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Pediatrics
Pertussis and
Pertussis syndrome
Zhi-min Chen
Dept. Pediatric Pulmonology, Children’s Hospital
Zhejiang University School of Medicine
Definition
Pertussis (whooping cough)
caused by Bordetella pertussis,
The pertussis syndrome
includes disease caused by Bordetella pertussis
and certain other infectious agents
Etiology
Bordetella pertussis
Gram-negative
Other infectious agents
Bordetella parapertussis
Adenovirus
Dual infection (of above)
Other common pathogens of protracted cough:
mycoplasma, chlamydia, RSV, parainfluenza virus
Epidemiology
Infect only humans and transmitted person
to person by coughing
Most contagious during the earliest stage
The peak incidence <4 m
The annual rate--100 to 200/100,000, higher
in developing countries
Clinical manifestation
The mean incubation period is 6 days.
The progression of pertussis
Catarrhal stage
Paroxysmal stage
Convalescent stage
Clinical manifestation
Catarrhal stage
nonspecific signs
• Injection
• increased nasal secretions
• low-grade fever
last 1 to 2 weeks
Clinical manifestation
The paroxysmal stage
approximately 2 to 4 weeks.
as catarrhal symptoms wane, coughing begins first
as a dry, intermittent, irritative hack;
then evolve into coughing in paroxysms during
expiration, causing young children to lose their
breath (machine-gun burst of uninterrupted
coughs).
Clinical manifestation
The paroxysmal stage
After the most insignificant startle from a draught,
light, sound, sucking or stretching, a wellappearing young infant begins to choke, gasp, and
flail extremities, eyes watering and bulging, face
reddened or purple, tongue protruding maximally
until at the seeming last moment of consciousness.
Characteristic whoop follows this paroxysm of
cough (the forceful inhalation against a narrowed
glottis).
Others: post-tussive emesis, conjunctival
hemorrages and petechiae on the upper body
Clinical manifestation
The Convalescent stage
gradual resolution of symptoms over
1 to 2 weeks.
residual cough may persist for
months, especially with physical
stress or respiratory irritants
Clinical manifestation
Young infants may not display the classic
pertussis syndrome:
the first signs may be episodes of apnea
unlikely to have the classic whoop
more likely to have CNS damage as a result of
hypoxia
more likely to have secondary bacterial pneumonia.
LABORATORY STUDIES
The diagnosis depends on isolation of B.
pertussis
Culture of nasopharyngeal swabs
Direct fluorescent antibody staining
Serologic tests are not useful for diagnosis of
acute infection.
Leucocytosis (20,000~ 50,000/mm3) with
lymphocytosis is characteristic beyond the
neonatal age
IMAGING STUDIES
NOT specific
Segmental lung atelectasis
not unusual during pertussis, especially during the
paroxysmal stage.
Perihilar infiltrates
common and similar to what is seen in viral
pneumonia.
Diagnosis and differential diagnosis
the diagnosis based on recognition of the
pattern of illness is quite accurate
Respiratory viruses such as RSV, parainfluenza
virus, and C. pneumoniae among infants and
M. pneumoniae in older children may produce a
bronchitic illness that is not distinguished
easily from pertussis.
Complications
Major complications:hypoxia, apnea, pneumonia,
seizures, encephalopathy, and malnutrition.
The most frequent complication is pneumonia
caused by B. pertussis itself or resulting from
secondary bacterial infection from S.
pneumoniae, Hib, and S. aureus.
Complications
Other complications
atelectasis, pneumomediastinum,
pneumothorax, or interstitial or
subcutaneous emphysema; epistaxis;
hernias; and retinal and subconjunctival
hemorrhages, otitis media and sinusitis .
Goal of therapy
Limit the number of paroxysms
Observe the severity of cough to provide
assistance when necessary
Maximize nutrition, rest, and recovery
without sequelae
Treatment
Erythromycin
given early, eradicates nasopharyngeal carriage
of organisms within 3 to 4 days and ameliorates
the effects of the infection.
not effective in the paroxysmal stage.
Azithromycin and clarithromycin
TMP-SMZ
Pertussis-specific immunoglobulin
( effective)
PREVENTION
Active immunization
acellular pertussis vaccine, given in
combination with the toxoids of tetanus
and diphtheria (DTaP with an efficacy of
70% to 90%;
Compared with older, whole cell pertussis
vaccines, acellular vaccines have fewer
adverse effects and local reactions.
PREVENTION
Erythromycin and other macrolides
effective in preventing disease in
contacts exposed to pertussis.
PREVENTION
Close contact <7y
should be given a macrolide antibiotic.
should receive a booster dose of DTaP, unless a
booster dose has been given within the preceding
3 years.
Close contact > 7y
prophylactic macrolide antibiotic for 10 to 14 days
NOT the vaccine.
Thank you
for your attention