Research and analysis

Outbreaks under monitoring: week 12 (week ending 22 March 2026)

Updated 26 March 2026

Disease or pathogen	Mpox
Location	Argentina
Status	New
Reporting date	16 March 2026
Summary	On 16 March 2026, Argentina’s Ministry of Health reported a clade Ib mpox case in Buenos Aires. The case reported no recent travel history but had multiple recent sexual exposures including with travellers, prior to symptom onset on 24 February 2026. This is the first detection of clade Ib mpox in Argentina. In the UK, clade Ib and clade IIb mpox cases have been reported. Up to 28 February 2026, 34 clade Ib mpox cases have been reported, with most reporting 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: Argentina

Disease or pathogen	Severe fever with thrombocytopaenia syndrome
Location	Taiwan
Status	New
Reporting date	19 March 2026
Summary	On 19 March 2026, Taiwan’s Centers for Disease Control reported a confirmed case of severe fever with thrombocytopaenia syndrome (SFTS) in Northern Taiwan in an individual with no travel history. The case was hospitalised following symptom onset in February 2026 and was later discharged. The source of infection is under investigation; ticks collected at the case’s residence did not test positive for SFTS virus. This is the third locally acquired case of SFTS detected in Taiwan, with one case previously reported in 2019 and 2022. 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: Taiwan

Disease or pathogen	Hepatitis A
Location	Italy
Status	New
Reporting date	19 March 2026
Summary	In 2026 up to 19 March, an increase in hepatitis A cases has been observed in the Campania Region, Italy, associated with undercooked bivalve molluscs. As of 18 March 2026, 133 cases have been reported in the region. According to media, 84 of these cases have been reported in Naples, representing a 10-fold increase in cases compared to the average number reported during the equivalent time period over the past decade.   In response, authorities have strengthened surveillance measures, case and contact management, vaccination and controls on food chain operations. During 2024, 889 new laboratory confirmed cases of acute hepatitis A infections were reported in England and Wales, representing the highest number of cases since 2017 (942 cases).
Further information	Hepatitis A: guidance, data and analysis NaTHNaC country information page: Italy

Disease or pathogen	Chikungunya
Location	Suriname
Status	Update
Reporting date	19 March 2026
Summary	On 19 March 2026, the International Federation of Red Cross and Red Crescent Societies (IFRC) reported an update on the chikungunya outbreak in Suriname declared during January 2026. As of 4 March 2026, 1,357 confirmed cases and one death have been reported across 8 districts. In response, authorities have strengthened control measures, including risk communication, surveillance, and vector control. In 2014, Suriname experienced their first reported chikungunya outbreak resulting in 700 cases. In the UK, an increase in travel-associated chikungunya cases was reported during 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  HAIRS risk assessment: Chikungunya virus - GOV.UK NaTHNaC country information page: Suriname