Twelve people tested positive for cholera last month and most of them reside in central Mumbai.
While five of the cases were from the B ward, which includes localities like Dongri, Sir JJ Marg, Pydhonie and Yellow Gate, two were in the E ward comprising Byculla, Agripada, Sewree and Kalachowkie. The civic body has started distributing chlorine tablets in these areas and has urged people to drink boiled water.
“Our health workers are screening the relatives and neighbours of cholera patients. We have also informed the hydraulic department to look for the source of contamination, if any.
The patients have tested positive for the eltor type of cholera, which is treatable and is a mild form,” said Manisha Mhaiskar, additional municipal commissioner, Brihanmumbai Municipal Corporation.
The surge in cholera cases is worrying doctors.
“Cholera is unusual in a city like Mumbai as the water we receive is already treated,” said Dr Dhanashree Kelkar, infectious disease consultant at Global Hospitals, Parel.
Health experts said gastroenteritis cases are predisposed to cholera and have advised caution.
While 1,297 people were treated for gastroenteritis in June this year, 1,135 were found to be suffering from the disease in June 2012. Doctors said cholera has high mortality in children if the treatment is not started on time.
“Usually, when we see a cholera outbreak, there is a common source of water contamination.
If all the patients don’t belong to the same locality, there is a need to find the contamination source,” said Dr Dipika Sur, deputy director and senior head, division of epidemiology, National Institute of Cholera & Enteric Disease, which has analysed 20,000 gastroenteritis cases, of which 20% tested positive for cholera.
“If the tea cup is washed with contaminated water, there is possibility of contracting the disease. Raw vegetables, if not washed properly, can also spread cholera causing bacteria,” said Kelkar.