Cancer and One Health - tumor-bearing individuals can act as super spreaders of symbionts in communities

Sep 21, 2026

Uploaded by Theodore

Cancer and the One Health framework are linked by an idea that tumor pathologies may increase hosts’ susceptibility to infections, potentially allowing infected hosts to function as super spreaders within ecosystems. Although biologically plausible, this hypothesis lacks experimental validation. Using Hydra cnidarians and the commensal ciliate Kerona pediculus, the study tests whether tumoral polyps amplify ciliate numbers and drive spillover infections to other community members, including cross-species effects. Results support enhanced proliferation on tumoral hosts, while spillover magnitude varies by recipient species.

LanguageEnglish

CategoryResearch & Report

FormatPDF

Pages7

Reading Time18 min

AccessFree to download

Introduction

One Health and cancer

Tumors and super spreader hypothesis

Background

Hydra hosts and tumor formation

Kerona pediculus and colonization

Study aims

Proliferation confirmation

Within- and between-species spillover evaluation

Material and methods

Protocol overview

Origin of hydras and ciliates

[www. nature.com/scientificreports](www. nature.com/scientificreports) OPEN Cancer and One Health: tumor‑bearing individuals can act as super spreaders of symbionts in communities Sophie Tissot1*, Jordan Meliani1, Matthew Chee1, Aurora M. Nedelcu2, Justine Boutry1, JácintTökölyi3, Rodrigo Hamede4, Benjamin Roche1,5, Beata Ujvari6, Frédéric Thomas1,7 & Antoine M. Dujon1,6,7 Recent theoretical advances in the One Health approach have suggested that cancer pathologies should be given greater consideration, as cancers often render their hosts more vulnerable to infectious agents, which could turn them into super spreaders within ecosystems. Although biologically plausible, this hypothesis has not yet been validated experimentally. Using a community of cnidarians of the Hydra genus (Hydra oligactis, Hydra viridissima, Hydra vulgaris) and a commensal ciliate species (Kerona pediculus) that colonizes them, we tested whether tumoral polyps of H. oligactis, compared to healthy ones, played an amplifying role in the number of ciliates, potentially resulting in a higher likelihood of infection for other community members through spillovers. Our results indicate that K. pediculus has a higher proliferation rate on tumoral polyps of H. oligactis than on healthy ones, which results in the infestation of other hydras. However, the magnitude of the spillover differed between recipient species. This study provides to our knowledge the first elements of proof of concept that tumoral individuals in communities could act as super spreaders of symbionts within and between species, and thus affect biotic interactions and dynamics in ecosystems. Keywords Neoplasm, Biotic interactions, Ecology, Outbreaks, Emerging diseases In the face of the numerous consequences of human activities on the planet (destruction of ecosystems, pollution, climate change…) together with the emergence or re-emergence of diseases, it is now established that a holistic approach, such as in the One Health framework, is essential1,2. This integrated approach aims to understand and address the complex links between human, animal, and environmental health3. By adopting a global perspective, One Health provides an effective response to contemporary challenges, fostering collaboration between disciplines that do not routinely interact (e.g. medical, veterinary, ecological, and social disciplines) . Although there has been a plethora of work in the One Health perspective in recent years (see4–6 for recent reviews), this area of research is still very active, and major implications are yet to be revealed. Given the diversity of the links between infectious agents and malignant pathologies7–9, Dujon et al.10 recently advocated for a greater reflection on the integration of cancer into the One Health perspective. For example, it is increasingly accepted that human activities are responsible for an increase in cancers in wildlife11–14, and this could affect the dynamics of parasite communities, given that cancers often lead to a greater vulnerability to infections through, for instance, immune suppression8, 15–17. More specifically, Dujon et al.10 predicted that cancer pathologies could increase the circulation rate of infectious agents in ecosystems, when hosts harboring 1CREEC/MIVEGEC, Université de Montpellier, CNRS, IRD, Montpellier, France. 2Department of Biology, University of New Brunswick, Fredericton, New Brunswick, Canada. 3MTA-DE “Momentum” Ecology, Evolution and Developmental Biology Research Group, Department of Evolutionary Zoology, University of Debrecen, 4032 Debrecen, Hungary. 4School of Natural Sciences, University of Tasmania, Hobart, TAS, Australia. 5Departamento de Etología, Fauna Silvestre y Animales de Laboratorio, Facultad de MedicinaVeterinariay Zootecnia, Universidad Nacional Autónoma de México (UNAM), Ciudad de México, México. 6School of Life and Environmental Sciences, Deakin University, Waurn Ponds, Victoria, Australia. 7These authors cont

FAQs

What does the One Health framework suggest about cancer and infectious diseases?

It suggests that cancer pathologies should be considered because tumors can make hosts more vulnerable to infectious agents, potentially turning hosts into super spreaders within ecosystems.

How did the study test the super-spreader role of tumor-bearing individuals?

It used Hydra species and the commensal ciliate Kerona pediculus to compare ciliate proliferation on tumoral versus healthy hydras and to evaluate spillover to other community members within and between species.

Did spillover infections occur, and did the strength of spillover depend on the recipient species?

Yes. K. pediculus proliferated faster on tumoral polyps of H. oligactis, leading to infestation of other hydras, but the magnitude of spillover differed between recipient species.

Sep 21, 2026

Uploaded by Theodore