Trophic interactions and the ecology of emerging lungworm infections under global warming

The risk posed to human and animal welfare by infectious diseases has been emphasised in recent years following the Covid-19 pandemic. With attention focused on viruses, parasitic diseases and their impacts on global health may sometimes be overlooked. This is despite many parasites causing zoonotic disease and posing a threat to biodiversity and conservation.

Angiostrongylus cantonesis is the leading cause of parasitic meningitis in humans globally, in addition to causing mortality in multiple threatened animal species. While closer to home, Angiostrongylus vasorum causes severe disease in domestic dogs and Crenosoma striatum is associated with respiratory disease in European hedgehogs which are classed as a vulnerable species in the UK.

The geographic and temporal ranges of several lungworm species appear to be shifting in response to climate change. However, climate modelling has shown that environmental conditions alone do not predict the current parasite distributions. Many species of lungworm have a complex life history requiring multiple hosts to complete each cycle. Parasite-host encounters and thus parasite prevalences are determined by behavioural and ecological factors that are as yet poorly understood.

By following the flow of parasites across different trophic levels and under differing climates, risk factors for transmission can be identified. In turn allowing more targeted action by One Health practitioners in preventing zoonotic disease, as well as informing conservationists and wildlife rehabilitators about risks to vulnerable animal species.

A combination of approaches will be employed during this project; behavioural experiments will be conducted on the feeding and thermoregulatory choices of gastropod host species in differing climates, samples from paratenic and definitive hosts will be examined to determine how parasitic infection affects host fitness, and molecular techniques will be used to track the movements of parasites through complex food webs. This project aims to investigate the ecology and epidemiology of A. vasorum and C. striatum species within wildlife species in the UK.

However, the findings will be used as a model for other closely related lungworm species. This is especially relevant given the recent incursion of zoonotic A. cantonensis into Southern Europe.