New Delhi: Much was blame was laid at the doorstep of the Tablighi Jamaat but a study by IIT Mandi has found that travellers from Dubai and the UK were the primary sources of COVID-19 import into India.
While the research, which has been published in the Journal of Travel Medicine, has found that the international travel was the main channel through which COVID-19 came to India, the main routes were from Dubai and the UK.
The study also found that infected cases from Tamil Nadu, Delhi and Andhra Pradesh played a lesser role in spreading the disease outside their communities, while those from Gujarat, Rajasthan, Maharashtra, Kerala, Jammu & Kashmir, and Karnataka played a significant role in local transmission. Some of them caused interstate transfer too.
The study tracked the diffusion of the coronavirus from the global to national level and identified a few superspreaders who played a central role in the transmission of the disease in India. According to Sarita Azad, an assistant professor at IIT Mandi, COVID-19 spread in phase one (Jan-April), traced by the travel history of patients, was mostly local transmission.
"The research team used the travel history of infected patients from January to April as the primary data source and a social network was created depicting the spread in the early phase of the pandemic. The research found that the maximum numbers of connections were established from Dubai (144) and the UK (64)," she added.
Azad explained that statistical metrics calculated from the data revealed that Dubai and the UK played a crucial role in spreading the disease in Indian states and were the primary sources of COVID-19 importations into India.
"Dubai's eigenvector centrality was the highest, which made it the most influential node. The statistical metrics calculated from the data revealed that Dubai and the UK played a crucial role in spreading the disease in Indian states and were the primary sources of COVID-19 importations into India.
"Based on the modularity class, different clusters were shown to form across Indian states, which demonstrated the formation of a multi-layered social network structure. A significant increase in confirmed cases was reported in states like Tamil Nadu, Delhi and Andhra Pradesh during the first phase of the nationwide lockdown, which spanned from March 25 to April 14," she said.
"The modularity class of states such as Tamil Nadu, Delhi, and Andhra Pradesh was low. Hence, it is likely that infected cases from these states played less of a role in spreading the disease outside their communities. Whereas states like Gujarat, Rajasthan, Maharashtra, Kerala, Jammu and Kashmir, and Karnataka played a significant role in the local transmission, and some of them caused interstate transfer too," she added.
Azad, who conducted the analytical study, along with her student Sushma Devi, said, "When a pandemic like COVID-19 subsides, a good research work serves as a record for the future. In this work, we have used real time data and demonstrated how the disease got diffused from the global to national level from January 30 to April 6. This will be an important contribution to understanding the disease transmission in India during the early phase of the pandemic."