KOLKATA: Laboratory tests of water samples collected from various south Kolkata pockets following the recent outbreak of Hepatitis-A has revealed presence of coliform and other bacteria in most of them. Of the 14 samples that were checked, 12 contained bacteria. According to KMC, the contaminated samples were all from packaged drinking water being sold in large jars.KMC authorities had earlier this week collected samples from 14 places, two from standposts that distribute water from one tap to another and the rest from packaged water that are sold in 10 litre or higher capacity jars.“According to the preliminary test report, no contamination have been found in the water standposts. But some confluent that causes jaundice have been found in the other water samples. Most of them have been collected from the packed water jars,” KMC mayor Firhad Hakim said on Saturday.It is unclear if water for the jars were locally sourced. In several peripheral areas where homes don’t have direct water supply, local vendors supply drinking water in such plastic jars.Aware that the source of the bacteria could be a pipeline, KMC has decided to inspect the underground pipes to check for corrosion and possible leakage. “We are carrying out inspection of all the underground lines and further tests will be conducted to find out the exact source where the water is getting contaminated,” the mayor said.Localities in the belt, including Ramgarh, Vidyasagar Colony, Baghajatin and Jadavpur are in the grip of panic following steady rise in Hepatitis A cases. According to civic officials, around 30 persons have so far been affected butlocals cite twice the number.A KMC’s team headed by the deputy chief medical officer (health) CMOH visited Baghajatin under ward number 99 on Saturday, and made door-to-door visits to inquire if anyone in those homes had taken ill. Water samples are being randomly collected from several water taps and packaged water jars. The civic team is also drawing up a list of persons affected by Hepatitis A and other water contamination related diseases.“The team is trying to locate the source of contamination and understand how the disease is spreading,” said a KMC water supply department official. An awareness campaign is also going on the issue, the official added.The outbreak was first reported from bordering areas of Ramgarh and Vidyasagar Colony three weeks ago but civic authorities allegedly ignored it in absence of confirmatory reports reaching the KMC headquarters. But after local RSP councillor Debasish Mukherjee raised an alarm and took up the matter with the municipal chief health officer in the KMC on Tuesday, a team of doctors from the health wing went to survey the affected areas on Thursday. They inspected the affected households and collected samples of water.