Abstract
Fasciola hepatica (liver fluke) is a physically and economically
devastating parasitic trematode whose rise in recent years has been
attributed to climate change. Climate has an impact on the free-living
stages of the parasite and its intermediate host Lymnaea truncatula,
with the interactions between rainfall and temperature having the
greatest influence on transmission efficacy. There have been a number
of short term climate driven forecasts developed to predict the
following season's infection risk, with the Ollerenshaw index being
the most widely used. Through the synthesis of a modified Ollerenshaw
index with the UKCP09 fine scale climate projection data we have
developed long term seasonal risk forecasts up to 2070 at a 25 km
square resolution. Additionally UKCIP gridded datasets at 5 km square
resolution from 1970-2006 were used to highlight the climate-driven
increase to date. The maps show unprecedented levels of future
fasciolosis risk in parts of the UK, with risk of serious epidemics in
Wales by 2050. The seasonal risk maps demonstrate the possible change
in the timing of disease outbreaks due to increased risk from
overwintering larvae. Despite an overall long term increase in all
regions of the UK, spatio-temporal variation in risk levels is
expected. Infection risk will reduce in some areas and fluctuate
greatly in others with a predicted decrease in summer infection for
parts of the UK due to restricted water availability. This forecast is
the first approximation of the potential impacts of climate change on
fasciolosis risk in the UK. It can be used as a basis for indicating
where active disease surveillance should be targeted and where the
development of improved mitigation or adaptation measures is likely to
bring the greatest benefits.
Year
2011
Category
Refereed journal