Whooping Cough

Question 1

What causes whooping cough

Answer 1

Bordetella pertussis (bacteria) → produces pertussis toxin
Transmitted by aerosol droplets
Infectious for 21 days (unless Abx)
A previously infected person can become re-infected, but the subsequent infections are usually less severe

Question 2

What are the symptoms of whooping cough

Answer 2

3 phases:
1. Catarrhal phase (1-2 weeks)
- nasal discharge, conjunctivitis, malaise, sore throat, fever, dry unproductive cough
2. Paroxysmal phase (1-6 weeks)
- Paroxysms/cough: severe dry cough
- May vomit/be apnoeic after/between
- More common at night
- May be productive: thick mucous plug/watery secretion
- Inspiratory ‘whoop’ heard
- Otherwise well, sleep undisturbed
3. Convalescent phase (up to 3 months)
- Gradual improvement in cough frequency and severity

Question 3

What are the differentials for whooping cough

Answer 3

Mycoplasma infection
Chlamydia pneumoniae/trachomatis
Adenoviruses
Bronchiolitis
Asthma
URTI
GORD

Question 4

What are the signs of whooping cough on examination

Answer 4

No crackles/crepitations and no wheeze

Question 5

What investigations should be done for whooping cough

Answer 5

bedside: nasopharyngeal swab/aspirate for PCR and culture
Bloods: anti-pertussis toxin IgG serology

Question 6

What is the criteria for whooping cough diagnosis

Answer 6

Clinical features with:
1. Bordetella pertussis isolated from a nasopharyngeal aspirate or nasopharyngeal/pernasal swab, or
2. Detection by real-time PCR of the pertussis toxin S1 promoter region (ptxA-pr), and the insertion element IS481, or
3. Anti-pertussis toxin IgG detected in serum or oral fluid in the absence of vaccination within the past year.

Question 7

What is the management for whooping cough

Answer 7

Notify local public health england (PHE) centre within 3 days (notifiable disease)
First line: Abx (presenting within 21 days)
- <1 month: clarithromycin
- >1 month: azithromycin

+ advice
- Rest (rest only if >21 days)
- Adequate fluid intake
- Paracetamol/ibuprofen
- Even with treatment there may be a non-infectious cough
- Isolate until 48h of abx treatment OR 21 days after symptoms started
- Contacts may require prophylaxis

Question 8

Who requires prophylaxis for whooping cough

Answer 8

Premature (<32w) unimmunised infants <2 months of age
Unimmunised infants (>32w birth) <2 months of age, no maternal pertussis vaccine
unimmunised/partially unimmunised >2 months
Pregnant women >32w
Healthcare workers working with infants and children
Those who share a household with infants too young to be fully vaccinated

Question 9

Describe the whooping cough vaccine

Answer 9

Reduces risk of developing pertussis, does NOT provide absolute protection
Protection level declines during childhood
Immunisation of mothers in pregnancy → reduces risk of pertussis of the infant in the first few months
Offered at 16-32 weeks

Question 10

What are the complications of whooping cough

Answer 10

Post-infectious cough: May last for 3 months or more - “the one hundred day cough”
Apnoea
Pneumonia
Seizures
Encephalopathy
Otitis media
Unilateral hearing loss
Bronchiectasis
Increased intra-thoracic and intra-abdominal pressure: pneumothorax, umbilical and inguinal hernia, rectal prolapse, rib fracture, herniation of lumbar intervertebral discs, urinary incontinence, subconjunctival or scleral haemorrhage
Frequent post-tussive vomiting can lead to severe dehydration and/or malnutrition.

Question 11

What is the prognosis for whooping cough

Answer 11

For people who have not previously contracted whooping cough AND are not vaccinated: may be left with a protracted cough that can last 3 months or more
Previous vaccination or infection: short-lived, mild symptoms and an isolated persistent cough
Mortality rate in children <6 months is 3.5%