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Diseases of Public Health Significance

Certain diseases need to be reported to the local Medical Officer of Health. Here you will find a list of these specified disease of public health significance.

Duties to Report Specified Diseases

Ontario's Health Protection and Promotion Act (HPPA) (external link) creates a legal duty for physicians and other healthcare professionals/practitioners, laboratories, and hospital administrators to report specified diseases to the Medical Officer of Health. These reporting duties are reinforced by the College of Physicians and Surgeons of Ontario. (external link)

Other health professional staff in long-term care homes and rest/retirement homes also have a duty to report suspect and confirmed cases of communicable diseases and outbreaks to the Medical Officer of Health. School partners, through Principals, also have legal duty to report under the same legislation.

Why Reporting?

Reporting of cases of infectious diseases and related conditions remains a vital step in controlling and preventing the spread of communicable disease. These reports are useful in many ways, including assurance of provision of appropriate medical therapy (e.g., for tuberculosis), detection of common-source outbreaks (e.g., in food-borne outbreaks), and planning and evaluating prevention and control programs (e.g., for vaccine-preventable diseases).

What Diseases Must Be Reported?

Under the authority of the Health Protection and Promotion Act (HPPA) (external link) and Regulation 569 (external link), suspect and confirmed cases or death caused by or contributing to diseases of public health significance are to be reported to the local Medical Officer of Health.

  • Acquired Immunodeficiency syndrome (AIDS)
  • Acute Flaccid Paralysis (AFP)
  • Amebiasis
  • Anaplasmosis
  • Anthrax*
  • Babesiosis
  • Blastomycosis
  • Botulism*
  • Brucellosis*
  • Campylobacter enteritis
  • Carbapenemase-producing Enterobacteriacease (CPE) infection or colonization
  • Chancroid
  • Chickenpox (Varicella)*
  • Chlamydia trachomatis infections
  • Cholera
  • Clostridium difficile Infection (CDI) outbreaks in public hospitals
  • Creutzfeldt-Jakob Disease, all types
  • Cryptosporidiosis
  • Cyclosporiasis
  • Diphtheria*
  • Diseases caused by a novel coronavirus, including:
    • Severe Acute Respiratory Syndrome (SARS)*
    • Middle East Respiratory Syndrome (MERS)*
    • Coronavirus disease (COVID-19)*
  • Echinococcus multilocularis infection
  • Encephalitis, including
    • Primary, viral
    • Post-infectious
    • Vaccine-related
    • Subacute sclerosing panencephalitis
    • Unspecified
  • Food poisoning, all causes
  • Gastroenteritis, institutional outbreaks*
  • Giardiasis, except asymptomatic cases
  • Gonorrhoea
  • Group A Streptococcal disease, invasive*
  • Group B Streptococcal disease, neonatal
  • Haemophilus influenzae b disease, all types, invasive*
  • Hantavirus pulmonary syndrome*
  • Hemorrhagic fevers, including:
    • Ebola virus disease*
    • Marburg virus disease*
    • Lassa Fever*
    • Other viral causes*
  • Hepatitis A, viral*
  • Hepatitis B, viral*
  • Hepatitis C
  • Influenza
  • Legionellosis
  • Leprosy
  • Listeriosis
  • Lyme Disease
  • Measles*
  • Meningitis, acute, including:
    • bacterial*
    • viral
    • other
  • Meningococcal disease, invasive*
  • Mumps
  • Ophthalmia neonatorum
  • Paralytic Shellfish Poisoning (PSP)*
  • Paratyphoid Fever*
  • Pertussis (Whooping Cough)*
  • Plague*
  • Pneumococcal disease, invasive
  • Poliomyelitis, acute*
  • Powassan Virus Infection
  • Psittacosis/Ornithosis
  • Q Fever*
  • Rabies*
  • Respiratory infection outbreaks in institutions*
  • Rubella*
  • Rubella, congenital syndrome*
  • Salmonellosis
  • Shigellosis*
  • Smallpox* and other Orthopoxviruses including mpox*
  • Syphilis
  • Tetanus
  • Trichinosis
  • Tuberculosis
  • Tularemia
  • Typhoid Fever*
  • Verotoxin-producing E. coli infection, including Haemolytic Uraemic Syndrome (HUS)*
  • West Nile Virus Illness
  • Yersiniosis

Diseases and outbreaks in institutions identified with an asterisk (*) must be reported immediately to the Medical Officer of Health by calling 311. Other diseases are to be reported the next business day.