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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