Bordetella pertussisBordetella pertussis
www.freelivedoctor.comwww.freelivedoctor.com
OutlineOutline
Bordetella PertussisBordetella Pertussis microbiology microbiologyWhooping Cough/Pertussis Whooping Cough/Pertussis VaccineVaccineCurrent problems with Current problems with B. pertussisB. pertussis
www.freelivedoctor.comwww.freelivedoctor.com
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)
www.freelivedoctor.comwww.freelivedoctor.com
TransmissionTransmission
Transmission occurs via respiratory Transmission occurs via respiratory dropletsdroplets
Very ContagiousVery Contagious
www.freelivedoctor.comwww.freelivedoctor.com
VirulenceVirulence
www.freelivedoctor.comwww.freelivedoctor.com
AdhesionsAdhesions
Filamentous hemagglutininFilamentous hemagglutininPertactinPertactinFimbriaeFimbriae
www.freelivedoctor.comwww.freelivedoctor.com
ToxinsToxins
Pertussis ToxinPertussis ToxinAdenylate Cyclase ToxinAdenylate Cyclase ToxinTracheal cytotoxinTracheal cytotoxinDermonecrotic toxinDermonecrotic toxinHeat-labile toxinHeat-labile toxin
www.freelivedoctor.comwww.freelivedoctor.com
Pertussis ToxinPertussis Toxin
Colonizing factor and endotoxinColonizing factor and endotoxinCell bound and extracellularCell bound and extracellular
www.freelivedoctor.comwww.freelivedoctor.com
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
www.freelivedoctor.comwww.freelivedoctor.com
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
www.freelivedoctor.comwww.freelivedoctor.com
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
www.freelivedoctor.comwww.freelivedoctor.com
DiagnosisDiagnosis
Isolation by cultureIsolation by culturePCRPCRDirect fluorescent antibodyDirect fluorescent antibodySerological testingSerological testing
www.freelivedoctor.comwww.freelivedoctor.com
TreatmentTreatment
Antibiotic therapyAntibiotic therapyErythromycinErythromycinAzithromycin and clarithromycinAzithromycin and clarithromycin
www.freelivedoctor.comwww.freelivedoctor.com
Pertussis VaccinePertussis Vaccine
1st Pertussis vaccine- whole cell1st Pertussis vaccine- whole cellAcellular vaccine now usedAcellular vaccine now usedCombination vaccinesCombination vaccines
www.freelivedoctor.comwww.freelivedoctor.com
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
www.freelivedoctor.comwww.freelivedoctor.com
Cases in 2003Cases in 2003
www.freelivedoctor.comwww.freelivedoctor.com
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
www.freelivedoctor.comwww.freelivedoctor.com
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
www.freelivedoctor.comwww.freelivedoctor.com
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
www.freelivewww.freelivedoctor.comdoctor.com
Vaccine problemsVaccine problems
Complications/SafetyComplications/SafetyMultiple administration Multiple administration Waning adolescent and adult immunityWaning adolescent and adult immunityStrain VariabilityStrain Variability
www.freelivedoctor.comwww.freelivedoctor.com
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
www.freelivedoctor.comwww.freelivedoctor.com