Assessing pathogenesis of the white spot syndrome virus (WSSV) in the whiteleged shrimp (Litopenaeus vannamei)

The pathogenesis of the white spot syndrome virus (WSSV) was studied experimentally with challenge exposure of one hundred post larvae Litopenaeus vannamei each aged 40 days. The shrimp L. vannamei larvae were first examined with Shrimp PC sub(a)R sub(e) Simplex detection kit and found to be free of WSSV. The Fenerropenaeus indicus tissues that showed the clinical signs and were PCR positive for the white spot disease (WSD) were used as the source of WSSV. The challenge exposure was accomplished by feeding minced tissue of the F. indicus to L. vannamei for 24 hours. Based on the results, the L. vannamei revealed the clinical sign of WSD after three days, the PCR was positive and all the shrimp specimens were died after ten days. The control group of the shrimp did not show any sign of WSD and their PCR was negative during the experiment.