Research and analysis

Outbreaks under monitoring: week 31 (week ending 2 August 2026)

Updated 6 August 2026

The following signal relates to an ongoing outbreak, with data as of 3 August 2026

Disease or pathogen	Bundibugyo virus disease (BVD)
Location	Multi-country
Status	Update
Reporting date	15 May to 2 August 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 3 August 2026 (in French), 3,874 confirmed cases and 1,751 confirmed deaths have been reported in the DRC. This is an increase of 514 confirmed cases and 264 deaths since the last Outbreaks Under Monitoring report. Confirmed cases have been reported in Ituri (3,375 cases), North Kivu (426 cases), Haut-Uele (63 cases), Tshopo (7 cases) and South Kivu (3 cases) provinces. On 16 July 2026, Uganda began a 42-day countdown to declaring its outbreak over, after health authorities discharged the last recovered patient. A total of 20 confirmed cases (including 2 deaths) have been reported in Uganda. The last case was reported on 21 June 2026. 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 continues to assess the risk of this event as very high in the DRC, high for Uganda due to cross-border transmission through imported cases and ongoing epidemiological links to the DRC, high for 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 3 August 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 31, 27 July to 2 August 2026

Disease or pathogen	Crimean-Congo haemorrhagic fever (CCHF)
Location	Spain
Status	Update
Reporting date	29 July 2026
Summary	On 29 July 2026, the Government of Castilla-La Mancha (in Spanish), Spain, reported a confirmed case of CCHF in a 46-year-old male. The case was detected in Puertollano, Ciudad Real Province, and has been transferred to the High-Risk Infectious Diseases unit at the Gomez Ulla Central Military hospital in Madrid. The source of exposure has not been reported, however, health authorities emphasised that transmission of CCHF is via Hyalomma tick bites. This is the third reported case of CCHF in Spain in 2026. Prior to this case, 2 cases were reported in Salamanca, of which one was fatal (in Spanish). Human cases of CCHF have been reported in Salamanca (in Spanish) and Castilla-La Mancha previously. 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: Spain

Disease or pathogen	Mpox
Location	Costa Rica and Ghana
Status	New
Reporting date	31 July 2026
Summary	On 31 July 2026, the World Health Organization (WHO) reported the first 2 confirmed cases of clade Ib mpox in Costa Rica. The source of exposure is unclear, and it is not known whether the cases were travel-associated or locally acquired. Clade II mpox has been reported in Costa Rica since 2022. In addition, WHO also reported the first confirmed case of clade Ib mpox in Ghana. The case was identified in an adult male who had travelled from the DRC where there is ongoing clade Ib mpox transmission. There have been no reports of onwards transmission associated with this case. Clade II mpox has been reported in Ghana since 2022. In the UK, cases of clade Ib and IIb mpox continue to be reported. Up to 30 June 2026, 100 clade Ib mpox cases have been reported, most of which had 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: Costa Rica and Ghana

Disease or pathogen	Severe fever with thrombocytopaenia syndrome (SFTS)
Location	China
Status	New
Reporting date	May 2026
Summary	On 23 July 2026, China’s Center for Disease Control and Prevention reported 900 cases of SFTS, including 33 deaths, during May 2026.  To compare, this is an increase in the number of newly reported monthly cases when compared to April 2026 (572 cases, including 21 deaths). SFTS is widely distributed across China, with clusters typically occurring in Henan, Hubei, Shandong, Anhui, Liaoning, Jiangsu and Zhejiang provinces. Cases are reported all year round but peak between May and July. 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: China