Abstract
The recent report of amoebic gill disease (AGD) and of Neoparamoeba perurans in Chile has made it necessary to develop practical tools that will be useful for carrying out epidemiological studies. The prevalence of AGD in Atlantic salmon was 55.7% (29/52 farms) and the epidemic curve was observed between May 2007 300 g reared in Los Lagos Region during summer and autumn season showed 3.7 (p=0.0004), 4.2 (p=0.0178) and 6.2 (p=0.0031) times greater risk to be AGD positive, respectively. The reduction of Atlantic salmon biomass reared in Chile closely related with ISA crisis could considerably have increased the infection pressure of N. perurans to rainbow trout (63.2%, 12/19 farms) and coho salmon (90.9%, 10/11 farms).
