An extensive new study has mapped RNA viruses across a large number of cities around the world, producing the first large-scale atlas of its kind. The researchers identified nearly 55,000 distinct types of virus, the vast majority of which had never been observed before — a resource they say could prove useful for both biological risk assessment and crime scene investigations.
The dataset comprises samples from 102 cities across 31 countries, led by East China Normal University in Shanghai and involving researchers around the world who analyzed roughly 3,000 samples collected from public places such as bus and train stations, banks, and hospitals. “Tell me which city you live in and I’ll tell you which viruses you’re carrying,” said Eran Elhaik, a geneticist at Lund University and one of the study’s authors.
A Viral Fingerprint for Every City
The statement may sound like a joke, Elhaik says, but he has good grounds for the claim when it comes to the cities included in the study. Through their analysis, researchers established which RNA viruses were present at various sampled locations and used that data to build a global atlas showing the prevalence of different viruses across the cities studied. Most of the viruses identified do not infect humans, but Elhaik believes there’s still great value in mapping the different strains and where they’re found.
That knowledge could be applied in forensic investigations, for instance, where virus analysis might give police additional clues and a better chance of linking a person or object to a specific location. A global virus atlas could also support environmental monitoring efforts that track biological threats, such as changes that might negatively impact ecosystems.
“Having a virus atlas that shows what the viral landscape in an area usually looks like can be a valuable frame of reference for detecting any abnormalities that may arise,” Elhaik explained.
An Unexplored Viral World
Of the nearly 55,000 virus variants identified in the study, almost 80% had never before been observed, underscoring just how little is known about the distribution of viral life on Earth. “Surprisingly little is known about how virus populations are distributed across the planet,” Elhaik noted.
The research makes clear that viruses are not evenly spread across the globe. Different cities and their surrounding areas host distinct virus populations, shaped by geography, local environment, and human activity. “Every city has its own unique viral landscape,” Elhaik concluded. “This gives us a sort of viral fingerprint that is specific to each individual location.”
The study, “Diversity and distinctive characteristics of the global RNA virome in urban and peri-urban environments,” was published in Nature Communications (DOI: 10.1038/s41467-026-73605-z).