Chapter 4.7.1 Pertussis

Pertussis is most severe in young infants who have not yet been immunized. After an incubation period of 7–10 days, the child has fever, usually with a cough and nasal discharge that are clinically indistinguishable from the common cough and cold.  In the second week, there is paroxysmal coughing that can be recognized as pertussis. The episodes of coughing can continue for 3 months or longer. The child is infectious for up to 3 weeks after the onset of bouts of whooping cough.

Diagnosis

Suspect pertussis if a child has had a severe cough for more than 2 weeks, especially if the disease is known to be occurring locally. The most useful diagnostic signs are:

  • Paroxysmal coughing followed by a whoop when breathing in, often with vomiting
  • Subconjunctival haemorrhages
  • Child not immunized against pertussis.
  • Young infants may not whoop; instead, the cough may be followed by suspension of breathing (apnoea) or cyanosis, or apnoea may occur without coughing.

Also, examine the child for signs of pneumonia, and ask about convulsions.


Subconjunctival haemorrhages
prominent on the white sclera

Treatment

Treat mild cases in children aged ≥6
months at home with supportive care.
Admit infants aged < 6 months to
hospital; also admit any child with
pneumonia, convulsions, dehydration,
severe malnutrition, or prolonged apnoea
or cyanosis after coughing.

Antibiotics

Give oral erythromycin (12.5 mg/kg four times a day) for 10 days. This does not shorten the illness but reduces the period of  infectiousness.

Alternatively, if available, give azithromycin at 10mg/kg (maximum 500mg) on the first day, then 5 mg / kg (maximum 250 mg) once a day for 4 days.

If there is fever, if erythromycin or azithromycin is not available, or if there are signs of pneumonia, treat with amoxicillin as possible secondary pneumonia.  Follow the other guidelines for severe pneumonia

Oxygen

Give oxygen to children who have spells of apnoea or cyanosis, severe paroxysms of coughing or low oxygen saturation < 90% on a pulse oximeter.

Use nasal prongs, not a nasopharyngeal catheter or nasal catheter, which can provoke coughing. Place the prongs just inside the nostrils and secure with a piece of tape just above the upper lip. Care should be taken to keep the nostrils clear of mucus, as this blocks the flow of oxygen. Set a flow rate of 1–2 litres/min (0.5 litre/min in young infants). Humidification is not required with nasal prongs.

Continue oxygen therapy until the above signs are no longer present, after which there is no value in continuing with oxygen.

A nurse should check, every 3 h that the prongs or catheter are in the correct place and not blocked with mucus, and that all connections are secure.

Airway management

During paroxysms of coughing, place the child in the recovery position to prevent inhalation of vomitus and to aid expectoration of secretions.

  • If the child has cyanotic episodes, clear secretions from the nose and throat with brief, gentle suction.
  • If apnoea occurs, clear the airways immediately with gentle suction under direct vision, breathe for the infant using a bag-valve mask ideally with a reservoir bag and connected to high-flow oxygen

Supportive care

  • Avoid, as far as possible, any procedure that could trigger coughing, such as application of suction, throat examination or use of a nasogastric tube (unless the child cannot drink).
  • Do not give cough suppressants, sedatives, mucolytic agents or antihis- tamines.

If the child has fever (> 39 °C, > 102.2 °F) that appears to be causing distress, give paracetamol.

Encourage breastfeeding or oral fluids. If the child cannot drink, pass a nasogastric tube and give small, frequent amounts of fluid (ideally expressed breast milk) to meet the child’s maintenance needs. If there is severe respiratory distress and maintenance fluids cannot be given through a nasogastric tube because of persistent vomiting, give IV fluids to avoid the risk of aspiration and avoid triggering coughing.

Ensure adequate nutrition by giving small, frequent feeds. If there is continued weight loss despite these measures, feed the child by nasogastric tube.

Monitoring

The child should be assessed by a nurse every 3 h and by a doctor once a day. To facilitate early detection and treatment of apnoeic or cyanotic spells or severe episodes of coughing, the child should occupy a bed in a place close to the nursing station, where oxygen and assisted ventilation are available. Also, teach the child’s mother to recognize apnoeic spells and to alert the nurse if these occur.

Complications

Pneumonia: This is the commonest complication of pertussis and is caused by secondary bacterial infection or inhalation of vomit.

Signs suggesting pneumonia include fast breathing between coughing episodes, fever and the rapid onset of respiratory distress.

Treat pneumonia in children with pertussis as follows:

  • Give parenteral ampicillin (or benzyl penicillin) and gentamicin for 5 days, or alternatively give azithromycin for 5 days.
  • Give oxygen as described for the treatment of severe pneumonia in Sections 4.2.1 and 10.7.

Convulsions. These may result from anoxia associated with an apnoeic or cyanotic episode or toxin-mediated encephalopathy.

If a convulsion does not stop within 2 min, give diazepam, following the guidelines in Chapter 1 (Chart 9).

Malnutrition. Children with pertussis may become malnourished as a result of reduced food intake and frequent vomiting.

Prevent malnutrition by ensuring adequate feeding, as described above, under Supportive care.

  • Haemorrhage and hernias
  • Subconjunctival haemorrhage and epistaxis are common during pertussis.
  • No specific treatment is needed.

Umbilical or inguinal hernias may be caused by violent coughing.
Do not treat them unless there are signs of bowel obstruction, but refer the child for surgical evaluation after the acute phase.

Public health measures

  • Give DPT vaccine to any child in the family who is not fully immunized and to the child with pertussis.
  • Give a DPT booster to previously vaccinated children.
  • Give erythromycin estolate (12.5 mg/kg four times a day) for 10 days to any infant in the family who is < 6 months old and has fever or other signs of a respiratory infection.