Grouper Iridovirus of Taiwan Disease (TGIV) - Viral Infections In Fish

Grouper Iridovirus of Taiwan Disease (TGIV)

CAUSATIVE AGENT:

Iridovirus (220-240 nm)

SPECIES AFFECTED:

Grouper, Epinephelus sp.

GROSS SIGNS:

Diseased fish swim in circles and are anemic. Fish lose appetite then become underweight and lethargic. The spleen of affected fish has abnormal hypertro-phied cells containing numerous icosahedral virions.

EFFECT ON HOST:

This virus has antigenic similarities with the red seabream iridovirus isolated in Japan, the epizootic, haematopoietic necrosis virus and the iridovirus iso-lated from sheatfish and the grouper iridovirus isolated in Thailand.

The disease affects farmed groupers, 5-8 cm in total length at 25-28°C. Acute disease causes up to 60% mortality. Experimentally infected fish reach a cumu-lative mortality of 100% in 11 days without other clinical signs.

DIAGNOSIS:

Signs of the disease; EM