Prevalence of monodon baculovirus in wild Metapenaeus species along the southwest coast of India

Viral diseases remain a major threat to the shrimp aquaculture industry because some can cause massive disease outbreaks. Samples of shrimp were collected from the offshore waters of southwest coast of India during November 1999 to August 2000. The samples consisted of 30 individuals (n=30) belonging to different species such as Metapenaeus monoceros, Metapenaeus elegans, Metapenaeus dobsoni, Solenocera choprai and Parapenaeopsis stylifera. The samples were screened for the presence of monodon baculovirus by histopathology and polymerase chain reaction (PCR). Of the 30 individuals examined, 4 specimens of M monoceros and 1 specimen of M elegans showed multiple occlusion bodies in the hepatopancreatic cells, suggestive of infection by MBV-like viruses. Samples positive for MBV by histopathology were found to be positive by nested PCR, confirming that the occlusions were indeed due to MBV. The results suggest that Metapenaeus spp. could serve as a reservoir of the virus in the natural environment. This study documents the presence of MBV in wild caught M. monoceros and M. elegans for the first time. (C) 2004 Published by Elsevier B.V.