Investigação dos vírus da síndrome de Taura e da Mionecrose Infecciosa em cultivos de camarão marinho Litopenaeus vannamei em Pernambuco

Abstract

Shrimp culture has grown rapidly worldwide and nowadays constitutes a solid industry generating jobs for thousand people. In any aquatic species, the transition from life in a wild environment to aquaculture systems is usually followed by several changes, such as culture densities, frequent degradation of environmental quality, mixing of populations of different origin and manipulations, etc. These facts increase the probability of outbreaks of serious diseases. Several virus diseases have occurred, threatening the sustainability of shrimp industry worldwide. Taura virus is considered one of the most harmful pathogens in the Americas, with cumulative mortality between 40 and 95%. Another virus, named Infectious Myonecrosis Virus (IMNV) was first identified in Litopenaeus vannamei reared in Northern Brazil and it is pointed as one of the main causes of the crash in shrimp production in 2004. The objective of this study was to investigate the prevalence of TSV and IMNV by Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) in Pernambuco state, in order to provide important information for the construction of a biosecurity plan. Eleven commercial farms, located in six different cities of the north and south coast, were randomly sampled betweenAugust and December of 2004. Among the 530 animals analyzed, none were vírus positive for Taura, suggesting that the prevalence of this pathogen is lower than 0,06%, even with recent outbreaks in nearby countries. The IMN virus prevalence lied between 0 and 35,56% among the farms, which is considered alarming and requires monitoring mechanisms at the national level. These results constitute the first survey of these shrimp virus carried out in the Americas using a total randomized sample.