* Acute Hepatopancreatic Necrosis Disease (AHPND) in Whiteleg

Overview

• In post-larvae within 20–30 days after stocking, the mortality rate can reach 100%.

• This disease has reduced global farmed shrimp production by 14%.

• The causative pathogen is Vibrio parahaemolyticus carrying both toxin-related genes (PirA, PirB).

Susceptible Hosts

• Whiteleg shrimp (Litopenaeus vannamei)

• Giant tiger prawn (Penaeus monodon)

Occurrence in Korea

• First occurred in Shinan (Jeonnam), Incheon, and Gyeonggi regions in 2016.

• After being designated as a statutory infectious disease (Jan 3, 2021), outbreaks were reported:

  1. Chungnam nursery farm (Apr 2021, mortality 30%)

  2. Shinan, Jeonnam grow-out pond (Aug 2021, mortality 68%)

• Control measures such as culling and quarantine were completed.

Occurrence Worldwide

• First reported in China (2009), and subsequently spread to:

  • Vietnam (2010), Malaysia (2011), Thailand (2012), Mexico (2013), Philippines (2015), Korea (2016), United States (2017).

Characteristics of Infection

• Transmission: Horizontal infection (via immersion, oral route)

• Major target organs: Hepatopancreas, stomach, midgut, hindgut

• Clinical and pathological signs: Whitening of hepatopancreas, necrosis and sloughing of hepatopancreatic epithelial cells, inflammation