Limits of Plague: Ecological Contraints on Plague Reservoirs

About the project

Yersinia pestis caused large plague pandemics in Medieval Europe, Central Asia and the Middle East. While its human burden is far lower today, the bacterium persists widely in the semi-arid deserts, steppes, montane meadows and the tropics of the Americas, Africa and Asia, in ground squirrels, jirds, voles, gerbils, rats & marmots, as well as their fleas.

The ecological constraints that define where plague can persist in the wild are unknown. For non-ecologists, it is tempting to assume that regions with the right species (or even genus) of rodent can be potential plague reservoirs, but that intuition breaks down rapidly when comparing the rodent distribution maps with plague reservoir maps.

Objectives

Our primary objective is to understand the ecological constraints that define where plague reservoirs can exist. We will approach this problem by building ecological niche models (ENMs) that avoid the limitations of other attempts (e.g. focused on a regional scope only, using limited datasets, and generic rather than plague-specific input variables). With a vast amount of data now available from the former USSR plague control program and from historical records, the main challenge for us lies in using the right methodology to build and project ENMs as far across the globe as is reliably possible, and to test and select the right plague-relevant input variables for the models (e.g.climate instability, soil properties).

Our use cases are both historic and current. We will answer how suitable medieval Europe, Asia and North Africa were as past plague reservoirs, something that since the ancient DNA breakthroughs in plague research is now heavily speculated upon, as well as learn more about the potential lifespan of those reservoirs. Finally, a better understanding what defines a
plague reservoir helps with plague surveillance now, and in a future world that is in flux with climate change.

Financing

This project is funded by the Research Council of Norway (RCN)

RCN Project Number: 288551 (Project data bank at RCN)

UiO Project Number: 144808

Period

01.03.2019 - 31.01.2024