MBV disease in shrimp – Causes and effective prevention methods

In brackish-water or saltwater shrimp farming, one of the major challenges for farmers is shrimp that do not grow well and become stunted. This is a common sign of MBV disease in shrimp, caused by a virus and for which there is currently no specific treatment. Therefore, recognizing early signs and implementing preventive measures from the outset is extremely important. In this article, Vemedim will work with farmers to clearly analyze the causes, symptoms, and guidance on how to prevent MBV disease for a bountiful harvest.

Causes of MBV disease in shrimp

MBV disease in shrimp, also known as stunted shrimp disease, is the cause of slow growth, poor feeding, and serious impacts on productivity. The main cause is the MBV (Monodon Baculovirus) virus, and there is currently no specific treatment.

MBV is a double-stranded DNA virus (dsDNA), enclosed in a rod-shaped protein coat. This virus usually parasitizes the epithelial cells of the midgut and the hepatopancreatic cells of shrimp. When infected, the virus replicates through several stages:

Latent stage (O): Infected cells begin to change, but symptoms have not yet appeared.
Stage 1: The cell nucleus swells slightly, chromosomes disintegrate and move close to the nuclear membrane; fat droplets appear in the cytoplasm.
Stage 2: The number of viruses increases rapidly, forming inclusion bodies in the cell nucleus.
Stage 3: The cell nucleus swells to twice its size, volume increases sixfold, the virus destroys the cell and spreads to neighboring cells or remains free in the mud and water.

*MBV disease in shrimp is caused by the MBV (Monodon Baculovirus) virus, making shrimp stunted and slow-growing*

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Symptoms of MBV disease in shrimp

MBV disease is not transmitted vertically but mainly horizontally. When shrimp are lightly infected with the virus, external signs are often not obvious. When the disease becomes severe, prominent symptoms include:

Reduced feeding, larvae and postlarvae grow slowly; a white line along the midgut may be observed in larvae.
Shrimp are less active, with a pale green or dark green body.
The chitin shell and appendages show signs of necrosis; algae, filamentous bacteria, and parasites attach to the shrimp’s body.
The hepatopancreas shrinks, turns whitish-yellow, has a fishy smell, and decomposes quickly.
Mortality can reach 70–100% within 3–7 days when the disease is severe.

In addition to observing signs, MBV disease can be diagnosed using the following methods:

Direct microscopic observation: Examine the midgut, hepatopancreas, and shrimp feces to detect single or clustered spherical viral inclusion bodies.
Malachite Green staining: MBV inclusion bodies stain clearly green after 5 minutes.
Hematoxylin–Eosin staining: Inclusion bodies are dark red, the cell nucleus is blue-violet, and the cytoplasm is pink to red.
PCR test: A modern method that accurately identifies MBV in shrimp seed before stocking, ensuring maximum safety.

*MBV disease in shrimp causes shrimp to be less active, with a pale green or dark green body*

Effective prevention solutions for MBV disease in shrimp

There is currently no specific treatment for MBV, so prevention from the start is the number one priority. Below are some practical suggestions to help farmers proactively prevent MBV disease in their shrimp ponds:

1. Choose quality shrimp seed from reputable hatcheries

Select healthy seed of uniform size (black tiger shrimp >12 mm, whiteleg shrimp >10 mm), with quick response when moved.
Check shrimp health upon receiving seed to ensure they are not infected with the virus that causes MBV disease in shrimp.
Perform PCR testing when first obtaining shrimp seed to eliminate the risk of infected seed, protecting the new shrimp crop from disease risk.

2. Prepare the pond thoroughly and keep it disease-free

Drain the water completely, remove sludge, and eliminate debris that may carry pathogens.
Sun-dry the pond bottom for 1–2 months for old ponds to destroy any virus remaining in the mud.
Clean the pond embankments, water inlet and outlet systems, net fencing, and liners to prevent pathogens from entering.

*The pond bottom should be thoroughly cleaned before stocking a new shrimp crop to prevent MBV disease in shrimp*

3. Ensure a safe water source

Treat water through settling ponds and check pH, dissolved oxygen, ammonia, nitrite, and nitrate levels.
Maintain a stable water environment and provide sufficient oxygen for shrimp.
Use appropriate filtration and water exchange measures to limit virus development.

4. Other supportive measures

Use probiotics to decompose organic matter, combined with herbal products that support and detoxify the liver, Anti Shock or Herbal Pro to boost shrimp resistance.
Feed shrimp a nutritious diet, avoid environmental shock, maintain health, and increase their ability to resist the virus that causes MBV disease in shrimp.
Treat water with ozone and disinfectants such as Vemedim BKC 80%, Vemedim Vime-Protex and Vemedim Vime-Iodine to ensure safety before stocking shrimp seed.

*Choose quality feed with full nutrition and proactively boost shrimp immunity to limit MBV disease in shrimp*

MBV disease in shrimp is a potential threat that affects growth rate, productivity, and farming profits. Although there is no specific treatment, choosing disease-free shrimp seed, thoroughly preparing the pond, controlling water quality, and caring for shrimp properly will reduce disease risk and help the crop achieve high productivity. With detailed guidance and supportive solutions from Vemedim, farmers can fully control MBV disease, improve economic efficiency, and enjoy a bountiful harvest. Contact Vemedim now for detailed advice!