major type of diseases affecting shrimps

shrimp diseases

1. Major Types of Diseases Affecting Penaeid Shrimp

2. Disease Any adverse alteration in the health or culture performance of individuals or populations of shrimp. Types of Disease: Infectious - caused by transmittable pathogens: viruses, fungi, rickettsia, protozoa, bacteria, metazoan parasites Non infectious diseases - non-transmittable agents: nutritional environmental/physical toxic, neoplastic, genetic

3. Proportional Losses attributed to different pathogen types

4. The occurrence of disease is a combination of the health of the animal, the condition of the environment, and the presence of a pathogen. Klesius (2003) Manifestation of the Disease HOST (Shrimp) ENVIRONMENT PATHOGEN (WSSV)

5. Vertical Horizontal Disease Transmission Vectors Reservoirs Portals of Entry - gill, abrasions, ingestion, active penetration

6. ENVIRONMENT Stress

7. OIE: Paris, france The World Organization for Animal Health (formerly the Office International des Epizooties (OIE)) is the world organisation for animal health recognized by the SPS Agreement. The World Organisation for Animal Health (OIE) is an intergovernmental organization coordinating, supporting and promoting animal disease control. The main objective of the OIE is to control epizootic diseases and thus to prevent their spread. It is recognized as a reference organisation by the World Trade Organization (WTO) and has a total of 182 member states. The OIE maintains permanent relations with 45 other international and regional organisations and has Regional and sub-regional Offices on every continent.

8. 1. WSD (White spot disease) 2. IHHN (Infectious Hypodermal & Haematopoietic Necrosis) 3. YHD (Yellow head disease) 4. IMN(Infectious Myonecrosis ) 5. TS ( Taura syndrome) 6. NHP (Necrotising hepatopancreatitis ) 7. AHPND /EMS (Acute Hepatopancreatic Necrosis Disease) 8. D E C A P O D I R I D E S C E N T V I R U S 1 ( D I V 1) OIE Listed Shrimp Diseases

9. Non oie listed but economically important diseases Enterocytozoon hepatopenaei (EHP) Monodon baculovirus Hepato pancreatic Parvovirus (HPV)

10. White Spot Disease

11. White Spot Disease White Spot disease is deadly disease of shrimp which leads to 100% mortality within 3 to 10 days of onset of disease. Causative agent : White Spot Syndrome Virus (WSSV) Transmission mechanism : transmitted vertically (trans ovum) - shrimp broodstock to seed, horizontally – consumption of infected shrimp, water-borne routes, dead shrimps Transmission of infection can occur from apparently healthy animals in the absence of disease. Dead and moribund (weak) animals can be a source of disease transmission.

12. Photo courtesy Dr.Lightner

13. Infectious hypodermal and haematopoietic necrosis virus (IHHNV)

14. History Discovered 1981 in Hawaii in juvenile L. stylirostris . 1991 - IHHNV shown to cause RDS in L. vannamei Integrated form of IHHNV found in 2006 in P. monodon from Indian Ocean. IHHNV is endemic in P. monodon upon which it has little measurable effect as shown by statistical analysis of large samples IHHNV infections are most severe in the Pacific blue shrimp, P. stylirostris , where the virus can cause acute epizootics and mass mortality (> 90%). IHHNV is the smallest of the known penaeid shrimp viruses. The IHHN virion is a 20–22 nm

15. Shrimp with IHHNV

16. Enterocytozoon hepatopenaei (EHP) New name: Ecytonucleospora hepatopenaei

17. Enterocytozoon hepatopenaei are obligate intracellular parasites known to infect shrimps. The spores are very small (1.1 ± 0.2 by 0.6-0.7 ± 0.1 μm ) and show the presence of a polar filament of 4-5 coils Development of the parasite generally occurs within the cytoplasm of the host-cell via nuclear proliferation, and spore formation (sporogony). EHP affects both P. monodon and P. vannamei and is suspected to also infect P. japonicus Introduction

18. How To Make a Diagnosis The best diagnosis comes from one or more tests &/or sources of information (i.e. gross signs, behaviour, history). Collaborative or confirmatory tests should always be used for a significant or unexpected diagnosis.

19. Steps to Disease Diagnosis Obtain & examine samples Gross signs, Unusual behaviour, Mortality rate Obtain history of stock, farm, region Get a sample & preserve it for the intended test: :- for wet-mounts, smears, etc. :- Davidson’s AFA (10% NBF, etc.) for histology, in situ DNA probes, immunohistochemistry w/ MAbs . :- live, iced , or frozen for DNA probes, PCR, antibody-based tests, toxicant analysis, microbiology, etc. :- ethanol for DNA probes or PCR :- transport buffers, media, etc. for microbiology, PCR Process samples and interpret results Make the diagnosis based on all available data.

20. ACKNOWLEDGEMENTS SINCERE GRATITUDE AND THANKS TO Chairman MPEDA Project Director, RGCA CAPL staff’s RGCA officials

21. Thank you