People travelling in a crowded Delhi train at the height of the COVID-19 pandemic in 2020. Credit: Subhra Priyadarshini
Coastal areas and hotter states of India, such as Kerala, Maharashtra, New Delhi, Tamil Nadu and Gujarat, with good railway links are at high risk for COVID-191, a new study reveals.
Understanding how the virus spread in India during the height of the COVID-19 pandemic can help policymakers respond better to current and future pandemics.
The study, led by Mousumi Gupta at Sikkim Manipal Institute of Technology in Rangpo, looked at the pattern of COVID-19 case distribution at a district level using Indian Council of Medical Research data from March 2020 to December 2022.
Using a time-bound convenience sampling method — where samples are chosen because they are convenient to capture snapshots of the advancing pandemic — the researchers grouped cases in a specific geographic area (clusters), identified hotspots, and analysed variability and uniformity in disease patterns by region.
The team overlaid clusters of positive cases on railway network lines in a mapping software ArcGIS to understand the connectedness of COVID-19’s spread over the first, second and third waves.
The spread of positive case clusters was linked with the railways. If cases rose sharply in a few districts located along major railway routes and were clustered in hot, humid climate zones, it signified viral spread along transit networks and the environmental conditions conducive to transmission.
The spike in these districts may lead to wider diffusion across connected regions in future, the researchers say. Further research could investigate the effectiveness of measures such as vigilance in railway traffic or increased sanitation in stations and on trains.
