Lymphocystis Disease Virus (LCDV) in Aquatic Environment

Abstract

Lymphocystis disease virus is an iridovirus which has a global distribution. It is the etiological agent of Lymphocystis disease, which is a common viral disease affecting marine, brackish and freshwater fish species. It is a self-limiting disease which retards the expected breeding time, causing significant economic losses. The mortality rate is usually low but it increases in aquaculture species as it is related to both environmental and management stress factors. Nodular lesions consisting of lymphocysts are the main pathognomonic characteristic of LCD. It is a dermatropic disease with the skin and fins being the primary target organs. However, in heavily affected fish they may cover the entire body establishing a systemic infection. Real-time PCR has been proposed as the best validated technique to detect LCDV in symptomatic, asymptomatic infected or fish that have recovered and other potential reservoirs. Disease control is based on preventive husbandry practices, as no effective treatments or commercially available vaccines currently exist. As the virus is horizontally and vertically transmitted, selection of LCDV-free fish, fish screening, removal of affected animals and other potential reservoirs, quarantine and disinfection rely on the basic principles of biosecurity. Cooperation between related scientists will develop general strategies, in order to come through viral disease prevention and control while vaccination as a specific prophylactic measure would be the key to LCD elimination.