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Interpreting this report

The report provides updates on known, high consequence infectious disease (HCID) events around the world as monitored by UK Health Security Agency’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 on the UK public.ÌýPast 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 and exceptionally low to negligible.

Incidents of significance of primaryÌýHCIDs

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Crimean-Congo haemorrhagic fever (CCHF)

ÌýGeographical 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 ). Portugal reported its first human case in with symptom onset in July 2024.
ÌýSources and routes of infection	• bite from, or crushing of, an infected tickÌý • contact with the blood, tissues or body fluids of infected humans or animals
ÌýUKÌýexperience to dateÌýÌý	Two cases have been reported in individuals who have travelled to the UK from and .
ÌýRisk rating Ìý	Low – rarely reported in travellers.
ÌýRecent cases or outbreaksÌý	During January 2025, were reported in Uganda. The confirmed case was a 45-year-old male farmer with a history of contact with cattle, goats and sheep. In 2024, 8 confirmed, 4 probable and 8 suspected cases of CCHF, including 4 deaths, were reported from 5 districts of Uganda. On 23 January 2025, (one of which was fatal) were reported in Mbirkilane, Senegal. A fatal case of CCHF was reported in a in Jamnagar, Gujarat, India on 28 January 2025. The case was hospitalised on 21 January 2025 and died on 27 January 2025.ÌýÌý

Ebola disease (EBOD)

ÌýGeographical risk areasÌý	ÌýMap of Ebola disease in Africa
ÌýSources and routes of infectionÌýÌý	• 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 fluidsÌý
ÌýUKÌýexperience to dateÌý	Four confirmed cases (one lab-acquired in the UK in 1976, 3 healthcare workers associated with West African epidemic 2014 to 2015).Ìý
ÌýRisk ratingÌýÌý	Very low – other than during the West Africa outbreak, exported cases are extremely rare.Ìý
ÌýRecent cases or outbreaksÌý	On , the Ugandan Ministry of Health confirmed an outbreak of Sudan virus disease (SVD) in Kampala, following laboratory confirmation of a fatal case in a 32-year-old male healthcare worker (HCW) on 29 January 2025. The case presented to multiple health facilities and to a traditional healer. As of, 45 contacts had been identified and isolated, including 34 HCWs and 11 family members. On , the World Health Organization (WHO) reported that they are supporting the Ugandan government’s outbreak response through facilitating access to a candidate vaccine and treatments (a monoclonal antibody and an antiviral), via clinical trials.Ìý Ìý

Lassa fever

ÌýGeographical risk areasÌý	Endemic in sub-Saharan West Africa.
ÌýSources and routes of infectionÌý	• contact with excreta, or materials contaminated with excreta from an infected rodentÌý • inhalation of aerosols of excreta from an infected rodentÌý • contact with infected human blood or body fluids
ÌýUKÌýexperience to dateÌý	. Prior to this, 8 imported Lassa fever cases had been reported since 1980, all in travellers from West Africa.
ÌýRisk ratingÌý	Low – overall, Lassa fever is the most common imported viral haemorrhagic fever (VHF) but importations to the UK are still rare.Ìý
ÌýRecent cases or outbreaks	Between , Nigeria reported 290 confirmed, 1 probable and 1,171 suspected cases of Lassa fever. 53 deaths were reported amongst confirmed cases (case fatality rate (CFR) of 18.3%). This is a lower CFR compared to the same time period in 2024 (18.6%). Confirmed cases have been reported from 10 out of 36 states. As of 26 January 2025, . Since 6 January 2022, 181 confirmed Lassa fever cases and 56 deaths have been reported in Liberia.Ìý

Marburg virus disease (MARD)

ÌýGeographical risk areas	Sporadic outbreaks have previously been reported in Central and Eastern Africa. Outbreaks were reported for the first time in (in 2021), (in 2022), and (in 2023) and (in 2024). Ìý
ÌýSources and routes of infection	• exposure in mines or caves inhabited by Rousettus bat colonies • contact with infected human blood or body fluids
ÌýUKÌýexperience to date	ÌýNo reported cases in the UK.
ÌýRisk rating	Very low – globally, 5 travel-related exported MARD cases have previously been reported in the literature.
ÌýRecent cases or outbreaks	On , the WHO received reports of 6 suspected MARD cases (including 5 fatalities) in the Kagera region of Tanzania. The outbreak was confirmed by Tanzania on , by which point 25 suspected MARD cases and 8 deaths had been reported in the Biharamulo District of the Kagera region. As of , Tanzania’s Ministry of Health reported 15 confirmed MARD cases and 2 deaths, with 281 contacts identified for follow-up. Ìý

AirborneÌýHCIDs

Avian influenza A(H7N9) virus

ÌýGeographical risk areas	All reported human infections have been .	Ìý
ÌýSources and routes of infection	• close contact with infected birds or their environmentsÌý • close contact with infected humans (no sustained human-to-human transmission)	Ìý
ÌýUKÌýexperience to date	No known cases in the UK.	Ìý
ÌýRisk rating	ÌýVery low (UKHSAÌýrisk assessment).	Ìý
ÌýRecent cases or outbreaks	No confirmed or suspected human cases were reported in January 2025.	Ìý

Avian influenza A(H5N1) virus

ÌýGeographical risk areas	Human cases have been predominantly reported in Southeast Asia, but also in Egypt, Iraq, Pakistan, Turkey and Nigeria. However, since the panzootic of A(H5N1) emerged in 2021, human spillover cases (clade 2.3.4.4b) have been reported in , the , and the UK. The first human cases of avian influenza A(H5N1) (clade 2.3.4.4b) from South America were reported in early 2023, from and . Since October 2023, 11 human cases of clade 2.3.2.1c have been reported in .
ÌýSources and routes of infection	• Close contact with infected animals (notably birds) or their environments • Close contact with infected humans is a theoretical risk although there is currently no evidence of any human-to-human transmission having occurred).
ÌýUKÌýexperience to date	Since December 2021, 7 detections were reported in the UK, , 4 in 2023, one in 2024, and one in 2025.
ÌýRisk rating	ÌýVery low (UKHSAÌýrisk assessment).
ÌýRecent cases or outbreaks	As of 27 January 2025, a total of and human cases of avian influenza A(H5) were reported in the US, across 10 states. The first human case of avian influenza A(H5) in 2025 was reported on , in a child from California with no known source of infection. On , a fatal case of avian influenza A(H5N1) was reported from health authorities in Louisiana State. The elderly patient had co-morbidities and exposure to a non-commercial backyard flock and wild birds. Investigations did not identify any additional cases or any evidence of human-to-human transmission. This is the reported in the US. The first fatal case of avian influenza A(H5N1) for Cambodia in 2025 was reported in Kampong Cham province on . The case was a 28-year-old man who had exposure to backyard poultry. On 27 January 2025, the UK Health Security Agency confirmed a human case of avian influenza A(H5N1) in the West Midlands region. The case acquired the infection on a farm, where they had close and prolonged contact with infected birds.

Middle East respiratory syndrome (MERS-CoV)

ÌýGeographical risk areas	MERS has been concentrated in countries from the Arabian Peninsula, with the majority of cases having occurred in the Kingdom of Saudi Arabia. Other previously affected countries in the region include . MERS is transmitted from camels and has been detected in camels from the Arabian Peninsula and also parts of North, West and Eastern Africa.
ÌýSources and routes of infection	• Transmission through the air •Direct contact with contaminated environment • Direct contact with camels or consumption of raw camel milk • Working in or exposure to healthcare settings where outbreaks are occurring airborne particlesÌý
ÌýUKÌýexperience to date	– 3 imported cases (2012, 2013 and 2018), 2 secondary cases in close family members of the case in 2013, 3 deaths.
ÌýRisk rating	ÌýVery low (UKHSAÌýrisk assessment).Ìý
ÌýRecent cases or outbreaks	No confirmed or suspected human cases were reported in January 2025.

Mpox (Clade I only)

ÌýGeographical risk areas	Central and East African countries including Ìý
ÌýSources 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
ÌýUKÌýexperience to date	Eight cases in total – 3 imported cases (2024), 3 imported cases (2025), 2 secondary cases in household members of a case from 2024.
ÌýRisk rating	ÌýThe importation risk of clade I mpox into the UK is considered . The risk of potential spread in the UK and risk of acquisition in the UK is considered low to medium. Travel-associated cases of clade I mpox have been reported from , , , , , , , , , , . Secondary transmission of cases within household contacts has been reported in the UK, and .
ÌýRecent cases or outbreaks	In endemic countries where clade I mpox is know to circulate access to subclade specific PCR or sequencing may be limited. Therefore, we report below all reported mpox cases from these countries, regardless of whether the samples have undergone specific subclade testing. A comprehensive list of mpox clade I affected countries is available from the UKHSA. Burundi declared an mpox outbreak on . As of 31 January 2025, have been reported. The Central African Republic reported and 3 deaths between 1 January 2024 and 8Ìý January 2025. Ìý As of the end of epidemiological week 3 (19 January 2025), the Democratic Republic of the Congo (DRC) had reported , including 1,392 deaths (CFR of 2%), from all 26 provinces. Ìý Kenya officially reported its first confirmed case of clade Ib mpox on . As of 26 January 2025, and one death had been reported. Most cases were reported from . Uganda first identified 2 confirmed cases of clade Ib mpox on . As of 29 January 2025, were reported from 84 districts. Rwanda declared an outbreak of clade Ib mpox on . As of 26 January 2025, were reported. Ìý Zambia reported its first clade Ib mpox case during . As of 30 January 2025, have been reported from Lusaka (11 cases), Copperbelt (5 cases) and Central (1 case) provinces. During January 2025, 6 countries outside of the African Region reported travel-associated cases of clade I mpox. Of these, 2 countries reported their first-ever detections ( and ) and 4 countries reported additional travel-associated cases (3 new cases in the United Kingdom, the and in the United States, in Thailand, and in Germany).

Nipah virus

ÌýGeographical risk areas	South East Asia, predominantly in . Cases have also been reported in Malaysia and Singapore.
ÌýSources 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
ÌýUKÌýexperience to date	ÌýNo known cases in the UK.
ÌýRisk rating	Exceptionally low to negligible – no travel-related infections in the literature.Ìý
ÌýRecent cases or outbreaks	No confirmed or suspected human cases were reported in January 2025.

Pneumonic plague (Yersinia pestis)

ÌýGeographical risk areas	Predominantly . Endemic in Madagascar, Peru, andÌýthe DRC.
ÌýSources and routes of infection	• flea bitesÌý • close contact with infected animalsÌý • close contact with human cases of pneumonic plague
ÌýUKÌýexperience to date	Last outbreak in the UK was in 1918.
ÌýRisk rating	Exceptionally low to negligible
ÌýRecent cases or outbreaks	No confirmed or suspected human cases were reported in January 2025.

Severe acute respiratory syndrome (SARS)

ÌýGeographical risk areas	Currently none. Two historical outbreaks originating from China in 2002 and 2004.
ÌýSources and routes of infection	• airborne particlesÌý • direct contact with contaminated environment
ÌýUKÌýexperience to date	related to the 2002 outbreak.Ìý
ÌýRisk rating	Exceptionally low to negligible
ÌýRecent cases or outbreaks	No confirmed or suspected human cases reported globally since 2004.

Incidents of significance of additionalÌýHCIDs

Argentine haemorrhagic fever (Junin virus)

ÌýGeographical risk areas	(central). Endemic to the provinces of Buenos Aires, Córdoba, Santa Fe and La Pampa.
ÌýSources and routes of infection	• direct contact with infected rodentsÌý • inhalation of infectious rodent fluids and excretaÌý • person-to-person transmission has been documented
ÌýUKÌýexperience to date	ÌýNo known cases in the UK.
ÌýRisk rating	Exceptionally low to negligible – was identified in Belgium in 2020.
ÌýRecent cases or outbreaks	No confirmed or suspected human cases were reported in January 2025.

Bolivian haemorrhagic fever (Machupo virus)

ÌýGeographical risk areas	Bolivia – (Mamoré, Iténez and Yucuma provinces) and Cochabamba (Cercado province).
ÌýSources and routes of infection	• direct contact with infected rodentsÌý • inhalation of infectious rodent fluids and excretaÌý • person-to-person transmission has been documented
ÌýUKÌýexperience to date	ÌýNo known cases in the UK.
ÌýRisk rating	Exceptionally low to negligible – travel-related cases have never been reported.
ÌýRecent cases or outbreaks	No confirmed or suspected human cases were reported in January 2025.

Lujo virus disease

ÌýGeographical risk areas	A single case acquired in Zambia led to a cluster in South Africa in 2008.
ÌýSources and routes of infection	• presumed rodent contact (excreta, or materials contaminated with excreta of infected rodent)Ìý • person to person via body fluids
ÌýUKÌýexperience to date	No known cases in the UK.
ÌýRisk rating	Exceptionally low to negligible – a single travel-related case has been reported. No cases have been reported anywhere since 2008.
ÌýRecent cases or outbreaks	No cases have been reported anywhere since 2008.

Severe fever with thrombocytopenia syndrome (SFTS)

ÌýGeographical risk areas	Mainly reported from China (south-eastern), Japan and Korea. Cases have also been reported in , , and . Serological evidence of SFTS in .Ìý
ÌýSources and routes of infection	• presumed to be tick exposureÌý • person-to-person transmission described in household and hospital contacts, via contact with blood or bloodstained body fluids
ÌýUKÌýexperience to date	No known cases in the UK.
ÌýRisk rating	Exceptionally low to negligible – not known to have occurred in travellers.
ÌýRecent cases or outbreaks	No confirmed or suspected human cases were reported in January 2025.

Andes virus (Hantavirus)

ÌýGeographical risk areas	ÌýChile and Southern Argentina.Ìý
ÌýSources 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
ÌýUKÌýexperience to date	ÌýNo known cases in the UK.
ÌýRisk rating	ÌýVery low – rare cases in travellers have been reported.Ìý
ÌýRecent cases or outbreaks	Between 30 December 2024 and 25 January 2025, the Buenos Aires Provincial Department of Health reported , and one death. Confirmed cases were recorded in the districts of Berisso (one case), La Plata (3 cases), and Pergamino (one case). The type of hantavirus was not reported.

Avian influenza A(H5N6) virus

ÌýGeographical risk areas	Mostly China. New strain reported in , and subsequently found in Western Europe in birds.Ìý
ÌýSources and routes of infection	Close contact with infected birds or their environments.Ìý
ÌýUKÌýexperience to date	ÌýNo known cases in the UK.Ìý
ÌýRisk rating	Very low – not known to have occurred in travellers (UKHSAÌýrisk assessment).
ÌýRecent cases or outbreaks	No confirmed or suspected human cases were reported in January 2025.

Avian influenza A(H7N7) virus

ÌýGeographical risk areas	Sporadic occurrence in birds across mainland Europe and the UK. in 1996, in 2003, and in 2013.
ÌýSources and routes of infection	• close contact with infected birds or their environmentsÌý • close contact with infected humans (no sustained human-to-human transmission reported)Ìý
ÌýUKÌýexperience to date	ÌýNo known cases in the UK.
ÌýRisk rating	ÌýVery low – human cases are rare, and severe disease even rarer.
ÌýRecent cases or outbreaks	No confirmed or suspected human cases were reported in January 2025.

Authors of this report

Emerging Infections and Zoonoses Team, UKHSA