Frequency of Detection and Survival of Infectious Pancreatic Necrosis Virus in a Carrier Population of Brook Trout (Salvelinus fontinalis) in a Lake

1975 ◽  
Vol 32 (4) ◽  
pp. 568-570 ◽  
Author(s):  
T. Yamamoto
Keyword(s):  
Brook Trout ◽  
Pancreatic Necrosis ◽  
Salvelinus Fontinalis ◽  
Infectious Pancreatic Necrosis Virus ◽  
Carrier Rate ◽  
Necrosis Virus ◽  
Infectious Pancreatic Necrosis ◽  
Pancreatic Necrosis Virus ◽  
Antibody Levels ◽  
Carrier Population

Brook trout (Salvelinus fontinalis) distributed from a hatchery into a small enclosed lake were examined for IPN virus carriers over a period of 21/2 yr. The carrier rate of 90% at the time of distribution decreased to 69%, but organ analysis showed differing trends in carrier rate. There was a decrease of virus in the pancreas–caeca (82–32%) and an increase in the feces (2–39%) whereas virus was detected to be present at a constant level in the kidneys (53–57%) and the spleen (8–14%). Virus was not detected in the gonads except for a few which yielded virus later in the sampling period.These data indicate that brook trout IPN carriers distributed from a hatchery into lakes do not readily lose their virus over a period of several years, and that both caeca and kidneys are organs of choice for the detection of virus.Neutralizing antibody levels were very low or nondetectable in the carrier population and could not be correlated with yield of virus.

Infectious Pancreatic Necrosis Virus Occurrence at a Hatchery in Alberta

1974 ◽  
Vol 31 (4) ◽  
pp. 397-402 ◽  
Author(s):  
T. Yamamoto
Keyword(s):  
Brook Trout ◽  
Pancreatic Necrosis ◽  
Salvelinus Fontinalis ◽  
Kidney Tissue ◽  
Infectious Pancreatic Necrosis Virus ◽  
Salmo Gairdneri ◽  
Necrosis Virus ◽  
High Incidence ◽  
Infectious Pancreatic Necrosis ◽  
Pancreatic Necrosis Virus

The presence of infectious pancreatic necrosis (IPN) virus in brook (Salvelinus fontinalis) and rainbow (Salmo gairdneri) trout was identified and further investigated. A high incidence of virus was found by virological examination of kidney tissue from yearling and older trout. By comparison, brook trout had a much higher incidence of virus than rainbow trout.The virus was isolated most frequently from the kidneys of both species of trout. These findings indicate that the examinations of peritoneal washes and feces is not adequate for the detection of IPN carrier fish.

Isolation of Infectious Pancreatic Necrosis Virus from the Blood and Blood Components of Experimentally Infected Trout

1982 ◽  
Vol 39 (1) ◽  
pp. 225-228 ◽  
Author(s):  
Robert N. Swanson ◽  
James H. Gillespie
Keyword(s):  
Rainbow Trout ◽  
Brook Trout ◽  
Pancreatic Necrosis ◽  
Salvelinus Fontinalis ◽  
Infectious Pancreatic Necrosis Virus ◽  
Salmo Gairdneri ◽  
Blood Components ◽  
Necrosis Virus ◽  
Infectious Pancreatic Necrosis ◽  
Pancreatic Necrosis Virus

Experimental infection with infectious pancreatic necrosis virus (IPNV) was achieved in yearling rainbow trout (Salmo gairdneri) and 7-mo-old brook trout (Salvelinus fontinalis) by intraperitoneal inoculation and by water contact, respectively. Blood removed periodically from both groups of fish was fractionated and various blood components examined for virus. IPNV was recovered consistently from the plasma and mononuclear-enriched blood fractions of the rainbow trout from 1 to 19 d postinoculation (DPI) and also was detected in the mononuclear fraction on 33 DPI. In the brook trout virus was recovered from 3 to 40 DPI in the plasma and from 7 to 40 DPI in the mononuclear fraction. Thus a viremia appeared to be important in the early stages of experimental IPNV infection and infectious virus was found both free in the plasma and in association with an undetermined cell population present in the mononuclear component of blood.Key words: infectious pancreatic necrosis, blood, fish disease, Salmo gairdneri, Salvelinus fontinalis

Infectious Pancreatic Necrosis Virus: Comparative Frequencies of Isolation from Feces and Organs of Brook Trout (Salvelinus fontinalis)

1971 ◽  
Vol 28 (7) ◽  
pp. 1064-1065 ◽  
Author(s):  
C. Frantsi ◽  
M. Savan
Keyword(s):  
Brook Trout ◽  
Bacterial Infections ◽  
Pancreatic Necrosis ◽  
Salvelinus Fontinalis ◽  
Infectious Pancreatic Necrosis Virus ◽  
Low Oxygen ◽  
Necrosis Virus ◽  
Infectious Pancreatic Necrosis ◽  
Pancreatic Necrosis Virus ◽  
Low Oxygen Concentration

When isolation of infectious pancreatic necrosis (IPN) virus was attempted simultaneously from feces and organs of brook trout (Salvelinus fontinalis), the virus was isolated more frequently from organs than from feces. However, the greater the degree of stress on the fish, the closer the number of isolations from feces appeared to approach that from organs, and the virus was isolated from both organs and feces of each of 10 fish accidentally exposed to low oxygen concentration for 4 days. The findings suggest that masked viral and bacterial infections may be detectable if fish are placed under stress.

Infectious Pancreatic Necrosis Virus: Quantification of Carriers in Lake Populations During a 6-Year Period

1979 ◽  
Vol 36 (5) ◽  
pp. 562-567 ◽  
Author(s):  
T. Yamamoto ◽  
J. Kilistoff
Keyword(s):  
Pancreatic Necrosis ◽  
Virus Isolation ◽  
Salvelinus Fontinalis ◽  
Infectious Pancreatic Necrosis Virus ◽  
Early Years ◽  
Necrosis Virus ◽  
Isolation Rate ◽  
Infectious Pancreatic Necrosis ◽  
Pancreatic Necrosis Virus ◽  
Carrier Population

An infectious pancreatic necrosis (IPN) carrier population of brook trout (Salvelinus fontinalis) planted in an isolated natural lake was tested for virus over a period of 6 yr. The initial isolation rate of 90% had decreased to 50% during this period indicating that there is a prolonged persistence of virus in infected animals of this species. The ceca with the associated pancreatic tissue of these fish yielded virus most frequently during the early years but the virus then decreased to low levels. Kidneys were the most consistent organs to yield virus throughout the study period. The feces yielded little virus at first but later increased for several years and then decreased. The spleen and liver yielded virus infrequently. Surgically removed gonads were the least frequent yielders of virus. The low virus isolation rate from progeny of the carrier population and from other planted fish indicated that transmission in the wild is probably infrequent. Other lakes with normal angling that had plantings with IPN carrier fish but subsequently planted annually with disease-free fish had populations whose carrier rate had decreased to undetectable levels within a 6-yr period. These findings indicated that the practice of planting IPN-free fish into areas where carriers were previously introduced may lead eventually to a carrier-free state. Key words: infectious pancreatic necrosis virus, Salvelinus fontinalis, virus persistence, carrier fish, virus isolation rate

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