Study Finds Half of Sampled Birds Have Competence for Lyme

March 8, 2021

https://onlinelibrary.wiley.com/doi/10.1111/geb.13256

RESEARCH PAPER

The macroecology and evolution of avian competence for Borrelia burgdorferi

First published: 21 January 2021
https://doi.org/10.1111/geb.13256
Read the full text

Abstract

Aim

Prediction of novel reservoirs of zoonotic pathogens would be improved by the identification of interspecific drivers of host competence (i.e., the ability to transmit pathogens to new hosts or vectors). Tick‐borne pathogens can provide a useful model system, because larvae become infected only when feeding on a competent host during their first blood meal. For tick‐borne diseases, competence has been studied best for Borrelia burgdorferi sensu lato (Bbsl), which causes Lyme borreliosis. Major reservoirs include several small mammal species, but birds might play an under‐recognized role in human risk given their ability to disperse infected ticks across large spatial scales. Here, we provide a global synthesis of the ecological and evolutionary factors that determine the ability of bird species to infect larval ticks with Bbsl.

Location

Global.

Time period

1983–2019.

Major taxa studied

Birds.

Methods

We compiled a dataset of Bbsl competence across 183 bird species and applied meta‐analysis, phylogenetic factorization and boosted regression trees to describe spatial and temporal patterns in competence, characterize its phylogenetic distribution across birds, reconstruct its evolution and evaluate the trait profiles associated with competent avian species.

Results

Half of the sampled bird species show evidence of competence for Bbsl. Competence displays moderate phylogenetic signal, has evolved multiple times across bird species and is pronounced in the genus Turdus. Trait‐based analyses distinguished competent birds with 80% accuracy and showed that such species have low baseline corticosterone, exist on both ends of the pace‐of‐life continuum, breed and winter at high latitudes and have broad migratory movements into their breeding range. We used these trait profiles to predict various likely but unsampled competent species, including novel concentrations of avian reservoirs within the Neotropics.

Main conclusion

Our results can generate new hypotheses for how birds contribute to the dynamics of tick‐borne pathogens and help to prioritize surveillance of likely but unsampled competent birds. Our findings also emphasize that birds display under‐recognized variation in their contributions to enzootic cycles of Bbsl and the broader need to consider competence in ecological and predictive studies of multi‐host pathogens.

___________________

For more:  

Category:

Lyme, research, Ticks

Comments Off on Study Finds Half of Sampled Birds Have Competence for Lyme