Incidence Rate and Spatial Analysis of Dengue Fever in Roi-Et Province

Abstract

This analytical retrospective cohort study aims to analyze spatial factors and study the incidence of dengue fever in Roi Et province. The study focuses on 9,481 patients who were lived and diagnosed at the various hospital in Roi Et province between January 1, 2018, and December 31, 2023. We obtained from the database of the Epidemiological Disease Surveillance System, EDSS. The factors such as demographic characteristics, climatic, and environmental factors. The Moran's I and Anselin Local Moran's I, LISA determined the relationship with incidence of dengue fever, and analyze the incidence rate which reported 95% confidence interval.

The study found that incidence rate of dengue fever in Roi Et province was 112.1 per 100,000 per year. The incidence rate of dengue fever increased, rising from 98.1 per 100,000 per year in 2018 to 268.6 per 100,000 per year in 2019. However, this trend reversed incidence rate decreasing from 115.9 per 100,000 per year in 2020 to 20.0 per 100,000 per year in 2021. Subsequently, the trend increased again with an incidence rate of 45.3 per 100,000 per year in 2022 to 123.8 per 100,000 per year in 2023. Moran's I analysis was spatially associated with variables in the same direction. The statistically significance of the clustered pattern, including average rainfall, average temperature, average relative humidity, average meters above sea level, and population density (p-value < 0.05). The LISA, we found that the 193 sub-districts with dengue according to the following variables: 14 sub-districts as for average rainfall, 43 sub-districts as for average temperature, 36 sub-districts as for average relative humidity, 32 sub-districts as for average meters above sea level, and 16 sub-districts as for population density. While the LISA, we reported district areas with dengue according to the following variables: 1 district as for container index (CI).

This study demonstrated that average rainfall, average temperature, average relative humidity, average meters above sea level, and population density were spatially associated to the incidence of dengue fever, or the incidence of disease in the same direction. These findings suggest the need for enhanced surveillance in these identified areas. Additionally, the study observed that dengue fever incidence rates decreased during the COVID-19 pandemic when travel restrictions were implemented and schools (areas with high population density) were closed. When normal conditions resumed, dengue incidence rates increased again. Therefore, an effective measure for controlling dengue fever is restricting the movement of patients and preventing mosquito bites to prevent dengue outbreaks in the area.