California Department of Public Health, Richmond, California, USA.
Emerg Infect Dis. 2011 Aug;17(8):1445-54. doi: 10.3201/eid1708.100411.
The Dynamic Continuous-Area Space-Time (DYCAST) system is a biologically based spatiotemporal model that uses public reports of dead birds to identify areas at high risk for West Nile virus (WNV) transmission to humans. In 2005, during a statewide epidemic of WNV (880 cases), the California Department of Public Health prospectively implemented DYCAST over 32,517 km2 in California. Daily risk maps were made available online and used by local agencies to target public education campaigns, surveillance, and mosquito control. DYCAST had 80.8% sensitivity and 90.6% specificity for predicting human cases, and k analysis indicated moderate strength of chance-adjusted agreement for >4 weeks. High-risk grid cells (populations) were identified an average of 37.2 days before onset of human illness; relative risk for disease was >39× higher than for low-risk cells. Although prediction rates declined in subsequent years, results indicate DYCAST was a timely and effective early warning system during the severe 2005 epidemic.
动态连续区域时空 (DYCAST) 系统是一种基于生物学的时空模型，它利用有关死亡鸟类的公共报告来确定人类感染西尼罗河病毒 (WNV) 的高风险区域。2005 年，在加利福尼亚州发生的 WNV 全州范围的疫情（880 例）期间，加利福尼亚州公共卫生部在加利福尼亚州 32517 平方公里的范围内前瞻性地实施了 DYCAST。每日风险图在线提供，并由地方机构用于确定公众教育活动、监测和蚊虫控制的目标。DYCAST 预测人类病例的敏感性为 80.8%，特异性为 90.6%，k 分析表明对>4 周的机会调整一致性具有中等强度。高危网格单元（人群）在人类疾病发病前平均提前 37.2 天确定；疾病的相对风险比低危细胞高 39 倍以上。尽管预测率在随后的几年中有所下降，但结果表明 DYCAST 在 2005 年严重疫情期间是一个及时有效的早期预警系统。
