Impact of farm management on expression of early mortality syndrome/acute hepatopancreatic necrosis disease (EMS/AHPND) on penaeid shrimp farms in Thailand.
Asian shrimp farming industry has experienced massive production losses due to a disease caused by toxins of Vibrio bacteria, known as early mortality syndrome/acute hepatopancreatic necrosis disease (EMS/AHPND) for the last 5 years. The disease can cause up to 100% cumulative pond mortality within a week. The objective of this study was to identify factors associated with AHPND occurrence on shrimp farms. A case-control study was carried out on shrimp farms in four provinces of Thailand. Factors related to farm characteristics, farm management, pond and water preparation, feed management, post-larvae (PL) shrimp and stock management were evaluated. Multivariable logistic regression analysis identified factors affecting AHPND occurrence at the pond level. Chlorine treatment, reservoir availability, use of predator fish in the water preparation, culture of multiple shrimp species in one farm and increased PL stocking density contributed to an increased risk of AHPND infection, while delayed first day of feeding, polyculture and water ageing were likely to promote outbreak protection. Additionally, the source of PL was found to be associated with AHPND occurrence in shrimp ponds, which requires further study at the hatchery level. Identification of these factors will facilitate the development of effective control strategies for AHPND on shrimp farms.
Faculty of Veterinary Medicine, Kasetsart University, Kamphangsaen, Nakhon Pathom, Thailand.|Department of Health Management, Atlantic Veterinary College, Centre for Veterinary and Epidemiological Research, University of Prince Edward Island, Charlottetown, PE, Canada.
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V
Boonyawiwat
Department of Health Management, Atlantic Veterinary College, Centre for Veterinary and Epidemiological Research, University of Prince Edward Island, Charlottetown, PE, Canada.
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http://orcid.org/0000-0003-4798-066X
T
Patanasatienkul
Expert Bureau Division, Department of Fisheries, Chatuchak, Bangkok, Thailand.
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J
Kasornchandra
Faculty of Veterinary Medicine, Kasetsart University, Kamphangsaen, Nakhon Pathom, Thailand.
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http://orcid.org/0000-0003-2968-9182
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Poolkhet
Rayong Coastal Aquaculture Research and Development Center, Department of Fisheries, Mueang, Rayong, Thailand.
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S
Yaemkasem
Department of Health Management, Atlantic Veterinary College, Centre for Veterinary and Epidemiological Research, University of Prince Edward Island, Charlottetown, PE, Canada.
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L
Hammell
Department of Health Management, Atlantic Veterinary College, Centre for Veterinary and Epidemiological Research, University of Prince Edward Island, Charlottetown, PE, Canada.
J
J
Davidson
D000818:Animals; D017756:Aquaculture / Q000379:methods*; D008136:Longevity; D033561:Penaeidae / Q000254:growth & development / Q000382:microbiology* / Q000502:physiology*; D013785:Thailand; D014733:Vibrio / Q000502:physiology*; D060753:Water Quality

Penaeus vannamei
; 
Vibrio parahaemolyticus
; acute hepatopancreatic necrosis disease; early mortality syndrome; farm management