The Tiruchi Corporation on Thursday started distributing nilavembu kudineer to the residents through its offices and at other public places in the city as a precautionary measure against outbreak of dengue fever. The herbal concoction, said to be effective in building immunity against dengue, would be distributed to school students. It would be made available at the Corporation main and zonal offices, Amma canteens and the bus stands also, Corporation Commissioner N.S.Prema said in a press release. She urged the residents to keep their surroundings clean around their houses and prevent stagnation of water to check breeding of mosquitoes.