Streptococcosis is a neurological bacterial disease that affects warm water fish in either salt or freshwater environments, typically in tropical regions. High stocking densities, poor water conditions, and high temperatures are the most favorable conditions for streptococcal outbreaks. Tilapia Streptococcosis infects fish from as young as 5 grams, and is present throughout the entire tilapia growth cycle. The predominant streptococcal diseases in tilapia are Streptococcus agalactiae and Streptococcus iniae. Streptococcus agalactiae is further classified by MSD into two biotypes (Biotype 1 & Biotype 2), based on their unique disease characteristics. Each S. agalactiae biotype infection is caused by serotype-specific strains.
External clinical signs for this deadly disease include: marked hemorrhages, cornea opacity, spinning near the water surface, erosion of the caudal fin, and exophthalmos (eye protrusion). Fish may also show a ‘C’ or ‘S’-shaped body posturing, lethargic behavior, and bloody abscesses around the mouth.
The internal signs can include: enlarged spleen, abdominal distention, pale liver, organ adhesion & inflammation.
Overfeeding, stress, and an open cage culture can increase the chances of more fish getting infected.
MSD Animal Health recommends disinfecting equipment, removing infected fish from healthy ones, and vaccinating fish at the right time to better protect your tilapia from streptococcosis.
There are currently no obvious geographical, physiological or environmental explanations for the country-to-country distribution of Streptococcus agalactiae, Biotype 1, and Streptococcus agalactiae, Biotype 2. However, it is likely that the distribution will change in time possibly through trade in live fish. MSD Animal Health continues to monitor the situation, collecting and analyzing strains from new disease outbreaks.
Vaccination can lead to healthier fish, enhancing the productivity of your farm. AQUAVAC® Strep Sa1 offers active immunity to reduce mortality against Streptococcosis caused by S. agalactiae Biotype 1 (serotype Ia and III) outbreaks. It is critically important to identify which serotype is present in your farm. The diseases and vaccines available are species and serotype specific. Contact your local vet or MSD Animal Health for disease sampling. To find out more information on AQUAVAC® Strep Sa1 for Streptococcus agalactiae Biotype 1, click below.
Vaccination can lead to healthier fish, enhancing the productivity of your farm. AQUAVAC® Strep Sa offers active immunity to reduce mortality against Streptococcosis caused by S. agalactiae outbreaks. It is critically important to identify which serotype is present in your farm. The diseases and vaccines available are species and serotype specific. To find out more information on AQUAVAC® Strep Sa for Streptococcus agalcatiae Biotype 2, click below.
Vaccination can lead to healthier fish, enhancing the productivity of your farm. AQUAVAC® Strep Si offers active immunity against S. iniae outbreaks. It is critically important to identify which serotype is present in your farm. The diseases and vaccines available are species and serotype specific. To find out more information on AQUAVAC® Strep Si for Streptococcus iniae, click below.
If you’d like to find out more about how AQUAVAC® can help improve the health of your stock and maximize the productivity of your farm, get in touch with MSD Animal Health today.
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