Tilapia Lake Virus disease (TiLVD)

- Prevention and control

o   Tilapia lake virus free tilapia

To limit the spread of TiLVD, it is crucial to use SPF tilapia that are devoid of TiLV to avoid the introduction of infected tilapia (Machimbirike et al., 2019).

o   Tilapia lake virus resistant tilapia

Selective breeding techniques to develop tilapia species with resistance to the disease can prove highly successful in disease control (Barría  et al., 2020).

o     Vaccination

No commercial vaccine is currently available. Tilapia produce anti-TiLV antibodies within 7–10 days of virus inoculation (Tattiyapong et al., 2020). Many TiLV immunizations have shown efficacy, however survival rates vary. The TiLV vaccine, produced using β-propiolactone (BPL) inactivation and Montanide IMS 1312 adjuvant, is an example (Zeng et al., 2021). This vaccination has 85.7% survival rate in lab challenge testing. Two alternative vaccines, injectable heat-killed and formalin-killed, are effective against Nile tilapia TiLV infection. Mai et al. (2021) found that the heat-killed vaccination had a relative survival rate of 71.3% and the formalin-killed vaccine 79.6%.

o   Immunstimulants and probiotics

 Immunostimulants can be used as an alternative to vaccines. They have broad-spectrum activity and are relatively cost-effective than vaccines. They are more suitable for younger fish as adaptive immunity is not fully developed. Probiotic bacteria can enhance fish immunity by promoting phagocytic activity, complement responses, lysozyme levels, and cytokine production. Probiotics must demonstrate efficacy and safety.

Zoonotic importance

No zoonotic importance was documented.