EU case definitions

Case definition

European Union (EU) case definitions provide standardised criteria for identifying and reporting communicable diseases to ECDC. These definitions only apply to surveillance at the EU/EEA level and ensure that every case in every Member State is classified similarly, which is essential for accurate and consistent disease surveillance across borders.

These definitions are set out in the Commission Implementing Decision (EU) 2018/945, which lists the diseases and health issues under EU surveillance. On 18 September 2026, a new Implementing Regulation (2026/2097) was adopted by the Commission. It will apply from 1 July 2028.

The new Implementing Decision includes emerging threats such as COVID-19 or mpox, for which ECDC until now used its own operational case definitions. These were tailored to effectively respond to new public health challenges and are regularly updated to reflect the latest scientific knowledge and surveillance needs.

Diseases

Commission Implementing Decision (EU) 2018/945 Implementing Regulation (2026/2097),
applicable from 1 July 2028.
Anthrax Anthrax
Botulism Botulism
Brucellosis Brucellosis
Campylobacteriosis Campylobacteriosis
Chikungunya virus disease Chikungunya virus disease
Chlamydia infections Chlamydia infections
Cholera Cholera
(COVID-19) COVID-19
Creutzfeldt-Jakob disease, variant (vCJD) Creutzfeldt-Jakob disease, variant (vCJD)
Cryptosporidiosis No longer subject to epidemiological surveillance at Union level.
Dengue Dengue
Diphtheria Diphtheria
Echinococcosis Echinococcosis
Giardiasis No longer subject to epidemiological surveillance at Union level.
Gonorrhoea Gonorrhoea
Haemophilus influenzae disease, Invasive  Haemophilus influenzae infection, invasive disease
Hepatitis A Acute hepatitis A
Hepatitis B Hepatitis B
Hepatitis C Hepatitis C
HIV infection and AIDS HIV infection and AIDS
Influenza Influenza in humans, seasonal
Influenza including Influenza A(H1N1) Influenza, zoonotic 
Legionnaires’ disease Legionnaires’ disease
Leptospirosis Leptospirosis
Listeriosis Listeriosis
Lyme neuroborreliosis No longer subject to epidemiological surveillance at Union level.
Malaria Malaria
Measles Measles
Meningococcal disease, invasive Meningococcal infection, invasive disease
Mpox Mpox
Mumps Mumps
Pertussis Pertussis
Plague Plague
Pneumoccocal invasive diseases Pneumoccocal infection, invasive diseases
Poliomyelitis Poliomyelitis
Q fever Q fever
Rabies Rabies and other Lyssavirus infections
Rubella Rubella
Rubella, congenital Rubella, congenital
Salmonellosis Salmonellosis
Shiga toxin /verocytotoxin -producing Escherichia coli (STEC/VTEC) Shiga toxin /verocytotoxin -producing Escherichia coli (STEC/VTEC)
Shigellosis Shigellosis
Smallpox Smallpox
Syphilis Syphilis
Syphilis, congenital Syphilis, congenital
Tick-borne encephalitis Tick-borne encephalitis
Toxoplasmosis, congenital Toxoplasmosis, congenital
Trichinellosis Trichinellosis
Tuberculosis  Tuberculosis 
Tularaemia Tularaemia
Typhoid and Paratyphoid fevers No longer subject to epidemiological surveillance at Union level.
Viral haemorrhagic fevers

Arenavirus infection

Crimean-Congo haemorrhagic fever

Filovirus infection

Hantavirus
West Nile virus infection West Nile virus infection
Yellow fever Yellow fever
Yersiniosis Yersiniosis
Zika virus disease Zika virus disease

 

Special health issues 

   
Antimicrobial resistance Antimicrobial resistance
Healthcare-associated infection Healthcare-associated infection

 

 

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