According to sources, at least one patient, Ratnabai is in a critical condition.

The patients, mostly residents of Kureishi Nagar Kasaiwada in Kurla, were admitted to the hospital in ones and twos since Monday. They were earlier suspected to be suffering from food poisoning. Confirming that the disease - which can turn fatal if not diagnosed and treated soon - has spread in the areas around Kurla, doctors at the hospital told The Indian Express. They said that the BMC's Health Department has already dispatched teams of doctors to check further spread of the disease.