Whooping cough/ pertussis

Question 1

Causes of pertussis

Answer 1

• Bordetella pertussis (bacteria)
• Identified per-nasal swab (PCR more sensitive

Question 2

Natural history of pertussis

Answer 2

• Highly contagious
• Endemic with epidemics occuring every 3-4 years
• Catarrhal phase: 1 week coryza- non-stop!
• Paroxysmal phase (3-6 weeks): characteristic paroxysmal/ spasmodic cough followed by a characteristic inspirtory whoop
  
  • worse at night
  • lead to vomiting
  • child red/ blue in face
  • mucous in nose/ mouth
• Epistaxsis and subconjunctival haemorrhages
  
  • ​vigorous coughing
• Convalscent phase: symptoms gradually decrease​
• Complications: pneumonia, convulsions, bronchiectiasis

Question 3

Effect of immunisation on presentation of clinical features

Answer 3

• Infants who have not completed their 1” vaccination at 4 months are particularly susceptibile- maternal ABs do not provide enough protection
• Reduces risk and severity of disease- does not guarantee protection
• Level of protection decreases steadily through childhood
• immunisation with a DTPa-containing (diphtheria-tetanus-acellular pertussis) vaccine is the best way to reduce the risk of whooping cough in children
• doses given at 2, 4 and 6 m, with booster doses at 18 m, 4 years and 10-15 years
• single booster dose of adult formulation pertussis vaccine (dTpa) for all pregnant women in their third trimester of pregnancy as their antibodies transfer to the newborn through the placenta
• A dose is also recommended for adult household contacts and carers (e.g. fathers, grandparents) of infants <6 months of age at least 2 weeks before beginning close contact with the infant to reduce the chance of passing on the bacteria.
• As whooping cough causes severe disease in the elderly, adults who are 65 years of age are recommended a single booster dose of dTpa if they haven’t received one already in the previous 10 years

Question 4

Treatment/ advise to parents

Answer 4

• Immunisation advice
• Erythromycin eradicates organism (only if treated at catarrhal phase)
• Siblings, parents and close contacts nay develop similar cough
  
  • erythromycin prophylaxis
  • unvaccinated infant contacts –> vaccinate