A survey in Andhra Pradesh, a major whiteleg shrimp region of India, found EHP on 64% of farms within one year. Losses can exceed 20–30% of a crop’s typical profit margin.
No mass mortality, but steady profit erosion
EHP (Enterocytozoon hepatopenaei) is a microsporidian parasite of the shrimp hepatopancreas. Infected shrimp grow slowly, sizes spread out and feed conversion gets worse. Because shrimp do not die all at once, many farmers only notice at a loss-making harvest.
How the survey was done
The team followed more than 145 farms for one year in the Krishna, East Godavari and West Godavari districts, where farms run 2–4 crops a year. Ponds were checked in three steps: looking at the shrimp in the pond, wet-mount microscopy of the hepatopancreas and RT-PCR.
Infection level was graded by the PCR CT value. The lower the CT, the more parasite:
- Healthy pond: no EHP detected.
- Moderately infected: CT above 25.
- Severely infected: CT below 25.
Main results
The most striking finding concerns harvest size. Moderately and severely infected ponds lost money when harvested at 100 shrimp/kg. Only by growing on to 60 shrimp/kg, helped by a higher price, did the crop turn a profit. EHP therefore pushes farmers into longer crops, with more cost and more risk.
What farmers should do
The article recommends integrated management rather than relying on any single solution:
- Thorough pond preparation: dry the bottom completely in the sun, apply lime and suitable disinfectants.
- Biosecurity: restrict access, do not share equipment between ponds, use filtered or treated water.
- Regular monitoring: watch growth rate and size uniformity, take hepatopancreas samples for wet mounts and PCR on a schedule.
- Stable water: keep water quality within range and use probiotics for water and pond bottom.
- Nutrition: support immunity and gut health through the diet, as part of the overall plan.
Sources
- The economic toll of EHP outbreaks in shrimp farming. Aqua Culture Asia Pacific, published online 27 February 2026 (print issue November/December, pp. 40–43).
This article is a synthesis and interpretation by Than Vuong, not a translation. Numbers come from the original articles; product promotion in the originals has been left out. Charts were redrawn by Than Vuong from the numbers and the 3D models were built by Than Vuong; the originals’ own figures and tables are not reproduced.
