What is EHP disease?
EHP infection (Hepatopancreatic microsporidiosis) is one of the serious deadly disease in shrimp farms that cause heavy economic loss. Enterocytozoon hepatopenaei (EHP) is a microsporidian parasite that replicates within epithelial cells of hepatopancrease which leads to growth problems in cultured shrimps.
What makes EHP stronger?
Though EHP doesn’t cause heavy mortality, it retards (slow down) the growth severely. EHP infection may be associated with the White fecal syndrome (WFS), AHPND, and necrosis.
EHP spores survive in an environment without a host. EHP develops and spreads very fast. Having a thick wall, EHP is able to withstand the chlorine treatment. EHP is not like Vibrio infection, a few spores are able to infect the whole system if disinfection is not done properly.
How to identify EHP?
There is no specific gross sign for this infection at the early stage. However the below signs may be highly associated with EHP infection.
- Severe Retardation in growth
- Size variation in shrimps
- Reduced feed intake
- Soft shell
Lab diagnosis like Histopathology, PCR analysis could confirm the infection.
Can you stop the infection?
It is difficult to control the EHP infection. Proper biosecurity measures and BMPs are the possible ways to avoid the infection.
- Check shrimps seeds for EHP infection by PCR method
- Stock EHP free shrimp seeds.
- Follow proper BMPs for pond preparation before stocking the seeds.
- Ponds should be disinfected and dried thoroughly before every stocking and make sure the pond is free from EHP.
Preventive measures at the hatchery level
- Test fecal samples of broodstocks for EHP infection to avoid EHP initially.
- Follow BMPs and biosecurity measures strictly
- Live feeds should be checked for infection before using it.
- Pasteurize live feeds by heating them for 10 mins to 72 degree C.
- Wash eggs and nauplii with formalin and iodine to remove microsporidian spores.