Pertussis
Description Diagnosis General and supportive measures Medicine treatment Referral ICD-10 code: A37.9 * Notifiable condition DESCRIPTION A communicable respiratory infection classically causing a paroxysmal cough followed by an inspiratory whoop (absent in young infants) with associated vomiting. Subconjunctival haemorrhages may be present. The cough can persist for 3 months or longer with t
Description
Diagnosis
General and supportive measures
Medicine treatment
Referral
ICD-10 code: A37.9
* Notifiable condition
DESCRIPTION
A communicable respiratory infection classically causing a paroxysmal cough followed by an inspiratory whoop (absent in young infants) with associated vomiting. Subconjunctival haemorrhages may be present. The cough can persist for 3 months or longer with the infectious period being between 2 weeks and 3 months. The disease is more severe in young infants where it may present with apnoea rather than an inspiratory whoop.
Classic pertussis is uncommon in the vaccine era and most cases present with non-specific respiratory symptoms.
Incubation period: 7–10 days. Range: 6–21 days.
DIAGNOSIS
- A definitive diagnosis is often not possible and treatment should be initiated in suspected cases prior to microbiological confirmation.
- May have profound leucocytosis, predominantly lymphocytosis, although leucocytosis is often absent, particularly in infants.
- PCR on nasopharyngeal aspirates is the preferred diagnostic modality.
- Cultures are usually negative, even in confirmed cases.
- Serology is of limited value early in the disease.
GENERAL AND SUPPORTIVE MEASURES
- Standard and droplet precautions for 5 days whilst on appropriate antibiotic therapy; for 21 days if not.
- Appropriate respiratory support for apnoea or respiratory distress/failure.
- Encourage oral feeding. If unsuccessful, provide nasogastric feeds.
MEDICINE TREATMENT
If hypoxic:
- Oxygen, 1–2 L/minute via nasal prongs.
- Macrolide e.g.:
- Azithromycin:
- < 6 months: 10 mg/kg/day for 5 days.
- ≥ 6 months: 10 mg/kg (max 500 mg) on day 1, then 5 mg/kg/day (maximum 250 mg) on days 2–5.
- Azithromycin:
Management of contacts
Prophylaxis for all household contacts and for health care workers with close contact:
- Azithromycin: as for treatment above.
REFERRAL
- Children with seizures or encephalopathy for further evaluation.
- Patients requiring intensive care, where none is available on site.
Standard Treatment Guidelines and Essential Medicines List for South Africa Paediatric Hospital _2023, 5th edition_Updated July 2024
Chapter 8: Infective/Infectious Diseases, 8.16 Pertussis