Global high consequence infectious disease events: summary November 2024

Question 1

Interpreting this report

Accepted Answer

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 and exceptionally low to negligible.

Question 2

Contact HCIDs

Accepted Answer

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	During November 2024, 31 new cases of CCHF and one associated death were reported in Afghanistan. Between 1 January and 30 November 2024, 1,191 suspected CCHF cases and 94 associated deaths (case fatality rate (CFR) of 7.9%) were reported. On 27 November 2024, media reported that 7 CCHF cases (no deaths) were registered in Senegal between 1 January and 27 November 2024, across 5 health districts. In Uganda, 20 CCHF cases were registered between 1 January and 27 November 2024. 7 fatalities were reported among cases.

Ebola virus disease (EBOD)

Geographical risk areas	Map of Ebola disease in Africa
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 November 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	Between 1 January and 24 November 2024, Nigeria reported 10,301 Lassa fever cases (1,089 confirmed; 9,195 suspected; 17 probable). 179 deaths were reported amongst confirmed cases (CFR of 16.4%). This is a lower CFR compared to the same period in 2023 (17.1%). Confirmed cases were registered from 28 out of 36 states. 425 cases (46 confirmed) were reported during November 2024. In Liberia, between 1 January and 25 November 2024, 212 cases (38 confirmed, 174 suspected) and 11 deaths (CFR of 29%) were registered across Liberia. In 2023, Liberia recorded 186 cases and 5 deaths.

Marburg virus disease (MARD)

Geographical risk areas	Sporadic outbreaks have previously been reported in Central and Eastern Africa. Outbreaks were reported for the first time in Guinea (in 2021), Ghana (in 2022), Equatorial Guinea and Tanzania (in 2023) and Rwanda (in 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 MARD cases have previously been reported in the literature.
Recent cases or outbreaks	On 27 September 2024, Rwanda’s Ministry of Health declared the countries first outbreak of MARD. As of 29 November 2024, 66 MARD cases, including 15 deaths, were reported. On 9 November 2024, the World Health Organization reported that health officials in Rwanda had discharged the last MARD patient, starting the mandatory 42-day countdown to declaring the end of the outbreak.

Question 3

Airborne HCIDs

Accepted Answer

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 November 2024.

Avian influenza A(H5N1) virus

Geographical risk areas	Human cases have been predominantly reported in Southeast Asia, but also in Egypt, Iraq, Pakistan, Turkey and Nigeria. Since 2022, human cases of clade 2.3.4.4b have been reported in Spain, the US, and the UK, Ecuador and Chile. Since October 2023, 11 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 is a theoretical risk although there is currently no evidence of any human-to-human transmission having occurred).
UK experience to date	Since December 2021, 7 detections were reported in the UK, one in 2022, 4 in 2023, and one in 2024.
Risk rating	Very low (UKHSA risk assessment.
Recent cases or outbreaks	On 13 November 2024, the Public Health Agency of Canada (PHAC) reported a confirmed avian influenza A(H5N1) human case in British Columbia. This is the first domestically acquired human case of avian influenza A(H5N1) in Canada. Genomic sequencing indicates that the virus is related to the avian influenza A(H5N1) viruses detected in the ongoing outbreak in poultry in British Columbia (clade 2.3.4.4b, genotype D.1.1). The case was detected via hospital-based influenza surveillance. In United States, 52 confirmed human cases of avian influenza A(H5) were reported between April 2024 and 18 November 2024. Of these, 21 cases reported exposure to infected poultry, while 30 cases were exposed to infected dairy cattle and the source of exposure in one case could not be determined. Most cases have been reported in California.

Middle East respiratory syndrome (MERS-CoV)

Geographical 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 Yemen, Oman, United Arab Emirates, Qatar, Bahrain, Kuwait, Jordan, Lebanon and Iran. MERS is transmitted from camels and has been detected in camels from the Arabian Peninsula and also parts of North, West and Eastern Africa.
Sources 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 particles
UK experience to date	Five 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 November 2024.

Mpox (Clade I only)

Geographical risk areas	Central Africa including Burundi, Cameroon, Central African Republic, Democratic Republic of the Congo, Gabon, Kenya, Republic of the Congo, Rwanda and Uganda.
Sources and routes of infection	• close contact with an infected animal (in an endemic country) or an infected person - including sexual contact • 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	Five cases in total – 3 imported cases (2024) and 2 secondary cases in household members of a case from 2024.
Risk rating	The importation risk of clade I mpox into the UK is considered low to medium. The risk of potential spread in the UK is considered low to medium. The risk of acquisition in the UK is considered low. Travel-associated cases of clade I mpox have been reported in Canada, Germany, India, Sweden, Thailand and United States.
Recent cases or outbreaks	In endemic countries where clade I mpox is known 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 25 July 2024. As of 25 November 2024, 4,197 mpox cases (2,050 confirmed) and one death have been reported from 45 out of 49 health districts. The Central African Republic (CAR) reported 425 cases of mpox (74 confirmed) and 2 deaths (CFR of 2.7%) between 1 January and 25 November 2024. Cases were reported in 6 of the 7 health regions. 52.7% of cases were in children under 15-years-old. Between 1 January and 25 November 2024, the Democratic Republic of the Congo (DRC) reported 49,390 mpox cases (11,154 confirmed), including 1,199 deaths (CFR of 2.4%), from all 26 provinces. Among the most affected provinces are South Kivu (14,627 cases and 38 deaths), followed by Equateur (7,989 cases and 392 deaths). Kenya reported its first confirmed case of clade Ib mpox on 31 July 2024. As of 30 November 2024, 23 mpox cases were reported. Uganda first identified 2 confirmed cases of clade Ib mpox on 15 July 2024. As of 24 November 2024, 683 confirmed cases and 2 deaths (CFR of 0.3%) have been reported. 48 districts have reported at least 1 confirmed mpox case. Most cases have been reported from Kampala (307 cases), Wakiso (102 cases) and Nakasongola (66 cases). Rwanda declared an outbreak of clade Ib mpox on 27 July 2024. As of 24 November 2024, 52 confirmed cases have been reported. During November 2024, 3 countries outside of the African region reported travel-associated cases of clade I mpox, including the United Kingdom, Canada and the United States. The cases had a travel history to clade I mpox affected African countries.

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 November 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	On 9 November 2024, media reported 2 suspected fatal cases of pneumonic plague in Antananarivo province, Madagascar.

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.

Question 4

Incidents of significance of additional HCIDs

Accepted Answer

Argentine haemorrhagic fever (Junin 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 November 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 November 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 November 2024, the Korean Disease Control and Prevention Agency reported 171 SFTS cases. This is a lower number of cases recorded during the equivalent 2023 period (198 cases).

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	On 8 November 2024, media reported a fatal case of hantavirus in a 66-year-old male in Tartagal, Salta province, Argentina. Between 1 January and November 2024, 15 hantavirus cases and 4 deaths have been reported in Salta province. In Bolivia, 18 cases of hantavirus have been reported across 4 out of 9 departments between 1 January and 17 November 2024. The cases were recorded in Santa Cruz (8 cases), Tarija (5 cases), La Paz (4 cases) and Cochabamba (one case). The type of hantavirus is not specified for the above 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.
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 November 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 November 2024.

Question 5

Authors of this report

Accepted Answer

Emerging Infections and Zoonoses Team, UKHSA

Global high consequence infectious disease events: summary November 2024