Whooping cough Flashcards
What is whooping cough?
Highly infectious notifiable upper respiratory disease
Which bacterium causes whooping cough?
Bordetella pertussis
How often does whooping cough peak?
Every 3-4 years
At what ages is a pertussis vaccination given?
2,3,4 months of age
Booster at 3 years and 4 months
When does immunity from the pertussis infection wane?
5-10yrs
Describe the severity of whooping cough in adults/adolescents
Mild
Describe the pertussis vaccine during pregnancy
Passive immunity through the transfer of maternal antibodies in-utero
What class of bacteria is Bordetella pertussis?
Gram negative bacillus
How does Bordetella pertussis spread?
Aerolised droplet infection
Describe the pathophysiology of Bordetella pertussis
Bacteria attach to respiratory epithelium and produce toxins which paralyse the cilia and promote inflammation, impairing clearance of respiratory secretions which lead to cough
How contagious is Bordetella pertussis?
Highly infectious with 90% of household contacts catching it
What are some risk factors for pertussis infection?
Non vaccination
Exposure to infected individual
List some differentials of whooping cough
Bronchiolitis Viral induced wheeze Bacterial pneumonia Asthma TB
What investigations are used for whooping cough
If cough <2weeks in duration - nasopharyngeal aspiration or nasopharyngeal swab for PCR
If cough >2weeks in duration - anti-pertussis toxin IgG serology is recommended for children <5yo, for children ages 5-17yo anti-pertussis toxin detection in oral fluid is recommended
FBC - lymphocytosis
Give the limitation of serology testing for whooping cough after immunisation?
False positive
Describe the symptoms of the catarrhal phase of whooping cough
Dry cough Rhinitis Conjunctivitis Irritability Sore throat Low grade fever
List the 3 stages of whooping cough
Catarrhal phase
Paroxysmal phase
Convalescent phase
How long may the convalescent phase last?
3 months
How long does the catarrhal phase last?
1-2 weeks
How long does the paroxysmal phase last?
2-8 weeks
Describe the symptoms of the paroxysmal phase
Severe paroxysms of coughing followed by an inspiratory gasp/whoop
What is more common instead of the whoop in children <3yo?
Apnoea and cyanosis
When are the paroxysm of coughing more common?
At night
What is associated with paronym’s of coughing in a child <3mo?
Vomiting and apnoea and cyanosis
What may be found on physical examination of a child with pertussis?
Petechiae on the face
Low grade fever
Conjunctival haemorrhage
Chest auscultation is usually normal
Who should be admitted to hospital with whooping cough?
<6mo and acutely unwell
Significant breathing difficulties
Feeding difficulties
Significant complications
Describe the management of whooping cough
Macrolide antibiotic <21days of cough - clarithromycin for those <1mo, azithromycin and clarithromycin for those >1mo
Co-trimoxazole is the 2nd line when clarithromycin is CI/poorly tolerated
Symptomatic relief - ibuprofen and paracetamol, fluids
List some complications of whooping cough
Secondary bacterial pneumonia
Seizures
Encephalopathy
Otitis media
Who are complications and poor mortality seen in?
Unvaccinated individuals
