Research and analysis

Outbreaks under monitoring: week 5 (week ending 1 February 2026)

Updated 5 February 2026

Disease or pathogen	Mpox (clade Ib)
Location	Comoros and Madagascar
Status	Update
Reporting date	17 December 2025 to 1 February 2026
Summary	On 31 December 2025, health authorities in Madagascar declared an outbreak of mpox (in Malagasy) following the country’s first detection on 17 December 2025. Clade Ib mpox infection was confirmed amongst cases by Institut Pasteur de Madagascar on 13 January 2026. As of 1 February 2026, 410 mpox cases (including 229 confirmed) have been reported across 23 regions, with most confirmed cases reported in Boeny (167 cases). Since the last outbreaks under monitoring report (week 4 of 2026), there has been an increase of 47 confirmed mpox cases in Madagascar. On 23 January 2026, the first mpox cases were reported in the Comoros in individuals with travel histories to Madagascar.  According to the Africa Centres for Disease Control and Prevention, as of 26 January 2025 9 confirmed mpox cases have been reported, with clade Ib mpox confirmed amongst these cases. In the UK, clade Ib and clade IIb mpox cases have been reported. Up to 31 December 2025, 21 clade Ib mpox cases have been reported. Most of the cases reported 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: Comoros and Madagascar

Disease or pathogen	Marburg disease
Location	Ethiopia
Status	Update
Reporting date	12 November 2025 – 26 January 2026
Summary	On 26 January 2026, Ethiopia’s Ministry of Health  declared an end to the Marburg virus disease (MARD) outbreak following two consecutive incubation periods (42 days) since the last confirmed fatal case was reported. A total of 19 cases were reported (5 probable and 14 confirmed cases), including 14 deaths (5 probable and 9 confirmed deaths). Cases were reported from Jinka, Malle and Dassenech districts in South Ethiopia Region, and Hawassa in Sidama Region. 857 contacts were identified and followed up. In response to the outbreak, public health measures were implemented at national and regional levels. In addition, WHO, through its country office and partners, provided technical, operational and financial support to the government to contain this outbreak. Genomic analysis suggests that the Marburg virus detected in this outbreak was the same strain as the virus reported in previous outbreaks in East African countries. Whilst the source of the outbreak was not identified, investigations confirmed the presence of fruit bats (a reservoir of Marburg virus) in the affected area. No known human Marburg cases have been reported in the UK. The risk of the outbreak to the UK public was assessed as very low.
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) - Ebola and Marburg: returning workers scheme - NaTHNaC country information page: Ethiopia