LOS ANGELES, June 21 (Xinhua) -- The California Department of Fish and Wildlife (CDFW) said Monday that due to an outbreak of Lactococcus petauri, a naturally occurring bacteria, approximately 350,000 infected catchable rainbow trout would be humanely euthanized.
The current outbreak, first detected in two trout hatcheries run by the department in April, has been spreading so far, the CDFW said in a statement.
The authority planned to combat the outbreak and improve hatchery capabilities by using of two different types of fish vaccines (immersion and injection) developed by scientists at the University of California, Davis, at the affected hatcheries, the statement said.
CDFW's fish pathologists believed that the bacteria may have been carried into the hatcheries by birds that picked it up from an environmental source.
Lactococcus petauri occurs naturally in the environment and is usually spread by movement of fish or eggs. Some of the infected fish can show symptoms including bulging eyes, lethargic or erratic swimming and increased mortality, or be asymptomatic while others show no signs of infection depending on several factors including water temperature and stress.
Fish-to-human transmission of this disease is rare and unlikely, CDFW noted, adding "as always, anglers should follow USDA recommendations on cooking fish to an internal temperature of 145 degrees F (62.8 degree centigrade)." ■