Kochi: Astrovirus and Rotavirus which spread through food and water caused the outbreak of acute diarrhoeal disease among the residents of DLF apartment complex in Kakkanad, Kochi, according to the reply furnished by Health Minister Veena George in the assembly on Monday.

According to the World Health Organization (WHO), rotaviruses are shed in very high concentrations and for many days in the stools and vomitus of infected individuals. Transmission occurs primarily by the faecal-oral route, directly from person to person or indirectly via contaminated fomites. An article on Sciencedirect.com notes that Astroviruses are increasingly recognized as significant gastrointestinal pathogens. Outbreaks often occur in closed populations, and attack rates are high in hospitalized children and in children in daycare centers. Viral shedding lasts for an average of 5 days after onset of symptoms, the article says.

The Minister said that coliform bacteria was detected in water samples collected from various blocks in the complex. It was found that cleaning and chlorination were not done properly in overhead tanks and tanks connected to treatment plant.

After the outbreak was detected, the health department has been co-ordinating with the residents association to disinfect water sources and water storage facilities. Besides water quality is being tested on a daily basis and chlorination is being done at regular intervals. The health officials have also directed the association to do bacteriological and chemical examination of water samples every six months.

The department also issued a notice under relevant sections of the IPC and Kerala public health act to the flat association, the Minister said. A standard operating procedure was prepared in co-ordination with the District medical office and Department of Community Medicine, Government Medical college, Kalamassery to prevent recurrence of such incidents in future. Over 400 residents reported sick following the disease outbreak in DLF apartment complex in June.