Whooping cough (Pertussis) Flashcards
Define whooping cough.
RTI characterised by paroxysms of coughing followed by a ‘whoop’ (sudden forced inspiration against closed glottis).
Explain the aetiology of whooping cough.
Bacterium Bordetella pertussis (gram -ve)
Incubation period of 7-10 (up to 21) days
Communicable for 3w from start of coughing via droplet spread.
Summarise the epidemiology of whooping cough.
Immunisation has decreased risk by 80-90%. Previously, epidemics occurred in the UK every 4 years.
Peak: 3 years.
In infants < 6 months, has much higher mortality.
What are signs and symptoms of whooping cough?
Catarrhal stage: 1w; Coryzal Sx.
Paroxysmal stage: 1-6w; paroxysms of continuous coughing, inspiratory ‘whoop’ +/- vomiting. Infants < 6m don’t whoop but may have apneic episodes.
Convalescent stage: weeks-months; chronic cough that becomes less paroxysmal.
What Ix are required for whooping cough dx?
Clinical dx, confirmed with
Per nasal swab culture for Bordetella pertussis: days-weeks to come back
PCR + serology increasingly used as availability more widespread
What is the management of whooping cough?
Oral macrolide (e.g. clarithromycin, azithromycin or erythromycin) if onset of cough within 21 days to eradicate organism + reduce the spread
Does not alter clinical course
What is the criteria for admission with whooping cough?
< 6m (increased mortality)
Inability to feed, vomiting, dehydration, weight loss
Respiratory distress/ apnoea +/- cyanosis
Evidence of pneumonia
What are complications associated with whooping cough?
Subconjunctival haemorrhage
Secondary infections: Otitis media, bronchiectasis, pneumonia (main cause of pertussis-related deaths).
Seizures (3%): If encephalopathy follows, ⅓ die, ⅓ remain neurologically impaired, ⅓ recover fully.
What is the prognosis of whooping cough?
Usually lasts 6-8w; however, a prolonged illness may occur (“100-day cough”).
Significant morbidity + mortality in infants < 6m in whom apnoea associated with paroxysms may cause sudden death.
Give a RF for whooping cough
Unvaccinated per schedule
Newborns
What signs and Sx may arise secondary to the paroxysmal cough?
Conjunctival haemorrhages
Petechiae
Reduced oral intake: dehydration + weight loss
Anoxia: syncope + seizures
Characterise the cough in Pertussis
Worse at night + after feeding
May be ended by vomiting
Associated central cyanosis
How do older children + adolescents differ in presentation of whooping cough?
May not exhibit distinct stages.
Sx: uninterrupted coughing, feelings of suffocation + headaches.
How should pertussis be managed from a public health view?
Notifiable disease
Household contacts should be offered abx prophylaxis
School exclusion: until 5d after commencing abx (or 21 days from onset of Sx if no abx)
