IPN (Infectious Pancreatic Necrosis) ‘“ What is It and Why Bother?
IPN (Infectious pancreatic necrosis) is clinically referred to as a severely infectious type of disease affecting various species of Salmonid fish. These are also fish types which are under intensive rearing environments. Lots of fish species in different portions of the world are infected with this viral disease which is categorized in the birnaviridae family.
The fish infected by IPN (Infectious pancreatic necrosis) are those less than six months although there are adult fish which are also carriers of the disease without apparent symptoms. Most of the common fish species highly vulnerable to the disease include brown trout or Salmon Trutta and rainbow trout or Oncorhynchus mykiss. Salmon species such as Atlantic and Pacific salmons are likewise at high risks.
The grave news is that the IPN (Infectious pancreatic necrosis) virus is also reportedly manifested in marine fish species. This includes yellowtail, halibut and turbot with freshwater fish species and estuarine showing subclinical covert infections.
How is IPN (Infectious pancreatic necrosis) transmitted?
The proliferation of this disease amongst specific fish species is contagiously transferred through horizontal contact. It transmits to other fish through water routes and ingestion of contaminated materials. It is also vertically transmitted through fertilized eggs from the spawning carrier fish. Infected fish could also secrete substances which are already infected thus resulting to direct contact transmission. Finally, asymptomatic carrier fish or the contaminated embryo may infect healthy stocks.
What are the sources of this virus?
IPN (Infectious pancreatic necrosis) is from the sexual fluids, feces and potentially urine. It could be transported through infected waters, contaminated fish nets and containers and other fishing equipment. There are also mammals and fish-eating birds which could transport and excrete the infectious virus.
What are the clinical diagnoses that determine IPN (Infectious pancreatic necrosis)?
The sudden and fast increase in the daily deaths or mortalities in the hatchery is one of the main and first signs of outbreak of the virus among salmonid fish species. Infected fish also tends to have a whirling, spiral and corkscrewing swimming motion. If you examine closely, you would see darkening pigmentation on the surface with the gills typically pale. Contaminated species also have distended abdomen and have long thin fecal casts with whitish appearance. There is basically an absence of food however milky or clear mucus in the stomach as well as anterior intestine is apparent.
Where does IPN (Infectious pancreatic necrosis) usually occur?
This viral disease affects various species of fish in a wide geographical distribution. Some of the most common locations with major salmonid farming countries are highly affected. These countries include North and South America, Asia, Europe and isolated reports from South Africa. The contamination of salmonid fish is quite common especially under intensive rearing conditions which are usual in salmonid hatcheries and sea cages.
IPN (Infectious pancreatic necrosis) gravely affects healthy fish species and eventually destroys the ecological balance and system. However, this viral outbreak could be prevented through sanitation and disinfection of vulnerable hatcheries, fry tanks and troughs and equipment.