Research and analysis

Global high consequence infectious disease events: summary April to October 2022

Updated 28 March 2024

Interpreting this report

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

It 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.

Likelihood assessment

Included for each disease is a ‘likelihood assessment’ – the likelihood of a case occurring in the UK – based on past UK experience and the global occurrence of travel-associated cases. Currently, all diseases are classified in one of three categories: Low, Very low and Exceptionally low.

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.

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 Asia. Spain has also reported locally acquired cases (first reported in 2016) (HAIRS risk assessment).
Sources and routes of infection	• bite from or crushing of an infected tick • contact with blood or tissues from infected livestock • contact with infected patients, their blood or body fluids
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
Likelihood assessment	Low – rarely reported in travellers.
Recent cases or outbreaks	As of 29 October, Afghanistan has reported 103 confirmed and 264 suspected CCHF cases during 2022. There have been 15 associated deaths. The media reported a case of CCHF in Chernoochene, Bulgaria, in July. In July, an individual tested positive for CCHF in Côte d’Ivoire, following consumption of meat from a sick ox. The media has reported 45 cases of CCHF in Georgia, including 3 deaths, as of August 2022. The media reported a fatal case of CCHF in the state of Gujarat, India in April, which is the second case reported in the state during 2022. The media reported 63 cases of CCHF in Iran, including 5 deaths, as of August 2022. Iraq has reported a higher number of CCHF cases in 2022, compared to previous years. As of 7 August, 287 confirmed cases were reported by the World Health Organization (WHO), although media sources report 299 confirmed cases. In 2021, 33 confirmed cases were reported. The media has reported 33 cases of CCHF and 4 associated deaths in Kazakhstan during 2022 from Kyzylorda and one additional case in Turkestan. Mauritania reported an outbreak of CCHF in February 2022 in Hodh El Gharbi Region. As of 27 April, 7 cases had been reported, including 2 deaths. Additionally, 3 cases were reported between 29 August and 31 October, bringing the total number of cases identified in 2022 to 10. Media sources have reported several cases of CCHF in Pakistan during 2022, including 9 cases in Balochistan; a fatal case and several suspected cases in Khyber Pakhtunkhwa; and 4 suspected cases (including one death) in Punjab. In 2021, 28 confirmed cases of CCHF were reported from Pakistan. The media has reported several cases of CCHF in Russia during 2022, including 24 cases in Rostov, 11 cases in Stavropol, 3 cases in Kalmykia and 2 cases in Volgograd. On 12 August, Senegal confirmed an outbreak of CCHF in Podor District, Saint-Louis region. The index case had a history of recent travel to Mauritania. As of 28 August, 5 cases and 2 deaths were reported. In July 2022, Spain confirmed 2 cases of CCHF in Bierzo, León Province, one of which was fatal. One case of CCHF had previously been reported in León Province in 2021. South Africa has reported 3 cases of CCHF so far in 2022, as of the end of October. Of these cases, 2 were in Western Cape Province and one in Eastern Cape Province. A total of 221 confirmed CCHF cases have been confirmed in South Africa since 1981. The media has reported several cases of CCHF in Turkey during 2022, including 12 cases in Sivas, 8 cases in Erzincan, 4 cases in Tokat, 2 fatal cases in Yozgat, a fatal case in Bingöl and a suspected case in Malatya. Uganda reported 5 confirmed cases of CCHF, including one death, between 12 July and 15 October 2022.

Ebola virus disease (EVD)

Geographical risk areas	Map of countries which have reported EVD cases.
Sources and routes of infection	• contact with or consumption of infected animal tissue (such as bushmeat) • contact with infected human blood or body fluids
UK experience to date	Four confirmed cases (1 lab-acquired in the UK in 1976, 3 healthcare workers associated with West African epidemic 2014 to 2015).
Likelihood assessment	Very low – other than during the West Africa outbreak, exported cases are extremely rare.
Recent cases or outbreaks	On 23 April 2022, the Democratic Republic of the Congo’s (DRC) Ministry of Health (MoH) announced a new outbreak of EVD caused by Zaire ebolavirus, in Mbandaka, Equateur Province. The outbreak was declared over on 4 July 2022, 42 days after the burial of the last confirmed case. During the outbreak, a total of 4 confirmed (4 deaths) and 1 probable (1 death) cases were reported. On 21 August 2022, DRC’s MoH declared an outbreak of EVD caused by Zaire ebolavirus, in Beni health zone, North Kivu Province. On 27 September 2022, the outbreak was declared over, which resulted in one confirmed, fatal case. On 20 September 2022, Uganda MoH declared an outbreak of EVD caused by Sudan ebolavirus, in Mubende District, Central Region. As of 31 October 2022, a total of 130 confirmed (43 deaths) and 21 probable cases (21 deaths) have been reported from 7 districts in Central and Western regions.

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	3 travel-related cases reported in 2022. Prior to this, 13 imported cases had been reported since 1971, all in travellers from West Africa.
Likelihood assessment	Low – overall, Lassa fever is the most common imported viral haemorrhagic fever (VHF) but is still rare.
Recent cases or outbreaks	In April 2022, the Ministry of Health and Public Hygiene of Guinea declared a Lassa fever outbreak in Guéckédou Prefecture. A total of 2 confirmed cases were reported in this outbreak. An additional outbreak of Lassa fever was detected in Guinea in September 2022, in Conakry and Kindia prefectures. A total of 18 confirmed cases, one probable case and 2 deaths were reported. In late September 2022, a single case of Lassa fever was confirmed in Nzérékoré Prefecture, which was not known to be epidemiologically linked to the previous cases, with no further cases identified. In 2022, as of 23 October 2022, a total of 156 cases of Lassa fever, including 52 confirmed cases and 17 deaths among confirmed cases (case fatality rate of 33%), have been reported in Liberia. In 2021, 112 suspected and 24 confirmed cases (15 deaths) were reported as of 21 November. In Nigeria, there have been 7,183 suspected and 958 confirmed cases of Lassa fever reported between 1 January and 30 October 2022. A total of 176 deaths have been reported amongst confirmed cases (case fatality rate of 18.4%). This is an increase in the number of reported cases when compared to the same period in 2021 (3,495 suspected, 403 confirmed cases and 89 deaths amongst confirmed cases, with a case fatality rate of 22.1%). Enhanced surveillance across the country has improved case detection. In April 2022, one imported case of Lassa fever was reported in South Africa, in an individual with recent travel history to Nigeria. No further cases were identified.

Marburg virus disease

Geographical risk areas	Sporadic outbreaks have previously been reported in Central and Eastern Africa. A human case was reported in August 2021 in Guinea; this was the first case to be identified in West Africa. Cases were reported in Ghana for the first time in July 2022.
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 known cases in the UK .
Likelihood assessment	Very low – globally, 5 travel-related cases have previously been reported in the literature.
Recent cases or outbreaks	In July 2022, Ghana reported an outbreak of Marburg virus disease. A total of 3 confirmed cases (2 deaths) were reported, all of which were epidemiologically linked. The outbreak was declared over on 16 September 2022, and was the first time that cases of Marburg virus disease had been identified in Ghana.

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.
Likelihood assessment	Very low (UKHSA risk assessment).
Recent cases or outbreaks	No confirmed or suspected human cases were reported between April and October 2022.

Avian influenza A(H5N1) virus

Geographical risk areas	Human cases predominantly in South East Asia, but also Egypt, Iraq, Pakistan, Turkey and Nigeria. Human cases were reported for the first time in Spain, the UK and the US in 2022.
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	One case reported in 2022.
Likelihood assessment	Very low (UKHSA risk assessment).
Recent cases or outbreaks	In April 2022, a human case of avian influenza A(H5N1) was reported in Colorado, US. The case had been involved in culling A(H5N1) infected poultry at a farm. The patient recovered and did not require hospitalisation. This is the first human case of A(H5N1) to be reported in the US. Spain reported 2 human cases of avian influenza A(H5N1), who were poultry workers on a farm in Guadalajara where A(H5N1) infection had been confirmed in poultry. The first case tested positive in September 2022 and the second case tested positive in October. Neither case experienced any symptoms and there was no evidence of human-to-human transmission. Both cases were likely infected through exposure to infected poultry or contaminated environments.

Middle East respiratory syndrome (MERS)

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
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.
Likelihood assessment	Very low (UKHSA risk assessment).
Recent cases or outbreaks	Between 29 December 2021 and 31 October 2022, 4 MERS-CoV cases were reported in Saudi Arabia: 2 cases in Riyadh (with symptom onset in December 2021 and June 2022), 1 case in Gassim (with symptom onset in March 2022) and 1 case in Makka Al Mukarramah (with symptom onset in April 2022). In Oman, one MERS-CoV case was reported in April 2022, from Al Dhahira Governorate. This was the first case to be reported from Oman since February 2019. Between 22 March and 3 April 2022, 2 MERS-CoV cases were reported in Doha, Qatar. Overall, 6 of the 7 MERS-CoV cases reported contact with camels; exposure history was reported as unknown for one case from Saudi Arabia.

Mpox (monkeypox) virus (clades I, IIa and IIb non-B.1 lineages only)

Geographical risk areas	West and Central Africa.
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
UK experience to date	Between 2018 and 2021, 7 cases of mpox were identified in the UK: 4 were cases imported from Nigeria, 2 were cases in household contacts and 1 was a case in a healthcare worker involved in the care of an imported case. Since May 2022, mpox cases with no recent travel to endemic countries have been reported in the UK, as part of the global mpox outbreak in non-endemic countries. In June 2022, the mpox virus strain associated with this outbreak (which falls within Clade IIb), was declassified as a HCID following review by the Advisory Committee on Dangerous Pathogens (ACDP) and agreement by the UK 4 nations public health agencies (see HCID status of mpox). See UKHSA mpox outbreak: epidemiological overview and WHO Emergency situation reports for further information about the outbreak. In the UK, 8 cases infected with non-B.1 lineages of mpox virus have been identified by genomic sequencing since the start of the global mpox outbreak in non-endemic countries.
Likelihood assessment	Very low – before the start of the global mpox outbreak in 2022, there were 8 recorded importations of mpox in non-endemic countries. These cases were in travellers to Israel (one case), Singapore (one case), the US (2 cases) and the UK (4 cases).
Recent cases or outbreaks	Mpox cases have been reported from several endemic countries during 2022 (all data as of 26 October 2022): Cameroon has reported 9 confirmed cases, 35 suspected cases and 2 deaths. The Central African Republic has reported 8 confirmed cases, 17 suspected cases and 2 deaths. The DRC has reported 184 confirmed cases, 4,068 suspected cases and 154 deaths. Ghana has reported 105 confirmed cases, 535 suspected cases and 4 deaths. Liberia has reported 3 confirmed cases, 48 suspected cases and no deaths. Nigeria has reported 552 confirmed cases, 1,272 suspected cases and 7 deaths. The Republic of the Congo has reported 5 confirmed cases, 14 suspected cases and 3 deaths.

Nipah virus

Geographical risk areas	South East Asia. Recent outbreaks in Bangladesh and India.
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.
Likelihood assessment	Exceptionally low – no travel-related infections in the literature.
Recent cases or outbreaks	No confirmed or suspected human cases were reported between April and October 2022.

Pneumonic plague (Yersinia pestis)

Geographical risk areas	Predominantly sub-Saharan Africa but also Asia, North Africa, South America, Western US.
Sources and routes of infection	• flea bites • close contact with infected animals • contact with human cases of pneumonic plague
UK experience to date	Last outbreak in the UK was in 1918.
Likelihood assessment	Exceptionally low – no travel-related infections in the literature.
Recent cases or outbreaks	In October 2022, the media reported 2 cases of pneumonic plague in Tibet, China. Both cases died in September, with one additional suspected case reported. In July 2022, the media reported a bubonic plague case from Ningxia Hui Autonomous Region. In 2021, one non-fatal case of human plague occurred in China. In July 2022, the media reported the confirmation of one bubonic plague case in Mongolia in the Must District, Western Khovd Province. Cases of pneumonic plague have not been reported from the DRC during the reporting period (April to October 2022). However, in 2022, up to 9 October, 615 suspected cases of bubonic plague have been identified, including 10 deaths (case fatality rate of 1.6%). All cases have been reported from the Rethy Health Zone in Ituri Province. During 2021, a total of 138 suspected cases, including 14 deaths (case fatality rate of 10.1%) were reported.

Severe acute respiratory syndrome (SARS)

Geographical risk areas	Currently none. Two 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 cases related to 2002 outbreak.
Likelihood assessment	Exceptionally low – not reported since 2004.
Recent cases or outbreaks	No confirmed or suspected human cases reported 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.
Likelihood assessment	Exceptionally low – one travel-related case was identified in Belgium in 2020.
Recent cases or outbreaks	Argentina has reported a total of 50 confirmed cases and 7 deaths from Argentine haemorrhagic fever in 2022, including: 27 confirmed cases in the province of Buenos Aires (as of 25 October), 18 in the province of Santa Fe (as of 11 September), 4 in the province of Córdoba (as of 11 September) and 1 in the city of Buenos Aires (as of 11 September).

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.
Likelihood assessment	Exceptionally low – travel-related cases have never been reported.
Recent cases or outbreaks	No confirmed or suspected human cases were reported between April and October 2022.

Lujo virus disease

Geographical risk areas	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.
Likelihood assessment	Exceptionally low – 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. First ever cases reported in Vietnam and Taiwan in 2019. 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.
Likelihood assessment	Exceptionally low – not known to have occurred in travellers.
Recent cases or outbreaks	In May 2022, the media reported that 5 cases of SFTS, including 4 deaths, were identified in Xinyang, Henan Province, China. In Japan, a total of 76 SFTS cases have been reported in 2022, as of 31 July. In South Korea, a total of 183 SFTS cases, including 32 deaths (case fatality rate of 17.5%) have been reported in 2022, as of 29 October.

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.
Likelihood assessment	Very low – rare cases in travellers have been reported.
Recent cases or outbreaks	As of 28 August, 38 hantavirus cases and 6 deaths were identified in Argentina during 2022. The type of hantavirus is not reported for nearly all cases. The confirmed cases include an individual in Chubut who developed symptoms in August 2022 and was a household contact of a previous fatal case that occurred in July 2022. Whole genome sequencing confirmed Andes virus in both cases. It is considered highly probable that human-to-human transmission occurred between the 2 cases. As of 16 October, 23 confirmed hantavirus cases and 5 deaths were reported in Chile during 2022. The type of hantavirus is not reported. In total, 37 hantavirus cases were reported in Chile during 2021.

Avian influenza A(H5N6) virus

Geographical risk areas	Mostly China. New strain 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.
Likelihood assessment	Very low – not known to have occurred in travellers (UKHSA risk assessment).
Recent cases or outbreaks	Between April and October 2022, 7 cases of avian influenza A(H5N6) were reported in mainland China, bringing the total number of human cases reported so far in 2022 to 24. One case each was reported from Henan, Jiangsu, Sichuan and Jiangxi, while 3 cases occurred in Guangxi (in April, July and September). Since 2014, 81 human cases have been reported in mainland China.

Avian influenza A(H7N7) virus

Geographical risk areas	Sporadic occurrence in birds across 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 of conjunctivitis associated with H7N7 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)
UK experience to date	No known cases.
Likelihood assessment	Very low – human cases are rare, and severe disease even rarer.
Recent cases or outbreaks	No confirmed or suspected human cases were reported between April and October 2022.