Research and analysis

Global high consequence infectious disease events: summary September to October 2020

Updated 25 April 2024

This report was published on Monday 30 November 2020.

Interpreting this report

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

It is divided into 2 sections covering all the defined HCID pathogens. The first 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. There are currently 3 categories: Low, Very Low and Exceptionally Low. This assessment is as of January 2019.

When considering clinical history, it is important to remember that cases can and do occur outside of the usual distribution area. It is not possible to assess accurately the risk of cases presenting to healthcare providers in England, but taken together it is inevitable that occasional imported cases will be seen.

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 Central and Eastern Europe, Central Asia, the Middle East, East and West Africa. First locally acquired case in Spain 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 confirmed cases (ex-Afghanistan 2012, ex-Bulgaria 2014).
Likelihood assessment	Low – rarely reported in travellers (23 cases in world literature).
Recent cases or outbreaks	India retrospectively reported 1 case for March 2020 in September, bringing the overall number of cases for 2020 to 4 with 1 death, significantly lower number than the 35 cases and 17 deaths reported in 2019. (India’s Integrated Disease Surveillance Programme week 28 2020 report). It is unclear at this stage if COVID-19 response activities affected CCHF surveillance and reporting and thus the incidence reported so far this year. Pakistan authorities reported 1 confirmed fatal case in a butcher in September and the media reported 1 suspected case in October.

Ebola virus disease

Geographical risk areas	Sporadic outbreaks in Western, Central and Eastern Africa.
Sources and routes of infection	• contact 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 HCWs 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	DRC - outbreak in Equateur province As of 31 October 130 cases (119 confirmed and 11 probable) including 55 deaths (CFR 42.3%) have been reported distributed over 13 health zones in Equateur province, DRC since 1 June 2020. The last confirmed case was reported on 28 September 2020. Two probable cases were retrospectively validated on October 24, 2020, both had died between July and August 2020. If no further new cases are reported, this outbreak may be declared over by 18 November 2020. There is an ongoing risk of new cases being reported as contacts of previous cases are still lost to follow up, the outcome for known confirmed cases in the community is indeterminate and safe and dignified burials continue to be a challenge. Surveillance, vaccination, communication, and infection prevention and control activities are still ongoing.

Lassa fever

Geographical risk areas	Endemic in sub-Saharan West Africa
Sources and routes of infection	• contact with excreta, or materials contaminated with excreta of infected rodent • inhalation of aerosols of excreta of infected rodent • contact with infected human blood or body fluids
UK experience to date	Fourteen cases since 1971, all ex-West Africa.
Likelihood assessment	Low – Overall it’s the most common imported viral haemorrhagic fever (VHF) but still rare (global total 35 reported since 1969).
Recent cases or outbreaks	Nigeria: in September and October the total number of confirmed cases did not increase significantly compared to August, with 24 and 21 cases respectively, mostly reported in Ondo and Edo States. The current incidence is in line with what is expected at this time of the year. The total number of confirmed cases for 2020 by 25 of October was 1,119. This is significantly higher than the 743 recorded for the same period in 2019, reflecting a higher-than-expected incidence during the seasonal transmission period in the first 3 months of the year. The reasons for this increase are unknown.

Marburg virus disease

Geographical risk areas	Sporadic outbreaks in Central and Eastern Africa
Sources and routes of infection	Contact with infected blood or body fluids
UK experience to date	No known cases in the UK.
Likelihood assessment	Very Low – 5 travel-related cases in the world literature.
Recent cases or outbreaks	No cases reported since November 2017.

Airborne HCIDs

Influenza A(H7N9) virus

Geographical risk areas	All human infections 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 (PHE Risk Assessment).
Recent cases or outbreaks	No confirmed or suspected human cases of H7N9 were reported in September and October.

Influenza A(H5N1) virus

Geographical risk areas	Human cases predominantly in South East Asia, but also Egypt, Iraq, Pakistan, Turkey, Nigeria. Highly pathogenic H5N1 in birds much more widespread, including UK.
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 (PHE Risk Assessment).
Recent cases or outbreaks	No confirmed or suspected human cases of H5N1 were reported in September and October.

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 second case, 3 deaths.
Likelihood assessment	Very Low (PHE Risk Assessment).
Recent cases or outbreaks	No new cases were reported in September or October and the 2020 total remains unchanged with 57 in Saudi Arabia (including 20 deaths), 2 in the United Arab Emirates and 1 in Qatar. It has been more than 150 days since the last case was reported in Saudi Arabia.

Monkeypox virus

Geographical risk areas	West and Central Africa.
Sources and routes of infection	• close contact with infected animal or human • indirect contact with contaminated material, such as bed linen
UK experience to date	Three cases in total – 2 imported (both September 2018) and 1 nosocomial transmission.
Likelihood assessment	Very Low – reported outside Africa for the first time in 2018 (2 in the UK and 1 in Israel).
Recent cases or outbreaks	Democratic Republic of Congo reported, from January to 4 October 2020 (latest data point), a total of 6,231 suspected cases of monkeypox with 203 deaths. This represents a significant increase in both cases and fatalities in the same time period in 2019 (3,580 cases and 64 deaths). Cases this year are widely distributed across 127 health zones from 17 out of 26 provinces. The reason for the increased case fatality rate is still unknown at this stage. Nigeria reported 1 confirmed case of monkey pox in the last week of September bringing the total number of confirmed cases for 2020 to 5 with no deaths, compared to 39 confirmed cases and 2 deaths (CFR 2.4%) in 2019.

Nipah virus

Geographical risk areas	Outbreaks in Bangladesh and India. South East Asia at risk.
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 cases reported in September and October.

Pneumonic plague (Yersinia pestis)

Geographical risk areas	Predominantly sub-Saharan Africa but also Asia, North Africa, South America, Western USA.
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	Democratic Republic of Congo’s Ituri province continues to report an increase in plague cases in a single health zone. Since the beginning of 2020 to 9 August (last update available), Ituri Province has reported a total of 124 cases and 17 deaths (CFR 18.7%) in 5 health zones. For 2019 (full year), 48 cases of bubonic plague including 8 deaths have been reported.

Severe acute respiratory syndrome (SARS)

Geographical risk areas	Currently none. Two outbreaks originating from China 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). Limited to the provinces of Buenos Aires, Cordoba, Santa Fe, Entre Rios 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 – travel-related cases have never been reported.
Recent cases or outbreaks	No confirmed or suspected cases were reported in September and October.

Bolivian haemorrhagic fever (Machupo virus)

Geographical risk areas	Bolivia – limited to the Department of Beni, municipalities of the provinces Iténez (Magdalena, Baures and Huacaraje) and Mamoré (Puerto Siles, San Joaquín and San Ramón).
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 cases were reported in September and October.

Lujo virus disease

Geographical risk areas	Single case acquired in Zambia lead 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 – not 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.
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	No cases were reported in September or October (consistent with previous years). Note: although Chinese authorities do not provide publicly available data on cases of SFTS, in July 2020, 37 cases were reported by the media as having occurred since April.

Andes virus (Hantavirus)

Geographical risk areas	Chile and southern Argentina.
Sources and routes of infection	• rodent contact (excreta, or materials contaminated with excreta of 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	No confirmed or suspected cases were reported in September or October. Argentina reported 1 case of hantavirus in October. Although investigations are still ongoing, it seems highly unlikely to be a case of Andes virus.

Influenza A(H5N6) virus

Geographical risk areas	Mostly China. New strain in Greece in March 2017, and subsequently found in Western Europe.
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 (PHE risk assessment).
Recent cases or outbreaks	No confirmed or suspected human cases of H5N6 were reported in September or October.

Influenza A(H7N7) virus

Geographical risk areas	Sporadic occurrence including Europe and the UK.
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 of H7N7 were reported in September or October.