# Norovirus outbreak spreads across Azores islands > Live situation record from CLSTR: https://clstr.news/situations/gastroenteritis-outbreak-in-faial-azores > Updated: 2026-08-28T12:02:50.000Z. Sources: 10. Developments: 3. An outbreak of acute gastroenteritis has affected the island of Faial in the Azores, with over 400 cases recorded at the Hospital da Horta between July 1 and August 12. This represents a significant increase from the 90 cases reported during the same period the previous year. Health authorities, including the Horta Health Delegation, have launched investigations to identify the cause. While testing is ongoing, officials have stated there is currently “no evidence” linking the outbreak to the public water supply. Preliminary findings suggest the illness may be caused by a highly transmissible virus, potentially from the norovirus group, which may have been introduced via air or sea travel. Epidemiological analysis indicates the outbreak began in mid-July, with an effective reproduction number that has stabilized at approximately 1.3. The illness has primarily affected adults, while the elderly have remained relatively spared. Health officials have advised residents to practice frequent handwashing and maintain hydration. By late August, the Azores Regional Health Authority confirmed the norovirus outbreak has spread to multiple islands, including São Miguel and Pico. While the virus is highly contagious, officials stated the situation is “not cause for alarm,” as most patients recover at home within one to three days. In Ponta Delgada, isolated instances of Salmonella and Campylobacter were also noted. Transmission rates appear to be declining; specifically, the effective reproduction number in Faial has fallen below one since August 19. ## Timeline ### 2026-08-28: Azores health authorities confirm norovirus outbreak across multiple islands The Azores Regional Health Authority has confirmed a norovirus outbreak across several islands, including São Miguel and Faial, though transmission rates in some areas are beginning to decline. 5 sources. https://clstr.news/cluster/azores-health-authorities-confirm-norovirus-outbreak-across-multiple-islands ### 2026-08-18: Faial experiences gastroenteritis outbreak in the Azores A gastroenteritis outbreak, potentially caused by a highly transmissible norovirus, is affecting hundreds on Faial island in the Azores, with investigations into its summer-related origins ongoing. 5 sources. https://clstr.news/cluster/faial-experiences-gastroenteritis-outbreak-in-the-azores ### 2026-08-14: Faial experiences gastroenteritis outbreak with over 400 cases Health authorities are investigating a gastroenteritis outbreak in Faial, Azores, after more than 400 cases were recorded at Hospital da Horta since July 1. 5 sources. https://clstr.news/cluster/faial-experiences-gastroenteritis-outbreak-with-over-400-cases --- Cite as: Norovirus outbreak spreads across Azores islands. CLSTR, https://clstr.news/situations/gastroenteritis-outbreak-in-faial-azores