New research in Mumbai, India shows that Covid-19 has spread much more in overcrowded slums than in richer areas.
The study shows a 57% infection rate in slums, compared with 16% in other areas.
The death rate for the disease in the study was 0.05% to 0.1%.
The research was done by the government think-tank Niti Aayog and the Tata Institute of Fundamental Research.
The study reviewed 7,000 people in three overcrowded areas in early July.
Mumbai has reported more than 110,000 cases and almost 6,200 deaths.