Dr Lightner-EXPOSICION EMS en Ecuador

8/11/2019 Dr Lightner-EXPOSICION EMS en Ecuador

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Documentation of an

Emerging Disease(Early Mortality Syndrome)

in SE Asia

D.V. Lightner, R.M. Redman, C.R. Pantoja,B.L. Noble, L.M. Nunan and Loc Tran

OIE Reference Laboratory for Shrimp Diseases

Department of Veterinary Science & MicrobiologyThe University of Arizona, Tucson, AZ, USA

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3

2009

2010

2011 2011

2012

Spread of EMS/AHPNS in Eastand SE Asia


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Early Mortality Syndrome (EMS)

EMS has two distinct phases:An acute phase

Acute Hepatopancreatic Necrosis Syndrome or AHPNS.

HP tubule cells (R, B, F & later E-cells) show acute lossof function.

Significant acute sloughing of HP tubule epithelial cells. Bacteria (of any kind) are not easily demonstrated by in

situhybridization with a 16S RNA universal probe.

Terminal phase ends with destruction of theHP by opportunistic Vibrio spp. 4


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Gross Signs of EMS/AHPNS

Significant atrophy of the hepatopancreas(HP).

Often pale, yellowish or white within theHP connective tissue capsule.

Black spots or streaks sometimes visible. HP does not squash easily between thumb

& finger.


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Juvenile Penaeus vannamei from Vietnam.Left with EMS; right appears normal.


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Juvenile Penaeus vannamei from Vietnam.Both with atrophied HPs indicative of EMS.


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Juvenile Penaeus monodon from Vietnam with EMS.The HP is pale & atrophied; the midgut is empty

except for sloughed HP cells.


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Juvenile Penaeus monodonfrom Vietnam.Left shrimp appears normal (except for black gills),

while right 2 show dark, atrophied HPs typical of EMS.


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Histopathology showingacute phase HP dysfunction

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Samples from South China

August/September 2010 &Vietnam July 2011 & 2012 &

December 2011 & 2012


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Normal hepatopancreas HP with early AHPNS;China 2010, P. vannamei


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Al-Mohana & Nott. 1989. Funct ional cytology of the hepatopancreas of Penaeus semisulcatus (Crustacea: Decapoda)

dur ing the moult ing cycle. Marine Biology (101) 535-544.12


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Case 11-214. P. monodon. Vietnam; Note proximal to distal progression of lesions. 20x

Case 11-254 P vannamei Vietnam; HP tubule epithelium sloughing significant


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Case 11-254. P. vannamei. Vietnam; HP tubule epithelium sloughing, significantproximal hemocytic inflammation & some tubules with putative vibriosis; 10x


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South China 2010: 10-361B/4; P. vannamei; 40x 18


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HP showing terminalphase of HP destruction

due to Vibriosis

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Samples from South China

August/September 2010 &Vietnam July 2011 & 2012 &

December 2011 & 2012


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Case 11-214. P. monodon. As the disease progresses, there is a secondary bacterialinfection of the HP (probably by opportunistic Vibriospp.)

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Case 11-254. P. vannamei. Vietnam; Terminal phase of EMS. Most HP tubules are destroyed.


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; p yMassive bacterial infection by a probable Vibriospp. 4x.

Case 11-254. P. vannamei. Vietnam; Terminal phase of EMS. Most HP tubules are


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; pdestroyed. Massive bacterial infection by a probable Vibriospp. 20x.


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South China 2010: 10-361B/2; P. vannamei#25, 10x24


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Case 11-214. P. monodon. Vietnam; Terminal phase of EMS. Most HP tubules aredestroyed. Massive bacterial infection by a probable Vibriospp.

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Case 11-214. P. monodon. Vietnam; Terminal phase of EMS. Most HP tubules are


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destroyed. Massive bacterial infection by a probable Vibriospp.

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Proposed Case Definition

for EMS/ AHPNS

Idiopathic no specific disease causing agent(infectious or toxic) has been identified.

Pathology:

acute progressive degeneration of hepatopancreas (HP)from medial to distal with dysfunction of all HP cells,prominent necrosis & sloughing of these tubule epithelial

cells. terminal stage shows marked inter- & intra-tubular

hemocytic inflammation & development of massive

secondary bacterial infections that occur in association withnecrotic & sloughed HP tubule cells.

P ibl Eti l i l A t


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Possible Etiological Agents

What We Know to Date:

Severe HP dysfunction followed by a terminal Vibrioinfection of the HP.

Vibriospp. may not be the agent(s) of AHPNS as the

terminal, bacterial phase of EMS appears to beopportunistic.

Feeds (e.g. a new ingredient) tested do not cause

AHPNS. Cypermethrin in aqueous static renewal bioassays or

when added to soil does not cause AHPNS in lab trials.

Tests for an infectious agent (viral, bacterial,parasitic agents) have been negative to date.


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Future planned studies

Comparative proteomics Search for a unique toxin.

Up and down regulation of proteins in EMS

affected and non-affected shrimp

Metagenomics

Compare bacterial populations from EMSaffected and non affected shrimp

Transmission studies with unique species ofbacteria isolated from shrimp with EMS.

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Acknowledgements

OIE (World Organization for Animal Health) fortravel to Vietnam & Thailand.

Department of Animal Health, MARD, Vietnam forlocal arrangements in Vietnam.

Uni-President feed Co. & Minh Phu Seafood Corp. in

Vietnam for funding toxicity & infectivity studies. CP Foods, Thailand for funding recent work on EMS.

World Bank & Global Aquaculture Alliance for travel.

FAO for funding research on EMS.31


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Thank youfor your attention!

Reference Lab for Shrimp Diseases

Documents

Dr Lightner-EXPOSICION EMS en Ecuador