Tilapia lake virus is a newly emerging virus that is associated with significant mortalities in farmed tilapia. This fact sheet describes the threat to industry, clinical signs, diagnosis, risk factors, prevention and control options and actions that must be taken to minimise the impact of this disease on the global tilapia aquaculture industry. All countries with a tilapia industry must be vigilant and act quickly to investigate cases of mortalities in farms.

Recently, we released a warning of TiLV in Thailand and an improved RT-PCR detection methodology. The Fish Health Platform in Centex, BIOTEC/Mahidol University has also obtained positive test results for TiLV in other Asian countries where it has not yet been reported. Many countries have been translocating tilapia fry/fingerlings prior to and even after the description of TiLV. We have prepared a map listing countries with confirmed reports of TiLV infections and 43 other countries that we believe have imported infected fish.

This disease card published by the World Organisation for Animal Health (OIE) provides information about tilapia lake virus (TiLV), a recently observed pathogen causing significant mortalities in cultured tilapia. The disease card provides details of the pathogen, modes of transmission, host range, geographical distribution, clinical signs, diagnostic methods, socio-economic significance, transmission risk and a list of available references. We urge laboratories to test for TiLV when abnormal tilapia mortalities occur.

Tilapia lake virus (TiLV) is an emerging disease of cultured tilapia in the Asia-Pacific region. Originally observed and reported in Israel, Ecuador, Colombia and Egypt, TiLV is now confirmed in cultured tilapia in Thailand causing mass mortalities. At risk is here is the US$7.5 billion global industry per annum, especially among the top tilapia-producing countries in the region including China, the Philippines, Thailand, Indonesia, Lao PDR and Bangladesh. This advisory describes signs of the disease and PCR detection methods.

Tilapia lake virus (TiLV) is an emerging virus that causes syncytial hepatitis of tilapia with mortalities of up to 90%. Recent disease outbreaks in Thai tilapia farms have been associated with high cumulative mortalities and histopathological features typical of SHT. Infection has now been confirmed. The semi-nested RT-PCR protocol described here may be used freely for non-commercial applications to detect TiLV. The authors urge laboratories in Asia to test for TiLV when abnormal tilapia mortality occurs.