Pertussis (Human)

Unique identifier / Notation

BI0227

Synonyms

Whooping cough

Pertussis is a highly contagious disease, which can be fatal, of the respiratory tract caused by the bacterium Bordetella pertussis (WHO, no date a).

Primary reference(s)

WHO, no date a. Pertussis. World Health Organization (WHO). Accessed 27 May 2025.

Annotations

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, 2024).

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 a).

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, 2024). 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).

During 2023, about 84% of infants worldwide (108 million) received 3 doses of diphtheria-tetanus-pertussis (DTP3) vaccine.

Key relevant UN convention / multilateral treaty

International Health Regulations (2005), 3rd ed. (WHO, 2016).

Drivers

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). Immunisation, the use of vaccines to produce immunity to specific diseases, is a global health and development success story, saving millions of lives every year. Vaccination is a highly effective method of preventing certain infectious diseases. Vaccines reduce the risks of getting a disease by working with each individual's natural defences to build protection (WHO, no date b).

The most common sociodemographic determinants associated with the reduction of vaccination uptake were economic status, age, education, and household composition (Eiden et al., 2022).

Impacts

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).

Multi-hazard context

Pertussis is easily transmitted from person to person, mainly through droplets. In 2022, there were more than 62,500 cases of pertussis globally and nearly 39,000 cases were reported in the Western Pacific Region. Pertussis can be prevented by immunisation. The Western Pacific Region had 93% coverage with three doses of diphtheria-tetanus-pertussis vaccine in 2022 (WHO, no date).

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 2023, about 84% of infants worldwide (108 million) received 3 doses of diphtheria-tetanus-pertussis (DTP3) vaccine, protecting them against infectious diseases that can cause serious illness and disability or be fatal. However, these global figures hide significant disparity among countries of different income strata, with low-income countries lagging behind (WHO, 2020; 2024)

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 a).

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 a).

Monitoring

The objectives of pertussis surveillance are to monitor disease burden and the impact of the pertussis vaccination programme, with a special focus on understanding the morbidity and mortality in children under 5 years of age, to generate data to inform vaccine schedule and delivery strategy decisions to optimize the impact of vaccination and to detect and guide public health response to outbreaks of pertussis (WHO, 2018).

WHO supports countries to conduct all-hazards strategic risk assessment in the contexts of health emergencies and disasters, which results in the development of a country risk profile. Empowered with the country risk profile, inclusive of a seasonal risk calendar, countries can anticipate potential emergencies before they occur to trigger early alerts and inform early actions (WHO, 2021).

WHO's Early Warning, Alert and Response System (EWARS) has been designed to improve disease outbreak detection in emergency settings, such as in countries in conflict or following a disaster from natural hazards. It is a simple and cost-effective way to rapidly set up a disease surveillance system. EWARS is deployed during an emergency as an adjunct to the national disease surveillance system. WHO works with Ministries of Health and health sector partners to train local health workers to use the system. After the emergency, EWARS should re-integrate back into the national system (WHO, 2023).