Pertussis

INTRODUCTION
 Pertussis, literally meaning “a violent
cough,” also known as whooping cough
or “the cough of 100 days,” was first
described in the Paris epidemic of 1578.
 Bordetella pertussis, the causative
organism, was discovered in 1906.
 Pertussis is a serious illnes with a very
high morbidity and mortality
 Cyclical epidemics continue to occur
every 2 to 5 years as they did in the
prevaccine era.

ETIOLOGY
 The causative organisms of pertussis are Bordetella
pertussis and Bordetella parapertussis coming from the
family Alcaligenaceae.
 It is a gram negative, aerobic, non-motile coccobacilli
ranging from 0.4-0.8 μm.
 Species B pertussis and B parapertussis cause pertussis
in humans.
 Other members of the genus are B bronchiseptica,
causing respiratory disease in various animals and
occasionally in humans
 B avium as well as B hinzii, which cause respiratory
disease in poultry and are very rarely found in humans.

TRANSMISSION
 Bordetella is spread by airborne droplets
 Pertussis often affects 100% of non-immune household contacts.
 Immunocompromised persons can also contract Bordetella bronchiseptica, which
typically affects animals and is commonly known as “a kennel cough.”
 Humans are the sole reservoir for Bordetella
 The organism is highly contagious, with the majority of cases occurring during
summer.
Risk factors for acquiring pertussis include:
 Pregnancy
 Epidemic exposure
 Lack of immunization
 Close contact with an infected individual

Reported Pertussis Incidence by Age Group

PATHOPHYSIOLOGY
Bordetella adheres to ciliated respiratory epithelial cells.
Local inflammatory changes occur in the mucosal lining of the
respiratory tract.
Released toxins (pertussis toxin, dermonecrotic toxin, adenylate
cyclase toxin, and tracheal cytotoxin) act locally and systemically

CLINICAL MANIFESTATIONS
 The Incubation period of 1 to 3 weeks
 The classic presentation of pertussis includes paroxysms of coughing,
protruded tongue, an inspiratory whoop with/without posttussive
vomiting.
 The classic presentation typically occurs as a primary infection in
unvaccinated children <10 years of age but it also may occur in vaccinated
children and adults
 Pertussis infection typically progresses through 3 distinct stages:
1.catarrhal phase
2. paroxysmal phase
3. convalescent phase.

CATARRHAL PHASE
 Presents similarly to other upper respiratory tract infections, with mild fever, fatigue, rhinorrhea, and
conjunctival injection.
 It lasts for 1 to 2 weeks and is the most infectious stage of the disease.
PAROXYSMAL PHASE
 During the paroxysmal stage, coughing spells increase in severity. The paroxysmal cough is distinctive: a long
series of coughs between which there is little or no inspiratory effort.
 These episodes may be triggered by cold or noise and are more common at night.
 Patients are nontoxic-appearing in between paroxysms, but during coughing episodes, may exhibit cyanosis,
diaphoresis, or apnea. Immediately following a paroxysm, patients may develop post-tussive emesis, syncope, or
apnea
CONVALESCENT PHASE
 A residual cough persists for weeks to months, usually triggered by exposure to another upper respiratory
infection or irritant.

 Increased intrathoracic pressure from coughing may result in petechiae above the nipple line, subconjunctival
hemorrhage, and epistaxis.
 Breath sounds are variable; auscultation may reveal clear lungs or rhonchi, while rales suggest superimposed
pneumonia. The inspiratory whoop or gasp is usually heard in children between 6 months to 5 years.

PERTUSSIS IN OLDER CHILDREN
 Older children with pertussis infection may be asymptomatic or have a mild cough
illness without any of the characteristic features (ie, paroxysms, whoop, posttussive
vomiting)
 Wheezing is another atypical finding.
 They tend to be carriers

DIAGNOSIS
 Nasopharyngeal culture and polymerase chain reaction (PCR) may yield
laboratory confirmation, but the fastidious and slow-growing Bordetella
organisms require specialized media, and cultures are typically not positive for
3 to 7 days.
 In adults, by the time the diagnosis is suspected, cultures are typically negative
(96%), and overall culture sensitivity is only 20% to 40%. PCR is more
sensitive and specific than culture, but testing is not widely available.
 In the emergency department, pertussis should be considered in patients with
prolonged cough, especially occurring in paroxysms or with whoops or post-
tussive emesis.

 During the late catarrhal and early paroxysmal phases,
leukocytosis with lymphocytosis may raise suspicion for
pertussis.
 Chest x-ray findings are nonspecific and may show
peribronchial thickening, atelectasis, or infiltrates. The classic
association, though not often seen, is a “shaggy” right heart
border

DIFFERENTIAL DIAGNOSIS
 Pertussis initially presents similarly to other respiratory infections, such as viral upper
respiratory infection, bronchiolitis, pneumonia, and tuberculosis.
 Key differentiating factors of pertussis include typical progression through the three
phases and persistent cough without fever.
 Foreign body aspiration should be considered in younger patients, and exacerbation of
chronic obstructive pulmonary disease should be considered in older patients with the
appropriate history.
 The striking leukocytosis may also be confused with leukemia.

TREATMENT
 Treatment of pertussis is largely supportive, including oxygen, suctioning, hydration,
and avoidance of respiratory irritants.
 Hospitalization is indicated for patients with superimposed pneumonia, hypoxia, central
nervous system (CNS) complications, or who are unable to tolerate nutrition and
hydration by mouth.
 Patients less than 1-year-old are not fully vaccinated and carry the greatest risk of
morbidity and mortality; they should be hospitalized regardless of symptoms.
 Antibiotic effect on the duration or severity of the disease is minimal when started in the
catarrhal phase and not proven effective when started in the paroxysmal phase.

 Infants younger than one month
o Azithromycin is the recommended macrolide antibiotic for the treatment of pertussis. It is
preferred over Erythromycin; Clarithromycin is not recommended.
o Both Azithromycin and Erythromycin are associated with increased risk of infantile
hypertrophic pyloric stenosis (IHPS), particularly in infants younger than two weeks. The
risk of IHPS with Clarithromycin is not known
 Infants and children older than one month – Any of the macrolide antibiotics can be used
for the treatment of pertussis
 Trimethoprim-sulfamethoxazole (TMP-SMX) is an alternative for children older than two
months who have a contraindication to or cannot tolerate macrolide agents or are infected
with a strain that is macrolide resistant
 We suggest 5 days for Azithromycin, 14 days for Erythromycin, 7 days for Clarithromycin,
and 14 days for Trimethoprim-sulfamethoxazole

PREVENTION
 Strict isolation is important while the patient remains infectious. Pertussis is contagious throughout
the catarrhal phase and for 3 weeks after the onset of the paroxysmal phase.
 DTaP (Diphtheria-Tetanus-Pertussis Vaccine) should be administered at 2 months of age
 The recommended DTaP series is 5 doses, administered at 2, 4, and 6 months, 15 through 18
months, and 4 through 6 years.

COMPLICATIONS
 Secondary pneumonia or otitis media may occur. Superimposed pneumonia is a major cause of
mortality in infants and young children and may be caused by aspiration of gastric contents during
paroxysms of cough or because of decreased respiratory clearance of pathogens.
 The most common causes of secondary bacterial pneumonia are Streptococcus pneumoniae,
Streptococcus pyogenes, Haemophilus influenzae, and Staphylococcus aureus; although viral
infections with the respiratory syncytial virus, cytomegalovirus, and adenovirus superinfections are
also common.
 Rarely (less than 2% of cases), CNS complications such as seizures and encephalopathy can occur,
likely secondary to hypoxia, hypoglycemia, toxins, secondary infections, or cerebral bleeding from
increased pressure during coughing.
 Pertussis toxin also causes histamine hypersensitivity and increased insulin secretion.
 Infants are particularly prone to bradycardia, hypotension, and cardiac arrest from pertussis

REFERENCES
 Yeh, MD, & M Mink, MD. (2022, May 18). Pertussis infection in infants and
children. Uptodate. Retrieved October 11, 2023, from
https://pro.uptodatefree.ir/show/5995
 Yeh, MD. (2021, December 1). Pertussis infection in infants and children:
Treatment and Prevention. Retrieved December 2022, from
https://pro.uptodatefree.ir/show/5997
 Administering Diphtheria, Tetanus, and Pertussis Vaccines. (2022,
September 6). cdc.gov.

Pertussis

More Related Content

What's hot

Similar to Pertussis

More from MariaDavis42

Recently uploaded

Pertussis