Emergence of a New Villain: Div1 Virus

The Div1 virus was first detected in samples of red claw crayfish in Fujian province of china in 2014. So, it has been around for a while. On June 1,2020 New Straits Times stated that Vietnam is on alert for this new deadly virus that could decimate its shrimp industry.

This virus is known to spread faster than a forest wild fire! Within a span of 2-3 days the entire pond gets infected and results in mass mortality. This can affect shrimps in all stages be it juvenile or fully grown.

Characterized by low appetite, lethargic swimming, empty gut, soft shell, reddish brown colour, broken antenna to name a few.

In the above figure, Clinical symptoms of giant freshwater prawn naturally infected with DIV1. (A) Overall appearance of an infected shrimp in water. (B) The blue arrow shows white, pale area at the base of the rostrum. The white arrow indicates pale and yellow atrophic hepatopancreas.

In the above figure, P. vannamei from laboratory: left group (healthy); right group (infected with DIV1). Source: Qiu et al., 2017

There is not much information on cause and transmission of this virus. Unlike what we did for the Covid-19 situation, we need to be prepared well in advance!

Here’s what we can do:

Prevent unwanted movement of people into the farm since humans can also be the source of pathogens, disinfect incoming water to prevent this viral infection.

The pond needs to be constantly monitored. Any abnormality needs to checked immediately since the spread of this disease is quick.

This infection is prone to occur in cold seasons and subsides when the temperatures are high. Therefore, we can infer that there are less chances for this infection to occur in summers.

If your shrimps get affected by Div1 virus, discard the infected shrimps immediately. Post infection, the pond should be disinfected thoroughly and dried for at least 2 months.

AquaConnect Suggested Products:

1. Ultraxide
2. Novib 500 gms
3. Pond Guard 1Kg

References:

MDPI and ACS Style

Qiu, L.; Chen, X.; Zhao, R.-H.; Li, C.; Gao, W.; Zhang, Q.-L.; Huang, J. Description of a Natural Infection with Decapod Iridescent Virus 1 in Farmed Giant Freshwater Prawn, Macrobrachium rosenbergii. Viruses 2019, 11, 354.