THE EXPERIENCES OF USING TILAPIA STREPTOCOCCUS VACCINES AS A BENEFICIAL TOOL FOR DISEASE CONTROL AND PREVENTIVE MEASURE IN THAILAND.

Prakan Chiarahkhongman* and Parinda Kamchum
 Aquaculture Promotion Company (APCO)
 Charoen Pokphand Foods public company limited (CPF), Bangkok Thailand.
 prakan@cpf.co.th

Streptococcosis in Tilapia has been found to be the most devastating disease as it may causes massive economic losses in Tilapia culture in Thailand. This is especially the case when it is the cause of mortality of large, nearly marketable fish. Streptococcosis can be either the  primary or secondary  infection followed various of parasitic infestation, flavobacterium spp., aeromonas spp. or even sometime can be found as poly infection. Streptococcus vaccines have been registered by Thai FDA and introduced for use in tilapia since 2014 with the purpose of preventing the spread of Streptococcus, as well as reducing mortality and economic losses.

In Thailand, after implementing a Streptococcus vaccination program, vaccinated tilapia fingerlings can be observed to have a superior FCR, ADG and survival rate compared with non-vaccinated fish (Figure. 1). In vaccinates, daily observation of mortality, especially the mortality from Streptococcosis during the larger life stages, has been found to be reduced (Figure. 2)

From our observations, the most satisfactory tilapia fingerlings come from trusted nurseries with good standard operating procedures (SOP), a nursery management program, good sanitation practices and a complete biosecurity system. Furthermore, the successful vaccination of fish depend on many factors, such as: management, fluctuation and seasonal factors, the size of the stocking fingerling, the acclimatization of fingerlings before stocking, health management and preventive measure, the parasitic control practices , the pollutant and water parameter factor of each culture area, etc. Multivalent vaccines that offer broad coverage against bacterial diseases are considered to have been developed to maximize the success rate of the customer. The trend of vaccinating fish in Thailand (especially in tilapia) is of  interest, with the aim to control the massive losses of fish caused by  Streptococcosis outbreak, and to reduce the usage of chemicals and antibiotics in aquaculture.