A survey to determine the presence and distribution of largemouth bass virus in wild freshwater bass in New York State

During 2004 and 2005 a survey was conducted to investigate the presence and geographic distribution of largemouth bass virus (LMBV) in New York State. This iridovirus is widely distributed across the eastern United States; however, it had not previously been reported in New York State. Two hundred and eighty-three wild largemouth bass Micropterus salmoides and 8 smallmouth bass M. dolomieu were collected from 37 locations across the state. No clinical signs of LMBV or mortalities attributable to the virus were observed in the fish collected. Using a quantitative polymerase chain reaction (QPCR) method, we detected LMBV in 28 fish from 13 locations. Viral cytopathic effect in cell culture was observed in 5 fish from 3 locations. The virus isolated from cell culture was confirmed to be LMBV by an independent PCR method. Statistical analysis of the largemouth bass samples collected during 2005 revealed a wide difference in prevalence between the QPCR results and the cell culture results. Analysis of possible predictors, including age, sex, and month collected, showed no significant associations with the QPCR results. This survey confirms the presence and wide distribution of a potentially pathogenic form of LMBV in multiple water systems across New York State.