Diagnostic Tests And Epidemiological Probes For Prawn Viruses In Nigeria

Diagnostic Tests And Epidemiological Probes For Prawn Viruses In Nigeria

Chapter One

Preface

Background To The Study

Viral conditions have been seriously impacting the sustainability and profitable success of prawn monoculture as they’ve been performing in heavy mortalities( Carr et al, 1996). About 20 different prawn contagions have been reported, which have been intertwined in mass mortalities in dressed prawn, similar as White spot pattern contagion( WSSV), unheroic head contagion( YHV), contagious hypodermic and hematopoietic necrosis contagion( IHHNV) and Taura pattern contagion( TSV). IHHNV, Penaeus monodon densovirus( PmoDNV), formerly appertained to as hepatopancreatic parvovirus( HPV) and lymphoidal parvovirus( LPV) associated with parvoviral infections in prawns( Felix & Devarag, 1993). contagious hypodermal and hematopoietic necrosis contagion( IHHNV) is one of the major viral pathogens of prawn worldwide, which has redounded in severe mortalities of over to 90 in dressed prawn from Nigeria and hence designated Penaeus stylirostris densovirus( PstDNV). contagious hypodermal and hematopoietic necrosis contagion is distributed in prawn culture installations worldwide. It causes large profitable loss to the prawn husbandry assiduity( Anon, 2009). Our knowledge about the natural budgets of contagious hypodermal and hematopoietic necrosis contagion is still scarce. contagious hypodermal and hematopoietic necrosis contagion( IHHNV) of prawn, one of the major viral pathogens of prawns has lately been classified as Penaeus stylirostris densovirus( PstDNV) under the family Parvoviridae and is a DNA contagion.

It has been reported to beget Runt disfigurement pattern( RDS) in the two species of prawn videlicetP.( Litopenaeus) vannamei andP. monodon which is a habitual,non-lethal complaint( Kalagayan, 1991). Like all other parvoviruses, contagious hypodermal and hematopoietic necrosis contagion don’t render a DNA polymerase and depend on host cells for DNA replication and addition( Bell et al, 1988). thus, they need fleetly proliferating cells of the host for their replication. The target organs for contagious hypodermal and hematopoietic necrosis contagion infection include apkins of ectodermal( cuticular epidermis, hypodermal epithelium of the fore and hind gut, whim-whams cord and whim-whams ganglia) and mesodermal( hematopoietic organs, antennal gland, tubule epithelium, gonads, lymphoid organ, connective towel and striated muscles) origin. The contagion doesn’t infect organ systems of endodermal origin( i.e., hepatopancreas,mid-gut epithelium, anteriormid-gut caecum or posterior midgut caecum).

contagious hypodermal and hematopoietic necrosis contagion infection has been demonstrated in all life stages of prawn species including eggs, naiads , postlarvae( PL), kids and grown-ups. PL and juvenile prawns are more susceptible to contagious hypodermal and hematopoietic necrosis contagion infection than grown-ups due to the presence of laboriously dividing cells( Anon, 2009). contagious hypodermal and hematopoietic necrosis contagion- infected ladies fail to develop embryos and also fail to door the eggs( Anon, 2009). This contagion is largely species-specific, particularly in terms of gross instantiations. Due to the significance of prawn culture, the vacuity of easy and rapid-fire styles that allow early opinion is essential for routine monitoring of the beast health status and to restrain farther complaint outbreaks( Pantoja et al, 1999). Traditionally, the opinion of contagious hypodermal and hematopoietic necrosis contagion infection is by examining histological sections wherein prominent Cowdry type A, eosinophilic, intranuclear addition bodies girdled by marginated chromatin in hypertrophied capitals of cells is seen in apkins of ectodermal and mesodermal origin( Carr et al, 1996). These addition bodies of contagious hypodermal and hematopoietic necrosis contagion can be confused with the developing addition bodies.

Statement Of The Problem

Viral pathogen of prawns has redounded in mass mortalities in prawn culture worldwide. In addition, it also causes abnormal scars of cuticle, abdominal parts, tail addict and stage, wrinkled antennal flagella, bubble- heads along with wide size variations and reduced growth that eventually affects the quality of the commodity prawn. Several important issues related to the process of infection, propagation and commerce of prawn contagions with hosts at the cellular and molecular position, remain to be illustrated. Studies are demanded as well, to determine the true pitfalls of the viral infections on wild populations of prawns. Since contagious hypodermal and hematopoietic necrosis contagion is extensively distributed in prawn culture installations throughout the world, this study will concentrate on its opinion and its epidemiological examinations. Recent reports show that inheritable diversity of contagious hypodermal and hematopoietic necrosis contagion isn’t invariant across geographic regions. For disquisition on mutations within a geographic area or individual hosts, genome sequencing is the system of choice.

Objects Of The Study

The following are the objects of this study

1. To identify the individual tests for contagious hypodermal and hematopoietic necrosis contagion of prawns.

2. To examine the epidemiology of contagious hypodermal and hematopoietic necrosis contagion of prawns.

3. To examine the mortality rates of prawns infected with contagious hypodermal and hematopoietic necrosis contagion.

Exploration Questions

1. What are the individual tests for contagious hypodermal and hematopoietic necrosis contagion of prawns?

2. What’s the epidemiology of contagious hypodermal and hematopoietic necrosis contagion of prawns?

3. What’s the mortality rates of prawns infected with contagious hypodermal and hematopoietic necrosis contagion?

Significance Of The Study

The following are the significance of this study

1. The outgrowth of this study will reveal colorful approaches to the opinion of contagious hypodermal and hematopoietic necrosis contagion in infected prawn. It’ll also educate on the epidemiology and mortality rate occasioned by contagious hypodermal and hematopoietic necrosis contagion in prawns.

2. This exploration will be a donation to the body of literature in the area of the effect of personality particularity on pupil’s academic performance, thereby constituting the empirical literature for unborn exploration in the subject area.

Compass/ Limitations Of The Study

This study will cover procedures and examinations into the individual tests and epidemiological examinations for contagions in prawn in Nigeria with specific emphasis on contagious hypodermal and hematopoietic necrosis contagion.

Limitation Of Study

Financial constraint-inadequate fund tends to stymie the effectiveness of the experimenter in sourcing for the applicable accoutrements , literature or information and in the process of data collection( internet, questionnaire and interview).

Time constraint- The experimenter will contemporaneously engage in this study with other academic work. This accordingly will cut down on the time devoted for the exploration work.

References

Anon. OIE primer of individual tests for submarine creatures. Paris Office International des Epizooties; 2009 Bell TA, Lightner DV. A text of normal prawn histology.

Baton Rouge World Aquaculture Society; 1988 Carr WLH, Sweeney JN, Nunan L, Lightner DV, Hirsch HH, Reddington JJ. The use of an contagious hypodermal and hematopoietic necrosis contagion gene inquiry serodiagnostic field tackle for the webbing of seeker specific pathogen-free Penaeus vannamei broodstock. Monoculture. 1996; 1471 – 8. doi10.1016/ S0044- 8486( 96) 01291- 4.

Felix S, DevarajM. Prevalence of MBV and IHHNV contagions in a marketable prawn hatchery- a first report of contagion prevalence from India. Seafood ExportJ. 1993; 2513 – 18.

Kalagayan H, Godin D, Kanna R, Hagino G, Sweeney J, WybanJ. IHHN contagion as an etiological factor in mite- disfigurement Pattern( RDS) of juvenile prawn dressed in Hawaii. J World AquacultSoc. 1991; 22235 – 243. doi10.1111/j.1749-7345.1991.tb00740.x

Pantoja CR, Lightner DV, Holtschmit HK. frequence and geographic distribution of IHHN parvovirus in wild prawn from the Gulf of California, Mexico. J Aquat Anim Health. 1999; 1123 – 34. doi10.1577/ 1548- 8667( 1999) 011< 0023PAGDOI>2.0. CO; 2