Infectious Hypodermal and Hematopoietic Necrosis Virus

Name

IHHN or Infectious Hypodermal and Haematopoietic Necrosis

Clinical signs

In juvenile shrimp, this disease causes runt deformity syndrome (RDS). Their growth and weight are unstable, and their carapace formation is slowed. Infected shrimp will swim to the surface of the water, stay motionless, then roll over and eventually sink to the bottom of the pond. This behavior may be repeated until death occurs. In addition, the abdomen and rostrum of the shrimp are deformed.

Method of diagnosis

Taking shrimp samples to the lab for further check using histopathology test and real-time PCR.

IHHNV effect on shrimp (Source: vinnbio.com)

Name

Infectious Hypodermal Haematopoietic Necrosis Virus (IHHNV) from Parvoviridae family

Pathogen type

Virus

Synonyms

No data

Characteristics

IHHNV is a single-stranded DNA virus with an average diameter of around 22 nm. This virus specifically targets the hypodermis, hemocytes, hematopoietic organs, and connective tissues. IHHNV is classified as a parvovirus C-1, which means it can cause mass death, spread rapidly in an area, and is difficult to treat.

Toxicity

When this virus infects shrimp, cannibalism can occur although the shrimp’s appetite decreases and the risk of mortality increases. This virus has a less significant effect on adult shrimp, but the opposite applies for shrimp in the post-larva and juvenile phases. The mortality rate may increase to 80-90% in two weeks. Besides mortality, this virus may cause shrimp to be tiny in size when harvested because their growth is slowed.

Predispositional factors

Selection of uncertified shrimp fry and a lack of measures to maintain water quality may lead to the emergence of this virus.

Transmission

This virus can spread through cannibalism among shrimps. Furthermore, the virus can transmit by contact with individuals who carry or are infected with the virus, from broodstock to offspring, and through water with infected shrimp in it.

Epidemiology

The disease has been reported in Ecuador, India, Indonesia, Malaysia, the Philippines, Peru, Taiwan, China, and Thailand. The initial identification occurred in 1981 in Hawaii.

Host or vector

IHHNV lineages can infect Penaeus vannamei, Penaeus stylirostris, and Penaeus monodon. There is also a possibility of spreading to other countries through the fry export system.

Infectious dose

No data

Incubation period

The disease emerges 35 days after transmission, and the virus has an incubation period of 5-14 days after contact.

Susceptibility to drugs

Not found

Susceptibility to disinfectants/probiotics

Not found

Physical inactivation

Not found

Early warning

Observing the shrimp fry’s physical form to check if any of its parts are deformed.

Prevention

Selecting Specific Pathogen Free (SPF) shrimp fry, especially the IHHNV-free certified one. Maintaining pond water quality during cultivation is also vital in preventing the virus from spreading.

Treatment

No information

Eradication

Conduct effective and controlled water quality management, such as maintaining the optimal DO range at 5-9 ppm and the temperature range at 28-32°C. Performing weekly water quality monitoring is also advised, for example by measuring TAN, NH₃, total alkalinity, and HCO₃.

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Ganjoor, M. 2015. A Short Review on Infectious Viruses in Cultural Shrimps (Penaeidae Family). Journal of Fisheries Science. 9 (3): 9-33.

Genics Pty Ltd. 2023. Genics Education Series: Infectious Hypodermal and Haematopoietic Necrosis Virus (IHHNV).

Infectious Hypodermal and Haematopoietic Necrosis Virus (IHHNV) of Penaeid Shrimp, Fisheries and Ocean Canada.

Infectious hypodermal and haematopoietic necrosis (IHHN) virus, Aquatic Animal Diseases Significant to Australia: Identification Field Guide 4th Edition Australia Government.

Mulyadi, M., C. R. Handayani, H. P. Kusumaningrum, dan A. Budiharjo. 2013. Prediksi Resistensi Udang Vaname (Litopenaus vannamei) terhadap Infectious Hypodermal and Hematopoietic Necrosis Virus (IHHNV) dari Tambak Intensif dan Semi Intensif Jepara Menggunakan Marka RAPD. BIOMA. Vol. 15, No. 2 : 73-80.

Lightner, D.V. and R.M. Redman. 1998. Strategies for the Control of Viral Disease of Shrimp in the Americas. Fish Pathology. 33 (4): 165-180.

Lotz, J.M. 1997. Special Topic Review: Viruses, Biosecurity and Specific Pathogen-free Stocks in Shrimp Aquaculture. World Journal of Microbiology & Biotechnology. 13: 406-413.

Rodriguez, S.A.S., B. Gomez-Gil, and A. Roque. 2009. Shrimp Disease and Molecular Diagnostic Methods.