samoa is facing a continuing dengue outbreak that began in early 2025 and extended into March 2026, with 17, 402 cumulative clinically diagnosed cases and 5, 117 laboratory‑confirmed cases. During EpiWeek 10 (02–08 March 2026 ET) there were 187 new notifications, a 7% decline from the previous week, alongside 10 new hospital admissions and no new ICU admissions or dengue‑related deaths. Transmission remains widespread across the main islands, and children under 15 years account for three quarters of all cases.
Samoa outbreak snapshot
As of 08 March 2026 ET the outbreak totals show 17, 402 clinically diagnosed cases with 5, 117 confirmed by laboratory testing. In EpiWeek 10 (02–08 March 2026 ET) the number of new cases fell by 7% to 187, while hospital systems recorded 10 new admissions for dengue during the week. There were no new admissions to intensive care units and no dengue‑related deaths recorded during that specific week. The figures indicate continued circulation but a short‑term reduction in newly notified cases for the reported week.
Transmission, serotypes and who is affected
Transmission remains widespread geographically, with 64% of cases on Upolu and 36% on Savaii. Children under 15 years represent 74% of all cases, highlighting the outbreak’s heavy impact on younger age groups. Laboratory serotyping shows two distinct virus patterns: roughly two thirds of typed cases are DENV‑1 and about one third are DENV‑2. These proportions describe current serotype distribution among the laboratory‑confirmed infections and are central to understanding the epidemiology during this phase of the outbreak in samoa.
What ends an outbreak and what to expect next
The established criterion for declaring an outbreak over is the absence of new laboratory‑confirmed cases for two full incubation periods. One incubation period is 14 days; therefore, a 28‑day stretch with no new laboratory‑confirmed cases is required to declare the outbreak over. That definition sets a clear, measurable threshold public health authorities must meet before any formal end can be announced.
Going forward, the next developments to monitor are weekly laboratory‑confirmed case counts and hospital admissions. Sustained declines in both indicators across consecutive weeks will determine whether the 28‑day threshold can be met. Public health attention will focus on keeping new laboratory confirmations at zero for two incubation periods while monitoring serotype trends and the high burden among children under 15. Continued surveillance on Upolu and Savaii will be critical to confirming interruption of transmission and formally closing the outbreak in samoa.
