Introduction

Spring viraemia of carp, also known as Swim Bladder Inflammation, is caused by a rhabdovirus called Rhabdovirus carpio.

It is the cause of contagious infection seen in all species of carp

Carp

Carp are various species of oily freshwater fish of the family Cyprinidae, a very large group of fish native to Europe and Asia. The cypriniformes are traditionally grouped with the Characiformes, Siluriformes and Gymnotiformes to create the superorder Ostariophysi, since these groups have certain...

 around 1 or 2 years of age in the Spring. The disease is widespread across the American and European continents.

Transmission is mainly horizontal via the faeces, but vectors such as the leech

Leech

Leeches are segmented worms that belong to the phylum Annelida and comprise the subclass Hirudinea. Like other oligochaetes such as earthworms, leeches share a clitellum and are hermaphrodites. Nevertheless, they differ from other oligochaetes in significant ways...

 and crustacean

Crustacean

Crustaceans form a very large group of arthropods, usually treated as a subphylum, which includes such familiar animals as crabs, lobsters, crayfish, shrimp, krill and barnacles. The 50,000 described species range in size from Stygotantulus stocki at , to the Japanese spider crab with a leg span...

s may also spread the disease.

Clinical signs and diagnosis

The virus enters through the gill

Gill

A gill is a respiratory organ found in many aquatic organisms that extracts dissolved oxygen from water, afterward excreting carbon dioxide. The gills of some species such as hermit crabs have adapted to allow respiration on land provided they are kept moist...

s and infects the swim bladder, leading to inflammation and buoyancy problems.

Systemic signs may include skin changes, decreased feeding and death.

Diagnosis relies on virus isolation, immunofluorescence

Immunofluorescence

Immunofluorescence is a technique used for light microscopy with a fluorescence microscope and is used primarily on biological samples. This technique uses the specificity of antibodies to their antigen to target fluorescent dyes to specific biomolecule targets within a cell, and therefore allows...

, ELISA

ELISA

Enzyme-linked immunosorbent assay , is a popular format of a "wet-lab" type analytic biochemistry assay that uses one sub-type of heterogeneous, solid-phase enzyme immunoassay to detect the presence of a substance in a liquid sample."Wet lab" analytic biochemistry assays involves detection of an...

 or PCR. Electron microscopy may reveal virus particles in the swim bladder wall.

Treatment and control

No treatment exists for the disease.

Biosecurity

Biosecurity

Biosecurity is a set of preventive measures designed to reduce the risk of transmission of infectious diseases, quarantined pests, invasive alien species, living modified organisms...

 measures such as prompt detection, isolation

Isolation (health care)

In health care, isolation refers to various measures taken to prevent contagious diseases from being spread from a patient to other patients, health care workers, and visitors, or from others to a particular patient...

 and disinfection

Disinfection

Disinfectants are substances that are applied to non-living objects to destroy microorganisms that are living on the objects. Disinfection does not necessarily kill all microorganisms, especially nonresistant bacterial spores; it is less effective than sterilisation, which is an extreme physical...

of tanks and equipment is important to prevent the spread of the disease.