The cases of malaria were reported in Chennai and Tiruvallur in more than 19 people after testing of samples. “The sampling and survey was conducted in all the cases for analysis to determine any other outbreaks. The district deputy directors are inspecting the area for similar outbreaks in other districts also. The number of outbreaks in case of water-borne diseases and vector-borne diseases have reduced this year,” said Dr TS Selvavinayagam, director of Public Health and Preventive Medicine.