Top 10 Most Infectious Diseases with Highest Death Rates

COVID is top of mind for everyone, but it doesn’t make the list of infections with the highest death rate.  Below is a list of human infectious disease case fatality rates (CFRs). A CFR is the proportion (percentage) of people diagnosed with a disease who die during the course of the disease. (Cf. mortality rate.) Values refer to optimally treated cases.

  • Prion diseases, or transmissible spongiform encephalopathies (TSE) = 100% case fatality rates
  • Primary amoebic meningoencephalitis, Naegleria fowleri = ~100%
  • Smallpox, Variola major, malignant (flat) or hemorrhagic types = ~95%
  • Anthrax, inhalational = >93%
  • Granulomatous amoebic encephalitis, Balamuthia mandrillaris & Acanthamoeba = ≥ 90%
  • Ebola virus disease (for EBOV “strain” outbreaks only: formerly Zaire Ebola virus) = ~ 83%
  • Lujo virus disease = 80%
  • Marburg virus disease = ≤ 80%
  • Ebola virus disease (for all types of ebolavirus outbreaks combined) = 60-65%
  • Aspergillosis, invasive pulmonary form = 50-90%