3. INTRODUCTION
Pertussis is also called as Whooping cough is a
highly contagious disease mainly of children
caused by Bordetella pertussis.
It is characterized by severe uncontrollable
coughing spells which can sometimes end in a
“whoop” sound when person breathes in.
Also called as “100 day cough” by Chinese.
4. In 2012, 2.49 cases were reported by WHO
globally when the DPT immunization was 83%.
In India after launch of immunization programme
in 1987, the reported cases dropped from 1.63
lakh to only 36,661 cases in 2013 ( 77% decline)
Underlying malnutrition and other respiratory
infections in children make then prone to this
disease.
Recently the disease shows increase incidence in
older children, adolescents and adults.(21%
adults had pertussis after serological studies of
adults with cough for more than 2 weeks)
5. Epidemiological Determinants
AGENT FACTORS-
Agent -Causative agent is Bordetella pertussis.
Also caused by B.parapertussis,
Viruses(parainfluenzae, adenovirus)
6. Source of infection- Only man is the known
source of infection.
Pervious case of pertussis which may be mild,
missed and unrecognised case is usually the
source of infection.
No chronic carrier state exist
Infective material –Nasopharyngeal and bronchial
secretion.
Fomites contaminated by such discharge are
also infective.
7. Infective period- Catarrhal stage most infective.
Extends from week after exposure to about 3
weeks after onset of paroxysmal stage.
Secondary attack rate- Average 90% in
unimmunized people.
8. HOST FACTORS
Age- Infants and pre-school (<5 years)
- Developing countries (20-30 months)
and developed countries (50 months)
-Highest mortality below 6 months.
Sex- More common among females.
Immunity-Immunity develops after a case or
immunization.
No cross immunity.
Secondary attack occur in declining
immune
person.
9. ENVIRONMENT
More cases occur during winter and spring.
Lower socio-economic group more prone than
well to do
groups due to overcrowding.
11. CLINICAL COURSE
Causes local infection by multiplying in the
surface epithelium of respiratory mucosa.
Leads to inflammation and necrosis of mucosa.
Occurs in 3 stages-
1. Catarrhal stage
2. Paroxysmal stage
3. Convalescent stage
12. 1. Catarrhal stage-
- Lasts for 10 days.
- Characterized by:
Insidious onset
Lacrimation
Sneezing
Coryza
Anorexia
Malaise
Hacking night cough that becomes
diurnal
13. 2. Paroxysmal stage
-Lasts for 2-4 weeks
-Characterized by burst of rapid,
consecutive
coughs followed by a deep, deep
pitched
inspiration (whoop)
- Followed by vomiting
In infants- Causes cyanosis and apnoea
In adults and adolescents-
Uncharacteristic,persistent cough
14. 3. Convalescent stage-
Lasts for 1-2 weeks
Decrease in paroxysms of coughing both in
freq and severity
Cessation of Vomiting
15. Complications
Occurs in 5-6% cases
Frequent in infants aged less than 6 months
Mainly- Bronchitis
- Bronchopneumonia (5.2%)
-Bronchiectasis
-Subconjuctival hemorrhage
-Epistaxis
-Heomptysis
-Punctate cerebral hemorrhage
-Coma and convulsions
16. Control of whooping cough
Cases and contacts-
1. Cases- Early diagnosis by
bacteriological exam. of nose and throat
secretions (60% chances within 10-14 days from
onset)
- Isolation of case
- Treatment of case- Erythromycin
30-50 mg/kg for 10 days
Septran , Ampicillin and
Tetracycline can also be used.
Given during incubation or
in early catarrhal stage to
prevent or moderate
clinical pertussis.
During paroxysmal stage
only eliminate bacteria
from nasopharynx
eliminating transmission
18. Active immunization
- Covered under National Immunization Programme
-Combined as DPT, DTWP or DTaP vaccine.
-Administered as 3 dose ( each dose 0.5 ml) IM at
1 month interval starting at 6 weeks.
-Booster dose at 18-24 months
-Acellular vaccine for older children and adults
19. Efficacy 85%
Duration of protection 6-12 years following complete
dose+ booster
HIV positive individuals should also be immunized
Adverse reactions- Early vaccine caused screaming
and
collapse.
-Give rise to local reactions at
site of
injection, mild fever and
irritability
-Rare vaccine reaction are-
Inconsolable
screaming, seizures, hypotonic
hypo-
responsive episode,
20. Contraindications- Anaphylactic reactions,
encephalopathy, history of epilepsy, convulsions
or similar CNS disorders , any febrile episode and
reaction to previous triple vaccine
• Passive immunization-
Hyperimmune globulin is given but efficacy no
established yet.