Pertussis (Human)

Primary reference(s)

WHO, no date. Pertussis. World Health Organization (WHO). Accessed 15 November 2020.

Additional scientific description

Pertussis, also known as whooping cough, is a highly contagious respiratory infection caused by the bacterium Bordetella pertussis. In 2018, there were more than 151,000 cases of pertussis globally (CDC, 2019).

Pertussis spreads easily from person to person mainly through droplets produced by coughing or sneezing. The disease is most dangerous in infants and is a significant cause of disease and death in this age group (WHO, 2018).

The first symptoms generally appear 7 to 10 days after infection. They include a mild fever, runny nose and cough, which in typical cases gradually develops into a hacking cough followed by whooping (hence the common name of ‘whooping cough’). Pneumonia is a relatively common complication, and seizures and brain disease occur rarely. People with pertussis are most contagious up to about 3 weeks after the cough begins, and many children who contract the infection have coughing spells that last 4 to 8 weeks. Antibiotics are used to treat the infection (WHO, no date).

Pertussis is diagnosed clinically by its symptoms and through laboratory confirmation. It should be suspected in anyone with a cough that does not improve within 14 days, a paroxysmal cough of any duration, or any respiratory symptoms after contact with a laboratory-confirmed case of pertussis (WHO, 2020a). Of note the symptoms in infants, in which the highest mortality is seen, may differ strongly from those in older children and adults in that the typical cough may not be present at all.

The World Health Organization (WHO) has published guidance on case classification and surveillance standards (WHO, 2018).

Metrics and numeric limits

Globally, it is estimated that there were 24.1 million pertussis cases and 160,700 deaths from pertussis in children under the age of 5 years in 2014, with periodic epidemics occurring every two to five years (WHO, 2018).

Examples of drivers, outcomes and risk management

The best way to prevent pertussis is through immunisation. The three-dose primary series diphtheria-tetanus-pertussis (DTP3) (-containing) vaccines decrease the risk of severe pertussis in infancy. During 2019, about 85% of infants worldwide (116 million infants) received three doses of DTP3 vaccine, protecting them against infectious diseases that can cause serious illness and disability or be fatal. By 2019, 125 Member States had reached at least 90% coverage of DTP3 vaccine (WHO, 2020a,b).

The WHO recommends the first dose be administered as early as 6 weeks of age; with subsequent doses given 4 to 8 weeks apart (age 10–14 weeks and 14–18 weeks). A booster dose is recommended, preferably during the second year of life. Based on local epidemiology, further booster doses may be warranted later in life (WHO, no date). 

Vaccination of pregnant women is effective in preventing disease in infants too young to be vaccinated. National programmes may consider vaccination of pregnant women with pertussis-containing vaccine as a strategy additional to routine primary infant pertussis vaccination in countries or settings with high or increasing infant morbidity/mortality from pertussis (WHO, no date).