Acute gastroenteritis in Trinidad and Tobago: identifying trend by season, geography, and demographics from 2006 to 2023.

Objectives: Acute gastroenteritis (AGE) remains a major public health and economic concern globally, including in Trinidad and Tobago, where one in ten residents is affected annually. Therefore, this study aimed to assess, for the first time, AGE trends from 2006 to 2023, focusing on demographic, seasonal, and geographic factors to guide targeted public health strategies. Methods: AGE surveillance data from 2006 to 2023, comprising all individuals presenting to any public healthcare facility in Trinidad and Tobago with AGE (defined as more than three watery stools within 24 hours), were obtained from the National Epidemiology Unit. Data were managed in Microsoft Excel and analyzed using Genstat 19 and Joinpoint Regression Program. Background characteristics were summarized descriptively using mean (SD) and frequencies. Trend analysis was performed while accounting for age group, month, year, season, and county to evaluate temporal and spatial variations in AGE incidence. Results: Between 2006 and 2023, a total of 353,269 AGE-related healthcare visits were recorded, with the highest burden in 2010 and the lowest in 2022. Overall, AGE incidence followed four phases: a decline (2006-2015, annual percent change [APC] -2.26, 95% confidence interval [CI]), an increase (2015-2018, APC 5.84, 95% CI), a sharp decline (2018-2021, APC -36.07, 95% CI), and a rebound increase (2021-2023, APC 43.26, 95% CI). By age group, AGE incidence declined in children under 5 years between 2010 and 2018 (APC -51.04, 95% CI), while in individuals aged 5 years and older, it decreased slightly from 2006 to 2015 (APC -1.11, 95% CI). Analysis by season showed different trends: in the dry season, there was an increase from 2015 to 2018 (APC 66.73, 95% CI), while in the wet season, there was a decrease from 2010 to 2018 (APC -24.00, 95% CI). Both wet and dry seasons also exhibited sharp declines during 2018-2021. Residents within the counties of Nariva, St. Patrick, Victoria, and Caroni recorded higher AGE incidence compared to other counties. Conclusions: The findings indicate higher AGE burdens across specific counties, variations in incidence between wet and dry seasons, and differences among age groups over the period 2006-2023, highlighting the need for age- and region-specific interventions, particularly in rural areas and during high-risk seasons. These results underscore the importance of enhanced AGE surveillance and the implementation of targeted public health measures in Trinidad and Tobago.