Ethnic conflict as a risk amplifier for resurgent P. vivax malaria in temperate zones: A case study from the Caucasus region

•Ethnic conflict facilitates the re-emergence of infectious and vector borne diseases.•The Caucasus region remains vulnerable to P. vivax malaria.•Further instability in the Caucasus will amplify infectious disease risks. One of the most protracted post-Soviet conflicts of the 1990s was a territorial dispute between Armenia and Azerbaijan over the contested Karabakh region. Years of ethnic violence led to the displacement of nearly a million refugees, as well as a public health crisis that included epidemics of malaria, diphtheria and other preventable diseases. Malaria is not usually considered a health risk in temperate climates, but seasonal epidemics were widespread throughout the Caucasus in the early decades of the twentieth century. This paper combines qualitative historical research with geospatial analysis to explore how endemic malaria was controlled during the Soviet era, and how ethnic conflict reconfigured local ecologies to facilitate the re-emergence of P. vivax after the Soviet collapse in the 1990s. This research reveals that ethnic conflicts have specific qualities that increase risks of infectious and vector borne disease outbreaks, even in places that have successfully achieved a modern health and mortality profile. The risk amplifiers of ethnic conflicts include 1) the creation of contested spaces controlled by separatists that are outside of any national public health surveillance system; 2) mass population movements and refugee outflows due to ethnic violence; and 3) changes in land use that expand potential mosquito breeding sites throughout the conflict zone. Continued hostilities between Armenia and Azerbaijan, combined with the repopulation of key vector species (specifically An. sacharovi) lead us to conclude that populations in the Caucasus remain vulnerable to resurgent outbreaks of ethno-nationalist violence as well as the return of seasonal malaria, even after decades of successful control.