Evaluation of white spot syndrome virus (wssv) in wild shrimp after a major outbreak in shrimp farms at Laguna, southern Brazil

Abstract

White spot syndrome virus (WSSV) infected Litopenaeus vannamei cultivated in ponds at Laguna, Southern Brazil, and caused huge economical losses. The objective of this study was to determine if WSSV infected wild shrimp were present in the Laguna estuarine system, which receives effluents of the shrimp farms. Samples were collected in the 2006 austral summer (February – 48 juvenile shrimp) and winter (August – 66 juvenile shrimp). Virus presence was tested by one-step and nested PCR in the 114 wild shrimp of three different species (Farfantepenaeus paulensis, Farfantepenaeus brasiliensis and Litopenaeus schmitti). All samples were negative for PCR method employed, indicating that prevalence of this disease in wild animals must be smaller than 5% per sampling period, or smaller than 3% when considering total number of tested shrimp (114 shrimp). So far, we may say that WSSV is not widely spread among native shrimp, even after strong disease outbreak in farms. However, more efforts need to be made in order to confirm these results.