Research and analysis

Global high consequence infectious disease events: summary December 2023

Updated 15 May 2025

Interpreting this report

The report provides updates on known, high-consequence infectious disease (HCID) events around the world as monitored by the UK Health Security Agency바카라 사이트™s (UKHSA) epidemic intelligence activities.

The report is divided into 2 sections covering all the defined HCID pathogens. The first section contains contact and airborne HCIDs that have been specified for the HCID programme by NHS England. The second section contains additional HCIDs that 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 potential HCID, 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 in HCID identification, 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 primary HCIDs

Contact HCIDs

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 (, with the latest case reported in 2022).
Sources and routes of infection	바카라 사이트¢ bite from, or crushing of, an infected tick  바카라 사이트¢ contact with the blood, tissues or body fluids of infected humans or animals
UK experience to date Â	Two cases have been reported in individuals who have travelled to the UK from and .
Risk ratingÂ	Low 바카라 사이트“ rarely reported in travellers.
Recent cases or outbreaksÂ	Between 1 January and 30 December 2023, the World Health Organisation (WHO) reported (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 . In Senegal, on 6 December 2023, the WHO African regional office (WHO AFRO) reported in Dahra and Matam districts. On 31 December 2023, media reported the detection of in Sindh Province, Pakistan during 2023, compared to 8 cases, including 7 deaths reported in 2022.

Ebola virus disease (EVD)

Geographical risk areasÂ	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 Â	바카라 사이트¢ contact with blood, tissues or body fluids of infected animals, or consumption of raw or undercooked infected animal tissue 바카라 사이트¢ contact with infected human blood or body fluidsÂ
UK experience to dateÂ	Four confirmed cases (one lab-acquired in the UK in 1976, 3 healthcare workers associated with West African epidemic 2014 to 2015).Â
Risk rating Â	Very low 바카라 사이트“ other than during the West Africa outbreak, exported cases are extremely rare.Â
Recent cases or outbreaksÂ	No confirmed or suspected human cases were reported in December 2023.

Lassa fever

Geographical risk areasÂ	Endemic in sub-Saharan West Africa.
Sources and routes of infectionÂ	바카라 사이트¢ contact with excreta, or materials contaminated with excreta from an infected rodent  바카라 사이트¢ inhalation of aerosols of excreta from an infected rodent  바카라 사이트¢ contact with infected human blood or body fluids
UK experience to dateÂ	. Prior to this, had been reported since 1971, all in travellers from West Africa.Â
Risk ratingÂ	Low 바카라 사이트“ overall, Lassa fever is the most common imported viral haemorrhagic fever (VHF), but importations to the UK are still rare.Â
Recent cases or outbreaksÂ	Between 1 January and 31 December 2023, Nigeria reported , 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 , including 189 deaths among confirmed cases, were reported.

Marburg virus disease (MVD)

Geographical risk areasÂ	Sporadic outbreaks have previously been reported in Central and Eastern Africa. A human case of MVD was reported in ; this was the first case to be identified in West Africa. for the first time in July 2022. MVD outbreaks were reported for the first time in and in .
Sources and routes of infectionÂ	바카라 사이트¢ exposure in mines or caves inhabited by Rousettus bat colonies 바카라 사이트¢ contact with infected human blood or body fluids
UK experience to dateÂ	 No reported cases in the UK.
Risk ratingÂ	Very low 바카라 사이트“ globally, 5 travel-related exported MVD cases have previously been reported in the literature.
Recent cases or outbreaksÂ	No confirmed or suspected human cases were reported in December 2023.

Airborne HCIDs

Avian influenza A(H7N9) virus

Geographical risk areasÂ	All reported human infections have been .Â	Â
Sources and routes of infectionÂ	바카라 사이트¢ close contact with infected birds or their environments  바카라 사이트¢ close contact with infected humans (no sustained human-to-human transmission)Â	Â
UK experience to dateÂ	No known cases in the UK.Â	Â
Risk ratingÂ	 Very low (UKHSA risk assessment).Â	Â
Recent cases or outbreaksÂ	No confirmed or suspected human cases were reported in December 2023.	Â

Avian influenza A(H5N1) virus

Geographical risk areasÂ	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 and the , and and 2023. The first human cases of avian influenza A(H5N1) (clade 2.3.4.4b) were reported from South America in 2023, from and .
Sources and routes of infection Â	바카라 사이트¢ close contact with infected birds or their environments 바카라 사이트¢ close contact with infected humans (no sustained human-to-human transmission)Â
UK experience to date	As of September 2023, 5 detections were reported in the UK, and 4 in 2023.
Risk ratingÂ	 Very low (UKHSA risk assessment).Â
Recent cases or outbreaksÂ	No confirmed or suspected human cases were reported in December 2023. Between 2003 and 21 December 2023, there has been reported globally.

Middle East respiratory syndrome (MERS-CoV)

Geographical risk areasÂ	The Arabian Peninsula 바카라 사이트“ Yemen, Qatar, Oman, Bahrain, Kuwait, Saudi Arabia and United Arab Emirates.Â
Sources and routes of infectionÂ	바카라 사이트¢ airborne particles 바카라 사이트¢ direct contact with contaminated environment  바카라 사이트¢ direct contact with camels or consumption of raw camel milkÂ
UK experience to dateÂ	바카라 사이트“ 3 imported cases (2012, 2013 and 2018), 2 secondary cases in close family members of the case in 2013, 3 deaths.Â
Risk ratingÂ	 Very low (UKHSA risk assessment).Â
Recent cases or outbreaksÂ	No confirmed or suspected human cases were reported in December 2023.

Mpox (clade I only)

Geographical risk areasÂ	Central Africa including, .Â
Sources and routes of infection Â	바카라 사이트¢ close contact with an infected animal (in an endemic country) or an infected person 바카라 사이트¢ contact with clothing or linens (such as bedding or towels) used by an infected person 바카라 사이트¢ direct contact with mpox skin lesions or scabs 바카라 사이트¢ coughing or sneezing of an individual with an mpox rash 바카라 사이트¢ consumption of contaminated bushmeat
UK experience 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 ratingÂ	 Very low 바카라 사이트“ no known importations of clade I mpox into the UK.
Recent cases or outbreaksÂ	Sequencing data is rarely available for mpox cases reported from endemic African countries where clade I MPXV is known to circulate. In 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 have been reported from 23 regions in the Democratic Republic of the Congo (DRC). On 28 December 2023, , of which 4 cases were infected through sexual transmission. In the Republic of the Congo, between 1 January and 24 December 2023, have been reported from 7 provinces. Â

Nipah virus

Geographical risk areasÂ	South East Asia, predominantly in . Cases have also been reported in Malaysia and Singapore.
Sources and routes of infectionÂ	바카라 사이트¢ direct or indirect exposure to infected bats 바카라 사이트¢ consumption of contaminated raw date palm sap 바카라 사이트¢ close contact with infected pigs or humansÂ
UK experience to date Â	 No known cases in the UK.Â
Risk ratingÂ	Exceptionally low/negligible 바카라 사이트“ no travel-related infections in the literature.Â
Recent cases or outbreaksÂ	No confirmed or suspected human cases were reported in December 2023.

Pneumonic plague (Yersinia pestis)

Geographical risk areasÂ	Predominantly . Endemic in Madagascar, Peru, and the DRC.
Sources and routes of infectionÂ	바카라 사이트¢ flea bites  바카라 사이트¢ close contact with infected animals  바카라 사이트¢ close contact with human cases of pneumonic plagueÂ
UK experience to dateÂ	Last outbreak in the UK was in 1918.Â
Risk rating	Exceptionally low/negligible
Recent cases or outbreaksÂ	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	바카라 사이트¢ airborne particles  바카라 사이트¢ direct contact with contaminated environment
UK experience to date	related to the 2002 outbreak.Â
Risk rating	Exceptionally low/negligible
Recent cases or outbreaks	No confirmed or suspected human cases reported globally since 2004.Â

Incidents of significance of additional HCIDs

Argentine haemorrhagic fever (Junin virus)

Geographical risk areas	(central). Endemic to the provinces of Buenos Aires, Córdoba, Santa Fe and La Pampa.
Sources and routes of infection	바카라 사이트¢ direct contact with infected rodents  바카라 사이트¢ inhalation of infectious rodent fluids and excreta  바카라 사이트¢ person-to-person transmission has been documentedÂ
UK experience to date	 No known cases in the UK.Â
Risk rating	Exceptionally low/negligible 바카라 사이트“ was identified in Belgium in 2020.Â
Recent cases or outbreaks	No confirmed or suspected human cases were reported in December 2023.

Bolivian haemorrhagic fever (Machupo virus)

Geographical risk areas	Bolivia 바카라 사이트“ (Mamoré, Iténez and Yucuma provinces) and Cochabamba (Cercado province).Â
Sources and routes of infection	바카라 사이트¢ direct contact with infected rodents  바카라 사이트¢ inhalation of infectious rodent fluids and excreta  바카라 사이트¢ person-to-person transmission has been documentedÂ
UK experience to date	 No known cases in the UK.Â
Risk rating	Exceptionally low/negligible 바카라 사이트“ travel-related cases have never been reported.Â
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.Â
Sources and routes of infection	바카라 사이트¢ presumed rodent contact (excreta, or materials contaminated with excreta of infected rodent)  바카라 사이트¢ person to person via body fluidsÂ
UK experience to date	No known cases in the UK.
Risk rating	Exceptionally low/negligible 바카라 사이트“ a single travel-related case has been reported. No cases have been reported anywhere since 2008.Â
Recent cases or outbreaks	No confirmed or suspected human cases reported since 2008.Â

Severe fever with thrombocytopenia syndrome (SFTS)

Geographical risk areas	Mainly reported from China (south-eastern), Japan and Korea. Cases have also been reported in , , and . Serological evidence of SFTS in .Â
Sources and routes of infection	바카라 사이트¢ presumed to be tick exposure  바카라 사이트¢ person-to-person transmission described in household and hospital contacts, via contact with blood or bloodstained body fluidsÂ
UK experience to date	No known cases in the UK.Â
Risk rating	Exceptionally low/negligible 바카라 사이트“ not known to have occurred in travellers.Â
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.Â
Sources and routes of infection	바카라 사이트¢ rodent contact (excreta, or materials contaminated with excreta from an infected rodent)  바카라 사이트¢ person-to-person transmission described in household and hospital contactsÂ
UK experience to date	 No known cases in the UK.Â
Risk rating	 Very low 바카라 사이트“ rare cases in travellers have been reported.Â
Recent cases or outbreaks	During December 2023, media reported that throughout 2023, cases of hantavirus have been reported , , and the of Chile. One case was also reported by media on 30 December 2023, in 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 , and subsequently found in Western Europe in birds.Â
Sources and routes of infection	Close contact with infected birds or their environments.Â
UK experience to date	 No known cases in the UK.Â
Risk rating	Very low 바카라 사이트“ not known to have occurred in travellers (UKHSA risk assessment).Â
Recent cases or outbreaks	On 22 December 2023, the Hong Kong Centre for Health Protection reported . 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. in 1996, in 2003, and in 2013.
Sources and routes of infection	바카라 사이트¢ close contact with infected birds or their environments  바카라 사이트¢ close contact with infected humans (no sustained human-to-human transmission reported)Â
UK experience to date	 No known cases in the UK.Â
Risk rating	 Very low 바카라 사이트“ human cases are rare, and severe disease even rarer.Â
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