Pertussis in the Tshwane District, Gauteng province, South Africa: A cross-sectional study.

Background: Pertussis remains a public health concern worldwide, particularly in infants and young children. Despite effective vaccines, challenges persist in addressing pertussis because of barriers such as limited healthcare access, inadequate vaccination coverage and weak surveillance systems, especially in low- and middle-income countries. Aim: To describe the demographic, geographic and seasonal distribution of pertussis cases reported in Tshwane District, Gauteng province, South Africa, from 2015 to 2019. Setting: The study was conducted in Gauteng's Tshwane District, which has seven sub-districts with diverse demographics ranging from highly urbanised to peri-urban and rural areas. Methods: A retrospective cross-sectional analysis of surveillance data was conducted for all pertussis cases notified in Tshwane between 1 January 2015 and 31 December 2019. Data were obtained from the district Pertussis Monitoring Database and validated against the District Health Information System. Descriptive statistics, chi-square tests and time-series analyses were applied. Results: A total of 272 cases were reported; 46.7% occurred in infants under 1 year, with those younger than 6 months comprising 39.7%. One-third were hospitalised, mostly infants. Most notifications originated from private facilities (73.5%), and spring-summer peaks were observed. Three infant deaths were recorded. Conclusion: Pertussis contributes substantially to the disease burden in Tshwane, particularly in early infancy. Strengthened immunisation programme, improved surveillance and equitable diagnostic access are essential to reduce morbidity and mortality. Contribution: This study provides district-level analysis of pertussis in Tshwane, highlighting inequities in vaccination reporting and diagnostic access and informing strategies to strengthen pertussis immunisation and surveillance.