Japanese bats have been found to carry a large number of new viruses, raising concerns about outbreaks of zoonotic infections

In a recent study published in the journal Microbes and Infection, scientists conducted an intensive DNA and RNA analysis of bat viruses from Yamaguchi Prefecture, Japan. They sequenced tissues from more than 130 bats (4 species) from four sampling sites and found that more than 60% were infected with at least one strain of zoonotic viruses.

Alarmingly, the study revealed significant genetic heterogeneity among some viral strains, particularly adenoviruses and astroviruses, indicating that these viruses may have evolved rapidly. In particular, the study identified ten new strains of herpesviruses, detected astrovirus in Japanese bats for the first time, and identified numerous representatives of the adenovirus and coronavirus families.

The study showed that more than 60% of the bats examined were infected with at least one virus strain and 36% were infected with more than one virus strain, indicating a high prevalence of zoonotic pathogens in Japanese bats.

The discovery of viral sequences genetically identical to strains found in China and Korea emphasizes a potential link between Japanese and mainland Asian bats, despite the common belief that these populations do not interact with each other.

Additional research into the life cycle and pathophysiology of these viruses is needed to develop action plans to control zoonotic transmission, thus preventing future outbreaks of bat-borne diseases.

Unfortunately, bats are known reservoirs (natural hosts) for more than 20,000 species of viruses (33 families), some of which cause zoonotic diseases, including rabies, Nipah virus, Hendra virus, Ebola virus, and coronavirus.

Recent studies show that the 2019 coronavirus outbreak (COVID-19), possibly the worst pandemic in human history, originated from Chinese bats. Therefore, monitoring bats and their viral parasites has become critical to prepare for future zoonotic outbreaks.

While bats in China and the western world have been the subject of extensive research, Japanese bats have been relatively little studied. To date, limited studies of bat-derived viruses have identified only 109 strains (9 families) from this country, which probably greatly underestimates the true pathogenic potential and diversity of these virus carriers.