Research and analysis
Outbreaks under monitoring: week 44 (week ending 2 November 2025)
Updated 31 December 2025
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| Disease or pathogen | Chikungunya |
|---|---|
| Location | France |
| Status | Situation update |
| Reporting date | 22 to 29 October 2025 |
| Summary | In France, have been reported between 1 May and 27 October 2025. This is an increase of 13 cases since the last report on . The number of locally acquired cases recorded in 2025 is the highest since 2010. For the first time ever, locally acquired cases were reported in the departments of Grand Est, Bourgogne-Franche-Comte, Centre-Val de Loire and Nouvelle-Aquitaine. The World Health Organization (WHO) states that the increased incidence in 2025 is in Reunion and the broader Indian Ocean region. In the UK, an increase in travel-associated chikungunya cases has been reported in 2025. Most cases reported travel to Sri Lanka, India and Mauritius. No locally acquired cases of chikungunya have ever been reported in the UK. |
| Further information |
Chikungunya: transmission, epidemiology and guidance  Chikungunya: epidemiology in England, Wales and Northern Ireland â¶Ä¯Â NaTHNaC country information page: |
| Disease or pathogen | Mpox (clade I) |
|---|---|
| Location | Multi-region |
| Status | Situation update |
| Reporting date | 20 to 31 October 2025 |
| Summary | In October 2025, community transmission of clade Ib mpox was reported for the first time in several European countries (, , and ), and . Some of the new cases in these countries ( and ) have been among gay, bisexual, and other men who have sex with men (GBMSM), and mark the first reported detections of clade Ib mpox in GBMSM. On 31 October 2025, the European Centre for Disease Prevention and Control reported . The imported case was in a man who had reported sexual contact with another man. In the UK,Ìýclade Ib and clade IIb mpox cases have been officially reported. As of 16 October 2025,Ìý have been reported, all in England. The last reported UK case was in August 2025. Most of the cases 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: UK epidemiological overview NaTHNaC country information page: , , , , , ,Ìý , |
| Disease or pathogen | Rift Valley fever |
|---|---|
| Location | Mauritania and Senegal |
| Status | Situation update |
| Reporting date | 26 September to 2 November 2025 |
| Summary | On 26 September 2025, Senegal’s Ministry of Health and Public Hygiene . As of 1 November 2025, including 25 deaths, have been reported. Most cases have been reported in Saint-Louis region (294 cases). This is an increase of 57 cases and 4 deaths since . The has stated that males account for 64% of confirmed cases. Between 1 January and 27 October 2025,  have been reported across 11 regions of Mauritania. This is an increase of 70 confirmed cases and one death since the last report with data valid up to .  suggests that the current RVF outbreak in Senegal is directly linked to the previous detections in Senegal (Fatick in 2020 and Matam in 2022) and Mauritania (2020). No known human RVF cases have been reported in the UK. |
| Further information |
Viral haemorrhagic fevers: origins, reservoirs, transmission and guidelines NaTHNaC country information page: and |