High Consequence Infectious Diseases
The list of high-consequence infectious diseases (HCIDs) will be reviewed and updated by the UK’s four nation Public Health agencies, with advisory committee input as required, if new HCIDs emerge that are relevant to the UK. Please visit UK Health Security Agency for the latest update https://www.gov.uk/guidance/high-consequence-infectious-diseases-hcid
Definition: In the UK, a high-consequence infectious disease (HCID) is defined according to the following criteria:
- acute infectious disease
- typically has a high case-fatality rate
- may not have effective prophylaxis or treatment
- often difficult to recognise and detect rapidly
- ability to spread in the community and within healthcare settings
- requires an enhanced individual, population and system response to ensure it is managed effectively, efficiently and safely
Classification: HCIDs are further divided into contact and airborne groups:
- Contact HCIDs are usually spread by direct contact with an infected patient or infected fluids, tissues and other materials or by indirect contact with contaminated materials and fomites
- Airborne HCIDs are spread by respiratory droplets or aerosol transmission, in addition to contact routes of transmission.
For details, please refer to the Northern Ireland Regional Infection Prevention & Control Manual: Addendum on High Consequence Infectious Disease (HCID) Personal Protective Equipment (PPE). Endorsed by the Advisory Committee on Dangerous Pathogens (ACDP), October 2025 NI addendum PPE for HCID
List of high-consequence infectious diseases
A list of HCIDs has been agreed upon by the UK 4 nation’s public health agencies, with advisory committee input as required:
Contact HCIDs | Airborne HCIDs |
Argentine haemorrhagic fever (Junin virus) | Andes virus infection (hantavirus) |
Bolivian haemorrhagic fever (Machupo virus) | Avian influenza A H7N9 and H5N1 |
Crimean Congo haemorrhagic fever (CCHF) | Avian influenza A H5N6 and H7N7* |
Ebola virus disease (EVD) | Middle East respiratory syndrome (MERS) |
Lassa fever | Nipah virus infection |
Lujo virus disease | Pneumonic plague (Yersinia pestis) |
Marburg virus disease (MVD) | Severe acute respiratory syndrome (SARS)*** |
Severe fever with thrombocytopaenia syndrome (SFTS) |
*Human-to-human transmission has not been described to date for avian influenza A(H5N6). Human-to-human transmission has been described for avian influenza A(H5N1), although this was not apparent until more than 30 human cases had been reported. Both A(H5N6) and A(H5N1) often cause severe illness and fatalities. Therefore, A(H5N6) has been included in the airborne HCID list despite not meeting all of the HCID criteria.
***No cases have been reported since 2004, but SARS remains a notifiable disease under the International Health Regulations (2005), hence its inclusion here.