india

Updated: Apr 02, 2020 20:43 IST

Nizamuddin, in the heart of Delhi, will see health workers from the integrated diseases surveillance programme start going door-to-door from Thursday as they seek to track and contain cases of Covid-19 in what has emerged the latest and biggest cluster of the coronavirus disease in the country.

Cases of Covid-19 around the country have been traced back to a religious congregation of the Tablighi Jamaat at its headquarters in the area, attended, through March, by thousands of the group’s members. On Wednesday, the last of the 2,346 people who had been in the building were evacuated; 536 of them were sent to the hospital and 1,810 placed in quarantine.

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Thus far, the congregation has been identified as being responsible for 358 infections and 9 deaths.

So, starting Thursday, everyone within a 3km radius (focal area) of the building and in the buffer area (5km radius) will be screened for symptoms. Those who are symptomatic -- a cough will do -- will be tested. This will entail door-to-door coverage, first in the focal area and then the buffer area.

“The cluster containment strategy has two components: one is to mark the epicentre and the buffer zone where extensive door-to-door surveys will be conducted. We do a complete lockdown in and around the area. The next step is identifying all potential positive cases by going in for aggressive testing. We pick samples from everyone with any respiratory illness in the area,” said a senior technical expert with the Union health ministry who asked not to be named.

The health ministry has come up with a detailed “Micro-plan for Containing Local Transmission of Coronavirus Disease (Covid-19)” in a defined geographic area.

The cluster containment strategy has been refined over the past two weeks and is being used in 12 clusters around the country. Nizamuddin is the 13th.

The strategy involves mobile testing units with experts that go to the epicentres of the clusters to collect samples.

The clusters where containment measures have been put in place over the past 10 days include Dilshad Garden in Delhi; Bhilwara in Rajasthan; Sangli in Maharashtra; Parts of Mumbai and Pune, also in Maharashtra; Srinagar in Jammu & Kashmir; Agra and Meerut in Uttar Pradesh; and Kasaragode, Ernakulam, Pathanamthitta and Kannur in Kerala. State governments have been asked to aggressively identify and contain cases that could lead to clustering. Movement in and around the epicentres of the clusters are completely prohibited. In Nizamuddin, for instance, these are the lanes in and around the Jamaat’s HQ, the Markaz Nizamuddin.

The government is already testing all severe acute respiratory infection (SARI) cases for Covid-19, but in clusters, it will test anyone with any kind of respiratory illness.

“SARI cases are usually hospitalised, but this (cluster containment) is about picking up samples from within the community. We have well-equipped mobile vans with adequately trained people to collect samples that are sent to these hot spots,” said the expert from the health ministry.

Doctors said cluster containment is the correct approach, especially because it aggressively widens testing.

“It is a very good idea to test aggressively as it will help in knowing the exact magnitude of the problem. To look for a solution you need to know the extent of problem. Covid-19 is a highly infectious disease that needs aggressive containment strategy, like locking down hot spot areas. No person should be allowed to leave these areas” said Dr Chand Wattal, chairman, clinical microbiology and immunology, Sir Ganga Ram Hospital.

Local clustering of cases usually occurs when family members, neighbours, friends or colleagues are infected by the same P0 (index patient, in medical terminology) or infect each other. Aggressive contact tracing is also a part of containment strategy.

“The increase in numbers during the past couple of days is related to the congregation in Delhi, and all efforts are being made to trace the contacts and quarantine and isolate suspected cases. Close to 1,800 people have been moved to various hospitals and quarantine facilities in and around Delhi, and we are expecting positive cases to increase as and when the results start pouring in. Our experts are at work to ensure the spread is contained,” said Lav Aggarwal, joint secretary, health ministry.