CHENNAI, June 17: The incidence of malaria in the city during 1996 saw an increase of 10%, while the occurence of cerebral malaria, a variation of the disease rose by an alarming 43%. However, according to the authorities, the shifting of the Kothwal Chavady market to Koyambedu is expected to decrease the occurence of the disease in an around Sowcarpet and Royapuram, which are some of the main bereding sources.