Research and analysis

Outbreaks under monitoring: week 22 (week ending 31 May 2026)

Updated 4 June 2026

The following relates to an ongoing outbreak, with data current to 2 June 2026

Disease or pathogen	Bundibugyo virus disease (BVD)
Location	Multi-country
Status	Update
Reporting date	15 May to 2 June 2026
Summary	On 15 May 2026, an outbreak of Ebola disease caused by Bundibugyo virus was declared in the Democratic Republic of the Congo (DRC) and Uganda. On 16 May 2026, the World Health Organisation (WHO) Director-General determined that the outbreak constitutes a public health emergency of international concern. As of 2 June 2026, 363 confirmed cases and 62 deaths have been reported in the DRC. This is an increase of 242 confirmed cases and 45 deaths since the last outbreaks under monitoring report. Confirmed cases have been reported in Ituri (341 cases), North Kivu (19 cases), and South Kivu (3 cases) provinces. In Uganda, as of 2 June 2026, 15 confirmed cases (including one death) have been reported. This is an increase of 8 confirmed cases since the last outbreaks under monitoring report. According to the Africa Centres for Disease Control and Prevention, 5 of the 15 cases are in health care workers. This represents the 17th recorded outbreak of Ebola disease in the DRC since the virus was first identified in 1976, with the last reported outbreak ending in December 2025 in Kasai Province. Bundibugyo virus was first identified in 2007 in Bundibugyo district, western Uganda. A second outbreak caused by Bundibugyo virus was reported in DRC in 2012. As of 2 June 2026, no imported cases associated with this outbreak have been reported in the UK. Previously in 2015, an imported case of Ebola virus disease was reported in the UK associated with the 2014 to 2016 West Africa outbreak. The WHO assesses the risk of this event as low at a global level, high at the regional level and very high at a national level. The risk of the current Ebola outbreak to the UK population is assessed as low.
Further information	Ebola: overview, history, origins and transmission Ebola virus disease: clinical management and guidance Ebola and Marburg haemorrhagic fevers: outbreaks and case locations UKHSA blog:  What is Ebola and how does it spread? Algorithm for the management of samples suspected of Ebola Virus Disease (in Spanish) NaTHNaC country information page: Democratic Republic of the Congo and Uganda

Disease or pathogen	Andes virus
Location	Multi-country
Status	Update
Reporting date	2 June 2026
Summary	On 2 May 2026, WHO was notified of a cluster of severe respiratory illness aboard a cruise ship carrying 147 passengers and crew from various countries. The cruise ship departed from Ushuaia, Argentina, on 1 April 2026, and travelled across the South Atlantic. On 2 May 2026, laboratory testing of samples taken from a case confirmed hantavirus infection. Further testing of samples from cases confirmed Andes virus infection. As of 2 June 2026, 13 cases (11 confirmed and 2 probable), including 3 deaths (2 confirmed and one probable) have been reported. No new cases have been reported since 27 May 2026. WHO currently assesses the risk of this event to the global population to be low. There is very low risk of hantavirus in the UK. Seoul hantavirus is the only species to have been identified in the UK and does not spread between people. It is possible that rare, travel-associated Andes virus infections may be seen in the UK in individuals returning from places where Andes virus is considered endemic, although none have been reported to date.
Further information	Andes hantavirus: epidemiology, outbreaks and guidance Hantaviruses: characteristics, diagnosis and epidemiology HAIRS risk assessment: hantavirus UKHSA blog: What is hantavirus? How is it transmitted and what are the symptoms? NaTHNaC Hantavirus and Hantavirus cruise ship outbreak NaTHNaC country information page: Argentina, Chile and Uruguay