Excess Mortality Among People with Communicable Diseases Over a 20-Year Period, Victoria, Australia

Background: Understanding mortality burden associated with communicable diseases is key to informing resource allocation, disease prevention and control efforts, and evaluating public health interventions. We quantified excess mortality among people notified with communicable diseases in Victoria, Australia.Methods: Cases of communicable disease notified in Victoria between 1 January 1991–31 December 2021 were linked to the death registry. Informational gain obtained through linkage and 30-day case fatality rates were calculated for each disease. Standardised mortality ratios (SMR) and 95% confidence intervals were calculated up to a year following illness onset.Findings: There were 1,032,619 cases and 5,985 (0.58%) died ≤30 days of illness onset. Diseases with high 7-day SMR signifying excess mortality included invasive pneumococcal disease (167.7, 95% CI 153.4–182.7); listeriosis (166.2, 95% CI 121.2–218.3); invasive meningococcal disease (145.9, 95% CI 116.7–178.3); legionellosis (43.3, 95% CI 28.0–62.0); and COVID-19 (21.9, 95% CI 19. 7–24.3). Most diseases exhibited a strong negative gradient, with high SMRs in the first 7-days of illness onset that reduced over time.Interpretation: We found evidence of substantially elevated all-cause mortality among people notified with communicable diseases. Not all elevated risk is likely directly attributable to the communicable diseases of interest, rather, it may reflect underlying comorbidities or behaviours in these individuals. Regardless of attribution, infection with communicable diseases may represent a marker of mortality. Key to preventing deaths may be through timely and appropriate transition to primary and preventive healthcare following diagnosis.Funding: No funding was provided for this study.Declaration of Interest: None to declare. Ethical Approval: Study approvals were obtained from the Victorian Government Department of Health Research Ethics Committee (reference: LNR/47982), and registered with Monash University Human Research Ethics Committee (reference: 30076)·