Communicable Disease Epidemiology Unit, National Centre of Epidemiology, Surveillance and Health Promotion, Istituto Superiore di Sanità (National Public Health Institute/ISS), Rome, Italy.
Epidemics. 2009 Sep;1(3):175-84. doi: 10.1016/j.epidem.2009.06.003. Epub 2009 Jun 23.
A competent vector of dengue and chikungunya viruses, Aedes albopictus, is present in Europe. As a first step towards assessing the likelihood of local transmission of these viruses in Europe, we estimated the number of viremic person-days among air-travellers arriving in the European Union (EU).
For dengue, we developed a Monte Carlo model with the following parameters: probability distributions based on quarterly incidences in endemic countries (years 2003-2007), passenger flow from endemic to EU countries (year 2006), duration of viremia, probability of being viremic upon arrival, distribution and period of vector activity in the EU. For chikungunya, due to scarce incidence data, we developed a model with point estimates.
We estimated at 4763 (range 3067-7019) the median dengue viremic person-days in 2006 with highest estimate among travellers from Asia during the third quarter. Dengue estimates among travellers arriving in EU Aedes-infested areas from April to October were 169 viremic person-days, 130 arriving in Italy. For chikungunya, we estimated 6 viremic person-days in EU Aedes-infested areas among air-travellers from India; all occurred in Italy.
Our results are a first step towards a real estimation of the risk of local dengue transmission in Europe. Further research is needed to better understand vector capacity and other factors related to virus transmission in temperate climates. Information on personal protection to travellers, early diagnosis and implementation of vector monitoring and control should be a priority in EU areas where the vector is established.
登革热和基孔肯雅热的媒介埃及伊蚊在欧洲存在。作为评估这些病毒在欧洲本地传播可能性的第一步，我们估算了抵达欧盟（EU）的航空旅行者中有多少人带有病毒血症。
对于登革热，我们开发了一个基于以下参数的蒙特卡罗模型：基于流行国家（2003-2007 年）的季度发病率的概率分布、来自流行国家到欧盟国家的旅客流量（2006 年）、病毒血症持续时间、到达时带有病毒血症的概率、在欧盟的媒介活动的分布和周期。对于基孔肯雅热，由于发病率数据稀缺，我们使用点估计开发了一个模型。
我们估计 2006 年的中位数登革热病毒血症人数为 4763 人（范围 3067-7019），其中第三季度来自亚洲的旅行者的估计值最高。4 月至 10 月抵达欧盟蚊虫滋生地区的旅行者中有 169 人带有病毒血症，其中 130 人抵达意大利。对于基孔肯雅热，我们估计从印度抵达欧盟蚊虫滋生地区的航空旅行者中有 6 人带有病毒血症；所有这些都发生在意大利。
我们的结果是对欧洲本地登革热传播风险进行实际估算的第一步。需要进一步研究以更好地了解在温带气候中与病毒传播相关的媒介能力和其他因素。向旅行者提供个人保护、早期诊断以及实施媒介监测和控制的信息应该是在已经建立媒介的欧盟地区的优先事项。
