Analysis of Epidemiological and Ecological Trend ：Applications of Time-Series Forecast Model

• Main Authors: Hsu, shu-mei, 許淑美
• Other Authors: Lin, Ruey S.
• Format: Others
• Language: en_US
• Published: 2000
• Online Access: http://ndltd.ncl.edu.tw/handle/06547447912319700985

碩士 === 國立臺灣大學 === 流行病學研究所 === 88 === Abstract Introduction: Due to the global climate change, mass vaccination, and changes in agriculture, the epidemiological patterns and especially the distribution of Japanese encephalitis (JE) have changed in recent years. Objectives: The aims of this study are (1) to analyze secular trend of JE between 1991-1999; (2) to elucidate the effect of climate (precipitation and temperature) on JE; and (3) to assess the change of epidemiological pattern in Taiwan after the introduction of mass vaccination. Methods: Reported cases and confirmed cases of JE between 1991-1999 and different kinds of relevant social-ecological archival data are collected. A series of time-series methods are applied to achieve the above objectives. Results: There is still a remarkable seasonal pattern identified from time trend after mass vaccination since 1968. Increasing trend from 1998 onwards is observed. The occurrence of JE in the present month is related to temperature and precipitation two months ago. This finding is consistent with transmission model of JE. The occurrence of JE tends to shift to late spring. Cases of JE occur more frequently in adults than in children. This suggests the schedule for mass vaccination of JE may be modulated. Conclusions: a series of time series model in this study are proposed to evaluate seasonal pattern of JE and forecast the number of cases. The effect of temporal sequence of climate on JE has been quantitatively assessed. The application of these results can aid one establishing the epidemiological surveillance curve of JE. This would be very helpful for detecting the epidemic of JE in advance.