Abstract
Simple Summary: Parasitic helminths represent one of the most pervasive challenges to
livestock, and their intensity and distribution will be influenced by climate change. There is
a need for long-term predictions to identify potential risks and highlight opportunities for
control. We explore the approaches to modelling future helminth risk to livestock under
climate change. One of the limitations to model creation is the lack of purpose driven data
collection. We also conclude that models need to include a broad view of the livestock
system to generate meaningful predictions.
Abstract: Climate change is a driving force for livestock parasite risk. This is especially
true for helminths including the nematodes Haemonchus contortus, Teladorsagia
circumcincta, Nematodirus battus, and the trematode Fasciola hepatica, since survival and
development of free-living stages is chiefly affected by temperature and moisture. The
paucity of long term predictions of helminth risk under climate change has driven us to
explore optimal modelling approaches and identify current bottlenecks to generating
meaningful predictions. We classify approaches as correlative or mechanistic, exploring
their strengths and limitations. Climate is one aspect of a complex system and, at the
farm level, husbandry has a dominant influence on helminth transmission. Continuing environmental change will necessitate the adoption of mitigation and adaptation strategies
in husbandry. Long term predictive models need to have the architecture to incorporate
these changes. Ultimately, an optimal modelling approach is likely to combine mechanistic
processes and physiological thresholds with correlative bioclimatic modelling,
incorporating changes in livestock husbandry and disease control. Irrespective of approach,
the principal limitation to parasite predictions is the availability of active surveillance data
and empirical data on physiological responses to climate variables. By combining
improved empirical data and refined models with a broad view of the livestock system,
robust projections of helminth risk can be developed.
Year
2012
Category
Refereed journal