Research and analysis

Outbreaks under monitoring: week 27 (week ending 5 July 2026)

Updated 16 July 2026

The following signal relates to an ongoing outbreak, with data as of 6 July 2026

Disease or pathogen	Bundibugyo virus disease (BVD)
Location	Multi-country
Status	Update
Reporting date	15 May to 6 July 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 17 May 2026, the World Health Organization (WHO) Director-General determined that the outbreak constitutes a public health emergency of international concern. As of 6 July 2026 (in French), 1,708 confirmed cases and 580 confirmed deaths have been reported in the DRC. This is an increase of 375 confirmed cases and 181 deaths since the last outbreaks under monitoring report. Confirmed cases have been reported in Ituri (1,214 cases), North Kivu (116 cases), and South Kivu (3 cases) provinces. In Uganda, as of 6 July 2026, 20 confirmed cases (including 2 deaths) have been reported. Of the confirmed cases, 15 were imported from the DRC and 5 were secondary cases among contacts. This is the 17th recorded Ebola disease outbreak in the DRC since the virus was first identified in 1976. The last reported outbreak, in Kasai Province, ended in December 2025. 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. WHO assesses the risk of this event as very high in the DRC, high for Uganda and countries with land borders adjoining countries with documented Bundibugyo virus detection, and low for the remaining countries in the African region, and globally. As of 6 July 2026, no imported cases associated with this outbreak have been reported in the UK. Previous experience from the 2014 to 2016 West Africa outbreak suggests a limited importation risk, with only one travel-related case reaching the UK outside of medical evacuations. The risk of the current 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? NaTHNaC country information page: Democratic Republic of the Congo and Uganda

Epidemiological week 27, 29 June to 5 July 2026

Disease or pathogen	Crimean-Congo haemorrhagic fever (CCHF)
Location	Afghanistan and Senegal
Status	Update
Reporting date	1 May to 21 June 2026
Summary	During May 2026, 176 new suspected cases of CCHF and 9 associated deaths were reported in Afghanistan. This represents a 15% increase in cases compared to April 2026 (153 cases and 7 deaths). This brings the total number of cases reported in Afghanistan in 2026 to 473 cases and 25 deaths. On 21 June 2026, the Africa Centres for Disease Prevention and Control reported 2 new confirmed cases of CCHF in Matam region, Senegal. A total of 6 confirmed CCHF cases have been reported in 5 regions across Senegal in 2026. Senegal reports sporadic cases of CCHF annually. During 2025, 8 cases, including one death, were reported, all from Birkelane District. CCHF is not present in the UK, nor are there any identified established populations of Hyalomma ticks, the principal vectors of CCHF virus. Confirmed CCHF cases have been imported into the UK, including one fatal case in 2012 and one in 2014.
Further information	Crimean-Congo haemorrhagic fever: origins, reservoirs, transmission and guidelines HAIRS risk assessment: Crimean-Congo haemorrhagic fever NaTHNaC country information page: Afghanistan and Senegal.

Disease or pathogen	Marburg virus disease
Location	Uganda
Status	New
Reporting date	30 June 2026
Summary	On 30 June 2026, Uganda notified the WHO of a confirmed case of Marburg virus disease (MARD) in Kyegegwa District, in the Western Region of the country. The case was originally identified through enhanced disease surveillance for Ebola.  In response, health authorities are monitoring all identified contacts; none of which have developed symptoms. Epidemiological investigations to determine the source of exposure, as well as the assessment of the public health risk, and community engagement, are ongoing.  Egyptian fruit bats (Rousettus aegyptiacus), the reservoir of Marburg virus, have historically been reported in Western Uganda in mining and cave environments. The last outbreak of MARD in Uganda was reported in Kween district in October 2017. To date, no known human MARD cases have been reported in the UK.
Further information	Marburg virus disease: origins, reservoirs, transmission and guidelines Viral haemorrhagic fever: ACDP algorithm and guidance on management of patients Marburg contact tracing (collection page) Ebola and Marburg: returning workers scheme NaTHNaC country information page: Uganda

Disease or pathogen	Mpox
Location	Norway
Status	New
Reporting date	26 June 2026
Summary	On 28 May 2026, Norway notified the WHO of one confirmed case of clade Ib mpox, in an individual who reported travel history to France. The case had been hospitalised and has since recovered. This represents Norway’s first reported case of clade Ib mpox. In response, health authorities carried out contact tracing and offered post-exposure vaccination to contacts. No additional cases have been reported. Since January 2025, up to 6 July 2026, 74 cases of clade Ib mpox have been reported in France. In the UK, cases of clade Ib and IIb mpox continue to be reported. Up to 31 May 2026, 67 clade Ib mpox cases have been reported, most of which have direct or indirect travel links to countries where clade Ib mpox is circulating.
Further information	Mpox: guidance Mpox clade Ib and clade IIb outbreak: epidemiological overview NaTHNaC country information page: Norway

Disease or pathogen	Severe fever with thrombocytopaenia syndrome (SFTS)
Location	Japan
Status	Update
Reporting date	28 June 2026
Summary	Japan’s Institute for Health Security reported 90 confirmed cases of SFTS across 28 prefectures in 2026, up to 28 June. The highest number of cases have been reported from Ehime (7 cases), Shizuoka (6 cases) and Aichi (6 cases) prefectures. During 2025, 191 cases were reported across Japan. The SFTS virus is not found in the UK, and no travel-associated cases have been reported in the UK to date.
Further information	Severe fever with thrombocytopaenia syndrome (SFTS): epidemiology, outbreaks and guidance. NaTHNaC country information page: Japan

Disease or pathogen	West Nile virus (WNV)
Location	United States
Status	New
Reporting date	1 July 2026
Summary	On 1 July 2026, the US Centers for Disease Control and Prevention (CDC) reported the earliest start to the WNV season in the US, as well as the highest number of cases reported by this time of the year since 2004. In 2026, up to 30 June, 48 human cases were reported across 12 states. 38 cases presented as the neuroinvasive form. The highest number of cases have been reported in Arizona (32 cases). Since 2004, an average of 10 human cases of WNV were reported to the US CDC by the end of June. The increase observed in 2026 has been associated with the early circulation of the virus. Additionally, as of 30 June 2026, 23 states have reported WNV activity in 2026, representing the highest recorded number in the past 10 years. No known locally acquired human WNV cases have been reported in the UK, however, there is a risk to UK residents who travel to endemic areas abroad. Between 2000 and June 2025, 7 confirmed WNV cases were recorded in UK residents, all travel associated. The probability of human infection with WNV in the general UK population is considered, at most, very low. For higher risk groups including individuals living, working or visiting areas with active human-biting mosquito vectors co-located with infected birds, the probability of infection would be considered low.
Further information	HAIRS risk assessment: West Nile virus West Nile virus: epidemiology, diagnosis and prevention Surveillance and updates for West Nile virus infection NaTHNaC country information page: United States