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This publication is available at https://www.gov.uk/government/publications/high-consequence-infectious-diseases-monthly-summaries/global-high-consequence-infectious-disease-events-summary-december-2023
Interpreting this report
The report provides updates on known, high-consequence infectious disease (HCID) events around the world as monitored bythe UK Health Security Agency’s (UKHSA) epidemic intelligence activities.
The report is divided into 2 sections covering all the definedHCIDpathogens. The first section contains contact and airborneHCIDsthat have been specified for theHCIDprogramme by NHS England. The second section contains additionalHCIDsthat are important for situational awareness.
Each section contains information on known pathogens and includes descriptions of recent events. If an undiagnosed disease event occurs that could be interpreted as a potentialHCID, a third section will be added to the report.
Events found during routine scanning activities that occur in endemic areas will briefly be noted in the report. Active surveillance, other than daily epidemic intelligence activities, of events in endemic areas will not be conducted (for example, actively searching government websites or other sources for data on case numbers).
The target audience for this report is any healthcare professional who may be involved inHCIDidentification, treatment and management.
Risk rating
Included for each disease is a current risk rating based on the probability of introduction to the UK and potential impact.Past UK experience and the global occurrence of travel-associated cases are also considered.
Currently, all diseases are classified into one of 3 categories:
- low
- very low
- exceptionally low/negligible
Incidents of significance of primaryHCIDs
Crimean-Congo haemorrhagic fever (CCHF)
| Geographical risk areas | Endemic in Africa, the Balkans, the Middle East and western and south-central Asia. Cases have also been reported in Russia and Georgia. Spain has previously reported locally acquired cases (first reported in 2016, with the latest case reported in 2022). |
|---|---|
| Sources and routes of infection | • bite from, or crushing of, an infected tick • contact with the blood, tissues or body fluids of infected humans or animals |
| UKexperience to date | Two cases have been reported in individuals who have travelled to the UK from Afghanistan in 2012 and Bulgaria in 2014. |
| Risk rating | Low – rarely reported in travellers. |
| Recent cases or outbreaks | Between 1 January and 30 December 2023, the World Health Organisation (WHO) reported 1,236 suspected CCHF cases, including 114 deaths (case fatality rate (CFR) of 9.2%) from Afghanistan. CCHF was confirmed in 383 of 1,098 cases tested since the beginning of 2023. In 2022, Afghanistan reported 286 suspected cases and 103 confirmed CCHF cases including 15 deaths. In Senegal, on 6 December 2023, the WHO African regional office (WHO AFRO) reported 2 laboratory confirmed cases of CCHF in Dahra and Matam districts. On 31 December 2023, media reported the detection of 5 cases of CCHF, including 2 deaths in Sindh Province, Pakistan during 2023, compared to 8 cases, including 7 deaths reported in 2022. |
Ebola virus disease (EVD)
| Geographical risk areas | Map of countries which have reported EVD cases up to January 2023. No outbreaks of EVD have since been reported. |
|---|---|
| Sources and routes of infection | • contact with blood, tissues or body fluids of infected animals, or consumption of raw or undercooked infected animal tissue • contact with infected human blood or body fluids |
| UKexperience to date | Four confirmed cases (one lab-acquired in the UK in 1976, 3 healthcare workers associated with West African epidemic 2014 to 2015). |
| Risk rating | Very low – other than during the West Africa outbreak, exported cases are extremely rare. |
| Recent cases or outbreaks | No confirmed or suspected human cases were reported in December 2023. |
Lassa fever
| Geographical risk areas | Endemic in sub-Saharan West Africa. |
|---|---|
| Sources and routes of infection | • contact with excreta, or materials contaminated with excreta from an infected rodent • inhalation of aerosols of excreta from an infected rodent • contact with infected human blood or body fluids |
| UKexperience to date | Three travel-related Lassa fever cases reported in 2022. Prior to this, 13 imported Lassa fever cases had been reported since 1971, all in travellers from West Africa. |
| Risk rating | Low – overall, Lassa fever is the most common imported viral haemorrhagic fever (VHF), but importations to the UK are still rare. |
| Recent cases or outbreaks | Between 1 January and 31 December 2023, Nigeria reported 9,155 suspected, 12 probable and 1,270 confirmed Lassa fever cases, with confirmed cases reported from 28 states. 227 deaths were reported among confirmed cases (CFR of 17.9%). This is an increase in cases and deaths when compared to 2022, when 8,207 suspected and 1,067 confirmed cases, including 189 deaths among confirmed cases, were reported. |
Marburg virus disease (MVD)
| Geographical risk areas | Sporadic outbreaks have previously been reported in Central and Eastern Africa. A human case of MVD was reported in August 2021 in Guinea; this was the first case to be identified in West Africa. MVD cases were reported in Ghana for the first time in July 2022. MVD outbreaks were reported for the first time in Equatorial Guinea in February 2023 and in Tanzania in March 2023. |
|---|---|
| Sources and routes of infection | • exposure in mines or caves inhabited by Rousettus bat colonies • contact with infected human blood or body fluids |
| UKexperience to date | No reported cases in the UK. |
| Risk rating | Very low – globally, 5 travel-related exported MVD cases have previously been reported in the literature. |
| Recent cases or outbreaks | No confirmed or suspected human cases were reported in December 2023. |
AirborneHCIDs
Avian influenza A(H7N9) virus
| Geographical risk areas | All reported human infections have been acquired in China. | |
|---|---|---|
| Sources and routes of infection | • close contact with infected birds or their environments • close contact with infected humans (no sustained human-to-human transmission) | |
| UKexperience to date | No known cases in the UK. | |
| Risk rating | Very low (UKHSArisk assessment). | |
| Recent cases or outbreaks | No confirmed or suspected human cases were reported in December 2023. |
Avian influenza A(H5N1) virus
| Geographical risk areas | Human cases have been predominantly reported in South East Asia, but also in Egypt, Iraq, Pakistan, Turkey and Nigeria. Human cases (clade 2.3.4.4b) were reported in Spain and the USAin 2022, and in theUK in 2022 and 2023. The first human cases of avian influenza A(H5N1) (clade 2.3.4.4b) were reported from South America in 2023, from Ecuador and Chile. |
|---|---|
| Sources and routes of infection | • close contact with infected birds or their environments • close contact with infected humans (no sustained human-to-human transmission) |
| UKexperience to date | As of September 2023, 5 detections were reported in the UK, one in 2022 and 4 in 2023. |
| Risk rating | Very low (UKHSArisk assessment). |
| Recent cases or outbreaks | No confirmed or suspected human cases were reported in December 2023. Between 2003 and 21 December 2023, there has been 882 confirmed human cases (including 461 deaths) of avian influenza A(H5N1) reported globally. |
Middle East respiratory syndrome (MERS-CoV)
| Geographical risk areas | The Arabian Peninsula – Yemen, Qatar, Oman, Bahrain, Kuwait, Saudi Arabia and UnitedArabEmirates. |
|---|---|
| Sources and routes of infection | • airborne particles • direct contact with contaminated environment • direct contact with camels or consumption of raw camel milk |
| UKexperience to date | Five MERS-CoV cases in total – 3 imported cases (2012, 2013 and 2018), 2 secondary cases in close family members of the case in 2013, 3 deaths. |
| Risk rating | Very low (UKHSArisk assessment). |
| Recent cases or outbreaks | No confirmed or suspected human cases were reported in December 2023. |
Mpox (clade I only)
| Geographical risk areas | Central Africa including, Central African Republic, Cameroon, the Democratic Republic of the Congo (DRC), Gabon and Republic of the Congo. |
|---|---|
| Sources and routes of infection | • close contact with an infected animal (in an endemic country) or an infected person • contact with clothing or linens (such as bedding or towels) used by an infected person • direct contact with mpox skin lesions or scabs • coughing or sneezing of an individual with an mpox rash • consumption of contaminated bushmeat |
| UKexperience to date | In June 2022, the Advisory Committee on Dangerous Pathogens (ACDP) recommended that the strain of monkeypox virus (MPXV) largely responsible for the global outbreak (clade IIb, B.1 lineage) should no longer be classified as an HCID. In January 2023, the ACDP recommended that all clade II MPXV should no longer be classified as an HCID. No cases of clade I mpox have been reported in the UK. Between 2018 and 2021, 7 cases of mpox were identified in the UK which would no longer be classified as HCID mpox, but were treated as HCID cases at the time: 4 of the cases were imported from Nigeria, 2 cases were household contacts and one case was a healthcare worker involved in the care of an imported case. |
| Risk rating | Very low – no known importations of clade I mpox into the UK. |
| Recent cases or outbreaks | Sequencing data is rarely available for mpox cases reported from endemic African countries where clade I MPXV is known to circulate. In Cameroon, 140 mpox cases (27 confirmed,113 suspected cases, and no deaths) have been reported from the Sud-Ouest Region, between 1 January and 24 December 2023. Between 1 January and 24 December 2023, a total of 14,200 mpox cases (1,215 confirmed and 12,985 suspected) and 715 suspected deaths have been reported from 23 regions in the Democratic Republic of the Congo (DRC). On 28 December 2023, media reported 21 cases of mpox in Kinshasa, DRC, of which 4 cases were infected through sexual transmission. In the Republic of the Congo, between 1 January and 24 December 2023, 95 mpox cases (21 confirmed and 74 suspected) and 5 deaths have been reported from 7 provinces. |
Nipah virus
| Geographical risk areas | South East Asia, predominantly in Bangladesh and India. Cases have also been reported in Malaysia and Singapore. |
|---|---|
| Sources and routes of infection | • direct or indirect exposure to infected bats • consumption of contaminated raw date palm sap • close contact with infected pigs or humans |
| UKexperience to date | No known cases in the UK. |
| Risk rating | Exceptionally low/negligible – no travel-related infections in the literature. |
| Recent cases or outbreaks | No confirmed or suspected human cases were reported in December 2023. |
Pneumonic plague (Yersinia pestis)
| Geographical risk areas | Predominantly sub-Saharan Africa but also Asia, North Africa, South America, Western USA. Endemic in Madagascar, Peru, andthe DRC. |
|---|---|
| Sources and routes of infection | • flea bites • close contact with infected animals • close contact with human cases of pneumonic plague |
| UKexperience to date | Last outbreak in the UK was in 1918. |
| Risk rating | Exceptionally low/negligible |
| Recent cases or outbreaks | No confirmed or suspected human cases of pneumonic plague were reported in December 2023. |
Severe acute respiratory syndrome (SARS)
| Geographical risk areas | Currently none. Two historical outbreaks originating from China in 2002 and 2004. |
|---|---|
| Sources and routes of infection | • airborne particles • direct contact with contaminated environment |
| UKexperience to date | Four imported SARS cases related to the 2002 outbreak. |
| Risk rating | Exceptionally low/negligible |
| Recent cases or outbreaks | No confirmed or suspected human cases reported globally since 2004. |
Incidents of significance of additionalHCIDs
Argentine haemorrhagic fever (Junin virus)
| Geographical risk areas | Argentina (central). Endemic to the provinces of Buenos Aires, Córdoba, Santa Fe and La Pampa. |
|---|---|
| Sources and routes of infection | • direct contact with infected rodents • inhalation of infectious rodent fluids and excreta • person-to-person transmission has been documented |
| UKexperience to date | No known cases in the UK. |
| Risk rating | Exceptionally low/negligible – one travel-related case was identified in Belgium in 2020. |
| Recent cases or outbreaks | No confirmed or suspected human cases were reported in December 2023. |
Bolivian haemorrhagic fever (Machupo virus)
| Geographical risk areas | Bolivia – cases have been identified in the departments of Beni (Mamoré, Iténez and Yucuma provinces) and Cochabamba (Cercado province). |
|---|---|
| Sources and routes of infection | • direct contact with infected rodents • inhalation of infectious rodent fluids and excreta • person-to-person transmission has been documented |
| UKexperience to date | No known cases in the UK. |
| Risk rating | Exceptionally low/negligible – travel-related cases have never been reported. |
| Recent cases or outbreaks | No confirmed or suspected human cases were reported in December 2023. |
Lujo virus disease
| Geographical risk areas | A single case acquired in Zambia led to a cluster in South Africa in 2008. |
|---|---|
| Sources and routes of infection | • presumed rodent contact (excreta, or materials contaminated with excreta of infected rodent) • person to person via body fluids |
| UKexperience to date | No known cases in the UK. |
| Risk rating | Exceptionally low/negligible – a single travel-related case has been reported. No cases have been reported anywhere since 2008. |
| Recent cases or outbreaks | No confirmed or suspected human cases reported since 2008. |
Severe fever with thrombocytopenia syndrome (SFTS)
| Geographical risk areas | Mainly reported from China (south-eastern), Japan and Korea. Cases have also been reported in Taiwan, Thailand, Myanmar and Vietnam. Serological evidence of SFTS in Pakistan. |
|---|---|
| Sources and routes of infection | • presumed to be tick exposure • person-to-person transmission described in household and hospital contacts, via contact with blood or bloodstained body fluids |
| UKexperience to date | No known cases in the UK. |
| Risk rating | Exceptionally low/negligible – not known to have occurred in travellers. |
| Recent cases or outbreaks | No confirmed or suspected human cases were reported in December 2023. |
Andes virus (Hantavirus)
| Geographical risk areas | Chile and southern Argentina. |
|---|---|
| Sources and routes of infection | • rodent contact (excreta, or materials contaminated with excreta from an infected rodent) • person-to-person transmission described in household and hospital contacts |
| UKexperience to date | No known cases in the UK. |
| Risk rating | Very low – rare cases in travellers have been reported. |
| Recent cases or outbreaks | During December 2023, media reported that throughout 2023, cases of hantavirus have been reported in the Nuble Region (6 cases), Los Lagos Region (5 cases, one death), and the Bío Bío Region (5 cases) of Chile. One case was also reported by media on 30 December 2023, in Cardenal Caro Province in the O’Higgins Region of Chile. The type of hantavirus was not specified for any of these cases. |
Avian influenza A(H5N6) virus
| Geographical risk areas | Mostly China. New strain reported in Greece in March 2017, and subsequently found in Western Europe in birds. |
|---|---|
| Sources and routes of infection | Close contact with infected birds or their environments. |
| UKexperience to date | No known cases in the UK. |
| Risk rating | Very low – not known to have occurred in travellers (UKHSArisk assessment). |
| Recent cases or outbreaks | On 22 December 2023, the Hong Kong Centre for Health Protection reported a fatal human case of avian influenza A(H5N6) in Mainland China. The case was a 33-year-old female living in Bazhong City, Sichuan Province, who had previous exposure to a live poultry market before the onset of symptoms on 20 October 2023. The case passed away on 14 November 2023. From 2014 to 22 December 2023, 88 human cases of avian influenza A(H5N6) were reported by mainland China health authorities. |
Avian influenza A(H7N7) virus
| Geographical risk areas | Sporadic occurrence in birds across mainland Europe and the UK. A human case was reported in Ireland in 1996, 89 cases were reported in the Netherlands in 2003, and 3 human cases were reported in Italy in 2013. |
|---|---|
| Sources and routes of infection | • close contact with infected birds or their environments • close contact with infected humans (no sustained human-to-human transmission reported) |
| UKexperience to date | No known cases in the UK. |
| Risk rating | Very low – human cases are rare, and severe disease even rarer. |
| Recent cases or outbreaks | No confirmed or suspected human cases were reported in December 2023. |
Authors of this report
Emerging Infections and Zoonoses Team, UKHSA
