Trends and Spatial Pattern Analysis of Typhoid and Paratyphoid Fever Incidence - Yunnan Province, China, 1989-2022.

Introduction: This study explored the incidence trends and spatial clustering of typhoid and paratyphoid fever (TPF) in Yunnan Province to provide scientific evidence for developing and improving prevention and control strategies.

Methods: Temporal trends were investigated by calculating the annual percent change (APC) and average annual percent change (AAPC), along with their 95% confidence intervals (CIs). The spatial clustering of TPF across Yunnan Province was examined using global Moran's I and local indicators of spatial association (LISA) statistics.

Results: A total of 206,066 TPF cases were reported in Yunnan Province from 1989 to 2022, with an average annual incidence of 13.98 per 100,000 population and a case fatality rate of 2.5 per 1,000. The greatest number of cases was reported during July and August. The 25-34-year age group had the highest incidence, and farmers were prominently represented. TPF incidence in Yunnan Province showed a significant decrease and spatial clustering. From 2005 to 2022, 13 county-level cities/counties/municipal districts in 5 prefectures (cities) in Yunnan Province were identified as statistically significant H-H spatial clusters of TPF incidence. A total of 24 TPF outbreaks were reported in Yunnan Province from 2005 to 2022.

Conclusions: The incidence of TPF in Yunnan Province showed a significant decrease and spatial clustering. Control strategies should focus on high-incidence areas, seasons, and populations to reduce the incidence of TPF.