The latest article on KHV.

[Werner]

Source: www.yomiuri.co.jp World News 15/12/2003 09:20:30





Carp herpes virus deals new blow to fish farmers

--------------------------------------------------------------------------------



The spread of the koi (carp) herpes virus (KHV), which has killed a large number of farmed carp in the country, is dealing a new blow to the carp-farming industry through the cancellation of carp-grading shows.



Mass deaths of the fish first took place in early October in Kasumigaura, Ibaraki Prefecture.



On Nov. 6, the deaths were confirmed to be the country's first case of KHV infection, with the virus now having spread to 22 prefectures, causing damage to carp breeders up and down the country.



Carp can be infected through contact with other KHV-stricken carp, or through infected water, and infected fish suffer a mortality rate close to 100 percent.



The virus has infected farmed carp used for food or ornamental purposes, as well as wild carp. The disease has rocked related industries, with many breeders forced to close their businesses.



Annual production of ornamental carp, known as nishikigoi, is estimated at about 6 billion yen.



On Dec. 3, the All Japan Nishikigoi Promotion Association, consisting of breeders and distributors, decided to cancel its annual carp-grading show, the country's largest, due to be held in January.



The cancellation is likely to have further adverse effects on breeders, since the show usually helps to raise prices for the fish.



Some dealers have complained of bad business as regular customers became reluctant to buy ornamental carp.



The virus outbreak comes despite efforts by the industry to keep the disease out of the country.



Since the outbreak of KHV in Israel in 1997, the contagion has spread to Europe, Indonesia, Taiwan and the United States.



In 1998, the association agreed to exercise restraint on carp imports to prevent KHV from entering the country, fearing the virus could kill expensive ornamental carp, which can fetch several million yen each.



An association executive said the association had asked the government unofficially to map out measures to deal with the virus, but because no carp were infected at that time, the government did not take the matter seriously.



The Agriculture, Forestry and Fisheries Ministry began full-scale studies of the problem last year, when the virus struck Indonesia.



In June, the ministry finally designated KHV a special virus subject to controls on the moving and disposal of infected fish.



In July, the ministry also established a system requiring importers to receive permission to import carp.



However, mass deaths of wild carp in Okayama Prefecture between May and July were found to have been caused by the KHV infection. The virus was widely believed to have entered the country immediately before the import controls were established.



To make matters more difficult, live carp cannot be tested to see whether they are infected. It is hard to prove that expensive ornamental nishikigoi are safe as they are valuable only if they are alive.



Some prefectures, including Niigata, which is the largest carp production center, have proposed to the government that nishikigoi and low-priced carp be contained together for a period of time. The low-priced carp can then be killed and examined to see whether they are safe.



However, because every prefecture has a different test system, there is no definitive way to ensure safety.



The industry breeding carp for food has also suffered from the contagion.



Ibaraki Prefecture, which produces about half of the nation's annual 2.8 billion yen production, extended by 20 days from the end of November the ban on moving carp, which is tantamount to suspending shipments, and proposed disposing of all carp to prevent the viral spread.



Breeders around Kasumigaura have decided to comply on condition that the prefectural government purchase their carp at market prices.



The ministry said it would fund half the cost to the prefecture of buying the carp, but the two sides are still trying to reach an agreement on prices and compensation ratios.



In the event all carp are disposed of, farmers will have to start over again by breeding baby fish. In other words, they will not be able to ship any carp for two to three years.



As natural carp also were found to have been infected with the virus in Kasumigaura, there are concerns that the business may prove too risky for any breeders to continue.



As the virus is believed to become inactive in temperatures lower than 13 C, breeders expect the spread of the disease to halt in winter.



However, Takaji Iida, head of the National Research Institute of Aquaculture's Aquatic Animal Health Division, warned that the contagion could recur next year even though infected carp might not reveal any symptoms during the winter.



Better tests for the disease and more effective controls on the movement and disposal of carp now will be essential if the government is to make any progress in halting the spread of KHV.

[Bern]

Thanks for that Werner.



The dates mentioned in that article are in line with information I have known for some years.



The article I print below in return is usefull in that it highlights the spread of the disease worldwide, but it does have the dates wrong about when KHV was first diagnosed etc.



The info comes from a recent symposium in Germany.



quote.



Global occurrence of KHV by 5 December 2003



modified abstract of lecture at the Institut f?r Zoologie,

Fischereibiologie und Fischkrankheiten, University of Munich, Germany,

2 December 2003



Olga Haenen*, Dieter Fichtner, Sven Bergmann, Guiseppe Bovo, Ron Stagg,

Anders Hellstr?m, Brian Dall Schyth, Ellen Ariel, Fran?ois Lieffrig,

Hannele Tapiovaara, Eija Rimaila-P?rn?nen, Rudolf Hoffmann, Hideo

Fukuda, Nobuaki Okamoto, Keith Way, Jeannette Castric, Gy?rgy Csaba,

Oren Gilad, Ofer Ashoulin, Oliver Hochwartner, Oskar Schachner, Fiona

Geoghegan, C.V. Mohan (NACA), C. Michel, Pedro Smith, Eva-Maria Bernoth,

David Bucke, Trevor Hastings, J. Barja, Peter-Joachim Enzmann, Igor

Shchelkunov, Motohiko Sano, M. Yoshimizu



*) Head of the National Reference Laboratory of Fish and Shellfish

Diseases, CIDC-Lelystad, Institute for Animal Science and Health, P.O.

Box 2004, 8203 AA LELYSTAD, The Netherlands, E-mail: olga.haenen@wur.nl



Koi Herpes Virus (KHV) is known to cause significant gill and skin

disease in koi and carp (Cyprinus carpio). Especially the big carps are

affected. Since its introduction KHV has spread rapidly over the world.

In this abstract you will find scientific data, obtained by personal

communication with Olga Haenen (via E-mail mostly from co-authors e.g.)

and literature, as far as known to the first author. Therefore, it

cannot be the total true global situation on KHV. However, in case of

KHV positive results, most data are to be taken serious. No special

rights can be taken from this abstract.



The development of KHV in the last few years is as follows:



EUROPE:

• Belgium: The disease is present since 1999 in koi, first in hobbyist

ponds, than in koi production sites. Mortalities varied, but reached

90%. Diagnosis was done by PCR. Some carps showed symptoms, but no KHV

was diagnosed.

• Denmark: One KHV outbreak in July 2002 in carps of <10 cm from a

wholesaler pond with disease (also SVCV was isolated), summer 2003: two

importers with Japanese koi (13-15 cm) were KHV positive from the same

source. KHV diagnosis was done by PCR on gill tissue.

• England: 36 outbreaks in 2002 in a wide range of carp sizes, all by

PCR, 9 also by virus isolation at KF-1 cells; outbreaks continued in

2003.

• Finland: no outbreaks sofar, never virus isolated from koi.

• France: KHV outbreak in 2003 in carps/koi (?) from Israel (Munich

meeting). They have tests stand by: virus isolation and PCR.

• Germany:

o Riems: 21 KHV cases in 2002 by PCR, virus isolation,

immunofluorescence, E.M., June 2003 67 cases, since June 123 cases (4-6

cases in carp) in all sizes of koi/carp, but mostly in bigger fish;

mortalities 50-100% (koi) and 80-100% (carps)

o Munich: regulary outbreaks: up to 60 in 2002 in all sizes of koi,

partly in common carp; mortalities up to 100%, with may be a tendency to

a reduced rate. In so called “survivors” or “immunized “carps only a few

deaths in combination with transport stress; method: PCR and histology

• Austria: first outbreak summer 2003 in koi in a private pond, tested

by PCR (M?nchen)

• Switzerland: KHV outbreak in 2003 (Munich meeting).

• Poland: exported common carps were KHV positive (Riems)

• Hungary: no outbreaks sofar, but some suspicions (Munich meeting)

• Luxemburg: KHV positive (Munich meeting)

• Italy: KHV positive (Munich meeting).

• Spain: no diagnosis yet and no suspicions of KHV

• Scotland: no outbreaks sofar

• Ireland: no outbreaks sofar

• Sweden: no outbreaks sofar, prevention by quarantaine with virus

isolation at KF-1 cells

• The Netherlands: >30 outbreaks since July 2002, by PCR, histology, of

which only 1 in 2002 by virus isolation. It occurred sofar only in koi,

and not in carp, mostly in big fish. Mostly the water temperature was

between 20 and 27?C. At 30?C mortality was halted.

• Russia: no suspicions, no outbreaks, but no diagnosis; the koi branche

grows in the mean time.



ASIA:

• Indonesia since April 2002 (NACA)(confirmed by PCR : Java since May

2002, 30% in carp; Sumatra since Nov 2002, 80% in carp), outbreaks

continued.

• Thailand: no KHV yet? It actively surveillances for KHV.

• Singapore: no KHV yet? It actively surveillances for KHV.

• Taiwan (January 2003: many outbreaks, >80% in koi, no confirmation

yet?),

• Philippines: probably KHV positive?

• Malaysia: probably KHV positive?

• Japan (pers.comm. N.Sano): KHV PCR tests are done since 2001. In

May-June 2003 the first outbreak occurred in common carp and koi of 1-3

kg in a river in Okayama Prefecture, Western Japan. Oct 2003 acute

mortalities occurred in Ibaraki Prefecture, Lake Kasumigaura (660 tons)

en Lake Kitaura (200 tons), Eastern Japan; mid Oct 2003 it peaked. The

water temp was 17?C. Phytoplankton bloom may have been the stress

factor. In the mean time 22 metric tons were distributed from Lake

Kasumigaura to 21 prefectures (Fukuda, pers.comm.). Mid Nov already 4

rivers were infected (Yoshimizu, pers.comm.) . By end Nov 2003

mortalities reached 1200 tons in total. Clinical signs included severe

gill necrosis and sunken eyes. There was new legislation in Japan since

July 2003 (requirement of an infection free certificate). Ibaraki

Prefecture has officially prohibited movements of common carp from the

affected areas to other areas. All koi shows were cancelled for Nov 2003.

• China: handpicked koi from China were KHV positive (CEFAS). In Hong

Kong, a KHV outbreak in 2001 killed many kois in 2 weeks (G.Chu).

• Other NACA (Network of Aquaculture Centres in Asia-Pacific)-countries:

Bangladesh, Cambodia, Hong Kong SAR, India, Korea (DPR), Myanmar, Nepal,

Pakistan, Sri Lanka, Thailand, Vietnam. Other participating (non-member)

governments include Iran, Rep. of Korea, Lao PDR and Singapore: no

outbreaks yet.



MIDDLE EAST:

• Israel: May 1998 KHV was first diagnosed (Tinman & Bejerano, 1999)

after imports of koi from Europe. Since than it spread further. Israel

uses active immunisation schemes and developed an attenuated vaccine

(see below).



AFRICA:

• South Africa: There was an outbreak autumn 2003, in which KHV was

proven (meeting Munich)(details not known).



UNITED STATES: The disease was present since 1990; KHV was isolated from

diseased adult koi, showing irregularly colored gills (Hedrick et al.,

2000). See references.



SOUTH AMERICA:

• Chile: no outbreaks of KHV yet.

• further more no data available.



AUSTRALIA: No outbreaks yet.



In 2001-2003 the EU reference laboratories of fish diseases discussed

the impact of KHV related to possible notification. It was decided from

the discussion to keep KHV a non notifiable disease, because of the

problems of diagnosis.



Diagnosis: KHV replicates at Koi Fin-1 cells (developed by Hedrick et

al., 2000), and also at Common Carp Brain cells (CCB)(Neukirch et al.,

2001).More and more labs use the PCR. Antisera from rabbit and

monoclonal antibodies are produced in Riems. Riems also developed

transfection and electroporation of KHV for research and in future

diagnosis. New tests are also in development in Munich. At CEFAS, a

nested-PCR assay is in development for screening of KHV carriers.

Furthermore, CEFAS has developed an in situ hybridisation assay, for

localisation of KHV DNA in infected fish tissues, and a modified PCR

assay for detection of DNA in archive fixed and paraffin-embedded tissue

(Way et al., pers.comm. 2003). This enables to trace KHV back in archive

material. Gilad (pers.comm.) developed further an ELISA and Taq Man PCR

for KHV. The latter test has the advantage, that from 10 KHV molecules

the amount of virus can be traced.



In Munich cohabitation experiments were done, also for detection of

latent infections. CEFAS did virus transmission studies with various

species of cyprinid fish: only carp were affected. In Japan, Tanaka

studied the KHV outbreaks in Indonesia: almost all KHV positive fish

also had Flavobacterium columnare and it occured also at >28˚C. Gilad

(pers.comm.) did bath exposures to KHV: at 28?C disease developed

quicker than at 22?C, than at 18?C. At 13?C no mortality was seen from

KHV. Riems studies cell cultivation of carps with KHV.



There is one publication about a KHV vaccine (Ronen et al., 2003): a

live, attenuated vaccine of non-pathogenic virus. They named the disease

Carp Nephritis and Gill Necrosis (CNG) of koi, caused by the virus CNGV.

Gilad studied a formaline killed injectable KHV vaccine, and challenged

with KHV 6 weeks after immunization: no protection was found. Gilad

studies passive immunization and the use of injectable anti herpesvirus

drugs, like Acyclovir?.



Israel uses an immunization scheme for 3 month old kois (Ofer Ashoulin,

OATA, Hull, pers.comm): They are kept for 5 days at 23-24?C in

cohabitation with diseased KHV positive older kois. Just before they get

diseased, the water temperature goes up to 30?C for at least 30 days,

which inhibits disease. Than the water temperature is lowered to 24?C.

The water quality is kept very well all the time. They sell the koi when

they are 10 months old. This method works even better with older koi,

they said. They claim, the kois are free of KHV after their

immunization. Moreover, they tested naturally resistant fish: They were

KHV PCR negative, they didn’t get KHV under stressful conditions, they

did not transmit KHV to naive fish following immunosuppression

treatment, and they were unable to transmit the disease following

cohabitation and injection with KHV.



KHV has become a world problem, and threatens now, after the koi, the

cultured and wild common carp populations. It is not yet a notifiable

disease. Should this soon be altered? The impact of the current global

situation of KHV is subject to discussion.



References

• Amita, K., Oe, M., Matoyama, H., Yamaguchi, N. and Fukuda, H. (2002).

A survey of koi herpesvirus and carp edema virus in colorcarp cultured

in Niigata Prefecture, Japan. Fish Pathology 37(4): 197-198 (in Jap.

with English abstract and tables).

• Ariav, R., Tinman, S., and Bejerano, I. (1999). First report of newly

emerging viral disease of Cyprinus carpio species in Israel. Abstract of

poster, EAFP Conference, Rhodes, Sept 1999.

• Benet-Perelberg, A. et al., 2002. Characterization of resistant fish

to Koi Virus (KV) Disease. Poster OATA conference, Hull, Nov 2002.

• Body,A., F. Lieffrig, G. Charlier and Collard, A. (2000). Isolation of

virus-like particles from koi (Cyprinus carpio) suffering gill necrosis.

Bull. EAFP 20: 87-88.

• Bretzinger, A., Fischer-Scherl, T. Oumouna, M., Hoffmann, R. and

Truyen, U. (1999). Mass mortalities in koi carp, Cyprinus carpio,

associated with gill and skin disease. Bull. Eur.Ass.Fish Pathol. 19(5):

182-199.

• Gilad, O., Yun, S., Adkinson, M.A., Marty, G.D., Leutenegger, C.M.,

Bercovier, H. and Hedrick, R.P. (2002a) Effect of water temperatures on

the pathogenesis of koi herpesvirus (KHV), and development of an ELISA

for KHV detection in previously exposed fish. Abstract of oral

presentation, 2002 (?).

• Gilad, O., Yun, S., Adkinson, M.A., Way, K., Willits, N.H., Bercovier,

H. and Hedrick, R.P. (2003). Molecular comparison of isolates of an

emerging fish pathogen, koi herpesvirus, and the effect of water

temperature on mortality of experimentally infected koi. J. Gen. Virol.

84: 2661-2667.

• Gilad, O., Yun, S., Andree, K.B., Adkinson, M.A., Zlotkin, A.,

Bercovier, H., Eldar, A. and Hedrick, R.P. (2002b). Initial

characteristics of koi herpesvirus and development of a polymerase chain

reaction assay to detect the virus in koi, Cyprinus carpio koi. Dis.

Aquat. Org. 48: 101-108.

• Gray, W.L., Mullis, L., LaPatra, S.E., Groff, J.M. and Goodwin, A.

(2002). Detection of koi herpesvirus DNA in tissues of infected fish. J.

Fish Dis. 25: 171-178.

• Haenen, O., Fichtner, D., Bergmann, S., Bovo, G., Stagg, R.,

Hellstr?m, A., Schyth, B.D., Ariel, E., Lieffrig, F., Tapiovaara, H.,

Rimaila-P?rn?nen, E., Hoffmann, R., Fukuda, H., Okamoto, N., Way, K.,

Castric, J., Csaba, G., Gilad, O. and Ashoulin, O. (2003). Koi

Herpesvirus – the global situation. Abstract of oral presentatioon at

the CEFAS Workshop on Carp Diseases, June 2003, Weymouth, UK.

• Haimi, M and Ariav, R. (2000). A short report on a newly emerging

viral disease of koi (Cyprinus carpio) and its relevance to the future

exportation of coldwater ornnamental fish from Israel. OFI Journal 30,

Feb 2000: 10-11.

• Hedrick, R.P., Groff, J.M., Okihiro, M.S. and McDowell, T.S. (1990).

Herpesviruses detected in papillomatous skin growths of koi carp

(Cyprinus carpio). J. Wildlife Dis. 26(4): 578-581.

• Hedrick, R.P., Gilad, O., Yun, S., Spangenberg, J.V., Marty, G.D.,

Nordhausen, R.W., Kebus, M.J., Bercovier, H. and Eldar, A. (2000). A

herpesvirus associated with mass mortality of juvenile and adult koi, a

strain of a common carp. J. Aq.Anim. Health 12: 44-57.

• Hoffmann, R. (2000). Koiseuche bedroht Karpfenteichwirtschaft. Fischer

und Teichwirt 11: 432.

• Hoffmann, R. (2001). Herpes-Viren bei Koi. KLAN koi magazin 2: 62-65

• Hoffmann, R., Just, F. and El-Matbouli, M. (2001). Koi herpes virus

infection in koi and common carp in Germany. Abstract of oral

presentation, EAFP Conference, Dublin, Sept 2001.

• Japan Times, The, Nov 3 , 2003. Herpes virus kills 860 tons of carp.

• Neukirch, 2001. Virusinfektionen bei Koi. KLAN koi magazin 3: 47-53.

• Neukirch, M., B?ttcher, K., Bunnajirakul, S. (1999). Isolation of a

virus from koi with altered gills. Bull.Eur.Ass.Fish Pathol. 19(5):

221-224.

• Neukirch, M. and Kunz, U. (2001). Isolation and preliminary

charcterization of several viruses from koi (Cyprinus carpio) suffering

gill necrosis and mortality. Bull.Eur.Ass.Fish Pathol. 21(4): 125-135.

• Neukirch, M. and Steinhagen, D. (2003). Influence of temperature and

pH on the infectivity of viruses isolated from koi. Poster at EAFP

Conference, Sept 2003, Malta.

• OATA, 2001. Koi Herpes Virus (KHV). Report of the Ornamental Aquatic

Trade Association (OATA), Wilts, UK. 33 p.

• Oh, M.J., Jung, S.J., Choi, T.J., Kim, H.R., Rajendran, K.V., Kim,

Y.J., Park, M.A. and Chun, S.K. (2001). A viral disease occurring in

cultured carp Cyprinus carpio in Korea. Fish Pathol. 36(3): 147-151.

• Perelberg, A., Smirnov, M., Hutoran, M., Diamant, A., Bejerano, Y. and

Kotler, M. (2003). Epidemiological description of a new viral disease

afflicting cultured Cyprinus carpio in Israel. The Israeli J. of

Aquaculture – Bamidgeh 55(1): 5-12.

• Ronen, A., Perelberg, A., Abramovitz, J., Hutoran, M., Tinman, S.,

Bejerano, I., Steinitz, M. and Kotler, M. (2003). Efficient vaccine

against the virus causing a lethal disease in cultured Cyprinus carpio.

Vaccine 21 (32): 4677-4684.

• Tinman, S. and Bejerano, I. (1999). Field observations of a herpes

viral disease of koi carp (Cyprinus carpio) in Israel. Abstract EAFP

conference Rhodes, Sept 1999.

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[maleri]

Bern



I would belive that this fish were imported from China.



Denmark: One KHV outbreak in July 2002 in carps of <10 cm from a

wholesaler pond with disease (also SVCV was isolated), summer 2003: two

importers with Japanese koi (13-15 cm) were KHV positive from the same

source. KHV diagnosis was done by PCR on gill tissue.



Lars

[MikeM]

Excellent info!

[Werner]

Thanks Bern--



I was still trying to translate the Munich KHV Symposium to post it to the boards.

[Werner]

Here's another article--



sorry, duplicate from below

[Bern]

I received the following this morning, source ZNA.

QUOTE.





Japanese authority announced by law that :-

[1] KHV is an official designated disease.

[2] Authorized the local authority (principal of prefecture) to command for :-

a) Restrict or prohibit movement of KHV infected or doubt of KHV infected carp or koi.

b) To burn or bury KHV infected or KHV dead carp or koi.

c) To disinfect(sterilize) net/pond & container/equipments & accessaries that are suspected with contact of KHV.

d) Charge fine or imprisonment to whom violate above rules.

[3] Authorized the local authority (principal of prefecture) to do :-

e) Send officials to inspect where KHV infection is suspected.

f) To order the person to present report who keep and/or possess carp and koi.

[4] Others

g) Report to relevant local authority if you find carp or koi died rapidly and any of above cases.

h) Pond water disinfected with medicine should be neutralized before draining out.



UNQUOTE.



I thinks this adequately demonstrates that KHV is being taken seriously at the highest level.



rgds

Bern

[Andrew]

Thanks Bern,

I don't think there was ever a doubt that the Japanese would not take this most seriously.

What will be interesting now is to see how many, if any, instances of any of the above being carried out occur.

Can anyone confirm for fact that KHV has been identified at a koi breeder in Japan?

[Bern]

I think you need to change that.



Koi in ornamental lakes and rivers have been found to be infected, that's a known.



How about "Can anyone confirm for fact that KHV has been identified at a koi-breeder in Japan?"



I certainly haven't seen anything to that effect yet.



rgds

Bern

[Andrew]

Ok Bern, that is exactly what I meant and accept that maybe the question I originally posted wasn't specific enough.

Edited now accordingly.