Hobbyists,
I need some opinions. And, what better place than a koi board to come for those <grin>.
Project KHV is strongly considering financing a Koi Dealer Best Health Practices (BHP) Certification Program that would address KHV specifically. Toward that end, we are discussing alternatives within such a program.
In order for a program to be effective it needs two major aspects:
- To be perceived as worth while, and
- Substantial participation
We have reviewed the scientific literature, conferred with the science folk, the dealers, the vets and to a certain extent, the hobbyists. This is an attempt to gain more input from the hobbyists.
In structuring our BHP program, we have thus far taken the “best” to mean the best balance between effective and practical. Here is some pertinent information:
- Active KHV can be uncovered by a quarantine at the permissive temperature for three weeks. If symptoms are observed, symptomatic fish may be sampled and tested using PCR methods. Any positive result should result in killing the batch and sanitizing the system.
- We would love to include meaningful testing for latency. Unfortunately there are currently no definitive tests for latency.
- There are a few tests for antibodies to KHV (KHVab) and we can safely conclude that every fish with KHVab has been exposed to the disease. Then, if we grant the premise that this is a herpesvirus and that it will produce latency, we can conclude that a positive KHVab test would possibly indicate a latent infection.
- Here’s the scientific part of the rub: there is testing that confirms previously infected fish can develop either a latent infection or a persistent low level (no symptoms) infection and later become infective (St-Hilaire et al. 2005). However, that same testing failed to support a theory that ALL previously infected fish will be carriers, i.e., currently no way to sort the wheat from the chaff (if there is a difference).
- Here comes the economic part of the rub. KHVab testing is not cheap, e.g., $20@ at UGA and £17.88@ in lots of 10 and £12.34@ in lots of 100 or more thru the CEFAS lab in England.
- Further to the economic rub: In order to obtain a scientifically meaningful sample, defined by CEFAS as either a 95% confidence that you’ve “found” the thing you’re looking for at either the 10% or 2% level, you’d need to test, 30 or 150 fish, respectively. See: http://www.cefastechnology.co.uk/khv...creen-inst.htm I think you can quickly see how this would be cost prohibitive at a dealer. (And yes, I know that the CEFAS site is referring to PCR testing at that link – the statistics work the same for all “looked for” parameters). The numbers change with small batch sizes but they remain substantial.
- If we toss vaccinated fish into the mix, testing for KHVab gets really messy quickly.
We’re considering a BHP that ONLY looks for active KHV disease and does so by the process described in the first item just above (i.e., quarantine and observe, kill if symptoms and PCR are positive, sell if not). It will NOT identify latent carriers. We believe this procedure, while not perfect, is the only economically viable option and will certainly “improve the process.”
So the question to hobbyists is:
How do you view the “quarantine and observe” option for a BHP program: - A reasonable step right now even though it will NOT catch latency,
- Not worth doing, or
- You have another option?
Sorry for the long rant but I felt it would be difficult to have an informed opinion w/o it.
While you can certainly post on the board, I would appreciate it if you would also email me privately at
scover@pacbell.net with your opinions (it’s a logistics thing).
You all have my sincere thanks in advance.
Best regards,
Spike Cover