Pesticides and Antibiotics used in Farmed Shrimp in the Mekong Delta, Vietnam: Are they associated with Acute Hepatopancreatic Necrosis Syndrome (AHPNS)?

Shrimp farming growth has led to increased use of drugs and chemicals for prevention and  treatment of infectious diseases. Antibiotics (e.g. enrofloxacin) and pesticides (e.g.  endosulfan and deltamethrin) have been reported as the most commonly used products. Although the use of enrofloxacin and furazolidone were prohibited in Vietnam since 2009, they were reported to have been used occasionally in shrimp aquaculture. Endosulfan is still used in agriculture and aquaculture, despite its prohibition since 2004. Deltamethrin has widely been used as agriculture pesticide, wild crustaceans elimination in shrimp farming, treatment of water quality and reduction of diseases. From 2010 to 2013, there were new agents of insecticides, fungicides and herbicides were used to protect the rice fields or integrated rice-shrimp areas.

AHPNS outbreak appeared in large region and seriously affected to shrimp farming, and pesticides were found in water and sediment in these shrimp ponds. Pesticides may interact with Vibrio parahaemolyticus, the causative agent of AHPNH, and make them more dangerous. However, the impacts of pesticide contaminations on farmed shrimp and its interaction with V. parahaemolyticus have not been well studied. With intensification in shrimp production, the pressure from AHPNS has greatly increased, some farmers have dealt empirically with AHPNS by using chemicals and antibiotics without laboratory diagnostic support and veterinary supervision. This will consequently increase antibiotic resistance and rise the related problem of unregulated antibiotic residues and human food safety. Therefore, studies on epigenetic changes in shrimp exposed to these pesticides and antibiotics will be crucial to address these concerns.