FAO issues alert over lethal virus affecting popular tilapia fish
According to the Food and Agriculture Organization of the United Nations (FAO), a highly contagious disease is spreading among farmed and wild tilapia, one of the world’s most important fish for human consumption.
According to the Food and Agriculture Organization of the United Nations (FAO), a highly contagious disease is spreading among farmed and wild tilapia, one of the world’s most important fish for human consumption. Tilapia Lake Virus (TiLV) has now been confirmed in five countries on three continents: Colombia, Ecuador, Egypt, Israel, and Thailand. The FAO warns that countries importing tilapias should take appropriate risk-management measures—intensifying diagnostics testing, enforcing health certificates, deploying quarantine measures, and developing contingency plans.
While the pathogen poses no public health concern, it can decimate infected populations. For example, outbreaks in Thailand triggered the deaths of up to 90% of stocks. In 2015, world tilapia production, from both aquaculture and capture, amounted to 6.4 million tons, with an estimated value of $9.8 billion, and worldwide trade was valued at $1.8 billion. The fish is a mainstay of global food security and nutrition, according to FAO’s Global Information and Early Warnings System (GIEWS).
It is not currently known whether the disease can be transmitted via frozen tilapia products, but “it is likely that TiLV may have a wider distribution than is known today and its threat to tilapia farming at the global level is significant,” GIEWS said in its alert. More research is required to determine whether TiLV is carried by non-tilapine species and other organisms such as piscivorous birds and mammals.
Currently, actively TiLV surveillance is being conducted in China, India, Indonesia, and it is planned to start in the Philippines. In Israel, an epidemiological retrospective survey is expected to determine factors influencing low survival rates and overall mortalities including relative importance of TiLV. In addition, a private company is currently working on the development of live attenuated vaccine for TiLV.