RC5 Resp MRCEM syllabus

	aka whooping cough
Etiology	Bordetella pertussis, despite sounding like a cheese, is a gram negative coccobacillus.
Epidemiology	Incomplete immunisation = ↑↑ risk
Pathogenesis	Virulence factors: - fimbriae - exotoxin → thickened bronchial secretions, paralysis of cilia
Clinical presentation	- Incubation 7-10 days - 1-2 weeks nonspecific symptoms → classic cough +/- vomiting after coughing fits ➥ infants more likely to show atypical s/s: apnoea, difficulty feeding ➥ Cough can last 2-3 months (100-day cough) Higher risk if incomplete immunisation
Investigations	Nasopharyngeal swab If symptoms present >2/52, pertussis IgG serology can be used if age >17 FBC: lymphocytosis
Management	Symptomatic management - Macrolides - only really effective if established before paroxysms Antibiotics do not alter the clinical course once the disease is established - Considered noninfectious after 3/52 hence no abx after 3/52 symptoms - or 14 days according to CKS... HIGHLY infectious, R0 = 15-17 Complications: apnoeas, cyanosis

Prescribing

Prescribe a macrolide first line:
- For infants aged under 1 month, clarithromycin is preferred. Azithromycin may be used although there are limited data in this age group.
- For children aged over 1 year, prescribe azithromycin or clarithromycin.
- For non-pregnant adults, prescribe azithromycin or clarithromycin.
- For pregnant women, prescribe erythromycin. The second line option is azithromycin and third line clarithromycin, as alternatives where necessary.
If macrolides are contraindicated or not tolerated, prescribe co-trimoxazole.
- Do not prescribe co-trimoxazole to pregnant women or infants younger than six weeks old.

role of abx

Applies to:
- Children
- staff working with children including school and healthcare workers
stay out from school until:
- 48h on appropriate abx
- 21 days from onset of coughing if no abx and well enough to return
avoid contact with infants under one year who are unvaccinated, partially vaccinated, or pregnant women

Vaccination
Catch up on any missed vax
Booster if last dose >5y ago
Prophylaxis:

is for:
- those at ↑ risk complications, or
- ↑ risk transmission
macrolide 1st line = clarithromycin/azithromycin; erythromycin in pregnant patients; co-trimoxazole if macrolides contraindicated

Vaccine uptake 92.9% of 2yos in 2023 vs 96.3% in 2014