Interface between Bats and Pigs in Heavy Pig Production

Area of Science:

• Veterinary Virology
• Zoonotic Disease Epidemiology
• Wildlife-Livestock Interactions

Background:

• Bats are implicated as reservoirs for zoonotic viruses, raising concerns about potential epidemic outbreaks.
• Understanding virus circulation at the wildlife-livestock interface is crucial for public health and agricultural biosecurity.

Purpose of the Study:

• To investigate the presence and biodiversity of bats associated with intensive pig farms in northern Italy.
• To assess the circulation of mammalian orthoreoviruses (MRVs), coronaviruses (CoVs), and astroviruses (AstVs) in bats and pigs.
• To determine the directionality of viral exchange between bats and pigs.

Main Methods:

• Bat surveys and guano collection at intensive pig farms in northern Italy.
• Molecular detection and characterization of MRVs, CoVs, and AstVs in bat and pig samples.
• Phylogenetic analysis to identify reassortant viral strains and infer transmission pathways.

Main Results:

• No bat viruses were detected in pigs, suggesting rare direct spillover from bats to pigs.
• Several MRVs, CoVs, and AstVs circulated undetected in pigs, including a reassortant MRV with potential bat-derived genes.
• Swine-origin AstV and MRV strains were identified in bat guano, indicating pig-to-bat viral transmission.

Conclusions:

• Direct viral spillover from bats to pigs appears infrequent in this intensive farming setting.
• Viral exchange between pigs and bats occurs, with evidence suggesting a more frequent transmission from pigs to bats.
• Enhanced biosecurity measures in indoor farming systems are recommended over bat displacement for disease prevention.