Increase in pertussis cases in South Africa
Following a period of reduced pertussis activity during 2020–2021, South Africa experienced a marked resurgence in 2022 and 2023. Case numbers declined in 2024 but have shown a gradual increase from 2025 into early 2026. Clinicians are therefore encouraged to consider pertussis (whooping cough) in the differential diagnosis of respiratory illness, particularly among infants and unvaccinated individuals and ensure that all children receive the full schedule of pertussis-containing vaccines (at 6, 10 and 14 weeks; 18 months; and 6 and 12 years of age). In addition, pregnant women should receive the maternal dose during the third trimester of each pregnancy to protect newborns in the first months of life.
Pertussis, caused by Bordetella pertussis, is a vaccine-preventable respiratory infection and a notifiable medical condition under the National Health Act (Act No. 61 of 2003). In South Africa, pertussis vaccination is included in the Expanded Programme on Immunisation (EPI) and as part of antenatal care. Immunity following vaccination is thought to last for 5–6 years. Periodic increases in pertussis cases can occur in vaccinated populations every 3–5 years.
During 2025, there were 614 confirmed pertussis cases reported through the Notifiable Medical Conditions (NMC) surveillance system. Over half of the cases (56%, 344/614) occurred in children under 5 years of age. Infants 6 months and younger represented nearly one-third of cases (29%, 175/614), highlighting the vulnerability of this age group and the importance of maternal vaccination to prevent illness in this age group. Geographically, case distribution was concentrated in two provinces: the Western Cape led with 205 confirmed cases reported (33%), followed by Gauteng with 144 confirmed cases (24%), but this could reflect differences in diagnostic, testing and reporting practices rather than the true distribution of illness. While case numbers increased towards the end of 2025 compared to earlier months, they remained below the peak levels recorded during the 2022-2023 period.
The upward trend has continued into 2026, with 161 confirmed cases already reported in the first seven weeks (1 January – 22 February 2026). This indicates ongoing transmission and warrants close monitoring and appropriate public health response measures including increased efforts to ensure timeliness and high coverage of EPI vaccines and increased uptake of maternal vaccination.
Clinicians are reminded to maintain a high index of suspicion for pertussis and ensure that suspected and confirmed cases are notified. Diagnostic testing should be performed where appropriate, and post-exposure prophylaxis is recommended for close and high-risk contacts, including pregnant women and infants.
Parents and caregivers of children ≤ 12 years are encouraged to ensure that children are up to date with all routine vaccinations, including booster doses, and to seek medical attention promptly if symptoms develop. In 2024, booster doses at 6 and 12 years of age were introduced in the public sector, and these additional doses are important to ensure continued protection beyond early childhood.
Pertussis symptoms can vary between individuals. Early symptoms often resemble a common cold and may include nasal congestion, runny nose, mild sore throat, and a dry cough, usually with little or no fever. After several days, the cough typically becomes more severe, occurring in paroxysmal bouts that may be followed by a characteristic “whoop” or vomiting.
Additional information on the diagnosis, management, and public health response to pertussis is available on the NICD website: https://www.nicd.ac.za/diseases-a-z-index/pertussis/.
