Pertussis, also known as whooping cough, is a highly contagious respiratory illness caused by the bacterium Bordetella pertussis. It primarily affects the respiratory tract and is characterised by severe coughing fits, often followed by a “whoop” sound during inhalation. Early symptoms mimic a cold, including a runny nose, mild fever, and occasional cough, before progressing to more severe coughing. Infants may experience pauses in breathing (apnoea) instead of the whoop. Transmission occurs through respiratory droplets, making it highly contagious. Complications, especially in young children, can include pneumonia, seizures, and, in extreme cases, death. Vaccination is the most effective prevention method, with antibiotics used to treat early infections.
The Samoa Ministry of Health declared a pertussis epidemic on 28 November 2024, after observing a significant increase in cases. From September to 30 December 2024, a total of 286 cases were reported, comprising 17 confirmed and 269 suspected cases. Upolu remains the most affected island, accounting for 99% of the reported cases, while only one case has been recorded in Savai’i.
Among the reported cases, 50% involve children under five years old, with 33% being less than one year old. Male cases slightly outnumber female cases, representing 55% and 45%, respectively. Since 16 September 2024, the onset date of the first reported case, 32% of all cases required hospitalisation at Tupua Tamasese Meaole Hospital (TTMH).
Laboratory testing has faced delays as samples are referred to overseas facilities in Auckland and Melbourne for confirmation. Out of 231 samples collected, 17 tested positive, 42 negative, and 172 results remain pending. Vaccination records reveal that four confirmed cases involved incomplete vaccinations, with ongoing investigations into the vaccination status of the remaining confirmed cases.
Routine immunisation coverage in Samoa for 2024 shows a steady decline across the four pertussis vaccine doses: 100% for dose 1 (6 weeks), 95% for dose 2 (10 weeks), 86% for dose 3 (14 weeks), and 65% for dose 4 (15 months). Efforts to catch up on missed doses are underway.
The Ministry of Health has issued alerts urging clinicians to report suspected and confirmed cases while emphasising contact tracing and sample collection. The Risk Communication and Community Engagement (RCCE) Committee continues to promote vaccination awareness and preventative measures.
As Samoa addresses this public health challenge, collaborative efforts between health professionals, laboratories, and the community remain vital to controlling the epidemic and preventing further transmission.
