Treatment or Protection Strategies

Prevention & Control
Currently, there are no licensed vaccines or treatments for PKD. In the past, malachite green, the antibiotic fumagillin DCH and its synthetic analogue TNP-470 have been used therapeutically with some efficacy, but concerns over toxicity to fish, residue levels and environmental issues have prevented wide adoption of these treatments. Husbandry measures including lowering summer water temperature (using bore-hole water), delaying transfer of naïve stocks to endemic waters until later in the year (to allow acquired immunity but not clinical disease to develop), eliminating secondary pathogens and reducing feeding rates have been implemented in attempting to limit economic losses. Much interest has focused on controlling bryozoan proliferation of inlet waters to farms, but the high level of infectivity of the innumerable spores released from relatively small colonies of bryozoans would mean that such control measures would have to be meticulously successful to confer protection to stock. Further research continues into vaccine and chemotherapeutant development with several possible candidates envisaged.