Colombo Municipal Council (CMC) Chief Medical Officer Dr. Pradeep Kariyawasam yesterday said the number of Chikungunya cases may double with the onset of the rainy season in the city as shortage of staff has badly crippled day-to-day functions of his department. There are many reported cases in Bambalapitiya where a Chikungunya prevention programme is being implemented with residents' help, he said. Chikungunya mosquitos breed in fresh water. The residents should ensure that their environment is free from mosquito breeding grounds, Dr. Kariyawasam said. He appealed to the public not to wait till CMC labourers inspect their environment and dispose garbage which may have become mosquito breeding grounds. They should keep them outside their gates to enable the CMC employee to collect them, he said. This situation may set beyond our control unless the staff shortage is rectified by the Western Provincial Council. This department should have 120 employees for the epidemic controlling programmes but I have only 55. My staff is facing many obstacles in carrying out fumigation which should only be done in the evenings. They are not allowed to overtime too as a cost cutting measure, he said. Spraying and fumigation are part and parcel in the Chikungunya prevention. Spraying only destroys larvae. Fumigation is vital to kill adult mosquitoes, Dr. Kariyawasama said. "We have received reports of Hepatitis and Leptoprosis in the Colombo North area and our officials have launched awareness programmes in the schools and public places,' he said.