New Delhi, June 2 (IANS) Amid a fresh wave of Covid-19, caused by the SARS-CoV2, a new study by researchers at the Indian Institute of Technology (IIT) Madras showed that viruses follow seasonal and yearly cycles.

The international study, undertaken along with a team of scientists from the universities of Wisconsin-Madison and Texas at Austin, focussed on viruses in freshwater lakes.

The researchers used cutting-edge Machine Learning (ML) tools to study 465 freshwater lake samples from Madison, Wisconsin, collected over more than 20 years — representing the longest DNA-based monitoring of a natural environment on Earth.

By sequencing all the DNA from the lakes using a method called metagenomics, the researchers reconstructed 1.3 million virus genomes.

The study enabled the researchers to learn how viruses change with the seasons, over decades, and in response to environmental shifts.

“Viruses follow seasonal and yearly cycles, with many reappearing year after year, showing remarkable predictability,” said the researchers in the paper, published in the Nature Microbiology Journal.

“Viruses can ‘steal’ genes from their hosts and repurpose them for their own benefit. Viruses evolve over-time, with some genes becoming more dominant due to natural selection,” they added.

The findings also revealed the vital roles viruses play in ecosystems, not just by influencing the environment but also by supporting other organisms.

The team found 578 examples of viral genes that help with critical processes like photosynthesis and methane use — highlighting how viruses are beneficial to the health and stability of natural systems.

“The Covid-19 pandemic has shown us just how important it is to track viruses. Understanding how viruses emerge, evolve, and interact with their environments is critical — not only for responding to pandemics but also for recognising the vital roles they play in ecosystems. Yet, long-term studies of viral communities, particularly in natural environments, are rare,” said Dr. Karthik Anantharaman, Visiting Professor, at Wadhwani School of Data Science and AI, IIT Madras.

“This lack of data creates a significant knowledge gap, hindering our ability to predict how viruses influence both human health and environmental stability. By investing in long-term viral monitoring, we can better prepare for future outbreaks and uncover the complex ways viruses contribute to the health of our planet,” added Anantharaman, who is also an Associate Professor of Microbial and Viral Ecology at the University of Wisconsin-Madison, US.

In addition, studying viruses in freshwater systems can transform how we manage water resources, natural ecosystems, and public health, said the team.

These findings also open doors to innovative strategies for ecosystem management, such as using viruses to restore balance in disrupted environments such as polluted lakes.

–IANS

rvt/