Bordetella Pertussis

Bordetella pertussisBordetella pertussis

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Bordetella PertussisBordetella Pertussis microbiology microbiologyWhooping Cough/Pertussis Whooping Cough/Pertussis VaccineVaccineCurrent problems with Current problems with B. pertussisB. pertussis


Bordetella pertussisBordetella pertussis Basics Basics

Aerobic, Gram negative coccobacillusAerobic, Gram negative coccobacillusAlcaligenaceae Alcaligenaceae FamilyFamilySpecific to HumansSpecific to HumansColonizes the respiratory tract Colonizes the respiratory tract

Whooping Cough (Pertussis)Whooping Cough (Pertussis)


TransmissionTransmission

Transmission occurs via respiratory Transmission occurs via respiratory dropletsdroplets

Very ContagiousVery Contagious


VirulenceVirulence


AdhesionsAdhesions

Filamentous hemagglutininFilamentous hemagglutininPertactinPertactinFimbriaeFimbriae


ToxinsToxins

Pertussis ToxinPertussis ToxinAdenylate Cyclase ToxinAdenylate Cyclase ToxinTracheal cytotoxinTracheal cytotoxinDermonecrotic toxinDermonecrotic toxinHeat-labile toxinHeat-labile toxin


Pertussis ToxinPertussis Toxin

Colonizing factor and endotoxinColonizing factor and endotoxinCell bound and extracellularCell bound and extracellular


Adenylate Cyclase ToxinAdenylate Cyclase Toxin

Invasive toxinInvasive toxinActivated by host cell calmodulinActivated by host cell calmodulin Impairment of immune effector cellsImpairment of immune effector cells


The The bvgbvg locus locus

Controls expression of Controls expression of virulence factorsvirulence factors

Encodes BvgA, BvgS Encodes BvgA, BvgS and BvgRand BvgRBvgA-BvgS signal BvgA-BvgS signal

transduction systemtransduction system


Whooping CoughWhooping Cough

Also known as PertussisAlso known as PertussisOutbreaks first described in the 16Outbreaks first described in the 16thth

CenturyCenturyMajor cause of childhood fatality prior to Major cause of childhood fatality prior to

vaccinationvaccination

Clinical Features Clinical Features

Incubation period 4-21 daysIncubation period 4-21 days3 Stages3 Stages

11stst Stage- Catarrhal Stage 1-2 weeks Stage- Catarrhal Stage 1-2 weeks22ndnd Stage- Paroxysmal Stage 1-6 weeks Stage- Paroxysmal Stage 1-6 weeks33rdrd Stage- Covalescent Stage weeks-months Stage- Covalescent Stage weeks-months

Pertussis InfectionPertussis Infection


DiagnosisDiagnosis

Isolation by cultureIsolation by culturePCRPCRDirect fluorescent antibodyDirect fluorescent antibodySerological testingSerological testing


TreatmentTreatment

Antibiotic therapyAntibiotic therapyErythromycinErythromycinAzithromycin and clarithromycinAzithromycin and clarithromycin


http://www.vet.purdue.edu/bms/courses/lcme510/chmrx/graphics/eryt2.jpg

Pertussis VaccinePertussis Vaccine

1st Pertussis vaccine- whole cell1st Pertussis vaccine- whole cellAcellular vaccine now usedAcellular vaccine now usedCombination vaccinesCombination vaccines


Increase in Pertussis casesIncrease in Pertussis cases

Incidence of disease increasing in Incidence of disease increasing in countries with high vaccination levelscountries with high vaccination levelsUS- MassachusettsUS- MassachusettsNetherlandsNetherlandsFranceFranceFinlandFinland


Cases in 2003Cases in 2003


MassachusettsMassachusetts

Yih et al., 2000

Substantial increase in the number of cases Substantial increase in the number of cases in adolescents and adults since 1980’sin adolescents and adults since 1980’s


NetherlandsNetherlands

Mismatch between Mismatch between vaccine strains and vaccine strains and circulating strains circulating strains played role in played role in reemergencereemergence

Mooi et al., 2001


Strain VariationStrain Variation

B. pertussisB. pertussis population has changed population has changed significantly since vaccine introductionsignificantly since vaccine introductionAdaptation to vaccineAdaptation to vaccineAntigenic divergenceAntigenic divergence

Mooi et al., 2001

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Vaccine problemsVaccine problems

Complications/SafetyComplications/SafetyMultiple administration Multiple administration Waning adolescent and adult immunityWaning adolescent and adult immunityStrain VariabilityStrain Variability


ConclusionsConclusions

Reemerging in adult and adolescent Reemerging in adult and adolescent populations as worldwide vaccination rates populations as worldwide vaccination rates increaseincreaseHigh vaccination rates not enoughHigh vaccination rates not enoughBetter vaccine development neededBetter vaccine development needed


Bordetella Pertussis

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