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Prevalence of Taura syndrome virus (TSV) and Infectious hypodermal and haematopoietic necrosis virus (IHHNV) in white shrimp (Penaeus vannamei) populations and susceptibility to infection of some aquatic species native to Thailand  [PDF]
Ruangsri, J.,Kiriratnikom, S.,Sukrakanchana, N.,Arunrat, S.
Songklanakarin Journal of Science and Technology , 2005,
Abstract: This study aimed to survey the prevalence of some infectious diseases e.g. Taura syndrome virus (TSV) and Infectious hypodermal and haematopoietic necrosis virus (IHHNV) in white shrimp (Penaeus vannamei) populations and to assess the impact of such infectious agents to indigenous aquatic animals in Thailand. Samples of both larval and juvenile or adult shrimp from each region of the country were collected and screened for TSV and IHHNV using the polymerase chain reaction (PCR) technique. Viruses isolated from affected shrimp were used for determine the susceptibility to infection of some aquatic species native to Thailand.A total of 163 samples of larval shrimp from hatcheries were screened. The results showed infection with TSV and IHHNV in 3.68 and 44.17%, respectively. As high as 7.32% TSV infection was detected in shrimp samples collected from the South Eastern coast, followed by the Eastern and Central regions with percentages of 5.56 and 4.53, respectively. Shrimp with the highest rate of IHHNV infection, 55.56% were collected from the Eastern region. A total of 192 samples of shrimp reared in grow-out ponds were also collected. The results showed shrimp were infected with TSV and IHHNV with percentages of 6.67 and 67.19, respectively. The highest prevalence of IHHNV (up to 90%) was found in samples collected from the lower Southern region. The highest prevalence of TSV infection (11.29%) was reported in shrimp from the Central region. A study of the susceptibility to TSV and IHHNV infection of some indigenous aquatic species of Thailand was also carried out. The results showed many aquatic species native to Thailand e.g. black tiger shrimp (Penaeus monodon), speckled shrimp (Metapenaeus monoceros), dwarf prawn (Macrobrachium equideus), krill (Acetes sp.), mantis lobster (Chloridopsis immaculatus), freshwater prawn (Macrobrachium lanchesteri and M. rosenbergii), mangrove crab (Sesarma sp.) and mud crab (Scylla serrata) were susceptible to viruses and died due to infection. The mortality of affected species associated with a causative agent was confirmed in most species, except the mud crab and freshwater prawn (Marcrobrachium rosenbergii). However, viral particles can be still detected in surviving animals 10 days after infection. The results of this study will be a helpful tool employed in establishing measures on disease control and reduction of risk with the importation of white shrimp broodstock.
Sequence diversity of the infectious hypodermal and hematopoietic necrosis virus (IHHNV) in cultured shrimp populations in the Philippines
Christopher M. A. Caipang,May Flor J. Sibonga,Jane S. Geduspan,Mary Jane S. Apines-Amar
Advances in Environmental Sciences , 2011,
Abstract: Partial sequence the capsid protein gene of a Philippine isolate of the infectious hypodermaland hematopoietic necrosis virus (IHHNV), a single-stranded DNA virus that infects both wild andcultured shrimps was identified. The obtained sequence shared 96-97% nucleotide identity with thecapsid protein gene of the other IHHNV isolates. Phylogenetic analyses showed that the capsid proteingene of the different IHHNV isolates did not cluster in terms of geographical location, indicating thewidespread distribution of the virus. Among the Philippine isolates, IHHNV apparently has high geneticdiversity. A sequence obtained from an IHHNV-infected shrimp postlarvae, Penaeus monodon in CentralPhilippines did not cluster with the other Philippine isolates and could represent a distinct isolate. Theresults of this study support the earlier findings that IHHNV has a high evolutionary rate, and given thisobserved phenomenon, strict monitoring of the movement of shrimps among geographic regions must beobserved to prevent the occurrence of future disease outbreaks due to this viral pathogen.
Genetic Signature of Rapid IHHNV (Infectious Hypodermal and Hematopoietic Necrosis Virus) Expansion in Wild Penaeus Shrimp Populations  [PDF]
Refugio Robles-Sikisaka,Andrew J. Bohonak,Leroy R. McClenaghan Jr,Arun K. Dhar
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0011799
Abstract: Infectious hypodermal and hematopoietic necrosis virus (IHHNV) is a widely distributed single-stranded DNA parvovirus that has been responsible for major losses in wild and farmed penaeid shrimp populations on the northwestern Pacific coast of Mexico since the early 1990's. IHHNV has been considered a slow-evolving, stable virus because shrimp populations in this region have recovered to pre-epizootic levels, and limited nucleotide variation has been found in a small number of IHHNV isolates studied from this region. To gain insight into IHHNV evolutionary and population dynamics, we analyzed IHHNV capsid protein gene sequences from 89 Penaeus shrimp, along with 14 previously published sequences. Using Bayesian coalescent approaches, we calculated a mean rate of nucleotide substitution for IHHNV that was unexpectedly high (1.39×10?4 substitutions/site/year) and comparable to that reported for RNA viruses. We found more genetic diversity than previously reported for IHHNV isolates and highly significant subdivision among the viral populations in Mexican waters. Past changes in effective number of infections that we infer from Bayesian skyline plots closely correspond to IHHNV epizootiological historical records. Given the high evolutionary rate and the observed regional isolation of IHHNV in shrimp populations in the Gulf of California, we suggest regular monitoring of wild and farmed shrimp and restriction of shrimp movement as preventative measures for future viral outbreaks.
Rapid Detection of the Philippine Isolate of Infectious Hypodermal and Hematopoietic Necrosis Virus (IHHNV) in Shrimp, Penaeus monodon Using Loop-Mediated Isothermal Amplification (LAMP)
Christopher Marlowe A. Caipang,May Flor J. Sibonga,Jane S. Geduspan
International Journal of Animal and Veterinary Advances , 2012,
Abstract: The aim of this study was to standardize a Loop-Mediated isothermal Amplification (LAMP) assay for the detection of the Philippine isolate of Infectious Hypodermal and Hematopoietic Necrosis Virus (IHHNV) in postlarvae of shrimp, Penaeus monodon. The assay was optimized at an incubation time of 1 h at 63oC. The assay was highly specific for IHHNV and did not cross-react with other shrimp viruses including Hepatopancreatic Parvovirus (HPV), Monodon Baculovirus (MBV) and White Spot Syndrome Virus (WSSV). The limit of detection of the IHHNV using the LAMP assay was 10 pg of DNA/mL or 10 fg of the genomic DNA per LAMP reaction and was 10 times more sensitive than conventional PCR in detecting the viral pathogen from infected samples. These results demonstrated that LAMP is a simple and sensitive diagnostic technique that has potential application for routine detection of IHHNV infections in shrimp hatcheries in the Philippines.
Development of a multiplex real-time PCR assay for detection of WSSV and IHHNV

XIE Zhi-Xun,XIE Li-Ji,PANG Yao-Shan,LU Zhao-Fa,XIE Zhi-Qin,SUN Jian-Hua,DENG Xian-Wen,LIU Jia-Bo,TANG Xiao-Fei,

水生生物学报 , 2009,
Abstract: White spot syndrome virus (WSSV) and Infectious hypodermal and haematopoietic necrosis virus (IHHNV) are responsible for significant economic loss in the shrimp industry. In order to simultaneously and massively identify WSSV and IHHNV, two pairs of primers and two TaqMan probes were designed and synthesized according to the conserved gene sequences of WSSV (AF369029) and IHHNV (AF218226) in GenBank. The reaction parameters such as the concentration of two pair of primers, two TaqMan probes and the reaction buffer were optimized to develop a multiplex real-time PCR assay for the rapid detection of WSSV and IHHNV. The multiplex real-time PCR assay was found to be specific and be able to detect and differentiate WSSV and IHHNV, and no positive results were observed when nucleic acid from Vibrio, Taura Syndrome Virus and Streptococcus were used as multiplex real-time PCR templates. The developed multiplex real-time PCR assay was compared with that of routine PCR. The sensitivity of multiplex real-time PCR assay was 2 and 20 template copies for WSSV and IHHNV respectively, and its sensitivity was 103 and 102 times higher than that of the routine PCR. The samples were examined using the multiplex real-time PCR repeatedly and the results indicated that the multiplex real-time PCR was reproducible. Different concentrations of WSSV and IHHNV could be identified when mixed together, which implied the assay could be applied to clinical confirmation for simultaneous infection of WSSV and IHHNV. The multiplex real-time PCR results of 30 routine PCR positive samples showed that one specific amplified curve was displayed when shrimp was infected by only one of these two viral pathogens, whereas two specific amplified curves were displayed when shrimp was infected by two viral pathogens. The result indicated that multiplex real-time PCR was able to detect and differentiate the presence of each pathogen in infected clinical shrimp. This multiplex real-time PCR assay is a quick, sensitive, specific and quantitative tool for detection of WSSV and IHHNV, and it will be useful for the control of WSS and IHHN in shrimp.
Selection of shrimp breeders free of white spot syndrome and infectious hypodermal and hematopoietic necrosis
Mello Junior, Carlos Cesar de;Delsol, Gael Yvan Leclercq;Motte, Emmerik;Escobar, Virna Alexia Cede?o;Rey, Pedro Filipe;Martins, Mauricio Later?a;Arana, Luis Alejandro Vinatea;Mello, Giovanni Lemos de;Farias, Alvaro Pestana de;Arguello, Xavier Antonio Serrano;Maridue?a, John Erick Monta?o;
Pesquisa Agropecuária Brasileira , 2011, DOI: 10.1590/S0100-204X2011000500011
Abstract: the objective of this work was to select surviving breeders of litopenaeus vannamei from white spot syndrome virus (wssv) outbreak, adapted to local climatic conditions and negatively diagnosed for wssv and infectious hypodermal and hematopoietic necrosis virus (ihhnv), and to evaluate if this strategy is a viable alternative for production in santa catarina, brazil. a total of 800 males and 800 females were phenotypically selected in a farm pond. nested-pcr analyses of 487 sexually mature females and 231 sexually mature males showed that 63% of the females and 55% of the males were infected with ihhnv. animals free of ihhnv were tested for wssv, and those considered double negative were used for breeding. the post-larvae produced were stocked in nine nursery tanks for analysis. from the 45 samples, with 50 post-larvae each, only two were positive for ihhnv and none for wssv. batches of larvae diagnosed free of virus by nested-pcr were sent to six farms. a comparative analysis was carried out in growth ponds, between local post-larvae and post-larvae from northeast brazil. crabs (chasmagnathus granulata), blue crabs (callinectes sapidus), and sea hares (aplysia brasiliana), which are possible vectors of these viruses, were also evaluated. the mean survival was 55% for local post-larvae against 23.4% for post-larvae from the northeast. sea hares showed prevalence of 50% and crabs of 67% of wssv.
Detección del virus de la Necrosis Infecciosa Hipodérmica y Hematopoyética (IHHNV) en camarones blancos cultivados asintomáticos, Litopenaeus vannamei (BOONE), en Venezuela.
Boada,Mélida; De Donato,Marcos; Rodulfo,Hectorina;
Revista Científica , 2008,
Abstract: the infectious hypodermal and hematopoietic necrosis virus (ihhnv) is a pathogen that may cause high mortalities in litopenaeus stylirostris and the runt deformity syndrome (rds) in l. vannamei. in order to detect the presence of ihhnv in asymptomatic, cultivated shrimp, it were analyzed shrimp samples of cultivated l. vannamei from 5 farms located in the east and west costs of venezuela. a total of 90 samples per farm were analyzed, using three sizes: pl8-pl15, juveniles of 5-6 g and of 12-15 g of weight. the dna was extracted from homogenized samples of pleopods, using commercial kits. the detection of ihhnv was carried out by both dot blot hybridization and pcr using the diagxotics kits shrimpprobe and shrimpcare simplex, respectively. a total of 7 positive samples from 4 (b, c, d and e) of the 5 shrimp farms studied were detected. the prevalence in the farms ranged from 1.1 to 3.3%. all positive samples corresponded to individuals of 5 to 6 g of weight. pcr was a more sensitive technique than the dot blot hybridization. the presence of ihhnv in asymptomatic shrimp at low values of prevalence could imply that the shrimp populations used for culture in venezuela are resistant or at least tolerant to this viral pathogen.
Virus de la necrosis hipodérmica y hematopoyética infecciosa (IHHNV) y virus del síndrome de Taura (TSV) en camarón silvestre (Farfantepenaeus aztecus Ives, 1891 y Litopenaeus setiferus Linnaeus, 1767) de La Laguna Madre, Golfo de México
Guzmán-Sáenz,Francisco M; Molina-Garza,Zinnia J; Pérez-Casta?eda,Roberto; Ibarra-Gámez,José C; Galavíz-Silva,Lucio;
Revista de biología marina y oceanografía , 2009, DOI: 10.4067/S0718-19572009000300012
Abstract: the occurrence of infectious hypodermal and hematopoietic necrosis virus (ihhnv) and taura syndrome virus (tsv) in wild shrimp litopenaeus setiferus (white shrimp) and farfantepenaeus aztecus (brown shrimp) captured from the estuary of la pesca in la laguna madre tamaulipas, mexico, are reported. this study was performed for histopathology and amplification of nucleic acids. the prevalence of tsv was 6.6% (12/180) and 4.4% for ihhnv (8/180). most cases were observed from november to march (15/180). the presence of these viruses in wild shrimp from the la laguna madre, alerts about the risk that are having the wild populations and the shrimp farms that are contiguous with the gulf of mexico, so it is suggested to establish a program of sanitary monitoring and to verify the impact of both viruses in the near shrimp farms of the la laguna madre.
罗氏沼虾(Macrobrachium rosenbergii)传染性皮下和造血器官坏死病毒(IHHNV)的流行病学调查  [PDF]
海洋与湖沼 , 2015, DOI: 10.11693/hyhz20150600168
Abstract: 传染性皮下和造血器官坏死病毒(infectious hypodermal and hematopoietic necrosis virus, IHHNV)是对虾养殖的重要病原之一,可感染多种虾种。罗氏沼虾(Macrobrachium rosenbergii)是中国养殖的重要沼虾品种之一。根据国际兽疫局(Office International des Epizooties, OIE)推荐的IHHNV检测方法,在中国大陆地区首次开展IHHNV在罗氏沼虾中的感染和流行情况调查。结果显示,在研究区的罗氏沼虾养殖区, IHHNV广泛流行,阳性率高达90%;但所有成年罗氏沼虾均未表现出明显的病症,仅表现为病毒的携带。通过基因序列分析显示,检测到的华南地区毒株属于Ⅰ型感染株,与菲律宾株进化关系较为接近;华东地区毒株属于Ⅱ型感染株,与东南亚株进化关系较近。本研究为IHHNV在罗氏沼虾内的感染、流行和防控提供了详细参考。
Patógenos introducidos al Perú en post larvas de Litopenaeus vannamei importadas Pathogen introduced to Peru by trade in postlarvae of Litopenaeus vannamei  [cached]
Mervin Guevara,Rubén Alfaro
Revista Peruana de Biología , 2012,
Abstract: El comercio internacional de animales acuáticos es uno de los factores más importantes en la introducción involuntaria de patógenos a una región libre de estos. Los patógenos introducidos han sido causa de enormes pérdidas económicas en organismos bajo cultivo y da os ecológicos en poblaciones silvestres. En este trabajo, utilizando la técnica de la PCR se analizaron postlarvas de Litopenaeus vannamei importadas desde Ecuador para ser utilizada en los cultivos de langostinos en Tumbes. La finalidad fue detectar patógenos como el virus de la mancha blanca (WSV), virus de la cabeza amarilla (YHV), virus de la necrosis hipodérmica y hematopoyética infecciosa (IHHNV), Baculovirus penaei (BP), virus del síndrome de Taura (TSV) y la bacteria de la hepatopancreatitis necrotizante (NHPB). Se analizaron 177 muestras de postlarvas en el a o 2009 y 274 en el 2010. En el a o 2009 se encontraron cuatro patógenos infecciosos en las postlarvas analizadas, siendo más frecuente el IHHNV (9,60%). En el a o 2010 la frecuencia de aparición de postlarvas infectadas con IHHNV fue mayor (16,79%). Tanto en el 2009 como en el 2010 se encontraron postlarvas positivas a NHPB, BP y TSV International trade of aquatic animals is the most important source for pathogens introduction in new areas, beginning cause of huge economic losses in growing animals and ecological damage. In this paper, we analyze Litopenaeus vannamei postlarvae imported for shrimp farming companies of Tumbes from Ecuador, in order to detect pathogens such as the white spot virus (WSV), yellow head virus (YHV), infectious hypodermal and haematopoietic necrosis virus (IHHNV), Baculovirus penaei (BP), Taura syndrome virus (TSV) and necrotizing hepatopancreatitis bacterium (NHPB). For this purpose, 177 samples of postlarvae in 2009 and 274 in 2010 from different larviculture laboratories of Ecuador were processed by the technique of PCR. In 2009, four infectious pathogens were present in postlarvae. In 2010 the frequency of occurrence of IHHNV –infected postlarvae was higher (16.79%). Both in 2009 and 2010 were found positive postlarvae NHPB, BP and TSV.
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