Global change, parasite transmission and disease control: lessons from ecology

Abstract

Parasitic infections are ubiquitous in wildlife, livestock and human populations, and healthy ecosystems are often parasite rich. Yet, their negative impacts can be extreme. Understanding how both anticipated and cryptic changes in a system might affect parasite transmission at an individual, local and global level is critical for sustainable control in humans and livestock. Here we highlight and synthesize evidence regarding potential effects of ‘system changes’ (both climatic and anthropogenic) on parasite transmission from wild host–parasite systems. Such information could inform more efficient and sustainable parasite control programmes in domestic animals or humans. Many examples from diverse terrestrial and aquatic natural systems show how abiotic and biotic factors affected by system changes can interact additively, multiplicatively or antagonistically to influence parasite transmission, including through altered habitat structure, biodiversity, host demographics and evolution. Despite this, few studies of managed systems explicitly consider these higher-order interactions, or the subsequent effects of parasite evolution, which can conceal or exaggerate measured impacts of control actions. We call for a more integrated approach to investigating transmission dynamics, which recognizes these complexities and makes use of new technologies for data capture and monitoring, and to support robust predictions of altered parasite dynamics in a rapidly changing world.This article is part of the themed issue ‘Opening the black box: re-examining the ecology and evolution of parasite transmission’.

Strategies of Phytophthora infestans adaptation to local UV radiation conditions

“…In conclusion, elevation of UV radiation associated with anthropogenic activity can exert critical influences on many aspects of biological, ecological, and evolutionary processes of species (Cable et al, ; Roig‐Sagués, Gervilla, Pixner, Terán‐Peñafiel, & Hernández‐Herrero, ; Siepielski et al, ; Zhan & McDonald, ). In agricultural and medical fields, there is considerable concern that such trend may have major impacts on disease ecology.…”

Lost in transmission…?

“…This reflects the recognition across many of the discussions that 'transmission' emerges from an interaction between host, parasite and environmental components, and so it is hard to interpret observed patterns of transmission without explicitly acknowledging the environment that the transmission is occurring within. This is becoming increasingly important as we consider transmission within an increasingly changing environment, be that in terms of climate, habitat composition, host availability and community composition, or other environmental stressors such as pollutants [3,4,6]. In particular, as emphasized by Cable et al [6] (but also picked up on by the various other articles on this topic), parasites typically show a remarkable ability to respond to environmental changes, either through plasticity or the capability for rapid genetic responses, emphasizing the need to urgently evaluate likely changes in risks of disease emergence and transmission as the environment changes.…”

“…The various participants then self-assembled into sub-groups to discuss these different aspects of transmission in full over the next 3 days. The articles in this issue [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15] largely represent the outcome of this process, with a few solicited to expand on areas not wholly covered at the retreat. While the list of topics represented within this issue may not be a completely exhaustive list of key topics in transmission, we believe that the broad profile of attendees has ensured that we have captured the majority of key challenges facing researchers in this field.…”

Climate Change and the Neglected Tropical Diseases

“…More recently, Ammophorus rubripes, a dung beetle, has been implemented as a potential carrier through experiments that demonstrated carriage of viable eggs by the beetles for up to 24 days (Gomez-Puerta et al, 2014). A broad range of synergistic and competing factors is likely to affect the ecology of any organism capable of dispersing eggs, leading perhaps to localised extinction (Brook et al, 2008), among other effects related to anthropogenic disruption of established ecosystems (Cable et al, 2017).…”

“…Success in implementing the WHO plans and the SDGs could spell the end for some or all the NTDs. But considerable literature exists, primarily derived from studies of parasites affecting wildlife that global environmental change may lead to responses by hosts, vectors and parasites themselves that could affect the outcome of interventions (Cable et al, 2017). Thus, it will be important to consider not just meeting targets set within the SDG and WHO documents, but how those targets are met.…”