In a report released by the Ministry of Health and Family Welfare (MoHFW), Centre has outlined its plans to contain the COVID-19 spread. "Clusters have appeared in multiple states, particularly Kerala, Maharashtra, Rajasthan, Uttar Pradesh, Delhi, Punjab, Karnataka, Telangana and UT of Ladakh. 211 districts are now reporting COVID-19 cases and the risk of further spread remains very high."
The report cites the example of the H1N1 Influenza pandemic, when it was observed that well-connected big cities with substantive population movement were reporting large number of cases, whereas rural areas and smaller towns with low population densities and relatively poor road/ rail/ airway connectivity were reporting only a few cases. "The current geographic distribution of COVID-19 mimics the distribution of H1N1 Pandemic Influenza," according to the document. "This suggests that while the spread of COVID-19 in our population could be high, it’s unlikely that it will be uniformly affecting all parts of the country. This calls for differential approach to different regions of the country, while mounting a strong containment effort in hot spots."
The cluster containment strategy would be to maintain the disease within a defined geographic area by early detection of cases, breaking the chain of transmission and thus preventing its spread to new areas. Noting that local transmission will lead to clustering of cases in time and space, epidemiologically linked to a travel related case or a positive case that has links to a travel related case, the health ministry has drawn out the plan. The strategy would be governed by numerous factors including the size of the cluster, the effectiveness of quarantine, the efficiency with which the virus is transmitting, and the environmental concerns including temperature and humidity. The geographical boundaries would be decided based on the containment zone, the buzzer zone, which is the adjoining blocks and districts to the containment zone, and the perimeter, which is the boundary which will be decided by the state administration. The ministry said with 211 districts now reporting COVID-19 cases, the risk of further spread remains very high.
India would be following a strategic approach for possible scenarios, namely travel-related cases reported in India, local transmission of COVID-19, large outbreaks amenable to containment and widespread community transmission of COVID-19 disease. According to the document, "containment for large outbreaks through geographic quarantine strategy calls for near absolute interruption of movement of people to and from a relatively large defined area where there is single large outbreak or multiple foci of local transmission" of COVID-19. "In simple terms, it is a barrier erected around the focus of infection. Geographic quarantine shall be applicable to such areas reporting large outbreak and/or multiple clusters of COVID-19 spread over multiple blocks of one or more districts that are contiguous," it said.
The cluster containment strategy would "include geographic quarantine, social distancing measures, enhanced active surveillance, testing all suspected cases, isolation of cases, quarantine of contacts and risk communication to create awareness among public on preventive public health measures", the document stated. As far as the evidence for implementing geographic quarantine is concerned, the document cited the H1N1 Influenza Pandemic. "This suggests that while the spread of COVID-19 in our population could be high, it's unlikely that it will be uniformly affecting all parts of the country," the ministry said while stressing this calls for differential approach to different regions of the country, while mounting a strong containment effort in hot spots.
Large-scale measures to contain COVID-19 over large territories have been tried in China. Mathematical modelling studies have suggested that containment might be possible especially when other public health interventions are combined with an effective social distancing strategy, the document stated. The authorities will do extensive contact tracing and active search for cases in containment zone, test all suspect cases and high risk contacts, isolate all suspect or confirmed cases, implement social distancing measures and intensive risk communication as part of the cluster containment strategy.
For large outbreaks amenable to containment, the documents stated that the strategy will remain the same but vary in extent depending upon spread and response to be mounted to contain it. It will also include implementation of social distancing measures, with strict perimeter control, providing chemoprophylaxis with hydroxychloroquine to all asymptomatic healthcare workers and asymptomatic household contacts of laboratory confirmed cases and further intensification of risk communication through audio, social and visual media.
In alignment with the strategic approach, the document provides action that needs to be taken for containing a large outbreak. The actions for mitigation phase will be dealt separately under a mitigation plan.