During the two day expert consultation, representatives from Vietnam, China, Malaysia and Thailand shared their experience on EMS. In Vietnam, the disease was observed since 2010, but the most widespread devastation due to EMS was reported since March 2011 in the Mekong Delta (South Vietnam). EMS affected the main shrimp production areas of Tien Gang, Ben Tre, Kien Giang, Soc Trang, Bac Lieu and Ca Mau provinces with a total shrimp pond area of around 98,000 hectares. In June 2011, unprecedented losses in P. monodon were reported in 11,000 ha of shrimp farms in Bac Lieu, 6,200 ha in Tra Vinh (causing a loss of over VND12 billion), and 20,000 ha in Soc Trang (causing VND1.5 trillion in losses) (Mooney, 2012). With Vietnam suffering the greatest loss due to EMS outbreak, the Food and Agriculture Organization of the United Nations (FAO) undertook an emergency mission in 2011 to assess the disease situation in the country, in collaboration with national and international shrimp health experts. As a follow-up on this emergency mission, FAO developed a national Technical Cooperation Programme (TCP) on emergency assistance to control the spread of this shrimp disease. Implementation of the national TCP in Vietnam commenced in April 2012.
In China, the occurrence of EMS in 2009 was initially ignored by most farmers. But in 2011, outbreaks became more serious especially in farms with culture history of more than five years and those closer to the sea using high saline water (Panakorn, 2012). Shrimp farming in Hainan, Guangdong, Fujian and Guangxi suffered during the first half of 2011 with almost 80% losses.
In Malaysia, EMS was first reported in mid-2010 in the east coast of peninsular states of Pahang and Johor. The outbreaks of EMS resulted in significant drop in P. vannamei production, from 70,000 mt in 2010 to 40,000 mt in 2011. Production for 2012 (up to May) was only 30,000 mt and worse was expected to come as unconfirmed reports on EMS outbreaks in the states of Sabah and Sarawak came in April 2012. In Thailand, so far 0.7% total shrimp ponds were reported to be affected by EMS, in Rayong, Chantaburi, Trat, Chacheongsao provinces located along the eastern Gulf.