Minor use permit for erythromycin in finfish
There are no antimicrobials permitted or registered for use in finfish in Australia effective against gram positive bacteria (e.g. Streptococcus and Lactococcus). In finfish aquaculture, erythromycin (ERYC) is the best antimicrobial against gram positive organisms. The aquaculture industry and the Subcommittee for Aquatic Animal Health identified access to this product for finfinfish as a priority. Bacterial diseases are increasingly managed by eradication, maintenance of animals of specified health status, vaccination, and good hygiene, but antimicrobial therapy remains vital for treating bacterial diseases in finfish aquaculture. Appropriate use of antimicrobials can alleviate illness and suffering, improve welfare, increase speed of recovery, reduce spread of infection. Use of ERYC is not intended for prophylactic treatment, but as a tool for veterinarians to manage disease outbreaks. Use in South Australia, for example, is sporadic (~1 to 2 times per 3-5 years for a sector). The Aquaculture industry is committed to Australia's antimicrobial strategy, and as required by APVMA this proposal includes an antimicrobial resistance risk assessment. Available data for ERYC can satisfy the APVMA module requirements for efficacy, chemistry and manufacture, toxicology, trade and occupational health and safety. These are available in published literature, a range of industry studies of animals treated off-label and laboratory studies. There is a lack of data to satisfy the requirements mainly in the environment modules and the antimicrobial resistance risk assessment.
ERYC was ranked low by the Expert Advisory Group on Antimicrobial Assessment (EAGAR) as an antimicrobial for which there are a reasonable number of alternative agents in different classes available to treat most infections. Although it is listed on the WHO list of essential medicines, it is registered for use in cattle, pigs and sheep (APVMA #84160) and poultry (APVMA #50742) in Australia and the WHO list can be modified locally to suit the availability and sophistication of the animal and human health systems in WHO member countries. The APVMA PAA assessed ERYC as suitable for assessment for use in finfish.
Minor use permit for oxytetracycline in non-salmonid finfish
Development of a national sector-specific biosecurity plan guideline and template for the sea-cage finfish (non-salmonid) industry of Australia.
Optimisation of treatment of Cryptocaryon irritans in Barramundi aquaculture
Significant losses of farmed barramundi have occurred in coastal marine aquaculture sites utilising marine water sources due to Cryptocaryon irritans infestations. The disease costs have had substantial impacts on commercial aquaculture operations. Cryptocaryon irritans has a direct life cycle with an adult in the skin or gills of the fish and asexual reproduction in the environment away from the fish. The life cycle of C. irritans is temperature and host dependant and treatment must be timed with critical phases of the life history to maximise efficacy. This project will establish this timing to provide guidelines for optimised treatment.
The existing treatments have substantial costs ($3K+/treatment) and a sub-optimal profile for environmental release with high toxicity and environmental persistence. This project will optimise doses of existing treatments, and identify and assess new treatments. Products identified as effective and safe will have optimised guidelines developed for delivery to ensure the best outcome for farms and the environment. Such improvements will support further expansion of the finfish aquaculture industry in Northern Australia.