on herpes virus specifically and then on herpes virus in other species of fish. You might also find a primer on SVC interesting and mind expanding regarding stress and how infectious agents have learned to work with seasons.
I would forget that wacky stuff that certain vet put out on 'heat treatments' as it only serves to confuse a basic understanding of the virus. That is basically a dead end treatment to stop the death rate.
The heat treatment I was referring to is administered BEFORE the fish are sick ( the incubation period for the virus is 8-14 days).
One you are in the disease mode, the cells are being distroyed ( the disease lasts only 21 days and then passes like a 'bad storm'. And it is estimated that 20% of any population exposed will be naturally resistant or immune. And as I mentioned, survivors of two outbreaks or exposures can't get infected again.
JR

[PapaBear]

I really appreciate the feedback. With so much written over time keeping current knowledge dissected from past assumptions becomes a problem.
Herpes type viruses being so divergent it is problematic and no doubt has weighed heavily on finding a true cure. The variant human strains being largely dormant with random outbreaks caused by different environmental influences, be it zoster, simplex, whatever... tends to cloud my thinking
As to your point Mike, I'm with you. Takeing a chance on one that has spent a little time in the suzy homemaker oven tank is just too risky for me to consider.

[johnsmith]

It's a funny thing larry, on one hand there are 'universial' truths about all viruses known as 'herpes' regardless of species. On the other hand, fish herpe viruses are unique an quite deadly compared to mammalian forms. Catfish, pike, angelfish, carp- they all have a deadly species specific herpes. JR

[KoiCop]

Sorry for the lack of information these past few days. I spoke to Paula Reynolds on Friday afternoon, who was in agreement that those people that bought Koi at the BKKS Show, were most likely in the clear, since those Koi would have almost definitely broken out with KHV, if a carrier were purchased and taken home. So, it looks like there was a carrier amongst our Koi that managed to get through quarantine, albeit between 18c and 23.5c without breaking out, assuming that the carrier were from the May shipment. On this particular shipment, we couldn\'t get the quaratine ponds below 18.0c, but figured that with the Koi being around 16c in the bags, and that there were three in-pond breedings in the first 10 days of quaratine (hence very bad water), and very sudden temperature ramping, that these Koi were in the clear. 17c is the generally accepted lower marker point prior to ramping, that should trigger an outbreak if a carrier is present. But, in the case, we feel that it is unlikely that it would have triggered anyway. But, the Koi shows 15c appeared to set the \'lower marker\', prior to us raising the temperature to 23.5c on our return, and hence triggering the problem. 23.5c was the temperature we hit just a day or two prior to the 20th. So, in theory, anyone who hit this temperature at around the same time, will have almost certainly triggered a problem, if one were present. Hitting this temperature sooner would have been even more certain to trigger.

Tomorrow, we should be taking delivery of the necessary blood sampling equipment to take blood samples for \'ELISA\' anti-body testing. Then, Wednesday and Thursday, we will blood sample each and every Koi we have, in all of our ponds, to see if we have any other carriers present. Further to this, we will be sending blood samples of all of the infected Koi to Vicki Vaughan in America, so that she can do investigative testing to try to establish which Koi was the original carrier that triggered the outbreak. This extensive testing will enable us to figure out exactly which customers Koi are at risk. But, the CEFAS ELISA test results won\'t return for around a week, and Vicki Vaughan won\'t have results for two weeks. Although temperature ramping is the generally accepted as adequate for triggering KHV, we feel that Anti-body testing is the only way we can be 100% that every single Koi is safe. Once we are confident that we have no carriers, we will then set up show vats outside, so that we can be certain to get temperatures lower, prior to putting the Koi back into the ponds, and ramping once again (for customers peace of mind rather than ours).

So, on Friday, we will \'hit the road\' and commence with the blood sampling of every Nisai, or older Koi that we have sold this year, at our customers convenience, and at customers ponds. This testing will take us from Devon, across through Surrey, up as far as Hull and Newcastle, and west as far as Preston. Hence, it is likely to take us up to two weeks to get to every customer. Koi that were sold from shipments prior to November 2005, will be excluded from this testing. As for Tosai, these Koi are the same as supplied to other dealers, and since we have taken sample Koi back from dealers for testing, and since these Koi were raised as siblings, these Koi will be excluded from testing, if dealers Koi are deemed to be in the clear. We have only had about 5 of these leave our premises, but if requested, we will test them anyway.

In the future, each and every Koi that we import will be individually ELISA tested immediately on arrival, and before any temperature ramping. This will become our policy to help regain public confidence in our Koi.

We are extremely sorry for any risk we have put people at, or any worry we have caused. We are counting our lucky stars that we haven\'t caused outbreaks in any customers ponds, and will make sure that any future risk of this will be completely eliminated by our extensive testing measures of all Koi sold since last November.

We sincerely hope that what has happened to us, doesn\'t affect your decision to buy Koi from any dealer. If you have confidence and trust in your dealer, please stick with them and continue to buy Koi from them.

As a footnote: Questions have been raised about how long ELISA testing can detect anti-bodies (\'potential carrier\' in laymans terms). It is documented from the Sept 2005 KHV Workshop at the EAFP Conference in Copenhagen, that KHV Anti-Bodies have been detected AT LEAST 12 months after exposure to the virus. Further to this, CEFAS say that even if a Koi were exposed to the virus perhaps five years ago (a question I asked them), then anti-bodies would still be present, which should show on the ELISA test. However, CEFAS said that their ELISA test is one they have made \'in-house\', and that thier test didn\'t guarantee the accuracy of anyone elses \'long-term post-exposure\' ELISA test result, so they could only comment on their own. The ELISA is the most accurate way to test if a carrier is present. But, only if you test each and every Koi!

It is said that KHV survivors will be immune to the virus. This simply isn\'t true. Even in a pond of only KHV survivors, the virus can be induced again, and mortalities will most likely occur. Each successive attempt however, would be progressively harder to induce.

I will keep you updated as soon as news unfolds.

Thank you for taking the time to read this.

Mike Snaden

[Regenmeneer]

Respect to Mike Snaden!

He is going all the way to handle this. He should be an example to every koi dealer faced with a KHV outbreak.

[Joansmithe]

Stand up guy. But makes me glad I'm not in the koi business!

He is incorrect however, - survivors are immune after two episodes at temperature. We see this all the time over here with the original Israeli stock that survived the outbreak years back- the new introduced fish keep dying but the 'healthy' fish keeps ticking as though nothing has happened. I know two people in NJ and one in Colorado that have the original survivor fish STILL in their ponds. I also almost had a heart attack when a well know dealer pointed to his show tank of healthy koi in a local koi show and said- " yea, these fish all had KHV last year and got cured by a heat treatment!" Yipes

JR