Epidemiological Characteristics and Space-Time Analysis of the 2015 Dengue Outbreak in the Metropolitan Region of Tainan City, Taiwan

Abstract

The metropolitan region of Tainan City in southern Taiwan experienced a dengue outbreak in 2015. This manuscript describes basic epidemiological features of this outbreak and uses spatial and temporal analysis tools to understand the spread of dengue during the outbreak. The analysis found that, independently of gender, dengue incidence rate increased with age, and proportionally affected more males below the age of 40 years but females above the age of 40 years. A spatial scan statistic was applied to detect clusters of disease transmission. The scan statistic found that dengue spread in a north-south diffusion direction, which is across the North, West-Central and South districts of Tainan City. Spatial regression models were used to quantify factors associated with transmission. This analysis indicated that neighborhoods with high proportions of residential area (or low wetland cover) were associated with dengue transmission. However, these association patterns were non-linear. The findings presented here can help Taiwanese public health agencies to understand the fundamental epidemiological characteristics and diffusion patterns of the 2015 dengue outbreak in Tainan City. This type of information is fundamental for policy making to prevent future uncontrolled dengue outbreaks, given that results from this study suggest that control interventions should be emphasized in the North and West-Central districts of Tainan city, in areas with a moderate percentage of residential land cover.

Measuring Consumer Willingness to Pay to Reduce Health Risks of Contracting Dengue Fever

“…Area variables are mainly areas where dengue fever has occurred, and it is even more obvious that residents attach great importance to the prevention of dengue fever. Whether in the area where the disease occurs or in the neighbourhood area, people are indirectly alert to the disease [5]. In terms of gender, men and women have different sensitivities to disease prevention.…”

“…In terms of gender, men and women have different sensitivities to disease prevention. Chuang et al [5] found that a relatively high proportion of women are infected with dengue fever. Nielsen et al [51] also pointed out that gender is significant in health risk assessment and has been found to potentially affect the reduction of health risks.…”

“…Further, families with children have more sensitivity to disease prevention. Children are also found to be the main group infected with dengue fever [5]. Regarding the disease prevention variables of dengue fever, disease awareness (infection vector, know vaccine) and prevention behaviors (activity, cognition) are often among the important indicators of disease prevention.…”

“…Since the 20th century, Taiwan has had a dengue epidemic every year, often triggered by imported cases [4]. The hot and humid climate and the high population density in urban areas of cities in southern Taiwan make them major dengue hotspots [5]. Since Taiwan's initial dengue epidemic in 1987-1988, there has been dengue outbreak almost every year in cities in southern Taiwan.…”

A Gut Commensal Bacterium Promotes Mosquito Permissiveness to Arboviruses

“…Both Hainan and Jiangsu are not dengue-prevalent regions (Gao et al, 2010;Lai et al, 2015). However, Guangzhou, Foshan, and Tainan are districts with recent dengue epidemics (Chuang et al, 2018;Wang et al, 2016;Xiao et al, 2016). In the A. albopictus Foshan, A. albopictus Guangzhou, and A. aegypti Taiwan Tainan strains, 8.3%-17.7% of the colonies of gut cultivable bacteria were S. marcescens.…”