Strengthening Mosquito Abatement for Safety and Health Act or the SMASH Act This bill reauthorizes for FY2020-FY2024 and revises the Centers for Disease Control and Prevention (CDC) grant program that supports state mosquito control programs. Among other changes, the bill expands the grant program so that grants may be used to address emerging, infectious mosquito-borne diseases and to improve existing control programs. The CDC must also give preference to applicants that have (1) a public health emergency due to a mosquito-borne disease, or (2) a control program that is consistent with existing state preparedness plans. The bill also reauthorizes for FY2020-FY2024 and revises the CDC epidemiology and laboratory capacity grant program, which helps public health agencies improve surveillance and response activities related to infectious diseases.