DAO 85:175-180 (2009)  -  DOI: https://doi.org/10.3354/dao02086

Macrobrachium rosenbergii nodavirus disease (white tail disease) in Australia

Leigh Owens1,*, Kathy La Fauce1, Karen Juntunen1, Orachun Hayakijkosol1, Chaoshu Zeng2

1School of Veterinary and Biomedical Sciences, and 2School of Marine and Tropical Biology, James Cook University, Queensland 4811, Australia

ABSTRACT: The index case of white tail disease (WTD) is presented in adult broodstock prawns Macrobrachium rosenbergii from the Flinders River in western Queensland, Australia, in mid-2007. Histological examination revealed extensive myonecrosis with massive infiltration of myonuclei and some haemocytes. Juveniles from the same broodstock but not from 3 other families displayed white muscle lesions. Low-grade chronic mortalities approaching 100% over 1 yr occurred. Reverse transcriptase polymerase chain reactions (RT-PCR) were attempted for both M. rosenbergii nodavirus (MrNV) with 2 sets of primers and for the satellite virus, extrasmall virus (XSV). All 3 PCRs generated amplicons of the expected sizes. Basic local alignment search tool (BLAST) analyses of the 3 consensus sequences identified a 91% match with MrNV viral capsid protein gene, 96% match with MrNV RNA-directed RNA polymerase gene, and a 99% match with M. rosenbergii XSV capsid protein gene. The clinical signs, histopathological lesions and RT-PCR amplicons could be reproduced in M. rosenbergii inoculated with cell-free extracts fulfilling River’s postulates. We conclude that this is an endemic strain of MrNV as the sequences are dissimilar to strains of MrNV circulating around Asia and the Americas. This case only poorly meets the Office International des Epizooties (OIE) case definition for WTD due to the age of the prawns involved and the nature of the inclusion bodies. Perhaps the OIE case definition needs broadening.


KEY WORDS: White tail disease . WTD . Macrobrachium rosenbergii . Broodstock . Macrobrachium rosenbergii nodavirus . MrNV . Extrasmall virus . XSV


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Cite this article as: Owens L, La Fauce K, Juntunen K, Hayakijkosol O, Zeng C (2009) Macrobrachium rosenbergii nodavirus disease (white tail disease) in Australia. Dis Aquat Org 85:175-180. https://doi.org/10.3354/dao02086

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