Quantifying the Emergence of Dengue in Hanoi, Vietnam: 1998-2009
Quantifying the Emergence of Dengue in Hanoi, Vietnam: 1998-2009
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DOI：
10.1371/journal.pntd.0001322
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发表时间：
2011-09-01
影响因子：
3.8
通讯作者：
Horby, Peter
中科院分区：
文献类型：
--
作者：
Hoang Quoc Cuong;Nguyen Tran Hien;Horby, Peter
背景资料：估计有24亿人生活在登革热传播风险地区，因此，在传播适宜性极低的地区确定登革热流行的因素相当重要。河内，越南是这样一个地区，并在2009年的大登革热爆发后，我们着手确定登革热是否正在出现在河内。方法和主要发现：我们进行了时间和空间分析25,983登革热病例通知河内1998年和2009年之间。计算年龄标准化发病率、标准化感染年龄和标准化死亡率（SMR）。使用准泊松回归模型来确定登革热发病率是否随时间增加。小波分析被用来探索登革热传播的周期性和与气候变量的关联。在排除1998年和2009年两个主要爆发年份并校正人口年龄结构变化后，我们发现1999-2008年期间登革热病例的发病率每年显著增加（发病率比= 1.38，95%置信区间= 1.20-1.58，p值= 0.002）。河内报告的登革热病例年龄偏高，中位年龄为23岁（平均26.3岁）。在调整人口年龄结构的变化后，在研究期间，登革热病例的中位数或平均年龄没有统计学显著变化。河内中心城区登革热发病率最高（SMR>3）。结论：河内是登革热低传播区，自1999年以来登革热发病率逐年上升。这一趋势需要通过血清学调查加以证实，然后进行研究，以确定这种出现的根本驱动因素。这些研究可以深入了解与建立地方性登革热的脆弱性相关的生物，人口和环境变化。
Background: An estimated 2.4 billion people live in areas at risk of dengue transmission, therefore the factors determining the establishment of endemic dengue in areas where transmission suitability is marginal is of considerable importance. Hanoi, Vietnam is such an area, and following a large dengue outbreak in 2009, we set out to determine if dengue is emerging in Hanoi.Methods and Principal Findings: We undertook a temporal and spatial analysis of 25,983 dengue cases notified in Hanoi between 1998 and 2009. Age standardized incidence rates, standardized age of infection, and Standardized Morbidity Ratios (SMR) were calculated. A quasi-Poisson regression model was used to determine if dengue incidence was increasing over time. Wavelet analysis was used to explore the periodicity of dengue transmission and the association with climate variables. After excluding the two major outbreak years of 1998 and 2009 and correcting for changes in population age structure, we identified a significant annual increase in the incidence of dengue cases over the period 1999-2008 (incidence rate ratio = 1.38, 95% confidence interval = 1.20-1.58, p value = 0.002). The age of notified dengue cases in Hanoi is high, with a median age of 23 years (mean 26.3 years). After adjusting for changes in population age structure, there was no statistically significant change in the median or mean age of dengue cases over the period studied. Districts in the central, highly urban, area of Hanoi have the highest incidence of dengue (SMR>3).Conclusions: Hanoi is a low dengue transmission setting where dengue incidence has been increasing year on year since 1999. This trend needs to be confirmed with serological surveys, followed by studies to determine the underlying drivers of this emergence. Such studies can provide insights into the biological, demographic, and environmental changes associated with vulnerability to the establishment of endemic dengue.