Dengue VirusDengue Virus

By: HERMAN.By: HERMAN.

Group 305Group 305

Plan of the presentationPlan of the presentation

CLASSIFICATIONCLASSIFICATION GENERAL INTRODUCTIONGENERAL INTRODUCTION STRUCTURE OF VIRIONSTRUCTURE OF VIRION PATHOGENESISPATHOGENESIS DISEASESDISEASES DIAGNOSISDIAGNOSIS PREVENTION & TREATMENTPREVENTION & TREATMENT

Dengue DeclassifiedDengue Declassified

Family: FlaviviridaeFamily: Flaviviridae Genus: FlavivirusGenus: Flavivirus Species: Dengue virusSpecies: Dengue virus

What is the Dengue What is the Dengue Virus?Virus?

Arbovirus Arbovirus Arthropod, Mosquito, bornArthropod, Mosquito, born

(Aedes aegypti)(Aedes aegypti) It is a pathogen that causes It is a pathogen that causes

Dengue fever (DF)Dengue fever (DF) Dengue hemorrhagic fever (DHF)Dengue hemorrhagic fever (DHF)

Can lead to Dengue shock syndrome (DSS)Can lead to Dengue shock syndrome (DSS)

Has four different serotypes (DEN-1,2,3,4)Has four different serotypes (DEN-1,2,3,4) First reported epidemics in 1780 in Asia, Africa, First reported epidemics in 1780 in Asia, Africa,

and North Americaand North America

Structure of virusStructure of virus

PATHOGENESISPATHOGENESISTRANSMISSION CYCLE OF DENGUE VIRUS

REPLICATION IN THE HUMAN CELLS

Target tissuesTarget tissues Dengue induces cytokine production in cellsDengue induces cytokine production in cells Cytotoxic factor effects endothelial cells Cytotoxic factor effects endothelial cells

involved in most of the followinginvolved in most of the following:: HeartHeart LiverLiver KidneysKidneys LungsLungs IntestinesIntestines SpleenSpleen Lymph nodesLymph nodes BrainBrain Skin (inflammatory rashes)Skin (inflammatory rashes)

DISEASESDISEASES

Dengue FeverDengue Fever Dengue Hemorrhagic FeverDengue Hemorrhagic Fever Dengue Shock SyndromeDengue Shock Syndrome

This is the process in which certain This is the process in which certain strains of dengue virus, complexes with strains of dengue virus, complexes with non-neutralizing antibodies can enter a non-neutralizing antibodies can enter a greater portion APCs thus increasing greater portion APCs thus increasing virus production. This generally occurs virus production. This generally occurs after a primary infection by a different after a primary infection by a different strain and results in DHF or DSSstrain and results in DHF or DSS

ANTIGEN-DEPENDENT ENHANCEMENT

Symptoms: DHFSymptoms: DHF

FeverFever HeadacheHeadache Muscle and joint painMuscle and joint pain DehydrationDehydration Nausea and/or Haematemesis (vomiting of blood)Nausea and/or Haematemesis (vomiting of blood) Epistaxis (Bleeding from the nose, mouth, or gums)Epistaxis (Bleeding from the nose, mouth, or gums) Haematuria (Blood in Urine)Haematuria (Blood in Urine) Pain behind the eyesPain behind the eyes Plasma leakagePlasma leakage Respiratory distressRespiratory distress Petechia (Skin rash) and/or Purpura (Lesions)Petechia (Skin rash) and/or Purpura (Lesions)

Diagnostic testsDiagnostic tests

Virus isolation by infection of mice using Virus isolation by infection of mice using infected mosquitoesinfected mosquitoes

Isolation in cultured mosquito cells and Isolation in cultured mosquito cells and identification by indirect IFidentification by indirect IF

Detection of IgM antibodies in the blood by Detection of IgM antibodies in the blood by PCR or Viral isolation (Serology)PCR or Viral isolation (Serology)

ELISA (Enzyme-Linked Immunoabsorbent ELISA (Enzyme-Linked Immunoabsorbent assay)assay)

Haemagglutination inhibition testHaemagglutination inhibition test

Prevention: Prevention: There is no specific treatmentThere is no specific treatmentRelieving symptoms and Relieving symptoms and

complicationscomplications:: Plasma volume replacementPlasma volume replacement Sedatives for restless patientsSedatives for restless patients Blood transfusion with Blood transfusion with

patients with significant blood patients with significant blood lossloss

Aspirin should be avoidedAspirin should be avoided

All efforts of control are aimed All efforts of control are aimed against mosquitoesagainst mosquitoes Elimination of breeding areasElimination of breeding areas Actions to prevent mosquito Actions to prevent mosquito

bites (repellant, nets, and bites (repellant, nets, and vapors)vapors)

Vaccinations are pendingVaccinations are pending Problem is that the Problem is that the

vaccination needs to prevent vaccination needs to prevent all four serotypesall four serotypes

TreatmentTreatment::

DHF

Morbidity and MortalityMorbidity and Mortality

More than 2.5 Billion people live in areas More than 2.5 Billion people live in areas that have a risk of infectionthat have a risk of infection

Over 100 million cases of Dengue Over 100 million cases of Dengue infection are reported each year globallyinfection are reported each year globally 500,000 cases pertain to DHF500,000 cases pertain to DHF

DHF has a 5% fatality rate for those DHF has a 5% fatality rate for those infectedinfected

People at high risk are children and the People at high risk are children and the elderlyelderly

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ATTENTIONATTENTION