State Key Laboratory of Organ Failure Research, Department of Biostatistics, Guangdong Provincial Key Laboratory of Tropical Disease Research, School of Public Health, Southern Medical University, Guangzhou, China.
Guangzhou Center for Disease Control and Prevention, Guangzhou, Guangdong, China.
PLoS Negl Trop Dis. 2020 Aug 7;14(8):e0008541. doi: 10.1371/journal.pntd.0008541. eCollection 2020 Aug.
In 2019, dengue incidences increased dramatically in many countries. However, the prospective growth in dengue incidence did not occur in Guangzhou, China. We examined the effectiveness of early start of Grade III response to dengue in Guangzhou. We extracted the data on daily number of dengue cases during 2017-2019 in Guangzhou and weekly data for Foshan and Zhongshan from the China National Notifiable Disease Reporting System, while the data on weekly number of positive ovitraps for adult and larval Aedes albopictus were obtained from Guangzhou Center for Disease Control and Prevention. We estimated the number of dengue cases prevented by bringing forward the starting time of Grade III response from September in 2017-2018 to August in 2019 in Guangzhou using a quasi-Poisson regression model and applied the Baron and Kenny's approach to explore whether mosquito vector density was a mediator of the protective benefit. In Guangzhou, early start of Grade III response was associated with a decline in dengue incidence (relative risk [RR]: 0.54, 95% confidence interval [CI]: 0.43-0.70), with 987 (95% CI: 521-1,593) cases averted in 2019. The rate of positive ovitraps also significantly declined (RR: 0.64, 95% CI: 0.53-0.77). Moreover, both mosquito vector density and early start of Grade III response was significantly associated with dengue incidence after adjustment for each other. By comparing with the incidence in Foshan and Zhongshan where the Grade III response has not been taken, benefits from the response starting in August were confirmed but not if starting from September. Early start of Grade III response has effectively mitigated the dengue burden in Guangzhou, China, which might be partially through reducing the mosquito vector density. Our findings have important public health implications for development and implementation of dengue control interventions for Guangzhou and other locations with dengue epidemics.
2019 年，许多国家的登革热发病率显著上升。然而，中国广州并没有出现预期的登革热发病率增长。我们研究了广州提前启动三级应对措施对登革热的效果。我们从中国国家法定传染病报告系统中提取了 2017-2019 年广州每日登革热病例数据，以及佛山和中山的每周数据，同时从广州疾病预防控制中心获取了成蚊和白纹伊蚊幼虫诱蚊诱卵器每周阳性率数据。我们采用拟泊松回归模型估计了 2019 年将三级应对措施的启动时间从 9 月提前到 8 月，从而预防的登革热病例数，并采用 Baron 和 Kenny 的方法探索蚊虫媒介密度是否为保护效益的中介因素。在广州，提前启动三级应对措施与登革热发病率下降相关（相对风险 [RR]：0.54，95%置信区间 [CI]：0.43-0.70），2019 年可避免 987 例（95%CI：521-1593）病例。诱蚊诱卵器阳性率也显著下降（RR：0.64，95%CI：0.53-0.77）。此外，调整相互作用后，蚊虫媒介密度和三级应对措施的启动时间均与登革热发病率显著相关。与未采取三级应对措施的佛山和中山的发病率相比，证实了 8 月开始实施该措施的获益，但 9 月开始实施则没有获益。提前启动三级应对措施有效地减轻了中国广州的登革热负担，这可能部分是通过降低蚊虫媒介密度实现的。我们的研究结果对广州和其他有登革热疫情地区制定和实施登革热控制干预措施具有重要的公共卫生意义。
