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What is Pertussis
 Bordetella pertussis also
referred to as Whooping
Cough
 Whooping cough is a
disease caused by a
fastidious pathogen that
invades the respiratory
system. This pathogen
secretes a toxin that
disrupts the normal
function of cilia in the
lungs, resulting in a severe
cough.
Gram-negative, aerobic coccobacillus
Humans are the only known host of pertussis.
Bordetella pertussis is found in the mouth, nose, and throat
Incidence
Pertussis occurs year-round, peaking in
the later part of the year.
Annual incidence peaks every three to
five years.
Adolescents and adults represent over
half of the reported cases nationally. Even
among highly vaccinated populations,
waning immunity leads to a substantial
number of susceptible older children and
adults.
Outbreaks are more likely in fall and
winter during cold and flu season
Adolescents and adults can serve as an
important reservoir for transmission to
young infants, who are at increased risk
for serious complications
Prevalence
Prevalence:
 Not all cases of whooping cough are reported or even diagnosed.
Many cases of whooping cough are misdiagnosed due to
individuals who have partial immunity (had only some of the
required vaccinations) because their cough is less severe and
mimics a common cold.
 There are approximately 40,000,000 cases of whooping cough
reported annually across the world.
 In 2010, approximately 27,550 cases were reported in the United
States, the most since 1959.
source: CDC
Whooping cough is the most common vaccine-preventable disease seen in the
U.S.
Symptoms
 Clinical symptoms of pertussis are similar to those of
other infections:
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Runny nose
No or low grade fever
Cough
These symptoms also appear with croup or bronchiolitis
respiratory syncytial virus (RSV) in children, viral or bacterial
pneumonia, and other causes of chronic cough in adults
therefore, isolation of the bacterium and confirmation of the
pertussis diagnosis if very important, particularly if an outbreak
is suspected.
Symptoms appear between 6 to 21 days (average 7 – 10) after exposure
Pertussis: Three Stages
 Catarrhal stage (prodromal stage; indistinguishable from the common cold):
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Runny nose
Sneezing
Mild cough
Low-grade fever
Malaise
 Paroxysmal stage:
After a week or two, Pertussis can be distinguished from the common cold by the
paroxysm associated with coughing.; cough ending in a high-pitched inspiratory
“whoop” sound, hence the name whooping cough.
Coughing fits can last up to 12 weeks (which is why whooping cough is often referred
to as the “100 day cough”). Fever is absent or minimal.
 Convalescent stage:
Period of recovery as the cough slowly becomes less violent and the respiratory
system begins to heal. May take up to 3 weeks to completely recover from B.
pertussis.
People with mild pertussis may have a persistent cough but without the whooping sound
Transmission
When an infected
person coughs or
sneezes, tiny germladen droplets are
sprayed into the air
and breathed into
the lungs of those
nearby.
Pertussis is transmitted through
respiratory and nasal secretions.
A coughing attack can be very forceful;
the velocity of air from a vigorous cough
through the nearly closed vocal cords
can approach 500 miles per hour.
Pertussis is transmitted through droplets
Transmission
Pertussis is highly contagious
Want proof?
 A person with pertussis will infect almost everyone in
their household if those people aren’t vaccinated.
 As many as 80% of immunized household contacts of
symptomatic cases acquire infection, mainly because of
waning immunity.
People with pertussis should avoid contact with others until they have been treated
with antibiotics for five days
Think Pertussis
THINK of pertussis in anyone with the following
symptoms, regardless of vaccination history:
A cough in a person who has been notified of a close exposure
to pertussis,
A paroxysmal cough of any duration, with whooping, posttussive vomiting/gagging or apnea, or
A persistent cough of unknown etiology, lasting more than
seven days.
Pertussis can strike at an age
Diagnostic Testing
 Several types of laboratory tests are commonly used
for the diagnosis of Bordetella pertussis. Culture is
considered the gold standard because it is the
only 100% specific method for identification. Other
tests that can be performed include :

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polymerase chain reaction (PCR) and
serology
 Serologic tests are
more useful for
diagnosis in later
phases of the disease.
 For the CDC single
point serology, the
optimal timing for
specimen collection is
2 to 8 weeks following
cough onset, when the
antibody titers are at
their highest; however,
serology may be
performed on
specimens collected up
to 12 weeks following
cough onset.
Diagnostic Testing
 Culture testing is the criterion standard for B pertussis
infection, owing to its high specificity (100%) for
identification.
 The best time frame for nasopharyngeal specimen
collection for culture testing is within the first 2 weeks
of cough onset, when viable bacteria are present.
Diagnostic Testing
 The best, but most difficult way is to try to detect the
causative organism (Bordetella pertussis) in the back
of the nose. This usually involves passing a swab on a
wire through a nostril to the back of the throat and
sending it to a medical lab to culture the material.
 This may take 5 to 7 days. If Bordetella pertussis or
parapertussis grows this is usually taken as proof that
it is whooping cough.
Communicability of Pertussis
 Patients are most infectious early in the
illness, but communicability may persist
for three weeks after onset of cough.
 During the first week of illness, symptoms
resemble “the common cold,” and
paroxysmal coughing gradually develops
during the second week of illness.
 Antimicrobial therapy decreases
communicability and may limit the spread
of disease.
Prevent The Spread
 Advise patients with suspect
pertussis to stay home from
school, work, or other activities
during which they could expose
others until they have completed
five full days of appropriate
antimicrobial treatment.
 The bacteria is shed in nasopharyngeal
secretions (droplets) and spreads when
secretions get into mucous membranes such
as the mouth, nose, eyes, or non-intact skin,
especially when droplets are disseminated
during coughing and sneezing.
 The incubation period for pertussis is
usually 7 to 10 days, but can range from four
to 21 days.
 Exception: If onset of cough was
more than three weeks prior, the
patient is no longer infectious,
even if the cough persists.
Communicability / Infectiousness
Cases are potentially infectious for the first
three weeks of cough.
Inform patients with suspected pertussis to stay at home and avoid
close contact with others until they have:
Completed the fifth day of an appropriate antibiotic
OR
Had cough symptoms for at least three weeks.
VDH Definition of close contact: within 3 feet of infected patient for:
(a)1 hr continuous period, or (b) 10 hrs/week.
Infectiousness after Antibiotic
 Patients are considered to be non-infectious after
completing the fifth day of appropriate antimicrobial
treatment; however, they should complete the full
regimen to avoid bacterial relapse.
Some health care providers are prescribing a one- or -three-day
course of azithromycin (Zithromax®) in place of the five-day course
that is currently one of the standard pertussis treatment options.
While this may be appropriate for some respiratory illnesses, the
data from published randomized clinical trials using a three-day
course for treatment of pertussis are insufficient.
The standard recommendations for a five-day course will remain
unchanged until new data from comparative studies are available.
Assessing Potential Contacts
Contacts of pertussis cases may include:
 Household members (who stay overnight in the same household)
 Day care contacts in the same home day care or in the same classroom
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within a day care center (in part because of the increased severity of
disease in very young children)
Persons who have had direct face-to-face contact with an infectious
pertussis case during coughing or sneezing
Students participating in extracurricular activities with a pertussis case
at least 10 hours per week
Other persons spending at least 10 hours per week with an infectious
case, during which time they are frequently in close proximity (i.e.,
within arm’s length)
Other contacts identified by public health in an outbreak situation
Local public health will work with the patient and the community to
identify close contacts
Prophylaxis
Antimicrobial prophylaxis of close contacts:
 Antimicrobial prophylaxis (same regimen as therapy for cases)
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may be recommended to patients who are asymptomatic but are
close contacts of pertussis cases.
Antimicrobial prophylaxis is recommended if exposure to an
infectious case occurred within the previous 21 days (the
maximum incubation period for pertussis).
Asymptomatic contacts receiving prophylaxis should not be
excluded from their usual activities.
Symptomatic contacts should be evaluated as suspect pertussis
cases.
In general, antimicrobial prophylaxis isn't recommended until
there has been laboratory confirmation of the suspect case.
Post Exposure
for Healthcare Workers
 Data on the need for postexposure antimicrobial
prophylaxis in T-dap immunized HCWs are
inconclusive.
 If 21 days have lapsed since onset of cough in the index
cause, chemoprophylaxis has limited value.
Source: American Academy of Pediatrics Red Book
Immunization of Case Contacts
Immunization of case contacts
 In addition to providing antimicrobial therapy to case contacts, providers should assess
pertussis vaccination status. Use DTaP or Tdap depending on the age of the case contact.
• Give DTaP to catch-up children under age 7 years for any vaccinations due or overdue.
There are two Tdap vaccines:
•Adacel, licensed for persons age 11 through 64 years
•Boostrix, licensed for persons age 10 years and older
• Give Tdap to children age 7-10 years who have an incomplete DTaP schedule or who have never received a
primary series of tetanus, diphtheria, and pertussis. In this instance, initiate a primary series giving Tdap as
the first dose, followed by a dose of Td one month later, and a second Td six months later. This off-label use is
ACIP recommended.
• Give Tdap is routinely at age 11-12 years. However, do not wait for the pre-adolescent check-up to provide Tdap
to household contacts; give it as early as age 10 years.
• Give Tdap to adolescents and adults age 13 and older who have not yet received a Tdap. Give the dose
regardless of the interval since the last Td.
Make special effort to give Tdap to all persons who have or will have contact with children under age 1
year.
• Give Tdap during every pregnancy, regardless of any doses given before pregnancy, preferably between weeks
27 and 36.
Vaccination
Diphtheria, Tetanus, and Pertussis Vaccines
There are several formulations of vaccines used to prevent diphtheria,
tetanus and pertussis. Some are combined with vaccines to prevent
other diseases and reduce the total number of shots that someone
receives at one office visit.
DTaP,
Tdap, and
the most commonly used vaccines in the U.S.
Td vaccines
One of these (DTaP) is given to children younger than 7 years of age,
and two (Tdap and Td) are given to older children and adults.
Tdap is similar to Td but also containing protection against pertussis.
Adolescents 11 through 18 years of age (preferably at age 11-12 years)
should receive a single dose of Tdap. One dose of Tdap is also
recommended for adults 19 years of age and older who did not get Tdap
as an adolescent. Expectant mothers should receive Tdap during each
pregnancy, preferably at 27 through 36 weeks. Tdap should also be
given to 7-10 year olds who are not fully immunized against pertussis.
Tdap can be given no matter when Td was last received. Updated Aug
2013
(Upper-case letters in these
abbreviations denote fullstrength doses of diphtheria (D)
and tetanus (T) toxoids and
pertussis (P) vaccine. Lower-case
“d” and “p” denote reduced doses
of diphtheria and pertussis used
in the adolescent/adultformulations. The “a” in DTaP
and Tdap stands for “acellular,”
meaning that the pertussis
component contains only a part
of the pertussis organism.)
Both DTaP and Tdap
protect against
whooping cough,
tetanus, and diphtheria.
Vaccination Efficacy
 Pertussis vaccine is about 85% protective against
pertussis infection
 For adolescents and adults, the Tdap vaccine has
reduced diphtheria and pertussis vaccine dose to
prevent local reactions (swelling, redness and pain)
after immunization.
Prevention
Herd immunity does not completely protect unvaccinated
children from pertussis.
While vaccination provides the best protection from
pertussis, some simple, basic hygiene steps can reduce the
transmission:
wash hands with soap and water
cover up coughs and sneezes
do not share cups and silverware
In the hospital setting implement Droplet Precautions until 5 days after approx antimicrobial therapy;
or if an antimicrobial therapy not initiated, until 3 weeks after onset of cough.
Life Long Immunity ?
Does the disease trigger long lasting immunity?
Whooping cough does not trigger long lasting immunity. In fact, it
is recommended that vaccinated adults repeat their vaccinations
every 5-10 years to fully protect themselves against B. pertussis.
Neither infection nor immunization provides lifelong immunity
The Risk of Epidemic
R0: (Reproductive ratio):
The R0 of pertussis is 12-17, depending on geographical location.
Because the R0 is greater than one, pertussis has the potential to
become an epidemic unless vaccinations are used to increase the
immunity of the population.
In The News
January 15, 2015
The CDC recommends a strategy called
“cocooning”, which is a theory that if
everyone who is in contact with a newborn is
vaccinated, this should dramatically decrease
the risk of pertussis being transmitted to an
infant.
A 25 day-old baby in Santa Barbara, CA died
this week from pertussis, commonly known
as whooping cough . The disease can be easily
prevented by the DTaP or Tdap vaccines (also
protect against tetanus and diphtheria), which
can be given to infants as early as 6 weeks to 2
months old. According to the California
Department of Public Health, infants who are
too young to be fully immunized or those who
are not vaccinated are most vulnerable to
severe and fatal cases of pertussis.
In 2014, 66 of the pertussis hospitalizations
cases were children four months of age or
younger.
Whooping cough,
an old disease
causing havoc in a
new era
In Review
 Whooping cough (pertussis) is a highly contagious
respiratory tract infection.
 Pertussis is a caused by the gram-negative coccobacillus
Bordetella pertussis.
 Pertussis is transmitted by droplet transfer (usually from
sneezing or coughing) from an infected person.
 In most cases, a negative pertussis result indicates the
absence of whooping cough.
In Review, cont.
•Adults are the most common source of pertussis infection in infants.
•Infants are at the greatest risk of serious complications, including death, from
pertussis. Approximately half of infants less than 1 year of age who get pertussis are
hospitalized.
•The Centers for Disease Control and Prevention (CDC) estimates that worldwide,
there are an estimated 16 million cases of pertussis and about 195,000 deaths per
year. Since the 1980s, there has been an increase in the number of reported cases of
pertussis in the US.
•In adults, whooping cough can cause coughing spells that can affect breathing,
eating, and sleeping. It can lead to cracked ribs and hospitalization.
•Vaccination of pregnant women with Tdap is especially important to help protect
infants. Pregnant women should get the vaccine late in the second trimester or in
the third trimester for each pregancy.