Between 1999 and 2008 Russia experienced a flare-up of transmission of vivax malaria following its massive importation with more than 500 autochthonous cases in European Russia, the Moscow region being the most affected. The outbreak waned soon after a decrease in importation in mid-2000s and strengthening the control measures. Compared with other post-eradication epidemics in Europe this one was unprecedented by its extension and duration. The aim of this study is to identify geographical determinants of transmission. The degree of favourability of climate for vivax malaria was assessed by measuring the sum of effective temperatures and duration of season of effective infectivity using data from 22 weather stations. For geospatial analysis, the locations of each of 405 autochthonous cases detected in Moscow region have been ascertained. A MaxEnt method was used for modelling the territorial differentiation of Moscow region according to the suitability of infection re-emergence based on the statistically valid relationships between the distribution of autochthonous cases and environmental and climatic factors. In 1999–2004, in the beginning of the outbreak, meteorological conditions were extremely favourable for malaria in 1999, 2001 and 2002, especially within the borders of the city of Moscow and its immediate surroundings. The greatest number of cases occurred at the northwestern periphery of the city and in the adjoining rural areas. A significant role was played by rural construction activities attracting migrant labour, vegetation density and landscape division. A cut-off altitude of 200 m was observed, though the factor of altitude did not play a significant role at lower altitudes. Most likely, the urban heat island additionally amplified malaria re-introduction. The malariogenic potential in relation to vivax malaria was high in Moscow region, albeit heterogeneous. It is in Moscow that the most favourable conditions exist for vivax malaria re-introduction in the case of a renewed importation. This recent event of large-scale re-introduction of vivax malaria in a temperate area can serve as a case study for further research.

中文翻译：

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在温带地区（俄罗斯莫斯科地区）重新引入间日间疟疾：地理调查

从1999年到2008年，俄罗斯大规模进口间日间传播的间日疟疾，其中在欧洲的俄罗斯共发生了500多例当地病例，而莫斯科地区受到的影响最大。在2000年代中期进口量减少并加强了控制措施之后，疫情迅速减弱。与欧洲其他根除后流行病相比，这一次的延续和持续时间是空前的。这项研究的目的是确定传播的地理决定因素。使用22个气象站的数据，通过测量有效温度的总和和有效感染季节的持续时间，评估了间日间疟疾的气候适宜程度。为了进行地理空间分析，已经确定了在莫斯科地区检测到的405例本地病例的位置。根据传染病复发的适宜性，使用了一个MaxEnt方法来模拟莫斯科地区的地域差异，该方法基于本地病例分布与环境和气候因素之间的统计有效关系。在1999-2004年爆发初期，气象条件对1999、2001和2002年的疟疾极为有利，特别是在莫斯科市及其周边地区的边界内。最多的病例发生在城市的西北边缘和毗邻的农村地区。农村建设活动在吸引农民工，植被密度和景观划分方面发挥了重要作用。观察到的截断高度为200 m，尽管海拔高度因素在较低的海拔高度上没有显著作用。最有可能的是，城市热岛还增加了疟疾的再引入。尽管间质性不同，但与间日间疟疾有关的致疟潜力很高。在莫斯科，在重新进口的情况下，存在重新引入间日间疟疾的最有利条件。最近在温带地区大规模重新引入间日间疟疾的事件可以作为进一步研究的案例研究。在莫斯科，在重新进口的情况下，存在重新引入间日间疟疾的最有利条件。最近在温带地区大规模重新引入间日间疟疾的事件可以作为进一步研究的案例研究。在莫斯科，在重新进口的情况下，存在重新引入间日间疟疾的最有利条件。最近在温带地区大规模重新引入间日间疟疾的事件可以作为进一步研究的案例研究。