On this page
Referral and warning signs
When to refer
Hospital admission (H/RR) required for: All infants <3-6 months with suspected pertussis. Patients with severe paroxysms, apnea, cyanosis, seizures. Patients with pneumonia or other significant complications. Patients unable to maintain hydration/nutrition orally.
Red flags
- Apneic episodes
- Cyanosis during or after coughing fits
- Seizures
- Signs of pneumonia (persistent fever, tachypnea between paroxysms, focal chest signs)
- Inability to feed / Dehydration
- Age < 3-6 months
Signs and symptoms
- Incubation period: 7-10 days.
- Stage 1: Catarrhal Phase (1-2 weeks): Resembles common cold - mild cough, rhinorrhea, low-grade fever, sneezing. Highly infectious stage.
- Stage 2: Paroxysmal Phase (1-6 weeks, can be longer): Severe, repetitive coughing fits (paroxysms) occurring in bursts. Inspiratory 'whoop' sound often follows paroxysm as patient gasps for air (may be absent in infants <6mo and adults). Post-tussive vomiting common. Cyanosis, apnea, exhaustion may occur during/after paroxysms, especially in infants. Conjunctival haemorrhages, facial petechiae from coughing.
- Stage 3: Convalescent Phase (Weeks to months): Gradual reduction in frequency and severity of coughing paroxysms. Cough may persist or recur with subsequent URTI.
Risk factors
- Incomplete or lack of pertussis vaccination (DPT/Pentavalent/Tdap).
- Infancy (<1 year), especially <6 months (highest risk of severe disease/death).
- Exposure to an infected individual (household contact, school).
- Waning immunity in adolescents and adults (who can transmit to infants).
Diagnosis
Clinical assessment
Clinical suspicion based on characteristic cough (paroxysmal, whoop, post-tussive vomiting) lasting ≥2 weeks, especially during an outbreak or with known exposure. Diagnosis often made clinically. Differential diagnosis: Other causes of prolonged cough (viral bronchitis, Mycoplasma/Chlamydia pneumonia, asthma, GERD, foreign body, TB), Croup (barking cough, stridor), Bronchiolitis (wheeze, younger infants).
Investigations
- Nasopharyngeal Swab/Aspirate:
- - Culture for Bordetella pertussis: Gold standard but sensitivity decreases after first 2 weeks of cough and after antibiotics. Requires specific media.
- - PCR for B. pertussis DNA: Highly sensitive and specific, preferred method, useful up to 3-4 weeks after cough onset.
- Blood: Complete Blood Count (CBC) may show marked lymphocytosis (high lymphocyte count), especially in infants/young children.
- Serology (Antibody testing): Useful later in illness (>2-3 weeks cough), requires paired sera or specific IgM/IgA interpretation. Less useful for acute diagnosis.
- Chest X-ray: Usually normal or may show peribronchial thickening; used to exclude pneumonia.
Diagnostic criteria
Clinical diagnosis based on characteristic cough illness ≥2 weeks, OR laboratory confirmation (positive culture or PCR).
Management
Non-pharmacological management
- Supportive Care:
- - Maintain hydration and nutrition (small, frequent feeds may be better tolerated).
- - Gentle suctioning of secretions if needed.
- - Oxygen therapy if hypoxic.
- - Minimize stimuli that trigger coughing paroxysms.
- Hospitalization: Required for infants (<3-6 months), severe cases with apnea/cyanosis/pneumonia/seizures, or inability to feed.
- Infection Control:
- - Droplet precautions for hospitalized patients until 5 days of effective antibiotic therapy completed.
- - Exclude cases from school/daycare until 5 days of antibiotics completed.
- - Reportable disease.
Pharmacological treatment
- Antibiotics: Primarily given to reduce infectivity (limit spread) and may shorten duration/severity if started early (within first 1-2 weeks of cough - catarrhal/early paroxysmal phase). Less effective if started later but still recommended to decrease transmission.
- - Macrolides are preferred:
- - Azithromycin: Child <6mo: 10mg/kg/day OD x 5 days. Child ≥6mo: 10mg/kg (max 500mg) OD on Day 1, then 5mg/kg (max 250mg) OD on Days 2-5. Adult: 500mg OD Day 1, then 250mg OD Days 2-5.
- - Erythromycin: 40-50 mg/kg/day divided QID (Adult 500mg QID) for 7-14 days (UCG 2023 specifically mentions 7 days). (More side effects, longer course).
- - Clarithromycin: Alternative macrolide.
- - Alternative if macrolide allergic/intolerant: Trimethoprim-Sulfamethoxazole (TMP-SMX) - Contraindicated in infants <2 months.
- Cough suppressants, antihistamines, mucolytics: NOT effective and NOT recommended.
- Corticosteroids: No proven benefit.
Monitoring
- Monitor respiratory status (frequency/severity of paroxysms, apnea, cyanosis).
- Monitor feeding and hydration.
- Monitor for complications (pneumonia, seizures).
Complications
- Apnea (especially infants)
- Pneumonia (secondary bacterial)
- Seizures (due to hypoxia or encephalopathy)
- Encephalopathy
- Weight loss / Malnutrition
- Dehydration
- Otitis media
- Subconjunctival haemorrhage, petechiae
- Pneumothorax, subcutaneous emphysema (from forceful coughing)
- Hernias (inguinal, umbilical), rectal prolapse
- Death (highest risk in young infants)
Prevention
- Vaccination: Routine childhood immunization with DTaP/Pentavalent vaccine. Adolescent and adult booster doses (Tdap) recommended to maintain immunity and reduce transmission to infants.
- Vaccination during pregnancy (Tdap) protects newborn.
- Post-exposure Prophylaxis (PEP): Antibiotics (usually macrolide) recommended for close contacts (household, daycare) especially if high-risk individuals (infants, pregnant women) are exposed, regardless of vaccination status.
Patient education
- Explain the stages of pertussis and prolonged nature of cough.
- Purpose of antibiotics (reduce spread, may lessen severity if early).
- Importance of completing antibiotic course.
- Need for supportive care (fluids, nutrition).
- How to manage paroxysms (minimize triggers).
- Signs of complications and when to seek urgent care.
- Importance of vaccination for prevention (childhood series, boosters).
- Need for antibiotic prophylaxis for close contacts.
Uganda-specific notes
Included in Pentavalent vaccine schedule. Diagnosis often clinical. Erythromycin is the antibiotic listed in UCG 2023. High mortality in young, unvaccinated infants. Post-exposure prophylaxis for contacts important.
References
- Uganda Clinical Guidelines (UCG) 2023
Chapter 5, Section 5.2.8