This ppt contains all the information about the epidemiology of Pertussis ( Whooping Cough). It is useful for students of the medical field learning Preventive and social medicine, Swasthavritta (Ayurved), and everyone who is interested in knowing about it

1. Pertussis
(Whooping
cough)
Dr. Shubhangi Kshirsagar
Assistant Professor
Department of Swasthavritta & Yoga
drssksagar@gmail.com

2. Pertussis
 An acute infectious disease, usually of
young children, caused by B. pertussis.
 It is clinically characterized by an insidious
onset with mild fever and an irritating cough,
gradually becoming paroxysmal with the
characteristic "whoop" (loud crowing
inspiration) often with cyanosis and
vomiting.
 The Chinese call it a “Hundred Day Cough”

3. Agent factors
a. Agent
 Large proportion of cases - B. pertussis
 Less than 5 % cases - B. parapertussis
 B. Pertussis elaborates an exotoxin and
endotoxin.
 The bacterium survives only for very short
periods outside the human body.
b. Source of infection - Case of pertussis (mild,
missed and unrecognized cases)
c. Infective material - Nasopharyngeal and
bronchial secretions

4. d. Infective period - infectious during
catarrhal stage
e. Secondary attack rate - 90 per cent in
unimmunized household contacts

5. Host factors
a. Age
 Highest incidence below 5 years
 Whooping cough is primarily a disease of
infants and pre-school children.
 Infants below 6 months have the highest
mortality.
 In older children, adolescents and adults,
pertussis is often unrecognized because of
its atypical course.
 However, older age groups represent an
important source of infection for susceptible

6. c. Immunity
 Recovery from whooping cough or adequate
immunization is followed by immunity.
 Second attacks may occur in persons with
declining immunity, but these are usually
mild.
 Infants are susceptible to infection from birth
because maternal antibody does not appear
to give them protection.

7. Environmental factors
 Pertussis occurs throughout the year.
 But it shows a seasonal trend with more
cases occurring during winter and spring
months due to overcrowding.
 Socioeconomic conditions and ways of life
also play a role in the epidemiology of the
disease.
 Thus, the risk of exposure is greater in the
lower social classes living in overcrowded
conditions.

8. Mode of transmission
 Droplet infection
 Direct contact
 Most children contract infection from their
playmates who are in the early stages of the
disease.

9. Incubation period
Usually 7 to 14 days, but not more than 3
weeks

10. Clinical features
 B. pertussis produces a local infection, the
organism is not invasive.
 It multiplies on the surface epithelium of the
respiratory tract and causes inflammation
and necrosis of the mucosa leading to
secondary bacterial invasion.
 Clinical course of the disease –
1. Catarrhal stage
2. Paroxymal stage
3. Convalescent stage

11. 1. Catarrhal stage
 Lasts for 10 days
 It is characterized by its insidious onset,
lacrimation, sneezing and coryza, anorexia
and malaise, and a hacking night cough that
becomes diurnal.

12. 2. Paroxysmal stage
 Last for 2-4 weeks.
 It is characterized by bursts of rapid,
consecutive coughs followed by a deep, high-
pitched inspiration (whoop).
 It is usually followed by vomiting.
 In young infants it may cause cyanosis and
apnoea.
 In adults and adolescents, uncharacteristic,
persistent cough may be the only
manifestation of the disease.

13. 3. Convalescent stage
 Last for 1-2 weeks
 The illness generally lasts 6 to 8
weeks.

14. Complications
 Complications occur in 5-6 per cent of cases,
most
frequently in infants aged less than 6
months.
 The chief complications of pertussis are
 Bronchitis
 Bronchopneumonia
 Bronchiectasis
 The violence of the paroxysms may
precipitate subconjunctival haemorrhages,
epistaxis, haemoptysis and punctate cerebral

15. Control of pertussis
1. Case and contacts
2. Active immunization
3. Passive immunization

16. Control of pertusis
1. Case & contacts
a. Case
1. Early diagnosis – bacteriological exam of throat
and nose secretion.
2. Isolation
3. Treatment – Antibiotics - Erythromycin 30-
50mg/kg body weight in 4 divided doses for 10
days
Alternate antibiotics- Ampicillin, Tetracycline

17. b. Contacts
 Infant & young children should keep away from
cases.
 Those who are in contact with whooping cough
case give prophylactic antibiotics
(Azithromycin/Ampicillin for 10 days)
 Booster dose of DPT/DT to their siblings

18. 2. Active immunization
 Combined DPT/Pentavalent vaccine 0.5ml IM
at one month interval starting at the age of 6
weeks (3 dose- 6, 10, 14 weeks)
 A Booster dose at 18-24 month
3. Passive immunization
 The merit of hyperimmune globulin in
pertussis
prophylaxis has yet to be established.
 So far, there is no evidence of its efficacy in

19. Thank You!