WSSV

White Spot Syndrome Virus (WSSV) was one of the first significant diseases in shrimp production to emerge and become pandemic, resulting in worldwide losses in the billions of dollars. WSSV was first discovered in 1992 after several outbreaks of a high mortality disease occurred in shrimp farms in Taiwan. It is estimated that Asia alone has lost more than $6 billion since 1992, and the Americas have lost $1-2 billion since WSSV was introduced in 1999. WSSV causes acute mortality, with entire ponds and crops being lost in 3-5 days. WSSV has since been characterized as a giant, enveloped, DNA virus that is one of the largest viruses ever discovered. It has become endemic in shrimp farming regions throughout the world and continues to threaten native crustacean species and shrimp farmers.

IMNV

Infectious Myonecrosis Virus (IMNV) was first discovered in 2002 after an outbreak of a severe, previously undescribed disease was reported in the northeastern regions of Brazil. This disease was eventually named infectious myonecrosis (IMN) and caused millions of dollars in losses in Brazil in 2003. IMNV eventually spread across the globe to Indonesia, resulting in significant financial losses in 2006. IMNV is a small non-enveloped dsRNA virus. IMNV causes a muscle necrosis, or white muscle, throughout the tail of the shrimp. This eventually can be lethal with typical losses of up to 70 percent of animals over a growout cycle. These insidious mortalities cause large increases in feed conversion ratio (FCR) and result in significant losses for the farmer.