The tally of COVID-19 patients inDharavi, Mumbai's biggest slum sprawl, increased to 1,145 on Friday after 84 more persons tested positive for the infection, a Brihanmumbai Municipal Corporation (BMC) official said.However, no new death was reported in Dharavi in the last 24 hours, the official said.The death toll in this slum is 53, the official said."Four deaths, which occurred in the past few days, were declared by the BMC's epidemic cell today," he said.Dharavi's highest number of 108 cases have been found in Matunga Labour Camp locality till May 14, he said.Dharavi, believed to be the biggest slum in India, is posing a tough challenge for the BMC and the Maharashtra government to contain the coronavirus spread, mainly due to its population density, which makes social distancing very difficult.