Tilapia Lake Virus (TiLV), a contagious disease plaguing fish farms, has now been confirmed in five countries on three continents: Colombia, Ecuador, Egypt, Israel and Thailand. However, the FAO said it is likely TiLV may have a wider distribution than is known.

FAO's Global Information and Early Warnings System released a special alert Friday warning the disease "threatens the livelihoods and food security of millions of people dependent on tilapia farming.

"While there is no public health concern for this pathogen, there is a significant risk of TiLV being translocated both inter- and intra-continentally through the movement of infected live tilapias in the absence of appropriate biosecurity measures.

"Tilapia producing countries need to be vigilant and take appropriate risk management measures ... to reduce the further spread and potential socio-economic impacts of this emerging disease."

There are many knowledge gaps linked to TiLV.

More research is required to determine whether TiLV is carried by non-tilapine species and other organisms such as piscivorous birds and mammals, and whether it can be transmitted through frozen tilapia products. It is not currently known whether the disease can be transmitted via frozen tilapia products.

The disease shows highly variable mortality, with outbreaks in Thailand triggering the deaths of up to 90 percent of stocks.

China, India and Indonesia are actively monitoring for it while the Philippines plans to start soon. Israel currently has an epidemiological retrospective survey, which is expected to determine factors influencing low survival rates and overall mortalities including relative importance of TiLV.

Also, a private company is currently working on the development of live attenuated vaccine for TiLV.

Just this month, the Network of Aquaculture Centres in Asia-Pacific (NACA) released a TiLV Disease Advisory; the World Organisation for Animal Health (OIE) released a Disease Card; and the WorldFish Center released a Factsheet: TiLV: what to know and do.

In 2015, world tilapia production, from both aquaculture and capture, amounted to 6.4 million metric tons, with an estimated value of $9.8 billion (€8.8 billion), and worldwide trade was valued at $1.8 billion (€1.6 billion).

China, Indonesia and Egypt are the three leading aquaculture producers of tilapia, a fish deemed to have great potential for expansion in sub-Saharan Africa.

---

For more seafood news and updates, follow us on Facebook and Twitter or sign up for our daily newsletter.