Description:

ORIGINAL SUMMARY

This new disease has been known as early mortality syndrome and is now commonly referred to as acute hepatopancreatic degenerative necrotic syndrome (AHDNS). Mass mortailty of shrimp from AHDNA has been reported in China (2009), Vietnam (2010) and Malaysia (2011). In June 2011, provinces of the Mekong Delta suffered unprecedented losses with tiger shrimp in 40,000 hectares of farm area affected. Over 11,000 hectares of shrimp farms in Bac Lieu have been destroyed. In 6,200 hectares of shrimp farms in In Tra Vinh, about 330 million shrimp have died causing a loss of over VND12 billion. In Soc Trang, 20,000 out of 25,000 hectares of shrimp farms have been destroyed, causing VND1.5 trillion (US$75 million) in losses. Initial evidence led investigators to beleive the disease was caused from microsporidiosis of the hepatopancreas. Relavent reference in the scientific literature may be; Kasetsart J. (2009). The Effects of Microsporidian (Thelohania) Infection on the Growth and Histopathological Changes in Pond-reared Pacific White Shrimp (Litopenaeus vannamei). Nat. Sci. 43: 680 – 688. These views maybe changing with the disease now possibly related to liver necrosis. In Mekong Delta of Vietnam, AHDNA has been associated with the use of pesticides.

UPDATE JULY 2013

Since the original summary report EMS has continued to cause significant losses in South East Asia. Articles appearing on the internet have been captured by AquaticHealth.net and most of the breaking stories are listed below. There are many more articles than those listed and these are available through our search the archive function. They can be retrieved by setting your preferred date range and entering EMS into the general search term and tags box.

The aetiology has been determined by Prof. Don Lightner, April/May 2013:

Lightner’s team found that EMS is caused by a unique strain of a relatively common bacterium, Vibrio parahaemolyticus, that is infected by a virus known as a phage, which causes it to release a potent toxin. The bacterium is transmitted orally, colonizes the shrimp gastrointestinal tract and then produces a toxin that causes tissue destruction and dysfunction of the hepatopancreas, the shrimp’s digestive organ.

Some countries have implemented policies that restrict the importation of frozen shrimp or other products from EMS-affected countries. Lightner said frozen shrimp likely pose a low risk for contamination of wild shrimp or the environment because EMS-infected shrimp are typically very small and do not enter international commerce. Also, his repeated attempts to transmit the disease using frozen tissue were unsuccessful.(reference nid:77100 see links below).

Forecast for EMS 12-06-2014 (working not shown)

EMS will be found in Indonesia in 2014 in the dry growing season July/Sept. YES/NO. Likelyhood estimate?

EMS will be found in India 2014 in the rainy growing season June/Sept. YES/NO. Likelyhood estimate?

EMS will be found in the Philippines by the end of 2014. YES/NO. Likelyhood estimate?

Forecast questions:

Is it only a matter of time before EMS becomes a major problem in Indonesia, Philippines or India?

SHRIMP NEWS INTERNATIONAL REPORT (See links) FEB 26 2012

“There are also unconfirmed reports of EMS in southern Thailand near the border with Malaysia and on the island of Sumatra in Indonesia, around Medan, which is across the Strait of Malacca from Malaysia.”

EARLY MORTALITY SYNDROME in SHRIMP [2010 and ongoing]

Forecast for EMS 12-06-2014 (working not shown)