Aquaculture for all

Review Of Catfish Aeromonas Disease

Health Catfish / Pangasius

A new catfish disease, caused bya previously unseen strain of the Aeromonas hydrophilabacteria, appeared in Alabama in the summer of 2009. Andy Goodwin, Professor/ Associate Director of Fish Health at the University of Arkansas Pine Bluff, gives an update on the new disease.

During the summer of 2009, the disease spread from pond-to-pond and farm-to-farm and final losses for the season were over 3,000,000 pounds.

The disease reappeared in the summer of 2010 producing major losses across that production region. The disease has also been seen on two farms in Southwestern Arkansas.

The UAPB Extension team have been working with the farms, harvesters, haulers and processors to insure that the disease does not spread to our major catfish production areas in Southeastern Arkansas.

A group of scientists from across the Southeast are working together to learn more about this new disease, its treatment and its prevention. What has been learnt is that the new strain of Aeromonas is indeed new and different from those that we have had in the past.

This new strain is able to cause disease in healthy fish during the summer when temperatures are high. Farmers should consider it a dangerous new disease and make every effort to make sure not to bring in onto their farms. The main routes of infection would be harvest equipment and infected fish. It is important that everybody is careful because your best protection is to make sure that your neighbor s farm does not get infected.

If you do bring the bacteria onto your farm, it will be hard to eradicate. It is very likely that all types and strains of Aeromonas bacteria are able to live free in the environment, and they are part of the bacteria community seen on the skin and in the gut of healthy fish.

This means that the new bacteria would probably persist for a very long time on a farm once it is introduced. Whenever conditions are right in the pond, the disease would be likely to pop up again and kill fish.

In the short term, some of the most important scientific work underway is to develop a method to detect this new strain of Aeromonas in healthy-looking fish and in pond water and sediments.
Once this tool is in hand, hopefully by this summer, the team will be able to do a much better job of answering the critical where is it now and how is it moving? questions.

In the meantime, the best guess is that the bacteria are still present during the winter months and farms need to continue to be extremely careful about biosecurity. If you bring it onto your farm it will be very difficult to get rid of it. It can be treated by antibiotics, but the medicated feeds are very expensive and would have a very big impact on your farms profitability. If you have any questions about how to protect your farm from Aeromonas, please contact the UAPB Fish Disease Laboratories.

August 2011