Pertussis

Pertussis (or whooping cough) is a bacterial disease caused by the gram-negative organism Bordetella pertussis (1,2).

• It is an upper respiratory tract infection with a characteristic, paroxysmal - whooping – cough.
• The organism is found in the back of the throat of an infected person (3).
• Bordetella parapertussis can also be responsible in some cases and is not preventable with presently available vaccines (1,2).

Transmission of the disease is from human to human by droplets (1).

• It is a highly contagious disease with close direct contact with an infected person resulting in transmission of the disease (1).
  • Up to 90% of household contacts develop the disease (2).
• Traditionally, droplet transmission has been accepted as occurring within 3 feet of the infected patient but recent studies have suggested that droplets can be dispersed to a distance of 6 feet (1.9 metres) during coughing.

The Chinese refer to whooping cough as the 100-day cough; this description gives the parents some idea of what to expect.

A positive history of pertussis vaccination does not preclude the diagnosis - the vaccination only confers 95% protection. Also, maternal antibody does not appear to confer any significant protection from infection.

In England and Wales, pertussis is a notifiable disease (diagnosis made on clinical grounds and laboratory confirmation is not required) (2,3).

UKHSA statistics show that cases of pertussis have risen in all age groups and in every region in England (4):

• of the 2793 cases confirmed between January and March 2024, around half (1420 cases, 50.8%) were in those aged 15 years or older and 28.6% were in children aged between 10 and 14 years (799 cases)
• in older children and adults, however, whooping cough is usually a mild illness.

References:

1. Heininger U. Pertussis: what the pediatric infectious disease specialist should know. Pediatr Infect Dis J. 2012;31(1):78-9.
2. Public Health England (PHE) 2018. Guidelines for the Public Health Management of Pertussis in England
3. Public Health England (PHE). Pertussis brief for healthcare professionals
4. Wise J. Whooping cough: What’s behind the rise in cases and deaths in England? BMJ 2024; 385 :q1118 doi:10.1136/bmj.q1118