Infectious disease surveillance and monitoring for animal and human health: summary February 2025
Updated 15 May 2025
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Interpreting this report
The UK Health Security Agency’s (UKHSA) Emerging Infections and Zoonoses (EIZ) team uses an integrated horizon scanning approach, which combines information on both human and animal health, to identify and assess outbreaks and incidents of new and emerging infectious diseases globally. For further information about the EIZ team’s horizon scanning process, please see our Epidemic intelligence activities.
This summary provides an overview of incidents (new and updated) of public health significance, which are under close monitoring. The incidents are divided into 2 sections: Notable incidents of public health significance and Other incidents of interest. For each notable incident of public health significance, an incident assessment is provided, based on the EIZ team’s interpretation of the available information.
The report also includes a section that focuses on Novel pathogens and diseases and a final Publications of interest section, which contains new publications relevant to emerging infections.
Epidemiological updates for diseases classified as a high consequence infectious disease (HCID) are published in UKHSA’s HCID monthly summary, unless they are considered a notable incident of public health significance, in which case a more detailed summary will be provided in this report.
For more information, or to sign up to the distribution list to receive an email alert when new reports are published, please contact epiintel@ukhsa.gov.uk
Notable incidents of public health significance
Summary of incidents
| Disease or infection | Location | New or update since the last report |
|---|---|---|
| Sudan virus disease | Uganda | Update |
| Clade I mpox | Multi-country | Update |
Sudan virus disease (SVD) - Uganda
Event summary
On 30 January 2025, Uganda’s Ministry of Health (MoH) confirmed an outbreak of Sudan virus disease (SVD) in Kampala. Sudan virus (SUDV) is one of 4 orthoebolavirus species that cause Ebola disease. This is the 8th Ebola virus outbreak in Uganda.
As of 27 February 2025, 9 confirmed SVD cases, including one death, were reported (case fatality rate (CFR) of 11.1%) across 5 districts; Wakiso (4 cases), Kampala (2 cases), Mbale (one case), Jinja (one case), and Mukono (one case). Two of the confirmed cases were family members of the initial confirmed fatal case, testing positive on the 31 January and 1 February 2025. Six further confirmed cases were reported on 11 February 2025. All cases have been reported amongst contacts of the initial case. 7 of the 8 cases received care at a treatment centre in Kampala and one case was treated in Mbale. All were discharged following recovery on 18 February 2024, after 2 negative tests taken 72 hours apart.
Figure 1. The epidemiological curve for confirmed cases of SVD in Uganda. Data were collated from official and media sources with a cutoff date of 28 February 2025
As of 27 February 2025, 45 contacts were identified, which included 34 healthcare workers and 11 family members. The MoH activated its national Incident Management Team to coordinate the outbreak response with support from the World Health Organization (WHO) and its health partners. Rapid response teams were deployed to Kampala, Mbale, and Wakiso districts to investigate the outbreak, determine its source, and trace contacts.
The WHO is supporting Uganda through operational, financial, and technical support and access to experimental candidate vaccine and therapeutics. On 3 February 2025, the WHO reported the launch of a vaccine trial for SUDV in Uganda. Using a ring vaccination strategy, the trial aims to assess the effect of one single, promptly given, dose of the candidate vaccine - whose safety and immunogenicity have already been demonstrated in Phase 1 - in protecting recent contacts and contacts of contacts of a newly confirmed case of SVD. The vaccination trial is led by the WHO in partnership with Uganda’s MoH, Makerere University and the Uganda Virus Research Institute.
Incident assessment
Of the 8 Ebola virus outbreaks reported in Uganda, 6 of these outbreaks (one in 2000, one in 2011, 2 in 2012, one in 2022, and the current outbreak) were due to SVD. Historically, CFR for SVD outbreaks was between 41% to 70%. The previous SVD outbreak in Uganda took place between September 2022 to January 2023 and resulted in 164 cases and 77 deaths (CFR of 47%). Uganda has previous experience of Ebola disease outbreaks and promptly established response measures to control the current outbreak.
On 21 February 2025, the WHO assessed the risk of potential serious public health impact as high, as there are no licensed vaccine or therapeutics for the prevention and treatment of SVD. They assessed there to be a high risk of many types of transmission chain due to: patient care in community health services, private facilities and private hospitals; and the use of traditional healers (who may have limited infection prevention and control measures).
In response to this outbreak, the UKHSA activated its Returning Workers Scheme aimed at monitoring the health of those deploying overseas who may exposed to SVD through their work. If a case of SVD were to be imported into the UK, there are a range of robust clinical, infection prevention and control measures available which would be adapted for use as necessary to reduce the risk of transmission. UK-specific clinical management guidelines and additional information on SVD can be found here.
Clade I mpox – Multi-country
Event summary
The International Health Regulations (2005) (IHR) Emergency Committee met again on 27 February 2025 to review the status of the ongoing clade I mpox, and extended its public health emergency of international concern (PHEIC) status until 20 August 2025.
The clade I mpox outbreak continues to be centered around countries in the African Region (Figure 2). Since the beginning of the outbreak, and throughout February 2025, most cases have been reported in the Democratic Republic of the Congo (DRC) (17,339 confirmed cases and 1,560 deaths as of 23 February 2025), Uganda (3,391 confirmed cases and 23 deaths as of 21 February 2025) and Burundi (3,568 confirmed cases as of 26 February 2025 and one death as of 26 October 2024).
Up to the end of February 2025, mpox cases typed as clade Ib have been reported in the DRC, Burundi, Rwanda, Uganda, Kenya, Zambia, Zimbabwe, and Angola.
Figure 2. Countries in the African region that have reported clade I mpox in the 2024 to 2025 outbreak. Data were collated from official and media sources with a cutoff date of 28 February 2025
Community transmission of clade I mpox has been reported in the DRC, Uganda, Burundi, Kenya, Rwanda, and Zambia. As of 21 February 2025, the majority of mpox cases in Uganda were in people aged 18-39-years-old, with 56.7% cases in men. Burundi has experienced a different case distribution. 36.9% of cases reported in children under 15-years-old and 31% of cases in young adults aged 20-30-years-old, a bimodal distribution that reflects an evolution in transmission patterns from initial clusters to household spread. The DRC has experienced a variation in mpox case distribution depending on the province: in Kinshasa, cases over 20-years-old are most affected, whereas in North Kivu and South Kivu, 50% of cases reported in children are under 10-years-old. The strain primarily circulating in the eastern DRC is clade Ib mpox, whereas multiple mpox strains are circulating in Kinshasa (a large urban hub).
Imported cases of mpox continue to be reported globally. The United Arab Emirates (UAE) notified the WHO of the first confirmed detection of clade Ib mpox in the country on 7 February 2025. The case had recent travel history to Uganda, and a symptom onset date of 11 January 2025 with mpox confirmed on 18 January 2025. Prior to this detection, clade Ib mpox cases with history of travel to the UAE had been reported in India, Oman, Pakistan, Thailand and China. This likely suggests undetected transmission of clade Ib mpox in the UAE. Elsewhere in Asia, China reported 7 travel-associated clade Ib mpox cases as of 2 February 2025.
The United States reported 2 new cases of clade Ib mpox in February, bringing the total number of imported cases to 4. The cases were reported in the states of New Hampshire on 7 February 2025 and New York on 11 February 2025. The cases both had a travel history to East Africa, though the exact countries were not specified. The cases are not epidemiologically linked. Cases have now been reported in the states of California, Georgia, New Hampshire and New York. No secondary clade Ib cases have been detected in the Americas Region to date.
Up to 28 February 2025, 10 cases of clade Ib mpox have been reported in the UK: all in England. All of these cases had direct or indirect travel links to countries where mpox clade Ib is circulating.
Incident assessment
During February 2025, Uganda in particular experienced an increase in mpox cases. Travel-associated clade Ib mpox cases continue to be reported outside of the African Region, with the most cases detected in the United Kingdom (10 cases), China (7 cases) and Germany (7 cases).
In February 2024, based on the information available at the time of the risk assessment, the WHO classified the overall global public health risk from clade Ib mpox as high. The WHO notes that all mpox outbreaks must be considered in their local context to gain a comprehensive understanding of the epidemiology, modes of transmission, risk factors for severe disease, viral origins and evolution, and relevance of strategies and countermeasures for prevention and control.
For the most recent UK risk and indicator assessments for clade Ib mpox, see UKHSA’s mpox technical briefing 10.
Summary of other incidents
| Disease or infection | Location | |
| Oropouche fever | Americas | |
| Cholera | Multi-country | |
| Poliovirus | Multi-country | |
| Yellow fever | South America | |
| Dengue | Multi-country | |
| Measles | United States |
Oropouche fever
Between 1 January and 24 February 2025, 5,514 confirmed cases of Oropouche fever and one suspected death were reported in Brazil. Since the beginning of 2025, most cases have been reported in Espirito Santo (4,643 cases), Rio De Janeiro (485 cases), and Paraiba (287 cases) states. In February 2025, case numbers reported each week declined from a peak of 1,044 cases in epidemiological week 3. In the last week of February, cases reported were lower than in the equivalent 2024 period. Recent research found Oropouche-positive historical cases of newborns with congenital malformations, and evidence of potential vertical transmission of Oropouche virus from parent to child.
In Panama, 153 Oropouche fever cases in Darién and Eastern Panama were reported between 1 January to 9 February 2025. No associated deaths have been reported in Panama to date. Oropouche fever was reported in Panama in November 2024 for the first time in 30 years.
Cholera
During February 2025, notable cholera outbreaks were reported in Angola, Zambia and South Sudan.
As of 25 February 2025, 5,336 cholera cases and 193 deaths were reported in Angola since the start of the outbreak on 7 January 2025, across 12 provinces. The most affected provinces include Luanda, Bengo and Icolo e Bengo. Most cases had been reported in children aged 2-5 years old, as of 23 February 2025. 20 rapid response teams have been deployed to the provinces of Luanda, Bengo, and Icolo e Bengo to detect active cases and to conduct engagement activities with communities. The Angolan MoH, with support from the WHO, Unicef, the World Bank and the International Committee of the Red Cross, carried out a five-day reactive vaccination campaign in January 2025, vaccinating more than 900,000 people, resulting in a vaccination coverage rate of 99.5%. The peak of the rainy season in Angola is in March and April, which may exacerbate water contamination and accelerate the spread of cholera.
As of 9 February 2025, South Sudan’s MoH reported 29,800 cholera cases and 496 deaths(CFR of 1.7%). Cases were reported in 34 out of 80 counties across 7 states. Most cases were reported from Rubkona (37.5%) and Mayom (12.6%) counties.
The Zambian Ministry of Health reported 265 cholera cases and 9 deaths (CFR of 3.4%) between 1 January and 14 February 2025. Cases have been recorded in the following districts: Chililabombwe (206 cases), Nakonde (27 cases), Chingola (14 cases), Kitwe (8 cases), Kalumbila (3 cases), Ndola (2 cases), Solwezi and Lusaka (one case each). On 9 February 2025, Zambia launched an oral cholera vaccination campaign in the district of Chililabombwe.
Poliovirus
As of 28 February 2025, 5 wild poliovirus type 1 (WPV1) cases have been reported in Pakistan in 2025. The 2 most recent cases were detected in Sindh and Punjab.
The first WPV1 case in Afghanistan of 2025 was reported in Badghis, during the week of 19 February 2025.
On 26 February 2025, the Global Polio Eradication Initiative reported a cVDPV2-positive environmental sample from the South East of England, United Kingdom. The sample was initially collected on 20 January 2025. Between September and December 2024, cVDPV2 detections in sewage were reported from Germany, Spain, Poland, Finland and the UK, all of which were genetically linked to a strain that emerged in Nigeria. No human cases have been detected in these countries.
Yellow fever
In 2025, yellow fever cases have been concentrated mainly in the state of São Paulo, Brazil, and the department of Tolima, Colombia. This is in contrast to 2024, where cases were mainly reported in the Amazon regions of Brazil, Bolivia, Guyana, Colombia and Peru, where sylvatic yellow fever is endemic. On 3 February 2025, the Pan American Health Organization raised an epidemiological alert for yellow fever in the Americas Region, and released a risk assessment on the implications for the Region on 14 February 2025. The risk of yellow fever outbreaks within the Region, particularly endemic countries, was classified as high with a high level of confidence based on the available information.
On 3 February 2025, the Brazilian MoH released a technical note warning about the increase in yellow fever transmission in the states of São Paulo, Minas Gerais, Roraima and Tocantins. As of 25 February 2025, 19 yellow fever cases and 13 deaths were reported in São Paulo state, in 2025. 14 of these cases were reported in Campinas, the third most populous municipality in the state. Since December 2024, 36 detections of yellow fever have been reported in non-human primates in the state. All 13 fatal cases had not been vaccinated against yellow fever.
As of 14 February 2025, 29 confirmed yellow fever cases and 14 deaths have been reported in Tolima, Colombia, since November 2024. Cases were concentrated in the municipalities of Purificación, Prado, Cunday and Villarrica. These municipalities are largely rural around the Galilea (forest) reserve area. The department of Tolima was not previously considered to be at risk for yellow fever outbreaks, and thus historically has had a low vaccination uptake. The Government of Tolima issued an ‘Orange’ hospital alert due to an exceedance in yellow fever cases on 11 February 2025.
Dengue
In 2025, yellow fever cases have been concentrated mainly in the state of São Paulo, Brazil, and the department of Tolima, Colombia. This is in contrast to 2024, where cases were mainly reported in the Amazon regions of Brazil, Bolivia, Guyana, Colombia and Peru, where sylvatic yellow fever is endemic. On 3 February 2025, the Pan American Health Organization raised an epidemiological alert for yellow fever in the Americas Region, and released a risk assessment on the implications for the Region on 14 February 2025. The risk of yellow fever outbreaks within the Region, particularly endemic countries, was classified as high with a high level of confidence based on the available information.
On 3 February 2025, the Brazilian MoH released a technical note warning about the increase in yellow fever transmission in the states of São Paulo, Minas Gerais, Roraima and Tocantins. As of 25 February 2025, 19 yellow fever cases and 13 deaths were reported in São Paulo state, in 2025. 14 of these cases were reported in Campinas, the third most populous municipality in the state. Since December 2024, 36 detections of yellow fever have been reported in non-human primates in the state. All 13 fatal cases had not been vaccinated against yellow fever.
As of 14 February 2025, 29 confirmed yellow fever cases and 14 deaths have been reported in Tolima, Colombia, since November 2024. Cases were concentrated in the municipalities of Purificación, Prado, Cunday and Villarrica. These municipalities are largely rural around the Galilea (forest) reserve area. The department of Tolima was not previously considered to be at risk for yellow fever outbreaks, and thus historically has had a low vaccination uptake. The Government of Tolima issued an ‘Orange’ hospital alert due to an exceedance in yellow fever cases on 11 February 2025.
On 19 February 2024, the Government of Tonga declared a dengue outbreak, following an increase in cases across the islands of Tongatapu, Vava’u, and ‘Eua. Between 14 and 27 February 2025, 77 dengue cases were reported from Tongatapu (36 cases), Vava’u (29 cases) and ‘Eua (12 cases). Most cases were individuals aged 10 to 19 years. The serotype for the confirmed cases was DENV-2, according to the first batch of samples collected from Tongatapu. Cases are expected to rise due to ongoing rain and adverse weather conditions.
Fiji declared a dengue outbreak in the Western Division on 3 February 2025, after reporting 200 cases since the beginning of 2025. Fiji typically observes an increase in dengue cases between October and April during the rainy season, however case numbers have increased above expected levels. Most cases have been reported amongst individuals aged 10 to 29 years old.
As of epidemiological week 7 of 2025, 3,431 dengue cases were detected in Ho Chi Minh City, Vietnam. This was an increase of 125.3% compared to the same period in 2024 and 49% higher than the most recent 3-year average. Typically, dengue outbreaks peak in Vietnam between July and November. In 2025, above-average rainfall and warmer temperatures have created ideal reproductive conditions for the dengue vector, Aedes aegypti.
Between 1 January and 15 February 2025, 43,732 dengue cases were reported in the Philippines. This is a 56% increase compared to the equivalent period in 2024 (27,995 cases). Most cases were reported in Calabarzon (9,111 cases), the National Capital Region (7,551 cases), and Central Luzon (7,362 cases). This increase in cases has been observed ahead of the rainy season in the Philippines (which occurs between June and November).
Outside of southeast Asia and the Pacific regions, a dengue positive mosquito was reported from Funchal, Autonomous Region of Madeira, on 8 February 2025. 2 locally acquired dengue cases were subsequently reported on 19 February 2025. The cases were diagnosed in early January, outside of the usual transmission period. Madeira recorded an outbreak of dengue between 2012 and 2013, with 1,080 confirmed cases. The majority of cases were in the municipality of Funchal.
Measles
The state of Texas, United States, continued to record cases in an ongoing measles outbreak in the South Plains and Panhandle region in February 2025. On 25 February 2025, the Texas Health and Human Services reported 124 measles cases associated with the outbreak, recorded from 9 counties: Gaines (80 cases), Terry (21 cases), Dawson (7 cases), Yoakum (5 cases), Dallam (4 cases), Martin (3 cases), Ector (2 cases), Lubbock and Lynn (one case each). 18 cases have been hospitalised and 5 cases have been reported amongst vaccinated individuals. All other cases are either unvaccinated or have an unknown vaccination status.
The Texas Health and Human Services reported the first measles related death on 26 February 2025. The case was a school-aged child, who was not vaccinated. The last death from measles in the US was reported in 2015.
On 11 February 2025, the first measles case in New Mexico in 2025 was reported in an unvaccinated teenager in Lea County; which borders Gaines County in Texas, where most measles cases associated with the current outbreak have been reported. The New Mexico case had no recent travel or exposure to known cases from the Texas outbreak.
Publications of interest
Chikungunya
There are 3 major lineages of chikungunya virus (CHIKV), that are genetically distinct: West Africa, East-Central-South Africa and Asia. These align with the geographical distribution of the virus prior to the 2006 spread of the East-Central-South African lineage to Asia and the spread of the Asian lineage into the Americas in 2013. Vaccines for viruses like chikungunya, which have multiple genotypes, need to be cross-protective, which generally requires cross-neutralisation. VLA1553, or IXCHIQ®, is a vaccine produced by Valneva, which was licensed by the US in 2023 and Europe in 2024. A recent study showed that the three major CHIKV lineages were inhibited by CHIKV-specific neutralizing antibodies present in the sera from humans vaccinated with VLA1553, with an effect independent of the amount of time since the patients were vaccinated. Additionally, the level of immune response was similar to the antibody levels detected in sera from chikungunya patients who had recovered from infection. These findings suggest that the VLA1553 vaccine could reduce chikungunya disease burden across all regions where these genotypes are found.
Crimean-Congo haemorrhagic fever (CCHF)
CCHF is an emerging tick-borne disease in Europe, with an expanding geographic range linked to the changing climate. Crimean-Congo haemorrhagic fever virus (CCHFV) is transmitted through the bite of an infected tick or via direct contact with blood or tissues of infected ticks, people, or livestock. The disease is endemic in the Balkans, and sporadic cases have been reported in southern Mediterranean countries, including Greece, Spain, and Portugal. The virus was detected for the first time in ticks in southern France in 2023. A serological study of cattle and wildlife in the French Mediterranean region was conducted on samples collected between 2008 and 2022. The study detected seropositivity in both cattle and wildlife, suggesting active circulation of CCHFV in parts of mainland France, particularly the Alpes-Maritimes and Pyrénées-Orientales regions. The importance of environmental and anthropogenic factors in shaping the dynamics of CCHFV transmission was highlighted, identifying that cattle in open natural habitats were more likely to be seropositive (due to these environments being favourable to ticks), and that male animals were more likely to be seropositive than females (which the authors suggested is linked to the larger home ranges of males increasing their exposure to ticks). The study highlights the need for enhanced surveillance and integrated approaches to monitor zoonotic pathogens.
Further reading
Related resources
1. High consequence infectious diseases monthly summaries
2. National flu and COVID-19 surveillance reports
3. Avian influenza (influenza A H5N1): technical briefings
4. Avian influenza (bird flu) in Europe, Russia and the UK reports
5. Bird flu (avian influenza): latest situation in England updates
6. Human Animal Infections and Risk Surveillance (HAIRS) group risk assessments and statements
7. Animal and Plant Health Agency (APHA) monitoring of disease in livestock and poultry monthly reports
Authors of this report
UKHSA’s Emerging Infections and Zoonoses team epiintel@ukhsa.gov.uk