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.