On EMS or also mentioned acute hepatopancreatic degenerative necrosis syndrome (AHDNS) the cause has been found, just recently. In fact a bacteriophage (= virus that only infect bacteria) infects the bacterium Vibrio parahaemolyticus and in the body of the shrimp the Vibrio starts to produce toxins (toxic excretions) which causes the animal to die. This cause would indicate that shrimp can be protected, either by destroying the bacteriophage or by killing the host bacterium (the Vibrio). Probably it is more practical to keep Vibrio under control as bacteriophages are smaller and more difficult to control to a level where they do no longer harm and they are generally present in all kinds of waters (oceans/lakes, etc). Vibrio parahaemolyticus is efficiently killed by Halamid®.