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. 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 to 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 (first reported in 2016, with the latest case reported in 2024). Portugal reported its first human case in August 2024 with symptom onset in July 2024.
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
UK experience 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 26 October 2024, the World Health Organization (WHO) reported 1,148 CCHF cases (251 confirmed), including 93 deaths (case fatality rate (CFR) of 8.1%), from Afghanistan. Confirmed cases were reported from 13 provinces. The most affected provinces include Kabul (170 cases), Balkh (23 cases) and Kunduz (20 cases). In 2023, Afghanistan reported 1,243 CCHF cases (383 confirmed), including 114 deaths (CFR of 9.2%). On 10 October 2024, media reported a fatal case of CCHF in Ahmedabad, India. CCHF was first reported in India in 2011 and since then sporadic cases have been reported. Iraq have reported a total of 211 cases of CCHF, and 26 deaths since the beginning of 2024, as reported by media on 13 October 2024. Most cases have been reported in Dhi Qar Province (40 cases, 6 deaths), followed by Nineveh Province (26 cases, 7 deaths). According to media on 28 October 2024, a case of CCHF was reported in Balochistan Province, Pakistan. This brings the total number of CCHF cases reported in the province to 41 cases in 2024. This is the same number of cases when compared to the equivalent period in 2023 period (41 cases). Between 9 August and 4 October 2024, one confirmed case of CCHF was reported in Keur Massar health district, Senegal. This brings the total number of cases reported in Senegal in 2024 to 6 confirmed cases.

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
UK experience 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 October 2024.

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
UK experience to date	Three travel-related Lassa fever cases reported in 2022. Prior to this, 8 imported Lassa fever cases had been reported since 1980, 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	On 3 October 2024, the WHO was notified of a confirmed Lassa fever case in a 63 year old male in Guéckédou prefecture, southern Guinea. The case experienced symptom onset and hospitalisation on 19 September 2024, and died on 23 September 2024. As of 25 October 2024, 27 cases of Lassa fever, including 2 deathshave been reported in Guinea in 2024. During 2023, Guinea reported 133 cases of Lassa fever, including 3 deaths. Between 1 January and 27 October 2024, Nigeria reported 9,835 Lassa fever cases (1,055 confirmed; 8,780 suspected; 17 probable). 175 deaths were reported amongst confirmed cases (case fatality rate (CFR) of 16.6%). This is a lower CFR compared to the same period in 2023 (17.0%). Confirmed cases have been reported from 28 out of 36 states. On 28 October 2024, the Iowa Department of Health and Human Services in the United States (US) reported a fatal case of Lassa fever, in an individual with recent travel history to West Africa. The case was hospitalised in an isolation unit and died on 28 October 2024. This represents the 9th travel-associated case of Lassa fever in the US in individuals returning from endemic regions. The US Centers for Disease Control and Prevention (CDC) assesses the risk to the US general public as extremely low.

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, in Tanzania in March 2023 and in Rwanda in September 2024.
Sources and routes of infection	• exposure in mines or caves inhabited by Rousettus bat colonies • contact with infected human blood or body fluids
UK experience 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	As of 31 October 2024, the number of confirmed MVD cases associated with the outbreak in Rwanda initially declared on 27 September 2024, has increased to 66 confirmed MVD cases, 15 deaths (CFR of 23%), and 49 recoveries. Most cases (80%) have been amongst healthcare workers associated with 2 healthcare facilities in the capital, Kigali. The WHO assesses the risk of this outbreak as very high at the national level, high at the regional level, and low at the global level. Epidemiological investigations identified that the outbreak initiated from a zoonotic origin, following the index case’s exposure to bats while cave mining.

Airborne HCIDs

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)
UK experience to date	No known cases in the UK.
Risk rating	Very low (UKHSA risk assessment).
Recent cases or outbreaks	No confirmed or suspected human cases were reported in October 2024.

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 USA in 2022 and 2024, and in the UK 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. Since October 2023, several human cases of clade 2.3.2.1c have been reported in Cambodia.
Sources and routes of infection	• close contact with infected animals (notably birds) or their environments • close contact with infected humans (no sustained human-to-human transmission)
UK experience to date	As of September 2023, 5 detections were reported in the UK, one in 2022 and 4 in 2023.
Risk rating	Very low (UKHSA risk assessment).
Recent cases or outbreaks	Since April 2024 and as of 29 October 2024, a total of 36 confirmed human cases of avian influenza A(H5N1) have been reported in the US. Of these, 15 cases reported exposure to infected poultry, while 20 cases were exposed to infected dairy cattle. The source of exposure for the case recorded in Missouri remains undetermined. Cases have been reported across California (16 cases), Colorado (10 cases), Washington (6 cases), Michigan (2 cases), Missouri (one case), Texas (one case) states. For further information see the US Centres for Disease Control and Prevention H5 Bird Flu: Current Situation webpage.

Middle East respiratory syndrome (MERS-CoV)

Geographical risk areas	Arabian Peninsula – Bahrain, Jordan, Iraq, Kingdom of Saudi Arabia, Kuwait, Oman, Qatar, United Arab Emirates, Yemen. Evidence has also been reported in Iran and Kenya.
Sources and routes of infection	• airborne particles • direct contact with contaminated environment • direct contact with camels or consumption of raw camel milk
UK experience 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 (UKHSA risk assessment).
Recent cases or outbreaks	No confirmed or suspected human cases were reported in October 2024.

Mpox (clade I only)

Geographical risk areas	Central Africa including Burundi, Cameroon, Central African Republic, Democratic Republic of the Congo, Gabon, Republic of the Congo, and Uganda.
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
UK experience to date	One travel associated case of clade Ib mpox was reported in the UK in 2024.
Risk rating	Low to Medium – one imported case of clade I mpox has been reported in the UK. Travel-associated cases of clade I mpox have been reported from India, Sweden, Germany and Thailand (one case each) with no onwards transmission.
Recent 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. Since Burundi declared an mpox outbreak on 26 July 2024, 3,557 mpox cases (1,509 confirmed) and no deaths have been reported from 43 out of 49 health districts as of 26 October 2024. Clade Ib mpox has been reported in Burundi. The Central African Republic (CAR) reported 387 cases of mpox (64 confirmed) and 2 deaths (CFR of 3.1%) between 1 January and 27 October 2024. Clade Ia mpox was detected in confirmed cases. Clade Ia mpox has been reported in the CAR. Between 1 January and 25 October 2024, the Democratic Republic of the Congo (DRC) reported 38,185 mpox cases (8,607 confirmed), including 1,049 deaths (CFR of 2.7%), from all 26 provinces. During 2023, the DRC reported its highest annual number of mpox cases (14,434 cases, including 728 deaths). Clades Ia and Ib mpox have been reported in the DRC. Between 1 January and 12 October 2024, Gabon reported 23 cases of mpox (2 confirmed). Although the clade type was not specified, clade Ia mpox has historically been reported in Gabon. On 22 October 2024, Germany recorded a case of clade Ib mpox in a traveller that had returned from east Africa. This is the fourth case of clade Ib mpox reported outside the African Region, and the second confirmed case in the European Region. Kenya officially reported its first confirmed case of clade Ib mpox on 31 July 2024. Up to 20 October 2024, 14 confirmed cases and one death have been reported across 11 counties. 10 out of the 14 cases have been travel associated to affected neighbouring counties. The mpox death was reported in an individual with HIV co-infection. Uganda first identified 2 confirmed cases of clade Ib mpox on 15 July 2024. As of 30 October 2024, 288 confirmed cases and one death have been reported. The mpox death was reported in an individual with HIV co-infection. In the Republic of the Congo (RoC), as of 25 October 2024, 239 mpox cases (22 confirmed) and no deaths were reported from 4 out of 12 departments. During 2023, 95 mpox cases, including 5 deaths, were reported. Clade Ia mpox has been reported in the RoC. Rwanda declared an outbreak of clade Ib mpox on 26 July 2024. Since then, a total of 3,723 mpox cases (26 confirmed) and no deaths have been reported up to 27 October 2024 in Rwanda. On 30 October 2024 the United Kingdom reported their first detection of clade Ib mpox in London, England. The case was an individual with travel history to clade Ib affected countries in the African region. This is the fifth case of clade Ib mpox reported outside the African Region, and the third confirmed case in the European Region.

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
UK experience to date	No known cases in the UK.
Risk rating	Exceptionally low to negligible – no travel-related infections in the literature.
Recent cases or outbreaks	No confirmed cases of Nipah virus infection were reported in October 2024.

Pneumonic plague (Yersinia pestis)

Geographical risk areas	Predominantly sub-Saharan Africa but also Asia, North Africa, South America, Western USA. Endemic in Madagascar, Peru, and the DRC.
Sources and routes of infection	• flea bites • close contact with infected animals • close contact with human cases of pneumonic plague
UK experience to date	Last outbreak in the UK was in 1918.
Risk rating	Exceptionally low to negligible
Recent cases or outbreaks	No confirmed or suspected human cases were reported in October 2024.

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
UK experience to date	Four imported SARS cases related to the 2002 outbreak.
Risk rating	Exceptionally low to negligible
Recent cases or outbreaks	No confirmed or suspected human cases reported globally since 2004.

Incidents of significance of additional HCIDs

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
UK experience to date	No known cases in the UK.
Risk rating	Exceptionally low to negligible – one travel-related case was identified in Belgium in 2020.
Recent cases or outbreaks	No confirmed or suspected human cases were reported in October 2024.

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
UK experience to date	No known cases in the UK.
Risk rating	Exceptionally low to negligible – travel-related cases have never been reported.
Recent cases or outbreaks	No confirmed or suspected human cases were reported in October 2024.

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
UK experience to date	No known cases in the UK.
Risk rating	Exceptionally low to negligible – a single travel-related case has been reported. No cases have been reported anywhere since 2008.
Recent cases or outbreaks	No cases have been reported anywhere 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
UK experience to date	No known cases in the UK.
Risk rating	Exceptionally low to negligible – not known to have occurred in travellers.
Recent cases or outbreaks	Between January and 26 October 2024, the Korea Disease Control and Prevention Agency reported 123 SFTS cases. This is a lower number of reported cases compared to the 5 year average (2019 to 2023) (201 cases). Between January and 30 October 2024, Japan’s National Institute of Infectious Diseases reported 106 SFTS cases. During October 2024, 5 SFTS cases were reported.

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
UK experience to date	No known cases in the UK.
Risk rating	Very low – rare cases in travellers have been reported.
Recent cases or outbreaks	No confirmed or suspected human cases were reported in October 2024.

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.
UK experience to date	No known cases in the UK.
Risk rating	Very low – not known to have occurred in travellers (UKHSA risk assessment).
Recent cases or outbreaks	No confirmed or suspected human cases were reported in October 2024.

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)
UK experience 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 October 2024.

Authors of this report

Emerging Infections and Zoonoses Team, UKHSA