A gamechanger for shrimp farming
Dr Aftabuzzaman, a physician by profession, started shrimp farming in Satkhira back in 1968. His farm was doing very well until a deadly infection left most shrimps of his farm dead in 1994. The infection was caused by white spot syndrome virus.
"It was then we came to know about the deadly virus infecting shrimps in farms across Cox's Bazar, Satkhira, Khulna and Bagerhat," said Aftabuzzaman, also a former state minister for fisheries and livestock and former president of Bangladesh Frozen Food Exporters' Association.
"Many left shrimp farming between 1994 and 1998 as a result," he said.
The white spot syndrome virus is still a great threat to the shrimp farmers in the country as there is no effective medicine or vaccine against it.
However, a group of researchers, from Chittagong University, Dhaka University, icddr,b and Chittagong Veterinary and Animal Sciences University, has discovered the genome sequence of the virus and also identified a new variant of it.
The researchers said the discovery will pave the way for developing an effective vaccine.
"The virus is lethal and highly contagious, and is responsible for causing white circular spots in shrimps, eventually leaving those dead within two or three days. This causes an annual loss of around US $60 billion to global shrimp sector," said Prof Dr Mohammad Raknuzzaman, chairman of Department of Fisheries at DU.
The virus infection can wipe out the entire stock of shrimps of an enclosure within a week," he added.
Shrimp cells have a receptor called "Rab7" as an accessory protein, through which the virus enters the shrimp's body to multiply and weaken the host until the shrimp dies, said Professor Adnan Mannan of Genetic Engineering and Biotechnology Department at CU, also a principal researcher of the study.
The virus was first observed in Bangladesh in 1994 at a hatchery in Cox's Bazar, he added.
Citing a study, he said 20 percent of shrimps produced in the country are lost every year due to this virus. To give an example of the financial blow the virus causes, he said the exported volume of shrimps decreased from 26,000 tonnes to 18,000 tonnes in 1998 because of it.
The genome sequencing of the virus paves way to develop an mRNA-based vaccine, said Adnan.
This genome sequence information has recently been accepted by the US National Center for Biological Information (NCBI) and the American Society of Microbiology, he added
Prof Zonaed Siddiki of Pathology and Parasitolgy Department at CVASU, also a co-principal researcher of the study, said, "The main objective was to identify the type of white spot syndrome virus active in Bangladesh, its characteristic features and variations through genome sequencing, and unravel the mystery of which toxic protein or gene of this virus plays a key role in infection and death of shrimps."
The results of this research will help farmers know the source of this virus and how it spreads, he added.
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