Timely identification of positive patients and isolation of their contacts is why Mumbai’s Dharavi, one of the world’s largest slums, has now reported more than 200 COVID-19 cases and 13 deaths, a civic health official said.

Mumbai is home to 44% (5.2 million) of Maharashtra’s slum population, accounting for 8% of all Indians living in slums. The population density of Mumbai city was 20,980 persons per sq km, as per Census 2011.

Dharavi now accounts for 5% (214) of the 4,232 cases reported in the city. Sanitation and civic amenities are sparse, and the environment so polluted that residents are highly vulnerable to illness and disease, IndiaSpend had reported in September 2018.

“Our strategy is to timely identify and isolate suspected patients,” Daksha Shah, deputy executive health officer with the Brihanmumbai Municipal Corporation (BMC), told IndiaSpend. “Because of this strategy, cases are seen on the rise.”

“On identifying a [positive] case, we are doing contact tracing and testing high-risk contacts of that patient within the family and the area,” Shah said. “Testing is more in the form of a targeted approach. Most cases that we have identified in Dharavi and also in other congested areas are among those contacts. We have quarantined them and taken relevant measures.”

As many as 92,112 people are home-quarantined in Mumbai, and 18,807 completed 14 days’ home quarantine on April 21. Of the total cases in the city, 39% or 1,647 cases were detected as a result of contact tracing, containment measures and fever clinics, as per BMC’s release.

“In addition to door-to-door screening in high-risk areas, people are also being screened at fever clinics in the vicinity, set up by the civic body,” Shah said.

Nearly, 4,000 tests were carried out in the city in a single day on April 23, according to Shah. “First, we assess the possible high- and low-risk contacts of the identified patient,” she said. “Immediate family members and people in the neighbourhood are labelled as high-risk contacts. We are testing all the high-risk contacts even if they are asymptomatic. And definite testing is happening of symptomatic contacts. Most of the patients among these contacts we are identifying are asymptomatic.”

In all, Mumbai has reported 4,232 cases and 168 deaths as of April 23 more than any other city or state in the country.