vega-heredia et al., 2011

REVIEW The Infectious Hypodermal and Haematopoietic Necrosis Virus: A Brief Review of What We Do and Do Not Know S. Vega-Heredia 1 , F. Mendoza-Cano 2 and A. Sa ´ nchez-Paz 2 1 Facultad de Ciencias Marinas, Universidad Auto ´ noma de Baja California, Ensenada, Baja California, Me ´ xico 2 Laboratorio de Ana ´ lisis Integral Acuı ´ cola, Centro de Investigaciones Biolo ´ gicas del Noroeste (CIBNOR), Hermosillo, Sonora, Me ´ xico Introduction Eve n when ma rine vir uses were des cri bed for the first time by Spen cer (195 5), thei r exis tence remaine d large ly ignored because of the relatively low abundances inferred through the use of cultured-based assays (Breitbart et al., 2007). It was not until 1989, when Bergh and colleagues repo rted high abundances of virus es in aqua tic environ- men ts , that the attention was foc ussed on the env iron- mental and epidemiological roles of marine viruses. Besi des being imp orta nt cata lysts of biog eoch emic al cycling influencing the availability of nutrients on the sea (Fuhrman, 1999), a vast reservoir of genetic and biologi- cal diversity, and a key factor driving the evolution of its hosts (Suttle, 2007), marine viruses probably infect all liv- ing organisms inhabiting seawaters (Suttle, 2005), and as a con seq uen ce they are a maj or cause of di sea ses and mortality in the oceans (Suttle, 2007). It is clear that marine virus es infec t sever al commercia lly importan t cult i- vated species, such as fish and shrimp, and for this reason they have been intensively studied. In recent years, several viral diseases have caused criti- cal economic losses to the global shrimp-farming industry (Chamberlain, 1994). To date, more than 20 viruses have been reported to infect cultured and wild shrimp (Light- ner , 1994; Ove rst ree t, 199 4). Among the se vir uses, the infectious hypodermal and haematopoietic necrosis virus (IHHNV) represent one of the most serious threats to the cul tur ed shrimp ind ust ry and the shrimp fish ery (JS A Shrimp Virus Work Group, 1997). Thus, this review pro- vides a brief overview of the current science on IHHNV and identifies areas for further development regarding this virus. Histo ry, Clinica l Signs and Geogr aphica l Distr ibu- tion of IHHNV During the early 1980s, the population of Penaeus styliros- tris rea red at the Uni ver sit y of Ari zon a’s exp eri men ta l shri mp culture facil ity on Hawa ii were severely affected by a highly lethal disease of viral aetiology. Examination by elect ron micr oscopy and hist opat holo gy of spec imen s Keywords: emerging diseases; virus; wildlife; pathogenesis Correspondence: Dr A. Sa ´ nchez Paz. CIBNOR, PO Box 83260, Hermosillo, Sonora, Me ´ xico. Tel.: 52 (662) 2 13 15 93; Fax: 52 (662) 2 12 12 01; E-mail: asanchez0 [email protected] Received for publication June 13, 2011 doi:10.1111/j.1865-1682.2011.01249.x Summary Given its high prevalence, its wide distribution and its remarkable capacity to cause severe mortality in shrimp, the infectious hypodermal and haematopoietic necrosis virus (IHHNV) may deserve far more attention than it has received, as it remains considered as one of the most serious problems plaguing the global shrimp farming industry. Furthermore, its real measurable impact over wild shrimp populations remains unknown. Undeniably, the progress that we have reached today on the knowledge of its geographical distribution, clinical signs, genetic diversity, transmission and virulence may help to identify and under- stand important aspects of its biology and pathogenesis. However, the informa- tion regarding the molecular events that occur during the infection process is sca rce. Thus, it ma y not be sur pri sin g to find that there are no the rap eut ic opti ons availabl e for the prophyla xis or trea tmen ts to reduce the deleteri ous impact of this viral pathogen to date. The aim of this review is to integrate and discuss the current state of knowledge concerning several aspects of the biology of IHHNV and to highlight potential future directions for this area of research. Transboundary and Emerging Diseases ª 2011 Blackwell Verlag GmbH • Transboundary and Emerging Diseases. 1

vega-heredia et al., 2011

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