Define Pertussis/Whooping cough :

Define : A acute infectious disease, usually of young children, caused by B. pertussis, clinically characterized by an insidious onset and mild fever and and irritating cough, gradually becoming paroxysmal and characteristics “Whoop” (loud crowing inspiration). The spectrum of disease vanes from severe illness to atypical and mild illness without whoop Chinese call it a “Hundred day cough.

Symptoms of whooping cough :

There are 3 stages of the clinical course of whooping cough

1) Catarrhal stage : Last for about 10 days

• Conjunctivitis
• Rhinitis
• Unproductive cough.

2) Paroxysmal stage (2-4 weeks) :

• Spasmodic cough, that ends with an inspiratory whoop (as air rushes past the narrowed glottis). The number of such paroxysms in 24 hours varies from an occasional attack 40 or 50, and they are more severe at night.
• Vomiting
• During the spasms the face becomes suffused or frankly cyanosed.
• Eyelids are swollen and there may be sub-conjunctival hemorrhage.

3) Convalescent stage (1-2 weeks) :

• Cough becomes less frequent.
• Sputum less tenacious.

Investigations of whooping cough :

1. Culture of swabs of nasopharyngeal secretions.

2. Serology :

• Agglutination test.
• Flurescent- antibody stanining.

Treatment of whooping cough :

1. Erythromycin 500mg 4 times a day orally for 10 days.
2. Possible alternatives are ampicillin, septran or tetracycline.
3. A cough suppressant e.g. Dextromethorphan or pholcodine.
4. Supportive care :

• Adequate hydration and nutrition must be maintained.
• Ventilation may be required.

Epidemiology of Whooping cough : 

Occurrence : Whopping cough is prevalent all over the world & usually occurs in endemic form.

Ecological triad :

1. Agent :The causative organism is B. pertussis. It is small, non-motile, Gram negative bacilli.
2. Host : Commonly 1-8yrs Children under 6 month are also affected. All races are equally susceptible.
3. Environmental factor : any time of the yr, but the incidence is higher during winter season.

Natural history :

1. Reservoir:  only man
2. Source of infection : respiratory discharge.
3. Mode of transmission : By-

• Contact
• Droplet infection
• Indirectly contaminated fomite

 4.Incubation period : Commonly 7 to 10 days rarely exceed 14 days.

Complications of whooping cough :

A. Respiratory system :

1. Bronchitis.
2. Bronchopneumonia.
3. Bronchiectasis.
4. Haemoptysis.
5. Atelectasis.

B. Eye : Sub-conjunctival hemorrhage.

C. Nose : Epistaxis.

D. Brain : Cerebral haemorrhage (Punctate),

E. Rectum :  Rectal prolapse.

F. Tongue : Ulceration of frenulum of tongue in children.

G. Umbilicus : Umbilical hernia.

Control & prevention of whooping cough:

A). Cases and contacts :

  a) Cases:

1) Early diagnosis: By bacteriological examination of nasopharyngeal swabs.

2) Isolation: For 3 weeks until the cessation of the whoop

3) Treatment :

• Erythromycin 500 mg 4 times a day orally for 10 days
• Possible alternatives are ampicillin, septran or tetracycline.
• A cough suppressant e.g. dextromethorphan or pholcodine.

b) Contacts :

1. Infants and young children should be kept away from cases.
2. Prophylactic antibiotic (erythromycin or ampicillin) treatment for 10 days.

B) Active immunization :

• Name of the vaccine : DPT (diphtheria pertussis-tetanus vaccine).
• Starting of vaccination : 6 weeks after birth.
• Dose : 0.5 ml.
• Number of doses : 3 doses
• Interval between each dose : 4 weeks.
• Mode of administration : IM
• Booster dose :  At 18-24 months.

C) Passive immunization.