Tracking of Hepatopancreatic parvo-like virus (HPV) disease in Litopenaeus vannamei of the hatcheries in the Bushehr Province

Presence of hepatopancreatic parvo-like vines (HPV) disease was assessed from June until October 2009 in Litopenaeus vannamei hatcheries and grow-out farms of the Bushehr province. Samples were collected from 6 hatcheries and 6 grow-out farms located in coasted areas. From each hatchery, 100 PL samples with average age PL5-PL8 and 20-30 samples from each grow-out farm with average age 105 to 120 days were collected. The samples were divided into three groups one used for gross sign and wet mount with Gimsa, the second group was preserved in Davidson Fixative and used for histopathology and the third group was fixed in ethyl alcohol 95% and used for polymerase chain Reaction (PCR). In gross sign 30%- 40% of the shrimp showed different sizes and some were smaller than the others. In the wet mount group with Gimsa staining of hepatopancrease, the inclusion body with basophilic color was seen. The histopathology indicated that the hepatopancreatic cell was infected and the basophilic inclusion body observed in many samples. The PCR examined with IQ 2000 Kit was negative. The rate of infection (ROI) was 1.1% for hatcheries and 32% for grow-out farms.