Global high consequence infectious disease events: summary February and March 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 the 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/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 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
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 30 March 2024, the World Health Organisation (WHO) reported 64 suspected CCHF cases, including one death from Afghanistan. CCHF was confirmed in 2 out of 48 suspected cases which have been tested since the beginning of 2024. The confirmed cases were from Balkh and Kapisa provinces. For comparison, in 2023, Afghanistan reported 1,243 suspected CCHF cases, including 114 deaths (case fatality rate (CFR of 9.2%)). A total of 1,098 suspected cases of suspected CCHF cases were tested in 2023, of which 383 were confirmed. On 22 March 2024, the Senegal Ministry of Health (MoH) reported a confirmed case of CCHF from Dakar. In 2023, Senegal reported 7 CCHF cases, including 2 deaths (CFR of 28.6%) from 6 regions. Between 28 January and 10 March 2024, Uganda reported 7 CCHF cases, 5 of which were confirmed, and 3 deaths (CFR of 42.9%). Cases were reported from Kampala, Kiruhura, Kyankwanzi, Lyantonde and Mbarara districts.

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 February or March of 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 6 January 2022 and 13 February 2024, Liberia has reported a total of 110 confirmed Lassa fever cases, including 32 deaths (CFR of 29%). Between 1 January and 31 March 2024, Nigeria reported 5,295 suspected, 17 probable and 806 confirmed Lassa fever cases, with confirmed cases reported from 27 states. 150 deaths were reported among confirmed cases (CFR of 18.6%). This is an increase in cases and deaths when compared to the equivalent 2023 period, when 4,338 suspected, 5 probable and 846 confirmed cases, including 148 deaths among confirmed cases (CFR of 17.5%), 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
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	No confirmed or suspected human cases were reported in February or March of 2024.

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 February or March of 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 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.
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	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	On 9 February 2024, the Cambodia MoH reported a fatal case of avian influenza A(H5N1) in a 9 year old male from Kratie Province. A subsequent confirmed case of avian influenza A(H5N1) was reported on 12 February 2024, from Kratie Province. This case, who reported no respiratory symptoms, was the 16 year old brother of the case reported on 9 February 2024. Dead poultry had been reported around the cases’ home, which were then consumed. On 21 February 2024, the Cambodia MoH reported the confirmation of an additional human case of avian influenza A(H5N1), in a 17 year old female from Kampot Province. Dead poultry were reported in or around the case’s home prior to symptom onset. Including these 3 latest cases, a total of 5 human cases of avian influenza A(H5N1) have been reported in Cambodia so far in 2024, from Prey Veng (one case), Siem Reap (one case), Kratie (2 cases) and Kampot (one case) provinces. After 9 years without reporting a case of avian influenza A(H5N1), 6 human cases (including 4 deaths) were reported in Cambodia during 2023. On 25 March 2024, Vietnam’s MoH reported a confirmed fatal case of avian influenza A(H5N1) in Khanh Hoa Province, Vietnam. The case had exposure to birds prior to symptom onset. Since 2003, a total of 129 human cases of avian influenza A(H5N1), including 65 deaths, have been reported in Vietnam.

Middle East respiratory syndrome (MERS-CoV)

Geographical risk areas	The Arabian Peninsula – Yemen, Qatar, Oman, Bahrain, Kuwait, Saudi Arabia and United Arab Emirates.
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	On 16 February 2024, the WHO reported that between 13 August 2023 and 1 February 2024, 4 laboratory-confirmed cases of MERS-CoV, including 2 deaths, were reported by the Ministry of Health of the Kingdom of Saudi Arabia. The cases were confirmed between 10 October and 16 November 2023. The cases were from Riyadh, Eastern, and Qassim regions and no known epidemiological links were identified between the cases. One of the 4 cases was a camel owner, while another had a history of indirect contact with camels (family members were camel owners). There was no clear history of exposure to known risk factors for the other 2 cases. Of the cumulative total of 2,609 MERS-CoV cases and 939 deaths reported globally since 2012, 84% and 91%, respectively, have been reported from the Kingdom of Saudi Arabia.

Mpox (Clade I only)

Geographical risk areas	Central Africa including, Cameroon, Central African Republic, the Democratic Republic of the Congo, Gabon and Republic of 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
UK experience to date	No cases of Clade I mpox have been reported in the UK.
Risk rating	Very low – no known importations of Clade I mpox into the UK.
Recent cases or outbreaks	Sequencing data is often not available for mpox cases reported from endemic African countries where Clade I monkeypox virus (MPXV) is known to circulate. Therefore, we report below all reported mpox cases from these countries, regardless of whether the samples have been sequenced or clade-tested. In 2024, as of 29 March, Cameroon has reported 14 mpox cases (2 confirmed), including one death from 5 regions. Cameroon reported 140 mpox cases, including one death, in 2023. In 2024, the Central African Republic (CAR) has reported 47 suspected mpox cases (no deaths) from 11 districts, as of 24 March. In 2023, the CAR reported 67 mpox cases, including 2 deaths. In 2024, as of 24 March, the Democratic Republic of the Congo (DRC) has reported 4,538 suspected (489 confirmed) mpox cases, including 296 deaths (CFR of 6.5%), from 19 of 26 provinces. While Clade I MPXV has been confirmed in samples from a small proportion of these cases, the number that have been clade-tested nationally is unclear. Approximately 70% of suspected mpox cases reported in the DRC in 2024, are among children under 15 years of age, with 60% of confirmed cases reported in males. However, South Kivu Province, where sexual transmission has been reported, has confirmed the most cases in women aged between 20 and 40 years. During 2023, the DRC reported its highest annual number of mpox cases (14,434 cases, including 728 deaths). In the Republic of the Congo, 43 mpox cases (19 confirmed and 24 suspected (no deaths)) were reported from 5 departments in 2024, as of 24 March. During 2023, 95 mpox cases, including 5 deaths were reported.

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/negligible – no travel-related infections in the literature.
Recent cases or outbreaks	No new cases of Nipah virus infection were confirmed in February or March of 2024 (2 cases were reported in February 2024 from Bangladesh; these cases were laboratory confirmed in January 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/negligible
Recent cases or outbreaks	Ituri Province in the DRC has reported a total of 205 suspected plague cases, including 7 deaths (CFR of 3.4%) since the beginning 2024, as of 22 March. It was not stated if these cases were bubonic and/or pneumonic plague. Plague is endemic in Ituri Province. On 8 March 2024, in the USA the New Mexico Department of Health reported a fatal plague case. It was not specified if this case was bubonic or pneumonic plague. The was the first human case of plague reported in New Mexico since 2021 and the first death since 2020.

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/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 February or March of 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/negligible – travel-related cases have never been reported.
Recent cases or outbreaks	No confirmed or suspected human cases were reported in February or March of 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/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
UK experience 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 February or March of 2024.

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 1 March 2024, media reported that one case of hantavirus has been reported in the Biobío region of Chile. According to the article, this was the first case reported in the region in 2024. On 4 March 2024, the Ministry of Health of the Province of Neuquén in Argentina, reported that a case of hantavirus had been confirmed. On 6 March 2024, media reported that a fatal case of hantavirus had been confirmed in the Province of Rio Negro, Argentina. 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.
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 February or March of 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 February or March of 2024.

Question 5

Authors of this report

Accepted Answer

Emerging Infections and Zoonoses Team, UKHSA

Global high consequence infectious disease events: summary February and March 2024