Abstract
BackgroundBetween 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.MethodsThe 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.ResultsIn 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.ConclusionThe 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.
Highlights
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
P. vivax largely predominated in temperate areas of European Russia and Siberia, whereas Plasmodium falciparum was widespread in sub-tropical Central Asia and Transcaucasia, which did not belong to Russia proper
Spatial distribution of malaria cases Between 1999 and 2008, 405 cases of vivax malaria transmission were recorded in Moscow region, of which 93 were observed within the borders of the city of Moscow (Fig. 2)
Summary
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. Plasmodium vivax is one of the species of human malaria that is evolutionary well adapted to temperate climatic conditions. Vivax malaria was widespread during the period of its greatest presence in Europe (19th Century), occurring even in the North (in southern England [2,3,4], southern Sweden [4], and being a serious problem in Finland [5]). There is very little information on malaria in Russia before the mid-19th century [6]. The limit of transmission of vivax malaria corresponded roughly to the border of the southern and middle taiga; it was endemic in the southern parts of Arkhangelsk region and occasionally it reached the city of Arkhangelsk itself (64o N) [7]
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
