Keynote Message

Increasing availability of weather data from surface and remote instrumentation, and better tools for collecting georeferenced data on animal disease, combine to create unprecedented opportunities to map and understand parasite spread. In this session, example attempts to respond to this opportunity will be presented, for parasites of large and companion animals. The strengths and limitations of different approaches will be discussed. In particular, the shortcomings of purely statistical models for parasite spread will be highlighted in the context of global climate change, and lack of unbiased data for companion animals. Awareness of these limitations is important for critical appraisal of increasingly popular climate change projections for disease. One solution is sounder mechanistic underpinning models, which can be validated by but not entirely calibrated on disease occurrence data. Models for the spread of heartworm, Dirofilaria immitis, provides examples of good practice in this area, but necessary biological data are often missing for companion animal parasites, and take time and funding to obtain. We should, therefore, expect more predictive models of parasite spread in future; but we should also expect more from them, including more transparent communication of model assumptions, and proper attempts to validate predictions. Practitioners should be suitably sceptical of predictions that fail to take these steps, and also have an important role in providing independent data to validate models. Better data collection and collation are needed if stronger models are to be developed; new technologies make this possible, but still require the will of practitioners who are often too busy to see the benefit.

Key References

1.  Genchi C, Mortarino M, Rinaldi L, et al. Changing climate and changing vector-borne disease distribution: the example of Dirofilaria in Europe. Veterinary Parasitology. 2011;176:295–299. DOI: 10.1016/j.vetpar.2011.01.012.

2.  Schnyder M, Schaper R, Bilbrough G, et al. Seroepidemiological survey for canine angiostrongylosis in dogs from Germany and the UK using combined detection of Angiostrongylus vasorum antigen and specific antibodies. Parasitology.2013;140:1442–1450. DOI: 10.1017/S0031182013001091.

3.  Morgan ER, Jefferies R, Krajewski M, et al. Canine pulmonary angiostrongylosis: the influence of climate on parasite distribution. Parasitology International.2009;58:406–410. DOI: 10.1016/j.parint.2009.08.003
http://www.sciencedirect.com/science/article/pii/S1383576909001020

4.  Rose H, Caminade C, Bolajoko MB, et al. Climate-driven changes to the spatio-temporal distribution of the parasitic nematode, Haemonchus contortus, in sheep in Europe. Global Change Biology.2016;22:1271–1285. DOI: 10.1111/gcb.13132.