Detection of channel catfish virus DNA in latently infected catfish

Channel catfish virus (CCV) disease is an acute haemorrhagic disease in juv enile channel catfish (Ictalurus punctatus). While fish that survive primar y CCV infection are suspected of being carriers of CCV, little is known con cerning CCV latency. In this report, fingerling catfish were infected with CCV by experimental immersion challenge, infected fish displayed clinical s igns of CCV disease, but 22% of infected fish survived the acute disease. A t 140 days post-infection, PCR analysis detected CCV DNA in the blood, brai n, intestines, kidney, liver and peripheral blood leukocytes of latently in fected fish, Further analysis indicated the CCV genome may exist as circula r or concatemeric DNA during virus latency. This study, employing an experi mental model of CCV disease, confirms that CCV establishes a latent infecti on of channel catfish.