Continental‐scale climatic gradients of pathogenic microbial taxa in birds and bats

Abstract

The connections of climatic variables to zoonotic and wildlife diseases remain uncertain. Here, we compiled a systematic database for the prevalence of 121 pathogenic microbial taxa in birds (ca 376 species) and bats (ca 39 species), including 11 939 observations from over 450 000 individuals across Europe and surrounding regions. We modelled the potential connection of climatic variables with the prevalence of 75 pathogenic microbial taxa at a multi‐pathogenic‐taxa level and of 17 most‐studied pathogenic taxa at a single‐pathogenic‐taxon level. According to the multi‐taxa model, the prevalence of bacterial taxa was positively associated with temperature, while this association was significantly weaker for eukaryotes and viruses. The prevalence of bacterial taxa was negatively associated with rainfall, while viruses showed a positive association with rainfall. These associations between climatic variables and prevalence of pathogenic taxa were not different between bird and bat hosts. According to the single‐taxon models, the prevalence of influenza A viruses, Plasmodium, and several bacterial taxa in birds and bats was positively associated with temperature. Rainfall showed positive associations with the prevalence of Usutu, Sindbis and Influenza A viruses but the directions of significant associations varied among bacterial taxa. Strikingly, this was evidenced also between bacterial taxa that share hosts and transmission mechanism hinting towards hitherto unknown features on pathogen ecology, e.g. Salmonella versus Campylobacter and Anaplasma versus Borrelia. Our results suggest that rising temperature and increasing precipitation will accelerate the threat of bird‐ and bat‐associated bacterial and viral pathogens to wildlife, domesticated animals and humans, respectively. However, the idiosyncratic relationships with climatic conditions among pathogenic taxa highlight the need for pathogen‐specific predictive models to understand future pathogen distributions.

Climate change, its impact on emerging infectious diseases and new technologies to combat the challenge

“…increased temperature and precipitation) are hypothesized to drive this pattern [ 21 ]. A recent study modelling potential connections between climate variables and pathogen prevalence has also suggested that elevated temperatures and greater precipitation will accelerate the transmission of bird- and bat-associated bacteria or viruses to wild and domesticated animals and humans [ 22 ]. One example of the potential impact of this process was the recent COVID-19 pandemic, where a SARS-CoV-2 progenitor virus that probably originated in southeast Asian horseshoe bats ( Rhinolophus sp.)…”

The Palearctic view on a bat fungal disease

“…In the Nearctic, large die-offs have only been reported in three species (M. lucifugus, M. septentrionalis, P. subflavus) (Cheng et al 2021). It is important to comprehend that the overlap in distribution of the host and the pathogen is likely greater than the distribution range for the incidence of the disease causing mortality (Xu et al 2023). Furthermore, high incidence of mortality appears to be restricted to a proportion of the overlapping distribution range, where factors contributing to disease intercede favourably.…”

Pathogenic taxa constitute a substantial portion of bat and wild bird fecal bacterial microbiota

“…This emphasizes the importance of understanding the microbiota of migratory birds and bats, and the prevalence of pathogens within the microbiota across geographical locations and habitats. Information such as this would also allow for a better understanding of the impact of climate change, such as temperature and rainfall alterations on pathogen prevalence in birds and bats 12 , and to predict the threat of disease outbreaks via modeling approaches.…”