Coronavirus: Clusters lead to a surge in spread but could help contain it too

Coronavirus: Clusters lead to surge in spread but could help contain it too

Migrants who comes from different part of India being shifted to their native place from Shelter home after note their names and addresses at Awadh Shilp Gram in Lucknow on tuesday.Express photo by Vishal Srivastav 31032020

The emergence of human clusters in which several people together have been found to be infected with coronavirus is likely to significantly alter the nature of spread of the disease in the country. While the number of infected persons has increased much faster in the last three days than at any other time since the outbreak, experts believe that from the perspective of containing the spread, the emergence of these clusters might be a good thing.

The number of positive cases in the country has more than doubled in the last five days, from just under 700 on March 26 to over 1400 today. Many of the new infected cases are concentrated in large groups, like in those linked to a religious meeting of Tablighi Jamaat in New Delhi. Such clusters, not all of them linked to the Tablighi Jamaat, have emerged in Meerut, Sangli, Ahmednagar, Delhi and Telangana.

Besides the fact that the source of transmission in most of these cases can reliably be traced, experts say such concentrated cases could also be easier for the health authorities to handle compared to isolated cases dispersed in population, in terms of isolating them and preventing further spread from them.

“The emerging news that nearly 100 cases in India could be traced back to people who attended a gathering in Delhi further strengthens the possibility that until so far, in almost all cases, the infection is traced back to a person coming from overseas. Such clustering of infections suggests that there is no community transmission,” said L S Shashidhara, a professor of biology at Ashoka University.

“Scientists should analyse the dynamics of infection in all clustered groups across India to understand how geo-climatic conditions and pre-medical history would influence the spread. A major caveat, however, is the absence of data on asymptomatic positive cases as we have not tested them at all,” he said.

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Gautam Menon, a professor of computational biology at the Institute of Mathematical Sciences, agreed with the contention that clusters could be easier to handle, but said that there were many other cases, outside of these clusters, that looked like very good evidence of community transmission.

“It is no doubt easier to track and isolate a large group of infected people in one place. But we are also seeing an increasing number of isolated cases now where the original point of transmission is not known, or is unclear. This is pointing towards what many of us have been saying for long, that community transmission is a reality and we cannot escape from that,” he said.

The government has already declared some of the locations where these clusters have emerged as ‘hot spots’, and has said that it will increase surveillance and testing of samples at these places.

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