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CASE
A 53-year-old male developed symptoms of malaise, fatigue,
and mild cough while on vacation in DELHI with his family.
Six days after the onset of symptoms, the patient returned
home to BIKANER still ill and complaining of a headache,
low grade fever, chest pains, and a cough.
Pt treated in line of the viral fever.
At day 10, the patient had a cough with the production of
purulent sputum.
A sputum specimen was collected and sent to the laboratory
for culture. Thepatientssymptoms persisted despite treatment
with ampicillin-clavulanic acid [Augmentin(R)].
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At day 14 of his illness, developed paroxysmal cough,
occasional vomiting after cough, and subconjunctival
hemorrhage.
At day 15 his illness was complicated by episodes of seizure,
with clonic movements of the arms and legs, brief loss of
consciousness, and confusion. The episodes were triggered by
mild, unremarkable coughing paroxysms.
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The Gram stain of sputum revealed Gram negative
coccobacilli.
The nested PCR from two different site of the nasophyrnx andsputum showed Bordetella pertussis.
This was supported by culture on LR media and serology.
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WHAT THIS CASE
INDICATES.
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RESURGENCE OF BORDETELLA PERTUSSIS IN ADULTS
PRESENTOR-Dr MAHAVEER SINGH
MODERATOR-Dr S.ANURADHA
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PERTUSSIS INCIDENCE IN USA
FROM 1990 TO 2011(AGE WISE) PROPORTION OF ADULT CASES
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PERTUSSIS INCIDENCE AND GENOME
ANALYSIS
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BORDETELLA PERUSSIS
Bordetella is a small (approximately 0.8 m by 0.4 m), rod-
shaped, coccoid, or ovoid gram negative bacterium that is
encapsulated and does not produce spores.
While nine species of Bordetellahave been identified to date,
only three additional members, B. bronchiseptica, B.
parapertussis, and B. holmesii, have been associated with
respiratory infections in humans and other mammals.
B. bronchiseptica produces infection in immunocompromised
and AIDS.
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VIRULENCE FACTOR OF
BORDETELLA PERTUSSIS
THE BVG -AS TWO
COMPONENT SYSTEM
ADHESIONS
1. FILAMENTOUS
HAEMAGGLUTININ
2. FIMBRIAE
3. PERTACTIN
TOXINS
1. ADENYLATE CYCLASE
2. PERTUSSIS TOXIN
3. DERMATONECROTIC
TOXIN
4. TRACHEAL CYTOTOXIN
LIPOPOLYSACCHARIDE
SECRETORY SYSTEMS
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Bvg-AS TWO COMPONENT SYSTEM
Bvg locus encodes proteins that
transmit extracellular signals to
the cellular transcription
machinery, causing changes in
gene expression. With theexception of tracheal cytotoxin,
expression of virulence factors is
coordinately regulated by the
products ofthe bvglocus. BvgS is a 135 kDa periplasmic
sensor histidine kinase.
BvgA, the response regulator, is a
23-kDa cytoplasmic protein .
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FILAMENTOUS HEAMAGGLUTININ-
Filamentous hemagglutinin is a
large (220 kDa) protein that formsfilamentous structures on the cell
surface. FHA binds to galactose
residues on a sulfated glycolipid
called sulfatide which is verycommon on the surface of ciliated
cells(respiratory epithelia).
Mutations in the FHA structural
gene reduce the ability of the
organism to colonize, and
antibodies against FHA provide
protection against infection
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FIMBRIE
B.pertussis fimbriae are
submicroscopic proteinaceousappendages that protrude from the
cell surface. They are comprised of
a major and a minor subunit.
The minor subunit, named FimD
binds to the integrin Vla-5, located
on monocytes. The major subunitbinds to sulfated sugars like heparan
sulfate, chondroitin sulfate and
dextran sulfate which are ubiquitous
in the respiratory tract
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PERTACTIN
Pertactin, a 69 kDa nonfimbrial
outer membrane protein, under
the control of the bvg locus, is
partly responsible for the
adhesion of the bacteria to the
host cells.
The mature protein has two
Arginine-Glycine-Aspartic acid
(RGD) sequences, at 225-227and 665-667. These sequences
mimics sequences on proteins
like fibronectin, vitronectin and
fibrinogen.
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PERTUSSIS TOXIN
PTx is a two component, A+B
bacterial exotoxin. The A subunit
(S1) is an ADP ribosyltransferase. The B component,
composed of five polypeptide
subunits (S2 through S5), binds
to specific carbohydrates on cell
surfaces. The A subunit gains enzymatic
activity and transfers the ADP
ribosyl moiety of NAD to the
membrane-bound regulatory
protein Gi that normally inhibits
the eukaryotic adenylate cyclase
and intracellular Levels of cAMP
increases.
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This has the effect to disruptcellular function, and in the caseof phagocytes, to decrease their
phagocytic activities such as
chemotaxis, engulfment, theoxidative burst, and
bacteridcidal killing
Systemic effects of the toxin
include lymphocytosis andalteration of hormonal activitiesthat are regulated by cAMP,such as increased insulin
production (resulting in
hypoglycemia) and increasedsensitivity to histamine(resulting in increased capillary
permeability, hypotension andshock).
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ADENYLATE CYCLASE
This toxin is a 45 kDa protein that may be cell-associated or
released into the environment. It is active only in the presenceof a eukaryotic regulatory molecule called calmodulin.
This toxin acts locally to reduce phagocytic activity and
probably helps the organism initiate infection.
TRACHEAL CYTOTOXIN
The tracheal cytotoxin is a peptidoglycan fragment, which
appears in the extracellular fluid where the bacteria are
actively growing. The toxin kills ciliated cells and causes their
extrusion from the mucosa. It also stimulates release of
cytokine IL-1, and so causes fever.
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DERMATONECROTIC TOXIN
The lethal toxin is a 102 kDa protein composed of four
subunits, two with a mw of 24kDa and two with mw of 30
kDa.
It causes inflammation and local necrosis adjacent to sites
whereB. pertussisis located.
LIPOPOLYSACCHARIDE
As a Gram-negative bacterium Bordetella pertussis possesses
lipopolysaccharide (endotoxin) in its outer membrane.
It is heterogeneous, with two major forms differing in the
phosphate content of the lipid moiety.
The unfractionated material elicits the usual effects of LPS
(i.e., induction of IL-1, activation of complement, fever,
hypotension, etc.
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PATHOGENESIS OF BORDETELLA PERTUSSIS
CLINICAL FEATURE
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Length Clinical Features
Stage 1: Catarrhal Usually 7-10 days; range
of 4-21
Characterized by:
Coryza
Low-grade fever
Mild, occasional cough (which gradually becomes more severe)
Stage 2: Paroxysmal Usually lasts 1-6 weeks,
but may persist for up to
10 weeks
Characterized by:
Paroxysms of numerous, rapid coughs due to difficulty expelling thick mucus from
the tracheobronchial tree.
Long aspiratory effort accompanied by a high-pitched "whoop" at the end of the
paroxysms
Cyanosis
Vomiting and exhaustion
Paroxysmal attacks:
Occur frequently at night, with an average of 15 attacks per 24 hours.
Increase in frequency during the first 1-2 weeks, remain at the same frequency for
2-3 weeks, and then gradually decrease.
Stage 3: Convalescent Usually 7-10 days; range
of 4-21
Characterized by:
Gradual recovery
Less persistent, paroxysmal coughs that disappear in 2-3 weeks
Paroxysms often recur with subsequent respiratory infections for many months after theonset of pertussis.
CLINICAL FEATURE
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VIDEO OF ADULT WHOOPING COUGH
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Classification of coughing episodes involving
pertussis based on cultures, serology, family
exposure, and clinical symptoms
1. B. pertussisisolated from the nasopharynx.
2. At least one of the following criteria fulfilled:
Significant increase in PT IgG.
Significant increase in FHA IgG without other criteria forparapertussis.
Both PT IgG and FHA IgG 6,000 in the same convalescentserum.
Family member with pertussis verified by culture or serology.
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3.Clinical pertussis with at least 3 weeks of paroxysmal cough and
known exposure to pertussis outside the family; serum samples
lacking or suboptimal timing in relation to onset of symptoms.
4.Known exposure to pertussis within or outside the household;
clinical symptoms not evaluable because of early erythromycin
treatment
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BORDETELLA PERTUSSIS IN ADULTS
Most cases of adult pertussis occur in those who have a history
of past pertussis vaccination or infection. Pertussis has been
found to be the cause in 1320% of adults presenting with
prolonged cough.
Adults and adolescents usually present late in the course of the
infection, often after 4 or more weeks of coughing
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COMPLICATIONS
The most frequent complication observed in children is
pneumonia, which occurs in 6% of cases.
In the first 2 months of life, pneumonia, seizures and
encephalopathy have been reported in 25%, 3% and 1% of
cases, respectively.
After childhood, the risk of complications increases with age.
Pneumonia has been observed in 2% of patients less than 30
years of age, as compared with 5%9% of older patients.
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Other complications observed in adults are syncope,urinary incontinence, back pain, rib fracture and
hernia.
Severe paroxysm, post-tussive cyanosis, whooping,
posttussive vomiting, apnea, pneumonia and seizures
are the most frequent reasons patients are admitted tohospital, regardless of age
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Complications
Children
Hypoxia
Apnea
Pneumonia
Seizures
Adults
Pneumonia
Rib Fracture
Weight LossHernias
Urinary Incontinence
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DIAGNOSIS OF BORDETELLA PERTUSSIS
CULTURE
Culture is considered to bethe gold standard.
Its sensitivity decreasessteeply if the specimen istaken more than 2 weeks
after onset of cough and isreduced by prior immunityfrom disease orimmunisation.
Results can be available in72 h, especially in high titreinfection, but 2 weeks arerequired before culture maybe definitively reported asnegative.
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DNA PCR
Polymerase chain reaction (PCR)methods enhance the probability ofidentification ofB.pertussis.
Conventional-semi nested (CsnPCR) andreal-time PCR (RtPCR) are two PCRtools employed for the detection of B.
pertussis with the former detecting
amplified target gene products visualizedby ultra violet (UV) light followingagarose gel electrophoresis and the lattermonitoring the fluorescence emittedthroughout PCR reaction phases
indicating gene amplification
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Novel real-time PCR assays targeting the Bordetella pertussis
insertion sequence IS481, the toxin promoter region and
Bordetella parapertussis insertion sequence IS1001 were
designed.
PCR assays were capable of detecting 10 copies of target
DNA per reaction, with an amplification efficiency of 90%.
Since positive results may be obtained even when theorganism is no longer culturable.
However, the sensitivity of PCR decreases with the duration of
symptoms, since the method is based on the detection of themicroorganism.
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SEROLOGY
Infection of bordetella pertusis is followed by increase in the
concentrations in serum of IgA, IgG, and IgM antibodies to
specific antigens as well as to preparations of the whole
organism.
The antibodies measured to detect infection are directed
against FIM2/3, PRN, and LPS
In contrast to natural infection, the primary immunization of
children induces mainly IgM and IgG antibodies
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Serologic diagnosis of pertussis may be suspected by thedemonstration of an increase in agglutinin titer or the use of
ELISA, showing an increase in IgA or IgG antibody titer to
PT, FHA, PRN, FIM, or to sonicated whole organisms in two
serum samples collected 2 to 4 weeks apart.
It is now clear that antibody responses to FHA and PRN alsooccur following other Bordetella infections, so that isolated
increases in titers of antibody against these antigens are not
specific forB. pertussisinfection..
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In addition, high titers of antibody to FHA may be the result of
cross-reacting epitopes of nonencapsulated H.influenzae,
M.pneumoniae, C.pneumoniae, and perhaps other bacteria
The greatest sensitivity and specificity for the serological
diagnosis of B. pertussis infection is achieved by ELISA and
measurement of IgG and IgA antibodies to PT.
A significant rise in titer (greater than or equal to twofold)
between acute-phase and convalescent-phase sera needs to be
demonstrated. In adolescents and adults, single high values ofIgG or IgA antibodies to PT also indicate infection.
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SINGLE SERUM SPECIMEN
Single-sample serology tests for antipertussis toxin IgG mustbe collected at least two weeks after symptom onset. A highantibody titer more than two years following vaccination
supports the diagnosis of pertussis.
A solitary antibody concentration of IgG anti-PT greater than
100-125 EU/mL suggests recent B. pertussis infection orexposure. A study in the Netherlands showed that a titer of 100EU/mL against this antigen has a sensitivity of 76 percent andspecificity of 99 percent for the diagnosis of acute pertussis.
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SEROLOGICAL CRIETARIA
Significant increase in ELISA diagnostics
1. Controll serum interassay variation Acute to convalascent phaseincrease in AB
50%
100%
1. MINIMUM LEVEL FOR CONVALESCENT SERUM
A. 4 TIMES MLD FOR ANTIBODIES TO PT
B. 32 TIMES MLD FOR ANTIBODIES TO FHA
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MANAGEMENT OF BORDETELLA
PERTUSSIS
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SPECIAL GROUPS
Postexposure prophylaxis
The decision to administer postexposure chemoprophylaxis is
made after considering the infectiousness of the patient and theintensity of the exposure, the potential consequences of severe
pertussis in the contact, and possibilities for secondary
exposure of persons at high risk from the contact (e.g., infants
aged
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Coughing (symptomatic) household members of a pertussis
patient should be treated as if they have pertussis.
Postexposure prophylaxis should be administered in exposure
settings that include infants aged
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CLOSE CONTACT PROPHYLAXIS
A close contact of a patient with pertussis is a person who had
face-to-face exposure within 3 feet of a symptomatic patient.
Close contacts also can include persons who Have direct contact with respiratory, oral, or nasal
secretions from a symptomatic patient.
Shared the same confined space in close proximity with a
symptomatic patient for >1 hour.
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PERTUSSIS VACCINE
The pertussis vaccine is available as:
DTaP (Diphtheria Toxoid-Tetanus Toxoid-acellular
Pertussis vaccine)
DTaP in combination with Haemophilus influenzae type b
(Hib) vaccine
DTaP in combination with hepatitis B and inactivated
polio vaccines
DTaP in combination with Hib, hepatitis B and inactivated
polio vaccines
Tdap (Tetanus Toxoid reduced-Diphtheria-acellular
Pertussis vaccine)
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VACCINE RECOMMENDATIONWho should receive the vaccine?
Most infants and children younger than seven years of age
should receive DTaP beginning at two months of age.
Children 7-10 years of age who are incompletely immunizedagainst pertussis should receive Tdap.
11-18 year olds should receive a single dose of Tdap instead of
a Td booster if they have completed the recommendedchildhood DTP/DTaP immunization series and have not
received Tdap. The preferred age for Tdap vaccination is 11-12
years.
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Adults 19-64 years of age should also receive a single dose of
Tdap to replace a single dose of Td for booster immunization
if their most recent tetanus toxoid-containing vaccine was 10
or more years earlier.
For adults(>65) who have not received Tdap vaccine and are
likely to come in contact with infants suffering from pertussis,
a single dose of Tdap vaccine (2 weeks before the contact with
the infant) is indicated if 2 years or more have elapsed sincethe last dose of Td vaccination.
d b i i l h h i h
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Tdap may be given at an interval shorter than 10 years since the
last tetanus toxoid-containing vaccine in order to protect against
pertussis in special conditions
Women
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Who should not receive the vaccine?
Those with a history of a serious allergic reaction (such as
anaphylaxis) to any of the vaccine components.
Those with a history of encephalopathy (e.g. coma or
prolonged seizures) not attributable to an identifiable cause
within 7 days of administration of a vaccine withpertussis components.
People with the following conditions should discuss with their
health care professional whether they should receive
DTaP vaccine.
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Moderate or serious reaction after receiving DTP or DTaP in
the past.
Seizure or have a parent or sibling who has had a seizure.
Brain problem that is unstable or getting worse.
People who are moderately or severely ill should consult withtheir physician before receiving any vaccine.
VACCINATION SCHEDULE
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VACCINATION SCHEDULE
A DTaP vaccine is given to most children at two, four, and six
months of age. A fourth dose of DTaP is given between 15 and18 months, and a fifth dose is given at age four to six years.
Children younger than age seven who should not receive the
pertussis vaccine should receive the DT (diphtheria-tetanus) vaccine.
Between the ages of seven and nine, Tdapwhich contains
the same amount of tetanus vaccine as DTaP or DT, butcontains much less diphtheria toxoid is given to protect
against tetanus, diphtheria and pertussis.
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At age 11-12 years, a booster shot of tetanus-diphtheria-
acellular pertussis (Tdap) is needed. It should be given no later
than 16 years of age. Every 10 years and thereafter, a booster
of Td is needed to maintain protection against diphtheria
and tetanus.
One booster dose of Tdap is recommended for adults to
replace a Td booster. Every 10 years thereafter, a booster of Tdis needed to maintain protection against diphtheria and tetanus
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.
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ADVERSE REACTIONS
Mild Problems (Common) Fever, redness or swelling, soreness or tenderness fussiness,
tiredness or poor appetite, vomiting.
Moderate Problems (Uncommon) Seizure.
Non-stop crying, high fever.
Severe Problems (Very Rare) Serious allergic reaction. Long-term seizures, coma, or lowered consciousness.
Permanent brain damage.
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RECOMMENDED WHO CASE
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RECOMMENDED WHO CASE
DEFINATIONS OF PERTUSSIS
Clinical case definition
A case diagnosed as pertussis by a physician orA person with a cough lasting at least two weeks with at least
one of the following symptoms:
Paroxysms (i.e. fits) of coughing
Inspiratory whooping
Post-tussive vomiting (i.e. vomiting immediately aftercoughing) without other apparent cause
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Criteria for laboratory confirmation-
Isolation ofBordetella pertussisor
Detection of genomic sequences by means of the polymerase
chain reaction (PCR) or
Positive paired serology.
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Suspect Case-
A clinical syndrome or illness consistent or compatible withpertussis and without other apparent cause such as:
Any acute cough illness with paroxysmal cough or inspiratory
whoop. Any acute cough illness in a person who is a close contact to a
patient with a confirmed or probable case.
Any cough associated with apnea in an infant.
Any acute cough illness lasting 7 days when there is areported outbreak of pertussis in the community.
Any acute cough illness with positive PCR results for B.pertussis that does not meet the clinical case definition.
Clinical case definition of pertussis for
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Clinical case definition of pertussis for
surveillance purposes
RESURGENCE OF BORDETELLA
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RESURGENCE OF BORDETELLA
PERTUSSIS IN ADULTS
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CAUSES FOR RESURGENCE
VACCINES OFBORDETELLA PERTUSSIS?A CAUSE OFRESURGENCE .
VNTR CHANGES AND MODIFICATION OF BACTERIAL
GENOME.
TRANSITION IN VACCINE.
ADAPTATION AND WANING IMMUNITY.
INCREASED DIAGNOSTIC EFFICACY.
VACCINES OF BORDETELLA PERTUSSIS
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VACCINES OF BORDETELLA PERTUSSIS
?A CAUSE OF RESURGENCE
Is polymorphism in pertactin and pertussis toxin driven by
host immunity, or is it the result of random fixation due to
genetic drift?
It is conceivable that the increase in fitness associated with
nonvaccine types of pertactin and pertussis toxin in vaccinated
populations is substantial enough to drive expansion of strains
carrying these protein variants.
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VNTR CHANGES AND MODIFICATION
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VNTR CHANGES AND MODIFICATION
OF BACTERIAL GENOME
The combined MAST-MLVA profiles were used to perform
clustering analyses of the DutchB. pertussisstrains isolated
before the introduction of the pertussis vaccine in 1953 and
isolates obtained before and after the pertussis epidemics in the
1990s, a period in which neither vaccine formulation norvaccine coverage have changed.
The analysis showed that the profiles from strains predating
the vaccination era were more diverse than those isolated inthe 1990s and only distantly related to the recent strains
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There was a strong decrease in diversity in the genotypes of
theB. pertussisstrains during and after the epidemics in the1990s, suggesting that these epidemics were caused by a
limited number of strains (clonal expansion).
MLVA markers may not reveal causal relationships but can be
helpful to signal clonal expansions and thus visualize the
spread of a subgroup of theB. pertussispopulation with
increased fitness, e.g., becauseB. pertussisis able to escape
host immunity.
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Previous studies showed that antibodies against Prn1, present
in the current vaccine, are less efficient in protecting against
pertussis in animals challenged with the other Prn variants.
Variation of theprngene is caused by variation in the number
and composition of the repeats in this virulence gene. Hence,this is an example of a VNTR within a virulence gene in which
variation results in antigenic change and possible vaccine
escape.
In biology, minimum spanning trees can easily be applied to
multistate data such as MLVA, MAST, or MLST profiles.
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MINIMUM SPANNING TREE
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ADAPTATION AND WANING IMMUNITY
The Ptx promoter showed a relatively high degree ofpolymorphism, suggesting that fine tuning of Ptx productionhas adaptive value.
Globally, ptxP1 and ptxP3 were the most prevalent ptxPalleles. The replacement of ptxP1 strains by ptxP3 strains inrecent times is a global phenomenon because it has beenobserved in 11 countries representing 4 continents; Asia,Europe, and North and South America.
When compared with ptxP1 strains, ptxP3 strains produced1.62 times more Ptx.
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INCREASED DIAGNOSIS AND
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INCREASED DIAGNOSIS AND
REPORTING
A recent study in Toronto, Canada, reports that a marked
increase in pertussis incidence in 2006 was associated with a
markedly increased volume of tests performed, primarily PCR-
based assays. Increased press reports and scientific literature
on the resurgenceofpertussis,as well as reports of pertussisvaccine trials and subsequent licensure of low dose acellular
pertussis vaccines for use in adults, may have also led to an
increase in clinician awareness and reporting.
TAKE HOME MESSAGE
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TAKE HOME MESSAGE
Pertussis is a respiratory infection which causes whoopingcough
Pertussis has its resurgence so it should be considered in caseof chronic cough of >2 week duration.
Typical symptoms are initially cold-like followed by a stage ofrapid coughing and finally a recovery stage of coughing whichcan last for weeks or months.
Diagnostics include a nasopharyngeal swab culture, DNAPCR, and ELISA test for antibodies.
Macrolides are the primary antibiotic used against an pertussisinfection.
Vaccination is still the single best way to prevent whoopingcough although not everyone will get an immune response andimmunity wanes with time. This means that people can still getwhooping cough if they have been vaccinated or if they havehad previous infection.
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