Disease library

A collection of technical publications relating to aquatic animal disease prevention, diagnosis and treatment.

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NACA publishes a wide range of aquaculture publications including technical manuals, workshop proceedings, better practice guidelines and several serials including Aquaculture Asia Magazine, the NACA Newsletter and the Quarterly Aquatic Animal Disease Report. To keep up to date with developments you could consider subscribing to our RSS feed

In this collection

Fact sheet: Tilapia lake virus (TiLV): What to know and do?

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.

Urgent update on possible worldwide spread of tilapia lake virus (TiLV)

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.

Tilapia lake virus (TiLV) - a novel Orthomyxo-like virus

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.

Disease advisory: Tilapia lake virus - an emerging threat to farmed tilapia in the Asia-Pacific region

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.

A warning and an improved PCR detection method for tilapia lake virus (TiLV) disease in Thai tilapia farms

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.

A new and improved PCR detection method for Enterocytozoon hepatopenaei (EHP) based on a gene encoding a spore wall protein

Hepatopancreatic microsporidiosis (HPM) caused by Enterocytozoon hepatopenaei (EHP) is a newly emerging disease of cultivated shrimp in Asia. Current evidence indicates that it can be associated with severe growth retardation that may not be clearly evident until the second month of culture and may cause low continuous mortality in the case of very severe infections. We present a new method for detecting EHP that has superior specificity to the first generation SSU-PCR developed in 2009.

Hepatopancreatic microsporidiosis caused by Enterocytozoon hepatopenaei: Disease card

This disease card describes the diagnosis and range of a microsporidian shrimp pathogen, Enterocytozoon hepatopenaei (EHP), first discovered in Penaeus monodon in Thailand in 2004. It infects only the tubule epithelial cells of the hepatopancreatic tissue of shrimp. EHP was later found to also infect P. vannamei cultivated in Thailand and is suspected to have been reported from P. japonicus in Australia in 2001. EHP has been reported from Vietnam and is associated with white faeces syndrome.

A two-tube, nested PCR detection method for AHPND bacteria

A new method for the detection of AHPND-bacteria (AP4) has been published and is available for download. The advantage of the AP4 method over the previously published AP3 method is that it has 100 times higher sensitivity. Because of its higher sensitivity, the bacterial culture enrichment step needed when using the AP3 with low levels of AHPND bacteria may be omitted. However, the AP4 method should not be considered as a replacement for AP3.

Acute Hepatopancreatic Necrosis Disease Card (updated June 2014)

Acute hepatopancreatic necrosis disease (AHPND) has recently been found to be caused by a pathogenic strain of Vibrio parahaemolyticus. This updated disease card provides a summary and guidance on disease signs at the pond level, at the animal level by histopathology, molecular diagnostic tools, host range, presence in Asia-Pacific, prevention and control and links to further information.

Acute Hepatopancreatic Necrosis Syndrome (AHPNS): Status Update

Since the Asia Pacific Emergency Regional Consultation on EMS/AHPNS held in August 2012 in Bangkok, Thailand, many news reports have been widely circulated that have led to various baseless speculations and conclusions on the true nature of AHPNS. This disease update/advisory has been issued to address the many circulating false and baseless speculations on the effects and spread of AHPNS in the region.