Research and analysis

Outbreaks under monitoring: week 38 (week ending 20 September 2026)

Updated 24 September 2026

The following signal relates to an ongoing outbreak, with data as of 21 September 2026

Disease or pathogen	Bundibugyo virus disease (BVD)
Location	Multi-country
Status	Update
Reporting date	15 May to 21 September 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 WHO Director-General determined that the outbreak constitutes a public health emergency of international concern. The outbreak in DRC remains a public health emergency of international concern as of the latest WHO Emergency Committee meeting, held on 18 August 2026. As of 21 September 2026, 7,773 confirmed cases and 3,759 confirmed deaths have been reported in the DRC. This is an increase of 515 confirmed cases and 249 deaths since the last Outbreaks Under Monitoring report. Cases have been reported in 63 health zones across 7 provinces (Ituri, North Kivu, South Kivu, South-Ubangi, Haut-Uele, Bas-Uele and Tshopo). Although most cases have been reported in Ituri (5,966 cases, including 2,737 deaths), a decrease in the number of newly reported cases has been observed since August 2026, while an increase has been reported in North Kivu (1,438 cases, including 872 deaths). This has become the largest recorded BVD outbreak and is the second largest Ebola disease outbreak to date. On 27 August 2026, WHO and the Africa Centres for Disease Control and Prevention declared the end of the outbreak in Uganda following no new cases since the last case was discharged from care on 16 July 2026. A total of 20 confirmed cases (including 2 deaths) were reported in Uganda. Of the confirmed cases, 15 were imported from the DRC and five 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 countries with land borders adjoining the DRC, and low for the remaining countries in the African region, and globally. As of 21 September 2026, no imported cases associated with this outbreak have been reported in the UK. Previous experience from the 2014–2016 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 38, 14 to 20 September 2026

Disease or pathogen	Avian influenza A(H5N1)
Location	Bangladesh
Status	Update
Reporting date	30 August 2026
Summary	On 30 August 2026, health authorities in Bangladesh notified WHO of a laboratory confirmed human case of avian influenza A(H5N1) infection in Rangpur division. The case is a child who experienced symptom onset on 15 August 2026 and was hospitalised on 17 August 2026. A nasopharyngeal swab and throat swab collected from the case tested positive for avian influenza A(H5N1). The case is reported to be improving clinically. In response, health authorities carried out investigations into the source of exposure. The case had no travel history outside of their area of residence but had exposure to ducks and chickens, including some that were ill, within the household and those adjacent. However, several backyard poultry tested negative for influenza A(H5). Close contacts were monitored and all remained asymptomatic, except for 2 healthcare workers who both tested negative for influenza A viruses. This is the fourth reported human case of avian influenza A(H5) in Bangladesh in 2026. In 2025, 4 cases were reported.
Further information	Avian influenza: managing human exposures to incidents in birds or animals NaTHNaC country information page: Bangladesh

Disease or pathogen	Crimean-Congo haemorrhagic fever (CCHF)
Location	Iran
Status	Update
Reporting date	16 September 2026
Summary	On 16 September 2026, media (in Persian) reported 31 cases of CCHF in Iran. According to the article, Yazd, Sistan, Baluchestan and Kerman provinces have reported the highest number of cases. Another article (in Persian) reports 11 cases in Yazd in 2026. Human cases of CCHF are reported annually in Iran. 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 rarely 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: Iran

Disease or pathogen	Malaria
Location	Germany
Status	New
Reporting date	18 September 2026
Summary	According to the European Centre for Disease Prevention and Control (ECDC), as of 18 September 2026, 8 cases of Plasmodium falciparum malaria, including 3 deaths, have been reported among 6 airport workers and 2 people living near Frankfurt International airport in 2026. These individuals experienced symptom onset between early July and early September and reported no travel to malaria-endemic areas. In response, German public health authorities are carrying out epidemiological investigations, including mosquito monitoring, to identify the likely source of infection. The cases are consistent with airport-associated malaria, which occurs sporadically when infectious Anopheles mosquitoes are inadvertently transported by aircraft from a malaria-endemic country. Airport malaria is uncommon, but it has been reported sporadically in Europe, cases may occur individually or in clusters, with clusters of up to six cases previously reported. ECDC assesses the risk of this event as very low. There is currently no evidence of local malaria transmission in the UK. Cases reported in the UK have been related to travel abroad.
Further information	Malaria: guidance, data and analysis Malaria prevention guidelines for travellers from the UK 2026 NaTHNaC country information page: Germany

Disease or pathogen	Mpox
Location	Multi-country
Status	New
Reporting date	August 2026
Summary	According to ECDC, 209 new cases of clade I mpox were reported across 16 countries in the European Union/European Economic Area in August 2026. This is a decrease from the 276 cases reported in July 2026. The highest numbers of new cases were reported from Germany (56 cases), Portugal (39 cases) and Spain (38 cases). Additionally, during this period, clade I mpox was reported from Estonia, Iceland and Malta for the first time. On 28 August 2026, the Korea Disease Control and Prevention Agency reported the first detection of clade Ib mpox in South Korea. The case reported exposure through sexual contact and was initially identified in June 2026. In the UK, cases of clade Ib and IIb mpox continue to be reported. Up to 31 August 2026, 168 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: Estonia, Germany, Iceland, Malta, Portugal, South Korea, Spain.

Disease or pathogen	Severe fever with thrombocytopaenia syndrome
Location	Thailand
Status	New
Reporting date	16 September 2026
Summary	On 16 September 2026, Thailand’s Department of Disease Control (in Thai) reported 10 cases of SFTS, and 5 deaths in Thailand between 2019 and 2026. According to media (in Thai), 3 cases, including 2 deaths, have been reported in 2026. Most cases were aged 50 years old or above and had a history of raising animals, including household pets. The first human case of SFTS in Thailand was detected in 2019. 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: Thailand