Bat-Pig Farm Interactions Raise Virus Transmission Concerns in Northern Italy

Northern Italy is experiencing increased contact between bat populations and pig farms, prompting research into the potential for virus transmission. Even as bats offer ecological benefits, gaps in farm biosecurity raise concerns about the spread of viruses between wildlife, livestock, and humans.

The Interconnectedness of Wildlife, Livestock, and Human Health

The interface between wildlife, livestock, and humans is a critical area for the emergence of infectious diseases, according to researchers at the Italian institute for animal health, food safety and zoonoses (IZSVe). Pig farms, in particular, can act as “hot spots” for the spread and emergence of dangerous viral variants.

Bats as Reservoirs for Coronaviruses

Bats are well-established reservoirs for a variety of coronaviruses, including those that have evolved to harm humans and livestock, such as SARS-CoV-2 and the porcine epidemic diarrhoea virus. Understanding the factors that contribute to viral spillover is crucial for protecting both animal and human health.

Eight Bat Species Frequent Northern Italian Pig Farms

At least eight species of bats are known to frequent areas surrounding pig farms in northern Italy. These bats routinely commute and forage over pig farms, creating a natural intersection that increases viral spillover risks. The study, conducted by an international team of researchers from Italy and the United Kingdom, mapped these interactions and assessed the environmental and farming conditions that facilitate contact between bats, their excreta, and pigs.

Biosecurity Gaps and Virus Transmission

A key finding of the research is the prevalent lack of physical barriers and effective biosecurity measures in many pig farms. This allows bat feces and potentially infectious material to approach into direct contact with pigs. Given the diversity of coronaviruses harbored by bats, this interface becomes a high-risk hotspot for viral transmission, potentially enabling cross-species infection and genetic recombination, which could result in novel viral strains.

Bats as Conservation Oases

Despite the risks, pig farms can also act as bat conservation oases in agricultural landscapes. In areas dominated by intensive agriculture, where environmental uniformity is reducing biodiversity, pig farms can provide bats with foraging opportunities and shelter. Bats deliver an important ecosystem service by controlling harmful insect populations, potentially reducing the require for pesticides.

Mitigating the Risk

Reinforcing biosecurity measures on pig farms is seen as a key step in mitigating the risk of exposure to coronaviruses and other viruses associated with wildlife. This includes addressing gaps in physical barriers and improving overall hygiene protocols.