WHO Disease Outbreak News

On 4 April 2026, the National IHR Focal Point of Bangladesh notified WHO of a significant increase in measles cases, driven by sustained domestic transmission. Since January 2026, Bangladesh has experienced a marked increase in measles cases. Geographically, cases have been reported across all eight divisions, in 58 out of 64 districts (91% of districts), indicating widespread transmission nationally. Since 15 March 2026 and as of 14 April, a total of 19 161 suspected measles cases and 2973 laboratory-confirmed measles cases have been reported. Moreover, 166 suspected measles-related deaths (CFR 0.9%) and 30 confirmed measles-related deaths (CFR= 1.1%) have been recorded. A total of 12 318 hospital admissions and 9772 hospital discharges have also been reported. The highest cumulative burden of suspected measles cases since 15 March 2026 has been reported in Dhaka (8263 cases), Rajshahi (3747 cases), Chattogram (2514 cases), and Khulna (1568 cases). In Dhaka, cases are concentrated in densely populated informal settlements, including Demra, Jatrabari, Kamrangirchar, Korail, Mirpur, and Tejgaon industrial and slum clusters. (HEOC, DGHS, 15 April 2026). Children aged under 5 years account for the majority of reported cases (79%), including children aged under 2 years (66%) and infants aged under 9 months (33%). A total of 166 suspected deaths have been reported (CFR 1%), mainly among unvaccinated children aged under 2 years.

On 21 March 2026, the National IHR Focal Point for Italy notified WHO of the identification of a human case of avian influenza A(H9) in an adult male. The patient had been in Senegal for more than six months and traveled to Italy in mid-March. Upon arrival, he visited the emergency department with a fever and a persistent cough. On 16 March, a bronchoalveolar lavage specimen was collected, which showed a positive Mycobacterium tuberculosis result, as well as detection of un-subtypeable influenza A virus. The patient was placed in a negative-pressure isolation room with airborne precautions. He was treated with antitubercular medication and antiviral oseltamivir. By 9 April, his condition was stable and improving. On 20 March, a regional reference laboratory identified the A(H9) subtype, and on 21 March, next-generation sequencing confirmed influenza A(H9N2). Initial genetic findings suggest the infection was likely acquired from an avian source linked to Senegal. Additional samples have been sent to Italy’s National Influenza Center, where further characterization confirmed virus subtype Influenza A(H9N2), with close genetic similarity to strains previously identified in poultry in Senegal. No direct exposure to animals, wildlife or rural environments was identified. There was also no reported contact with symptomatic or confirmed human cases. Further epidemiological investigations on the source of exposure are ongoing. Contacts identified in Senegal were asymptomatic. All identified and traced contacts in Italy have tested negative for influenza and completed the period of active monitoring for the onset of symptoms and the quarantine required by national guidelines. They also received oseltamivir as a preventive measure.

Since 10 December 2025, and as of 25 February 2026, 99 countries and territories have been identified as having received batches of infant formula products subject to recall due to contamination with cereulide toxin. During this period, 144 suspected and confirmed cases were reported across 10 countries. The epidemiological investigations and product‑traceback activities remain ongoing in many countries. The case definitions in use by the International Food Safety Authorities Network (INFOSAN) are currently: Suspect case: A person presenting symptoms of cereulide intoxication with a history of consumption of the recalled product, without laboratory confirmation in a clinical sample. Confirmed case: A person presenting symptoms of cereulide intoxication with a history of consumption of recalled product, with laboratory confirmation in a clinical sample. Health authorities are actively searching for cases and conducting laboratory testing of human specimens and infant formula products. However, case definitions used may differ from those established by INFOSAN, such as those established by the European Centre for Disease Prevention and Control, creating challenges with comparability of reported case numbers. Since this is not a routinely tested contaminant or condition, diagnostic challenges and limited surveillance capacity are hindering Member States’ ability to identify confirmed cases. One country has laboratory confirmed cases linked to the contaminated products (Belgium). The limited case numbers appearing in multiple, geographically separated areas is consistent with sporadic exposures to contaminated products that were widely distributed. ​Precautionary recalls have been issued across all countries and territories where products were distributed. These measures aim to prevent further exposures, although the speed and completeness of product recall and withdrawal vary by location according to various factors including inspection and enforcement capacities.

In December 2025, the United Kingdom detected the first reported case of a clade Ib/IIb MPXV recombinant strain.​5​ After classification of this case and posting in a public database as a novel MPXV recombinant strain, a case of mpox detected in India in September 2025 was retrospectively reclassified as a closely-related recombinant strain based on sequencing data. To date, these are the only known cases of this recombinant virus. Case detected in the United Kingdom of Great Britain and Northern Ireland The case was identified following testing of a vesicular swab from a traveler who had returned from a country in the Asia Pacific region in October 2025. During laboratory confirmation, the virus was initially typed as clade Ib MPXV by qPCR. Subsequent whole genome sequencing revealed that the MPXV strain identified was distinct from other known clade Ib MPXV strains with phylogenetic analysis indicating that the genome had regions similar to both clade Ib and clade IIb MPXV reference sequences, suggesting that it is an inter-clade recombinant. To confirm this unusual finding, sequencing was repeated on the original extract from the primary sample, a fresh extract from the same primary sample, a second swab collected from the patient at the same time, and a cultured isolate derived from the initial swab. This repeat sequencing yielded identical viral genome sequences from the two clinical swabs and the cultured isolate, supporting the initial findings of a new recombinant strain, and showing that it can replicate and presents potential for onward transmission. This strain is a recombinant MPXV, containing genetic elements from both clade Ib and clade IIb MPXV. A small number of contacts were identified and followed up in the United Kingdom; none developed any clinical features of mpox. Health worker contacts had worn full personal protective equipment (PPE) during provision of medical care to the patient. The authorities of the United Kingdom continue to investigate the significance of this recombinant MPXV strain through phenotypic characterization studies. Case detected in India On 13 January 2026, the National IHR Focal Point (NFP) of India notified WHO of a mpox case with an inter‑clade recombinant MPXV which was, upon whole-genome sequencing, found to have genomic elements of clades Ib and IIb MPXV. The recombinant virus was found in samples from a man with mpox who had presented for care in September 2025. The patient had reported recent travel from a country in the Arabian Peninsula, where he resides as an overseas worker. He developed symptoms on 1 September 2025, while still abroad. After his return to India, real‑time PCR confirmed MPXV infection on 11 September 2025. Clade differentiation PCR performed on 15 September 2025 initially identified this virus as clade II MPXV. Initial genomic sequencing analysis suggested features consistent with clade IIb MPXV. However, following the update of the global Nextclade database on 16 December 2025, which included the recombinant clade Ib/IIb MPXV strain reported by the United Kingdom, the virus from the patient in India was reclassified as belonging to the recombinant strain. Recombination analysis demonstrated mosaic patterns containing genomic regions derived from both parent clades. Following the initial diagnosis, the patient was hospitalized, did not experience any medical complications, and fully recovered, testing negative for MPXV on 29 September 2025. The case reported no close contacts in India, and no known secondary cases were identified following this introduction of the recombinant clade Ib/IIb MPXV in India. Full or near‑full genome retrieval (>99%) from both the sample and a sample-derived virus isolate enabled phylogenetic analysis showing >99.9% similarity to the recombinant strain detected in the United Kingdom. A total of 34 recombinant tracts were observed in the sequence reported by India, while 28 recombinant tracts were observed in the sequence reported by the United Kingdom; 16 recombinant tracts were common to both strains. This case in India therefore represents the earliest known detection of this recombinant strain globally, having preceded the event reported in the United Kingdom. Consistent with the case reported in the United Kingdom, clinical presentation was consistent with cases due to clade I or clade II MPXV (non-recombinant MPXV) infection.

On 3 February 2026, the Bangladesh IHR NFP notified WHO of one confirmed case of NiV infection that occurred in Rajshahi Division, northwestern Bangladesh. The case was confirmed by Polymerase Chain Reaction (PCR) and Enzyme-Linked Immunosorbent Assay (ELISA) testing on 29 January 2026. The patient is female, aged between 40-50 years, residing in Naogaon District, Rajshahi Division. She developed symptoms consistent with NiV infection on 21 January, including fever, headache, muscle cramps, loss of appetite (anorexia), weakness, and vomiting, followed by hypersalivation, disorientation, and convulsion. On 27 January, she became unconscious and was referred by a local physician to a tertiary hospital. She was admitted on 28 January, and the Nipah surveillance team collected throat swabs and blood samples. The patient died the same day. The patient reported repeated consumption of raw date palm sap between 5 and 20 January 2026. Following the confirmed diagnosis, an outbreak investigation team, including One Health stakeholders, started investigations on 30 January. A total of 35 contact persons has been identified, including three household contact persons 14 community contact persons and 18 hospital contact persons. Samples were collected from six symptomatic contact persons, including three from household, two from communities and one from hospital. All six samples tested negative for NiV infection by PCR and anti-Nipah IgM antibody detection by ELISA. As of 3 February, no additional cases have been identified. Contact persons are under monitoring. Bangladesh reported its first case of NiV infection in 2001. Since then, human infections have been reported almost every year. In 2025, four laboratory-confirmed fatal cases were reported from Bangladesh.

On 26 January 2026, the India IHR NFP notified WHO of two confirmed NiV infection cases that occurred in West Bengal State. Preliminary laboratory testing suggested NiV infection, and confirmation was received from the National Institute of Virology, Pune on 13 January 2026. The cases were confirmed through Reverse Transcription Polymerase Chain Reaction (RT-PCR) and Enzyme-Linked Immunosorbent Assay (ELISA) testing. The first case is a female nurse and the second case is a male nurse. Both cases were between 20 – 30 years old, from Barasat, North 24 Parganas district. Both cases developed symptoms typical of severe NiV infection in late December 2025 and were admitted to hospital in early January 2026. As of 21 January 2026, the second case showed clinical improvement, while the first case remained under critical care. Following the two confirmed cases, Indian health authorities identified and tested over 190 contact persons, including health and care workers and community contacts. All samples from contact persons tested negative for NiV. The Indian National Centre for Disease Control, announced on 27 January that no further confirmed cases have been detected in West Bengal from December 2025 to date.

On 14 November 2025, after the laboratory confirmation of suspected viral hemorrhagic fever (VHF) cases in Jinka town, South Ethiopia Regional State, Ethiopia, the Ministry of Health of Ethiopia declared an outbreak of Marburg Virus Disease (MVD). Molecular testing conducted by the National Reference Laboratory at the Ethiopian Public Health Institute (EPHI) identified Marburg virus (MARV) in patient samples. This was the first time Ethiopia was reporting a MVD outbreak. The first known case was an adult from Jinka town who developed symptoms on 23 October. The patient presented to the General Hospital the following day with vomiting, loss of appetite, and abdominal cramps. As of 25 January 2026, a cumulative total of 14 confirmed cases, including nine deaths (Case Fatality Rate (CFR) 64.3%) and five probable cases, all of whom had died, were reported by the Ministry of Health from Jinka, Malle and Dasench woredas in South Ethiopia Region and Hawassa in Sidama Region. As of 25 January 2026, a total of 857 contacts were listed who completed 21 days of follow-up, 760 from the South Ethiopia Region and 97 from the Sidama Region. As of 5 January 2026, 3800 samples were tested for the virus. On 26 January 2026, after two consecutive incubation periods (a total of 42 days), without a new confirmed case reported, after the last confirmed case died and was given a safe and dignified burial, on 14 December 2025, the Ministry of Health of Ethiopia declared the end of the MVD outbreak, as per WHO recommendations. Figure 1: Map of districts reporting confirmed and probable Marburg virus disease cases in Ethiopia, as of 25 January 2026

Since the first report of MERS-CoV in the KSA and Jordan in 2012, a total 2635 laboratory-confirmed cases of MERS-CoV infection, with 964 associated deaths (Case Fatality Ratio (CFR) of 37%), have been reported to WHO from 27 countries, across all six WHO regions (Figure 1). The majority of cases (84%; n=2224), have been reported from the KSA (Figure 2). Since the beginning of 2025 and as of 21 December, a total of 19 cases have been reported to WHO. Overall, 17 cases were reported in the KSA from five regions named: Riyadh (n=10), Taif (n=3), Najran (n=2), Hail (n=1), and Hafr Al-Batin City (n=1) (Figure 3). In addition, two travel associated cases of MERS-CoV infection have been reported in France, with likely exposure occurring during recent travel in the Arabian Peninsula (Figure 3). This disease outbreak news report focuses on the recent nine cases of MERS-CoV infection reported between 4 June - 21 December 2025: seven cases from the KSA and the two imported cases to France. The details of cases reported earlier in 2025 can be referred to in the previously published disease outbreak news on 13 March 2025 and 12 May 2025. Between 4 June and 21 December 2025, the MoH of the KSA reported a total of seven cases of MERS CoV infection. The cases were reported from three regions: Najran (2), Riyadh (3), and Taif (2). No epidemiological links were identified between the seven cases. In addition, between 2 and 3 of December 2025, the IHR NFP for France reported two cases of MERS – CoV with recent travel to the Arabian Peninsula during the month of November. Follow-up has been completed for all contacts and no secondary infections have been identified or reported. From September 2012, France has recorded a total of four laboratory-confirmed cases of MERS-CoV infection, including one death: two cases were reported in 2013, and the latest two cases in December 2025. All cases had been travelers exposed in the Arabian Peninsula and returning back to France. For additional details please see Table 1. Figure 1: Epidemic curve of MERS-CoV infections (2635) and deaths (964) reported globally between 2012-2025 Figure 2: Epidemic curve of MERS-CoV infections (2224) and deaths (868) reported in KSA between 2012-2025 Figure 3. Geographical distribution of MERS-CoV infections between 1 January and 21 December 2025 (n=19). Table 1: MERS-CoV cases reported by KSA and France between 4 June and 21 December 2025

Globally, influenza activity has increased since October 2025 with influenza A viruses predominant among the viruses detected globally. In many northern hemisphere countries, acute respiratory infection levels increase at this time of year. These increases are typically caused by seasonal epidemics of respiratory pathogens such as influenza, respiratory syncytial virus (RSV) and other common respiratory viruses. The exact timing of the onset, the duration, magnitude and the severity of each epidemic might vary by location, influenced by multiple factors such as type of circulating viruses (including influenza and other respiratory pathogens), relative population immunity and environmental conditions. In the northern hemisphere, some countries have reported early starts to the influenza season. In other countries, influenza activity is starting to increase, but has not yet reached the epidemic threshold. In the southern hemisphere, some countries have had unusually long seasons compared to previous years, with virus activity remaining higher than usual in recent months. Global influenza surveillance and monitoring is conducted through the Global Influenza Surveillance and Response System (GISRS), a WHO-coordinated network of over 160 institutions in 131 Member States. GISRS is tasked with conducting year-round surveillance and monitoring of influenza viruses and serving as the global alert mechanism for the emergence of novel influenza viruses and other respiratory pathogens with pandemic potential. In the northern hemisphere temperate and sub-tropical countries, areas and territories, influenza activity was generally low from June to August 2025. Activity gradually increased in September and continued to increase through November 2025. Influenza A viruses, especially A(H3N2) viruses, predominated during this period (Fig. 1). In the southern hemisphere temperate and sub-tropical countries, areas and territories, influenza activity generally decreased from June 2025 and remained low through August. However, a slight increase has been observed since September. Influenza A(H1N1)pdm09 viruses predominated in June and July; however, A(H3N2) viruses have predominated since September (Fig. 2). In tropical areas, there has been sustained influenza activity from June through November. Influenza A(H1N1)pdm09 viruses predominated through July. Since then, the proportion of influenza A(H3N2) viruses among reported detections has increased and has become predominant since the end of September (Fig. 3). Figure 1. Virus detections by subtype reported to FluNet, from 1 June to 30 November 2025 for the northern hemisphere temperate and sub-tropical countries, areas and territories. Source: GISRS: https://worldhealthorg.shinyapps.io/flunetchart/ Figure 2. Virus detections by subtype reported to FluNet, from 1 June to 30 November 2025, for the southern hemisphere temperate and sub-tropical countries, areas and territories. Source: GISRS: https://worldhealthorg.shinyapps.io/flunetchart/ Figure 3. Virus detections by subtype reported to FluNet, from 1 June to 30 November 2025, for tropical countries, areas and territories. Source: GISRS: https://worldhealthorg.shinyapps.io/flunetchart/ Genetic characteristics of recent seasonal influenza viruses Influenza A(H1N1)pdm09 and influenza B/Victoria lineage viruses continue to circulate in all regions albeit at low levels. Influenza A(H3N2) viruses Based on genetic sequence data available in GISAID, a mixture of A(H3N2) haemagglutinin (HA) clades and subclades are currently circulating globally; however, there has been a recent and rapid rise in a particular subclade of A(H3N2), J.2.4.1 (alias subclade K Nextclade/Nextstrain nomenclature). A(H3N2) subclade K viruses have genetically drifted from related J.2.4 viruses and have several amino acid changes in their HA in comparison. Detections of subclade K viruses are increasing in many parts of the world, with the exception, to date, of South America. Subclade K viruses were particularly evident from August 2025 in Australia and New Zealand and have now been detected in more than 34 countries over the last 6 months. Figure 4. Influenza A(H3N2) percent positivity reported for epidemiological week 48 (24 to 30 November) 2025 Source: GISRS: https://www.who.int/teams/global-influenza-programme/surveillance-and-monitoring/influenza-surveillance-outputs Overview of seasonal influenza by WHO Region African region Influenza detections in the WHO African Region overall increased in October with influenza A(H3N2) predominant. The timing and predominant virus varied by zone. In the western part of the region, influenza detections increased in September and October with A(H3N2) predominant since October. All seasonal subtypes have been detected continuously in the middle and eastern parts of the region. Influenza activity peaked in May 2025 in South Africa with almost exclusively A(H3N2) detections; in recent weeks influenza activity has increased slightly but remained low. Eastern Mediterranean Region While influenza activity in the WHO Eastern Mediterranean Region overall increased in October with A(H3N2) viruses predominant, there were variations by zone. In countries in the northern part of the region, influenza detections increased in October with influenza A(H1N1)pdm09 predominant and lesser proportions of influenza A(H3N2) and B virus detections reported. In the Arabian Peninsula, influenza detections also increased in October but with influenza A(H3N2) viruses predominant. European Region As of 21 November 2025, reported rates of influenza-like illness (ILI) and/or acute respiratory infection (ARI) in primary care were at baseline levels for most countries and areas of the WHO European Region. However, detections were increasing and regionally pooled test percent positivity in primary care sentinel surveillance rose above 10% in weeks 45 and 46 (ending on 15 November), marking the start of the 2025/26 influenza season for the European Region. This was approximately four weeks earlier than the median, but not out of the ordinary, with epidemiological trends similar to those observed in the 2022/23 influenza season. Influenza activity was variable between countries, with those in the west of the Region generally seeing earlier increases of influenza indicators compared to others. Influenza admissions, detections, and percent positivity in hospital surveillance were also increasing from inter-seasonal levels, with a higher proportion aged 65 years or older. A majority of influenza detections from sentinel and non-sentinel primary care and hospital surveillance systems were A(H3N2) viruses. Region of the Americas During the 2025 southern hemisphere season in the Americas, influenza transmission exceeded the seasonal threshold in mid-March, remaining mostly at low to moderate levels. Circulation was driven by influenza A(H1N1)pdm09, reaching a peak positivity of 19%. Activity then declined to low levels until the end of August, when an increase in circulation was observed, associated with influenza A(H3N2) in Brazil and Chile. As of beginning of November, Chile remains at moderate levels of influenza A(H3N2) transmission, without evidence of increased severity or rises in outpatient consultations. As of 4 November 2025, subclade K had not been detected in South America. In the northern hemisphere countries of the Americas, during week 45 of 2025, seasonal influenza circulation remained low, with influenza A(H1N1)pdm09 predominating in the Caribbean and Central America. In North America, influenza activity—although still low—was increasing, mainly driven by influenza A virus detections. While most detections in Mexico were influenza A(H1N1)pdm09, a predominance of influenza A(H3N2) has been observed in the United States and Canada, with growing detections of the A(H3N2) subclade K. South-East Asia Region Influenza detections in the South-East Asia Region started increasing from June, peaked in August and since then have generally remained low with some exceptions. During the 2025 till November, the proportion of Influenza A among all influenza viruses tested positive was 66% Influenza A(H3N2) was the predominant sub-type (43%) in transmission followed by A(H1N1)pdm09 (~20%). In Thailand, influenza detections of predominantly A(H3N2) increased in October and November. Influenza A(H3N2) detections also increased since July in Bangladesh and October in Sri Lanka. While the region has seen an increase in Influenza A(H3N2), 22 sequences of subclade K have been reported in GISAID from Nepal (1), India (4) and Thailand (17) as of 30 November. Western Pacific Region Since the beginning of October 2025, influenza seasonal activity has increased in the Western Pacific Region. In some countries, including Japan and the Republic of Korea, the onset of the typical seasonal influenza activity period started earlier than in previous years. As of 9 November 2025, influenza positivity ranged from 8% to 56% in the northern hemisphere countries. In southern hemisphere countries, influenza activity shows mixed trends; positivity has declined in Australia, remains high in New Zealand and is rapidly increasing in Fiji. The elevated influenza activity in New Zealand and Fiji is unusual for this time of the year. The predominant circulating influenza subtype is influenza A(H3N2), marking a shift from A(H1N1)pdm09, which predominated during the 2024-2025 northern hemisphere winter season. The increases in influenza have predominantly been driven by the expansion of A(H3N2) subclade K, which represents 89% of sequences submitted to GISAID from the Western Pacific Region (as of 21 November 2025).

Since the lifting of the second PHEIC for mpox on 5 September 2025, and as of 24 November 2025, 43 new confirmed cases of clade Ib MPXV have been reported across six WHO regions outside areas where sustained community transmission of this virus strain has been occurring. In four of these regions (Region of the Americas, South-East Asia Region, European Region and the Western Pacific Region), 24 cases had reported no recent international travel, suggesting local transmission. Based on this, Italy, Malaysia, the Netherlands, Portugal, Spain, and the United States of America are now considered to be experiencing community transmission of clade Ib MPXV. In addition, travel-related cases continue to be reported in many countries. Among the 43 cases, half (22) were documented among men who have sex with men, while other cases were linked to travel to countries with known community transmission of clade Ib, or secondary to travel-related cases (household contacts and/or sexual partners). This report provides an overview of these recent cases of mpox confirmed to be due to clade Ib MPXV, by WHO region and country, summarizing key available epidemiological information, followed by WHO’s rapid risk assessment and public health advice. Summary of reported mpox due to clade Ib MPXV in WHO Regions and countries from 5 September to 24 November 2025WHO African RegionSince the lifting of the PHEIC on 5 September 2025 and as of 24 November 2025, one country, Namibia, has reported clade Ib MPXV cases for the first time. Community transmission persists in Burundi, the Democratic Republic of the Congo, Kenya, Malawi, Mozambique, Republic of Congo, Rwanda, South Africa, the United Republic of Tanzania, Uganda, and Zambia. NamibiaNamibia notified WHO of one probable and two confirmed cases of mpox due to clade Ib MPXV. The index (probable) case linked to travel within the African Region and the two confirmed cases were his household contacts. No further cases have been reported following detection of this cluster. These are the first cases of mpox reported in the country. WHO Region of the AmericasTwo countries in the WHO Americas Region have reported a total of four confirmed cases of mpox due to clade Ib MPXV. One case detected in Canada had recently travelled, while three cases in the United States of America had no recent travel history or known epidemiological links to travellers. CanadaCanada notified WHO of one confirmed mpox case due to clade Ib MPXV in an adult male with recent travel outside of the country and reporting no sexual partners after returning to Canada. The case received counselling on preventing further transmission. United States of AmericaThe United States of America reported three unrelated cases of mpox due to clade Ib MPXV in Long Beach (one case) and Los Angeles (two cases) counties, California. All three occurred among men who have sex with men, none of whom had a history of recent international travel or known exposure to mpox cases. None of the individuals had a previous MPXV infection or prior orthopoxvirus vaccination, and one case was immunocompromised. All three individuals were hospitalized, received standard medical care, and have fully recovered. Prior to the lifting of the PHEIC, the United States of America had reported six cases of mpox due to clade Ib MPXV, all linked to travel. Public health authorities conducted contact tracing among household, healthcare-facility and social contacts. No additional cases of mpox due to clade Ib MPXV have been detected to date. Public health investigations suggest ongoing community transmission of clade Ib MPXV among men who have sex with men and their social networks in southern California. Viral genomic sequencing data indicate that the three California cases may be linked to a previously reported case in the country in August 2025. WHO South-East Asia RegionFrom 5 September to 24 November 2025, five cases of mpox due to clade Ib MPXV have been reported in the WHO South-East Asia Region, all in Thailand. All cases had a recent history of international travel and three self-identified as men who have sex with men. ThailandThailand notified WHO of five new cases of mpox cases due to clade Ib MPXV. The cases included four males, three of whom self-identified as men who have sex with men, and one female. Travel histories indicate associations with recent travel to the United Arab Emirates, Oman, and the Russian Federation, where exposure to infection is likely to have occurred. Prior to 5 September, Thailand had reported five cases of mpox due to clade Ib MPXV, all of which were associated with international travel. WHO Eastern Mediterranean RegionThree countries in the WHO Eastern Mediterranean Region, Egypt, Lebanon and Qatar have reported six cases of mpox. Although the clade was not documented in Egypt and Lebanon, two cases attributed to clade Ib MPXV were reported in Qatar. QatarQatar notified WHO of two cases of mpox due to clade Ib MPXV. One adult male and one adult female, linked to travel within the Eastern Mediterranean Region. Prior to this period, Qatar had reported three cases of mpox due to clade Ib MPXV, all of which were associated with international travel. WHO European RegionCountries in the WHO European Region have reported a total of 27 mpox cases due to clade Ib MPXV. Of these, 18 cases were classified as autochthonous, with no relevant history of recent international travel, suggesting undetected community transmission (Italy, the Netherlands, Portugal, and Spain). Two cases (reported from Belgium and the United Kingdom) were related to travel within Europe and five cases to travel outside of Europe (East Africa, Uganda, United Arab Emirates), either to or from countries experiencing community transmission of clade Ib MPXV but also to or from countries where no community transmission has been reported, including Angola, the United Arab Emirates, and Viet Nam. Furthermore, at least 15 of the 27 cases, and 14 of the 18 locally acquired cases occurred among individuals who self-identified as men who have sex with men. BelgiumBelgium reported to WHO one case of mpox due to clade Ib MPXV with recent travel to the Netherlands. This individual reported having had multiple sexual contacts with other men while in the Netherlands. Prior to 5 September, Belgium had reported six mpox cases caused by clade Ib MPXV, all linked to travel. France France notified WHO of one case of mpox due to clade Ib MPXV in an adult male traveller who had returned from East Africa. Prior to this period, France had reported three cases of mpox due to clade Ib MPXV, all linked to travel. Germany Germany notified WHO of three cases of mpox due to clade Ib MPXV. All three cases had a recent history of international travel: one, an adult male who had travelled to Angola, another an adult female who had travelled to Uganda, and the third, an adult male who had travelled to Viet Nam. Uganda has community transmission of clade Ib and Viet Nam has not previously reported cases of this subclade. Prior to 5 September, Germany had reported 12 mpox cases due to clade Ib MPXV, most of which were linked to travel. Greece Greece notified WHO of its first case of mpox due to clade Ib MPXV, in an adult male with a recent history of travel to the United Arab Emirates before arriving in Greece. IrelandIreland reported two cases linked to a small cluster which was reported before 5 September 2025. The index case had history of recent travel outside Europe. The first locally acquired case was a child (

On 15 November 2025, WHO was notified of a confirmed human infection with influenza A(H5) in the United States of America—the first reported in the country since February 2025 and the 71st since early 2024. On 20 November, CDC laboratory sequencing verified the virus as influenza A(H5N5), representing the first human case of this subtype reported globally. The patient was an adult with underlying medical conditions residing in Washington State. The patient developed symptoms including fever during the week ending 25 October 2025. During the week ending 8 November 2025, the patient was hospitalized with a serious illness and subsequently died on 21 November. Respiratory specimens collected at the healthcare facility tested positive for influenza A virus by RT-PCR and were presumptive positive for influenza A(H5) at the University of Washington. The specimens were sent to the Washington State Public Health Laboratory, where influenza A(H5) was confirmed using the CDC influenza A(H5) assay. The sample was received at the CDC on 19 November. Sequencing conducted at the University of Washington and at the CDC indicated this was an influenza A(H5N5) virus belonging to the H5 haemagglutinin (HA) clade 2.3.4.4b[1]. Public health investigation revealed that the patient kept backyard poultry and domestic birds. Additional epidemiological investigations are under way and include active monitoring of anyone who was in close contact with the patient.

The EVD outbreak in the Democratic Republic of the Congo (DRC) was declared on 4 September 2025. As of 30 November 2025, a total of 64 cases (53 confirmed, 11 probable), including 45 deaths (CFR 70.3%), have been reported from six health areas (Bambalaie, Bulape, Bulape Com, Dikolo, Ingongo and Mpianga) in Bulape Health Zone, Kasai Province. Since the last confirmed case reported on 25 September 2025, no new confirmed EVD cases have been reported. There have been five cases among health workers (four nurses and one laboratory technician), three of whom have died. The epicentres of the outbreak have been localised in Dikolo (26 cases, 15 deaths) and Bulape (24 cases, 22 deaths) health areas, which together account for 78.1% of the total cases reported and 82.2% of all deaths. The outbreak initially involved nosocomial transmission and a high-transmission funeral gathering, with high mortality among young children. As of 12 October 2025, a total of 572 contacts were followed up. On 1 December 2025, the Ministry of Health declared the end of the outbreak. This declaration came after two consecutive incubation periods (42 days) since the last person confirmed with EVD tested negative for the virus and was discharged on 19 October 2025, as per WHO recommendations. Figure 1. Map of confirmed and probable cases and deaths of Ebola virus disease, Bulape Health Zone, Kasai province, Democratic Republic of the Congo, as of 30 November 2025 Figure 2: Epidemic curve of confirmed and probable Ebola virus disease cases in Bulape Health Zone, Kasai province, Democratic Republic of the Congo, as of 30 November 2025

In 2025, from 1 January to 2 November, a total of 20 412 suspected diphtheria cases, including 1 252 deaths (an average case fatality ratio [CFR] – 6.1 %) have been reported across eight Member States in the WHO African Region (Algeria, Chad, Guinea, Mali, Mauritania, Niger, Nigeria, and South Africa). Of these suspected cases, 9 864 (48.3%) cases have been confirmed through laboratory testing, epidemiological linkage, or clinical diagnosis. Laboratory confirmation was conducted for 5.7% (n = 1 177) of the suspected cases. Women, children aged 5–18 years, and young adults under 30 years are the most affected, confirming that the immunity gap extends well beyond early childhood. The situation has further deteriorated in Mali, Mauritania, and Niger, in recent weeks, with increasing case numbers and geographic spread of the outbreaks reported in these countries. The resurgence of diphtheria across multiple countries in the WHO African Region constitutes a serious public health concern which led to its grading as a grade 2 emergency under the Emergency Response Framework of WHO. Timely case detection, coordinated response, and clinical management remain critical to limiting transmission and reducing the high fatality rates observed in recent outbreaks. However, response efforts are being hampered by a global shortage of DAT and limited laboratory diagnostic capacity. Effective outbreak control requires comprehensive, multi-sectoral action across all response pillars including emergency coordination, laboratory confirmation, enhanced surveillance and case finding, clinical management with life-saving DAT and appropriate antibiotics (in accordance with WHO guidelines), infection prevention and control (IPC). Sustained vaccination efforts, coupled with risk communication and community engagement (RCCE) are essential to interrupt transmission and protect high-risk populations. In addition, preventing the recurrence of diphtheria outbreaks in the African Region will require strengthened health systems, particularly through robust routine immunization coverage. Summary of individual country situations from 1 January to 2 November 2025 Algeria Algeria reported a diphtheria outbreak in October 2025 in Skikda province, with 13 suspected cases and two deaths (CFR 15%). Eight of the suspected cases were laboratory-confirmed, and none of the confirmed cases had received diphtheria vaccination. The outbreak affected both children and adults, with males accounting for 62.5% of confirmed cases. A previous outbreak in southern Algeria, reported in 2024, involved over 900 suspected cases and 119 deaths (CFR 13%). According to WHO/UNICEF estimates of national immunization coverage (WUENIC) for 2024, Algeria has high national immunization coverage (98% for the first Diphtheria-Tetanus toxoid-Pertussis [DTP] dose and 92% for the third), however geopolitical instability in neighboring countries has led to mass displacement into southern Algeria, where vaccination coverage among refugees is low. The lack of data since May 2025 and limited information sharing are key challenges to assessing the full scope of the outbreak. Chad From 1 January to 2 November 2025, Chad reported 4 462 suspected diphtheria cases and 47 deaths (CFR 1.1%), with only four laboratory-confirmed cases. The significant amount of suspected diphtheria cases compared to the limited number of laboratory-confirmed cases highlights the challenge in the country to obtain a laboratory-confirmed diagnosis. The outbreak affects 27 out of 215 health districts across 7 of 23 provincial health delegations, with active transmission ongoing in three regions. Most cases are among children aged 3–13 years, and vaccination status is unknown for the vast majority. Chad faces a complex humanitarian crisis marked by conflict, displacement, and food insecurity. The country hosts over 1.4 million refugees, including more than 870 000 Sudanese refugees and 300 000 Chadian returnees. The health system is overwhelmed, and multiple infectious disease outbreaks, including yellow fever, measles, cholera, and hepatitis E, are occurring simultaneously. WHO, UNICEF, and MSF are supporting response efforts, but challenges include delayed reporting, insufficient case management kits, and logistical constraints. A request has been submitted to Gavi for vaccine supply and operational funding for mass immunization campaigns. According to WUENIC, the DTP coverage in 2024 was 84% for the first dose and 68% for the third dose. Guinea Guinea has experienced a resurgence of diphtheria since June 2025, with 476 suspected cases and 123 deaths. The CFR among the suspected cases is 25.8%, the highest among affected countries. The outbreak has affected four of 38 prefectures (11%), with human-to-human transmission concentrated in the Kankan region, particularly in Siguiri district, which accounts for over 80% of reported cases and fatalities. Laboratory confirmation remains limited, with only 70 cases confirmed. The outbreak follows a major event in 2023 that affected multiple regions and led to over 4 500 suspected cases. Guinea’s response is hampered by delayed presentation to health facilities, and insufficient resources for clinical management and community engagement. The outbreak is occurring in gold mining areas with high population mobility, increasing transmission risk. According to WUENIC in Guinea for 2024, the immunization coverage remains low (77% for the first DTP dose and 63% for the third), and urgent needs include DAT supply, improved clinical pathways, and expanded vaccination efforts. Mali From 1 January to 2 November 2025, Mali has reported 430 suspected diphtheria cases and 29 deaths (CFR 6.7%), with 46 laboratory-confirmed cases. The outbreak has affected seven out of 11 regions (64%), including the capital city Bamako, with the number of affected districts increasing from three to 30 out of 75 in less than six weeks, representing a rapid geographic expansion. Mali is experiencing a complex humanitarian crisis driven by conflict, climate related disruptions, and limited access to basic services. In 2025, 6.4 million people required humanitarian assistance. Displacement and restricted access to healthcare have contributed to low immunization coverage among vulnerable populations. According to WUENIC in 2024, estimates show 91% coverage for the first DTP dose and 82% for the third. Challenges include underreporting, limited availability of DAT, and logistical constraints. The outbreak response is hindered by concurrent emergencies and overstretched health services. Mauritania From 1 January to 2 November 2025, Mauritania has reported 849 suspected cases of diphtheria and 33 deaths (CFR 4%), with 318 confirmed cases. After an initial delay, the outbreak was officially declared on 25 September 2025 and has rapidly expanded across 11 out of 53 departments (21%). An upsurge of cases has been observed since late September. The most affected age groups are children and adolescents aged 5–19 years, and women account for 60% of suspected cases. Only 10% of cases have documented vaccination history. Mauritania hosts the largest refugee camp for Malians, with over 118 000 refugees, mostly women and children. The outbreak coincides with a Rift Valley fever outbreak in some of the same regions. Response efforts are challenged by limited resource mobilization, weak active case finding, and insufficient community sensitization. Reactive vaccination campaigns have been initiated, but gaps remain in funding, logistics, and healthcare worker training. According to WUENIC in 2024, the immunization coverage is relatively high (95% for the first DTP dose and 86% for the third), but subnational disparities persist. Niger From 1 January to 2 November 2025, Niger has reported 1 926 suspected diphtheria cases and 122 deaths CFR (6.3%), with 765 laboratory-confirmed cases. The outbreak has affected 34 out of 72 health districts (47%) across eight regions, with most cases concentrated in Agadez, Diffa and Zinder. Compared to 2024, there have been fewer reported cases and deaths, but transmission remains active. Niger is facing a protracted humanitarian crisis driven by insecurity, climate related disruptions, economic pressures, and displacement. An estimated 2.6 million people require humanitarian assistance. According to WUENIC in 2024, the immunization coverage is relatively high (95% for the first DTP dose and 86% for the third), but recent outbreaks highlight gaps in vaccine access and delivery. A vaccination campaign in September 2025 achieved high coverage, and a second round is planned. Challenges include limited diagnostic and treatment capacity, insufficient vaccine quantities, low public awareness, and funding constraints. Nigeria Nigeria continues to report the highest number of diphtheria cases in the African Region. From 1 January to 2 November 2025, 12 150 suspected cases have been reported, with 8 587 confirmed and 884 deaths (CFR 7.2%). Confirmed cases have been reported from 240 Local Government Areas across 30 states. Most cases are clinically compatible, with only 3% confirmed by laboratory testing. The outbreak has disproportionately affected children and adolescents, with low vaccination coverage contributing to the spread. In Nigeria more than 2 million children are under-immunized, including those with zero-doses, highlighting the high risk of further spread. Reactive campaigns have been conducted in Imo, Kaduna and Lagos, targeting health workers and priority populations. The outbreak overlaps with areas targeted by the Big Catch-up initiative. Challenges include delayed laboratory confirmation, poor IPC practices, limited information, education and communication materials, and vaccine shortages. Discussions with Gavi are ongoing to secure additional support. According to WUENIC in 2024, the estimates show 71% coverage for the first DTP dose and 67% for the third. South Africa From 1 January to 26 October 2025, South Africa has reported 106 diphtheria cases, including 66 laboratory-confirmed respiratory cases, two laboratory-confirmed cutaneous cases, one probable respiratory case, and 37 asymptomatic carriers. The outbreak has affected 5 of 9 provinces (55%), highlighting the involvement of multiple provinces. Most cases and carriers are from the Western Cape, with additional clusters in Limpopo, Gauteng, KwaZulu-Natal, and Mpumalanga. CFR among probable and confirmed respiratory diphtheria cases was 18% (12/67). Most respiratory cases occurred in adults aged 18 years and older. Clusters have been documented among vulnerable populations, including individuals in correctional facilities. According to WUENIC in 2024, the immunization coverage remains below 80% in most provinces (76% for the first DTP dose and 74% for the third), and immunity gaps are widening. The outbreak response is challenged by competing priorities, limited human resources, and limited global supply of diphtheria antitoxin. Detailed case investigations and in-depth risk assessments are needed to guide targeted interventions. Geographical distribution of diphtheria outbreaks in the WHO African Region, January 2025 until 2 November 2025 Table 1. Summary of reported ongoing diphtheria outbreaks in the WHO African region, January – 2 November 2025 Table 2. Summary of vaccination coverage by diphtheria-affected country (WUENIC, 2024)

As of 20 November 2025, 33 laboratory tests have been conducted, of which six confirmed cases, including three deaths, have been reported. Of the six confirmed cases, three are currently alive and on treatment. In addition to the lab-confirmed cases, a further three epidemiologically linked cases could not be tested; all three are deceased and recorded as probable cases. A total of 206 contacts have been identified, and contacts are under active follow-up. The number of contacts will continue to change as the response evolves. Clinically, patients have presented with high-grade fever, headache, vomiting, abdominal pain, and watery or bloody diarrhoea. Haemorrhagic manifestations, including nose bleeding and vomiting blood were observed in five cases, consistent with multi-organ failure. As this is the first time Ethiopia is reporting MVD, WHO recommends that samples be shared with a reference laboratory for inter-laboratory comparison. Figure 1: Map of Ethiopia showing location of Jinka town

Mauritania Human cases: Between 27 September and 30 October 2025, a total of 46 confirmed human cases of RVF, including 14 associated deaths (case fatality ratio: 30%), were reported in eleven districts from thirteen regions (wilayas), three of which share international borders: Assaba (bordering Mali to the south), Brakna and Trarza (both bordering Senegal along the Senegal River). Out of a total of 190 samples tested, 46 were positive, i.e. a positivity rate of 24.2%. Animal cases: On 30 October 2025, the Mauritanian Ministry of Animal Resources reported a total of 62 animal outbreaks, with 235 positive samples out of 1106 collected and tested. The first animal cases, involving goats and dromedaries, were reported in August 2025. A total of 235 animal cases, including 71 deaths (two in camels and 14 in goats), have been reported in Aioun (Hodh El Gharbi region) and Timbedra (Hodh Ech Chargui region), both located in the southeast near the border with Mali, as well as in Maghta Lahjar (Brakna region) in the center of the country. In the Brakna region, 46 animal cases and 55 deaths have been reported to WOAH. Affected species include sheep, goats, dromedaries and cattle. RVF is endemic in Mauritania. The last major outbreak occurred in 2022, with 47 confirmed human cases, including 23 deaths (case fatality ratio 49%), mainly affecting pastoralists in nine of the fifteen regions. During this outbreak, cattle, camels and small ruminants were also affected, with positivity rates in animals approaching 21.2%. Senegal Human cases: Between 20 September and 30 October 2025, the Republic of Senegal reported a total of 358 confirmed human cases of RVF, including 28 deaths (case fatality rate: 7.8%). The cases were recorded in 22 health districts from eight administrative regions, with the vast majority (78%) reported in the Saint-Louis region. Additional cases have been reported in Dakar (nine cases), Fatick (12 cases), Kaolack (13 cases), Louga (18 cases), Matam (23 cases), Thiès (2 cases) and Tambacounda (2 cases). The affected districts in the Saint-Louis region, namely Dagana (32 cases), Pete (9 cases), Podor (32 cases), Richard-Toll (133 cases) and Saint-Louis (73 cases), are all located along the northern border with Mauritania, close to the Senegal River. Animal cases: Animal infections have been detected in the same areas as human cases. On 23 September 2025, authorities collected 1122 blood samples and four abortion samples from small ruminant herds in the affected villages. Laboratory analyses confirmed 36 positive samples from six herds. As of 29 October 2025, a total of 160 confirmed animal cases of RVF have been reported in sheep, goats and cattle in seven regions of Senegal: Dakar, Fatick, Louga, Matam, Saint-Louis, Tambacounda and Thiès. In addition, 640 animal abortions were reported in three regions. As of 22 October 2025, the country has notified WOAH of 26 RVF outbreaks, affecting a total of 59 animals, including two deaths. RVF is endemic in Senegal, with previous outbreaks affecting both human and animal populations. The last confirmed human case prior to this outbreak was reported in January 2025 in Touba, Diourbel region, while the last human case in the Saint-Louis region was in 2022. Figure 1. Geographic distribution of confirmed human RVF cases (404) and deaths (n=42) in Mauritania and Senegal, September 20 to 30 October 2025.

Global overview Globally as of December 2024, current or previous autochthonous transmission of CHIKV had been reported from 119 countries and territories across six WHO regions. In addition, 27 countries and territories had evidence of established and competent Aedes aegypti and Aedes albopictus vector populations but had not yet documented autochthonous CHIKV transmission. Per available data from January to September 2025, 263 592 suspected and 181 679 confirmed CHIKV disease cases and 155 CHIKV disease-related deaths have been reported globally. While certain WHO Regions are reporting lower case numbers compared to 2024, others are experiencing marked increases. This heterogeneity in regional trends complicates the interpretation of a global increase. Instead, the data suggest localized resurgence or emergence in specific geographic areas. The region of the Americas has reported the highest number of cases followed by the European region (comprised of cases reported predominantly from French Overseas Departments in the Indian Ocean). Table 1: Number of suspected and confirmed CHIKV disease cases and deaths by region in 2025, as of September 2025. *Note: the date of last report varies by country Figure 1: Geographical distribution of CHIKV disease cases as reported to WHO or Publicly shared by Ministries of Health from January to September 2025 Regional overview African region As of September 2025, a total of 2197 suspected and 108 confirmed CHIKV disease cases have been reported from four countries: Comoros, Kenya, Mauritius, and Senegal with Mauritius recording the highest number of cases. In Comoros, between 1 January to 31 May 2025 (epi week 1 and epi week 22), a total of four confirmed cases have been reported, while Senegal reported seven confirmed cases. In Mauritius, a total of 1583 cases have been reported between 15 March to 4 August 2025 (epi week 12 to epi week 32), including 1543 local and 40 imported cases. There have been no reported deaths. In Kenya, a chikungunya outbreak was confirmed in Mombasa County as of 8 June 2025 (epi week 23). By 6 July 2025 (epi week 27), a total of 614 cases had been recorded, including 97 laboratory-confirmed cases. Since then, no further cases have been reported. No chikungunya-related deaths have been recorded to date. Eastern Mediterranean Region As of September 2025, a total of 1596 suspected, and 67 confirmed CHIKV disease cases have been reported from Pakistan and Somalia. In Pakistan, CHIKV disease cases in 2025 have been reported at rates similar to those in 2024. A notable increase occurred between 4 May to 21 June 2025 (epi weeks 19 to 25), with 101 to 121 suspected CHIKV disease cases reported per week during this period. In Somalia, a chikungunya outbreak has been confirmed in Sool region, with 488 suspected cases reported between January and June 2025. Eight out of 10 samples tested were laboratory-confirmed for chikungunya. Somalia has also recorded imported travel related cases. European Region As of 15 September 2025, two European countries—France and Italy—have reported locally acquired cases of CHIKV disease. France has recorded 479 cases distributed across 54 clusters, with 40 clusters currently active. Italy has reported 205 locally acquired cases distributed across four clusters of which three clusters are currently active. A total of 56 456 CHIKV disease cases, and 40 deaths, have been reported from four countries in the European region in 2025. In France, the increased incidence of CHIKV outbreaks in 2025 represent a deviation from observed patterns in previous years. In 2024, only one CHIKV disease case was reported. The larger number of chikungunya cases this year, along with their early onset, are linked to an epidemic in La Réunion and the broader Indian Ocean region, driven by a viral strain that is highly adapted to the Aedes albopictus mosquito. In the French overseas department of La Réunion, a total of 54 517 confirmed cases and 40 deaths have been reported in 2025 (as of 14 September). There has been a steady decline in new cases since 26 April (epi week 17) indicating that the outbreak is waning. This marks the first autochthonous transmission of chikungunya on the island since 2014. In Mayotte, following two imported cases from La Réunion, the first locally acquired CHIKV disease case was confirmed in March 2025. As of 18 September 2025, a total of 1255 locally acquired cases, including 39 hospitalizations, have been reported. The transmission receded since August with only a few cases reported per week on average. Region of the Americas As of 20 September 2025, CHIKV disease transmission continues across the Americas in line with expected seasonal patterns. A total of 228 591 suspected cases have been reported from 14 countries, including 100 329 confirmed cases and 115 deaths. In Bolivia, a total of 5372 CHIKV disease cases have been reported, 73% of which are laboratory confirmed, along with four deaths. The outbreak primarily affected the department of Santa Cruz with 99% of cases (n=3905, including four deaths). Additionally, cases were reported in the departments of Beni, Chuquisaca, Cochabamba, Pando, and Tarija. Brazil accounts for nearly 96% of all reported cases and deaths in the region, with 96 159 confirmed cases and 111 deaths. In Cuba, between 1 January to 20 September, 34 cases of chikungunya were reported, all confirmed by laboratory by RT-PCR test, in the provinces of Guantanamo, La Habana, Matanzas, Pinar del Rio and Santiago de Cuba. Public health interventions have been implemented. South- East Asia Region As of early September 2025, over 34 628 CHIKV disease cases, both suspected and confirmed, have been reported in the WHO South-East Asia region, primarily from India and Bangladesh. In India, between 1 January and 31 March 2025, a total of 30 876 suspected cases and 1741 confirmed cases were reported. The states reporting the highest number of confirmed cases were Maharashtra, Karnataka and Tamil Nadu. In Bangladesh, the Institute of Epidemiology, Disease Control and Research between reported a total of 732 suspected CHIKV disease cases in Dhaka city between 1 January and 31 August 2025. Of these, 400 cases were laboratory-confirmed by RT-PCR. In Sri Lanka, a total of 151 confirmed CHIKV disease cases were reported from sentinel sites in Colombo, Gampaha and Kandy between 1 January 2025 and the second week of March 2025. According to the Epidemiology Unit Division situation report, dated 31 August 2025, the CHIKV disease cases continued to increase and peaked in June 2025. Over half of the reported cases were from the Western Province, with Colombo District alone reporting 33%. The most affected age group was 41–60 years (36.4%), although an increasing trend was noted among children. In Thailand, a total of 1128 CHIKV disease cases were reported between 1 January and 14 September 2025. Bueng Kan (142), Chiang Mai (411), and Loei (125) are the provinces reporting the most cases. The age distribution of cases is: 0-4 years 2%, 5-9 years 3%, 10-14 years 6%, 15-19 years 4%, 20-29 years 9%, 30-39 years 17%, 40-49 years 17%, 50-59 years 16%, ≥ 60 years 26%. Western Pacific Region A total of 21 299 CHIKV disease cases including four countries reporting imported cases, with no deaths, have been reported from 16 countries and areas in the Western Pacific region in 2025. Of these, five countries reported local transmission, six reported imported cases, and five reported no cases during the year. In China (excluding Hong Kong SAR, Macao SAR, and Taiwan, China), as of 27 September 2025, a total of 16 452 locally transmitted cases has been reported in Guangdong Province. All cases were laboratory-confirmed. This represents the largest documented chikungunya outbreak to date in China. The cases have been reported in 21 cities, mainly in Foshan City (10032), Jiangmen City (5209), Guangzhou City (590), Shenzhen City (128), Zhanjiang City (112), Zhuhai City (60), and Zhongshan City (54). Additionally, during 1-21 September, Guangxi Zhuang Autonomous Region reported 297 local and associated cases; Fujian Province reported 124 local and associated cases; and some other provinces (such as Hunan, Sichuan, and Hainan provinces) also reported a few local cases. According to the data as of 16 August 2025, among all locally reported cases nationwide, the age distribution is: 0-5 years 3.1 %, 6-17 years 13.6 %, 18-45 years 37.0 %, 46-60 years 23.3 %, 61-74 years 15.2 %, and ≥75 years 7.8 %. Up to now, all reported cases have been mild, with no severe cases or deaths. In Indonesia, as of 31 July 2025, a total of 3608 confirmed CHIKV disease cases across 19 provinces have been reported, compared to 1399 confirmed cases reported during the same period in 2024. No chikungunya-related deaths have been recorded to date. The risk of future increases persists, particularly during the transition from the rainy to the dry season, with heightened concern in the most populous and frequently visited provinces: West Java, Central Java, East Java, and Banten. The Ministry of Health of Indonesia has strengthened detection and reporting through its Early Warning Alert and Response System (EWARS) and has implemented response measures in high-risk areas. In Malaysia, as of 2 August 2025, a total of 40 CHIKV disease cases have been reported in 2025, compared to the 63 cases reported during the same period in 2024. No chikungunya-related deaths have been recorded to date. During the current reporting year, three chikungunya clusters were reported. Case investigation, integrated vector management, community engagement, and multisectoral collaboration efforts were implemented. All outbreaks were successfully contained within two weeks of detection, indicating an effective public health response and outbreak management. In Philippines, as of 16 August 2025, a total of 628 CHIKV disease cases have been reported, a 78% decrease from 2886 cases reported in the same period in 2024. The national trend has been fluctuating, with 46 cases reported from 20 July to 2 August 2025, which is 10% lower than the 51 cases reported two weeks prior (6 to 19 July 2025). Cases ranged from 1 to 87 years old, with a median age of 33. Females accounted for 66% of cases (414 out of 628). There was one death reported (CFR: 0.16%). Local health authorities have investigated areas with clustering of cases to determine risk factors and implement vector control activities In Singapore, as of 20 September 2025, 25 cases of CHIKV disease cases have been reported, compared to 12 cases reported during the same period in 2024. The majority of the cases were individuals with recent travel to chikungunya-affected areas. No chikungunya-related deaths and no sustained local transmission have been reported. The Communicable Diseases Agency Singapore continues to monitor the situation closely and provides ongoing guidance on prevention and control measures, particularly focusing on vector control to limit further transmission.

Between 1 January and 29 August 2025, the Bangladesh IHR NFP notified WHO of four confirmed fatal Nipah virus (NiV) infection cases that occurred at different times from four separate districts across three different divisions (Barisal, Dhaka, and Rajshahi) of Bangladesh. All cases were confirmed through Reverse Transcription Polymerase Chain Reaction (PCR) and Enzyme-Linked Immunosorbent Assay (ELISA) testing, and no epidemiological links were reported to have been identified between the cases. The first case was a young adult woman from Pabna district, Rajshahi division, with symptom onset on 25 January. She was admitted to a community hospital on 26 January and referred to another hospital the next day. She died on 28 January, and laboratory confirmation of NiV was received on 29 January. A total of 96 contacts were reported to be identified, and all tested negative for NiV. The second case was an adult man from Bhola district, Barisal division, who developed symptoms on 13 February and was admitted to hospital on 19 February. He was transferred to another hospital the next day and died on 22 February. NiV infection was confirmed on 21 February. A total of 71 contacts were reportedly identified, and all tested negative for NiV. The third case was an adult man from Faridpur district, Dhaka division, with symptom onset on 17 February. He was admitted to hospital on 25 February and died the same day. NiV infection was confirmed on 26 February. A total of 66 contacts were identified, and all tested negative for NiV. The fourth case was a male child from Naogaon district, Rajshahi division, with symptom onset on 3 August. He was admitted to a hospital on 8 August and moved to the intensive care unit the following day. He died on 14 August. Samples collected on 10 August tested positive for NiV on 22 August. An outbreak investigation team was deployed the same day. A total of 72 contacts were identified, and samples from 11 symptomatic contacts were collected. Six tested negative, while the results for the remaining are awaited. This case was reported outside the typical season (December to April). The first three cases had a history of consuming raw palm sap. However, the fourth case had no history of consuming raw palm sap, and the likely source/s of infection remain under investigation. None of the cases appears to be linked to each other. Fruit bats, the known reservoir for NiV, are present in the affected regions. Since the report of the first case in 2001, human infections have been reported almost every year, with case fatality ratios (CFR) varying between 25% (in 2009) and 100% (in 2024). In 2024, five laboratory-confirmed fatal cases of NiV were reported from Bangladesh (Figure 1, Figure 2). Figure 1. Annual number of reported Nipah virus cases and deaths, 1 January 2001 – 9 September 2025, Bangladesh. Source: Institute of Epidemiology, Disease Control and Research, Bangladesh. https://iedcr.portal.gov.bd/site/page/d5c87d45-b8cf-4a96-9f94-7170e017c9ce/- Figure 2. Distribution of Nipah cases in Bangladesh, 2001-2025, as of 14 August 2025

On 1 September 2025, WHO received an alert from the Ministry of Health of the Democratic Republic of the Congo (DRC) regarding suspected cases of EVD in the Bulape Health Zone, Kasai Province, DRC. The first known suspected index case was admitted to the Bulape General Reference Hospital on 20 August 2025. The patient was a pregnant woman at 34-weeks of gestation who presented with symptoms of fever, bloody diarrhoea, haemorrhage, vomiting, asthenia, followed by multiple organ failure. She died on 25 August 2025. Two of the health-care workers that had initially been in contact with this first case also developed similar symptoms and died. As of 4 September 2025, a total of 28 suspected cases, including 15 deaths, of which four are health-care workers (case fatality ratio (CFR): 54%) have been reported from three areas of the Bulape health zone (Bulape, Bulape Com and Dikolo) and Mweka health zone. About 80% of the suspected cases are aged 15 years and older. Five blood samples from five suspected cases and a naso-pharyngeal swab from a probable death were collected from the three health areas and shipped to the National Public Health Laboratory (INRB) in Kinshasa for testing. On 3 September 2025, the laboratory testing conducted at INRB confirmed Ebola virus (EBOV)[1] through GeneXpert and Polymerase Chain Reaction (PCR) assays. The results obtained from whole genome sequencing suggest that the outbreak is a new zoonotic spillover event and is not directly linked to the 2007 Luebo or 2008/2009 Mweka EVD outbreaks.[2] Figure 1. Map of suspected cases and deaths of Ebola virus disease by health zone, as of 4 September 2025

In 2025, the global cholera situation continues to pose a significant public health challenge across multiple regions. Between 1 January and 17 August 2025, a total of 409 222 cholera/AWD cases and 4738 deaths were reported globally, from 31 countries.[1] During the same period in 2024, 510 638 cases and 3248 deaths were reported from 28 countries, representing a 20% decrease in cases, but a 46% increase in deaths. In 2025, the Eastern Mediterranean Region recorded the highest number of cholera/AWD cases (230 991 cases, six countries), followed by the African Region (172 750 cases, 23 countries), the South-East Asia Region (2985 cholera/AWD cases, five countries), and the Region of the Americas (2496 cases, one country). Cholera-related deaths were highest in the African Region (3763 deaths, CFR 2.2 %), followed by the Eastern Mediterranean Region (943 deaths, CFR 0.4%), the Region of the Americas (31 deaths, CFR 1.2%), and the South-East Asia Region (One death, CFR 0.03%). Meanwhile, the European and Western Pacific regions have not reported any outbreaks. Cholera is resurging in a number of countries, with some that had not reported substantial case numbers in years, including Chad and the Republic of the Congo, while others, including the Democratic Republic of the Congo (DRC), South Sudan, and Sudan, are experiencing outbreaks that are continuing from 2024, with significant geographic expansion. The spread into previously unaffected areas is complicating containment efforts and straining fragile health systems. These trends reveal deep systemic weaknesses in health systems, Water, Hygiene, and Sanitation (WASH), and disease surveillance systems, especially in countries facing humanitarian crises. Cross-border transmission is occurring, underscoring the urgent need for stronger surveillance, timely reporting, and coordinated response across international borders. The disease burden remains high, particularly in the following countries currently experiencing acute outbreaks: Chad, DRC, the Republic of the Congo, South Sudan, and Sudan. These countries continue to report high transmission rates, case fatality rates, and experience significant challenges in outbreak control and access to care. However, differences in case definitions and reporting systems have been observed across countries and regions, which may affect the comparability of data and the interpretation of trends. Therefore, given these complexities, the data presented here likely underestimates the true burden of cholera and should be interpreted with caution. Figure 1. The global cholera and acute watery diarrhoea (AWD) cases per 100 000 population, 1 January to 17 August 2025 * * Afghanistan and Myanmar report AWD cases. Figure 2. Number of cholera cases by epidemiological week of reporting, as of 17 August 2025. Data source: WHO Figure 3. Cholera cases by epidemiological week of reporting (Chad, Republic of the Congo, DRC, South Sudan and Sudan) available as of 17 August 2025. Data source: WHO Overview of selected countries Cholera is resurging in a number of countries, including some that have not reported cases in years; the countries highlighted in this report continue to report high transmission rates, case fatality rates, and experience significant challenges in outbreak control and access to care. For a more detailed overview of cholera globally, please refer to the regularly produced global cholera situation report. Chad On 24 July 2025, Chad officially confirmed a cholera outbreak, following the report of the first suspected case on 13 July from Dougui Camp in Chokoyane health district, located in Ouaddaï province along the border with Sudan. Between 13 July and 19 August, the country reported a total of 776 cholera cases, including 53 deaths, resulting in a case fatality rate (CFR) of 6.8%. Of these deaths, 27 occurred in the community, highlighting gaps in timely access to care. Laboratory confirmation has been obtained for 32 cases through culture testing. As of 19 August, suspected cholera cases have been reported from two provinces (Ouaddaï and Sila) and six health districts: Abdi, Adré, Amleyouna, Chokoyane, Farchana and Hadjer Hadid. Among these, Chokoyane is the most affected, accounting for 541 cases and 25 deaths, with a district-specific CFR of 4.6%. Republic of the Congo Between 23 June and 17 August 2025, the Republic of the Congo reported a total of 457 suspected cholera cases and 35 deaths, resulting in a CFR of 7.7 %. The outbreak, which began in the Brazzaville district, has been spreading to districts along the Congo River. Brazzaville has recorded a CFR of 4.8 % (269 cases; 13 deaths), while Congo-Oubangui has experienced a significantly higher CFR of 11.7 % (188 cases; 22 deaths). The most affected age group is 15 to 24 years, accounting for 19% of all reported cases. Democratic Republic of the Congo From 1 January to 10 August 2025, the Democratic Republic of the Congo has reported a total of 46 800 cholera cases and 1362 deaths, resulting in a CFR of 2.9%. Cholera cases have been reported in 16 out of the country’s 26 provinces, with Kwango being the most recently affected as of week 31. During week 32, the country recorded 1887 new cases and 84 deaths, representing a 4.8% and 1.2 % decrease compared to the previous week, respectively. In the past four weeks, 57.4% of all cases have been concentrated in Kinshasa, North-Kivu, South-Kivu and Tshopo provinces. Kinshasa alone has reported 1781 cases and 136 deaths, with a notably high CFR of 8%. In week 31, Kinshasa recorded 126 cases and five deaths, with a weekly CFR of 4%. This shows a declining trend compared with the previous weeks. South Sudan From 1 January to 17 August 2025, South Sudan has reported a total of 71 825 suspected cholera cases and 1194 deaths, resulting in a CFR of 1.7 %. The outbreak has affected 55 of 80 counties across eight states and three administrative areas, demonstrating widespread transmission throughout the country. During the most recent reporting month, from 21 July to 17 August 2025, 2472 cases and 36 deaths were recorded nationwide. Between 14 July to 13 August 2025, approximately 74% of the cases reported were concentrated in Unity State, the Abyei Administrative Area, and Central Equatoria. Unity State reported 1562 cases and 10 deaths, Abyei recorded 988 cases and two deaths, while Central Equatoria registered 244 cases and two deaths. Sudan Between 1 January and 11 August 2025, Sudan has reported a total of 48 768 cholera and acute watery diarrhoea cases, along with 1094 deaths, resulting in a CFR of 2.2 %. The outbreak has affected all 18 states, with the majority of cases, 72 % reported from Khartoum (22 225 cases), North Kordofan (7394 cases), and White Nile (5622 cases). Cholera has also been confirmed in all five Darfur states, where both cases and deaths are rising. New areas, including border localities near Chad, have recently reported cases, indicating expanding transmission. The reported cholera burden varies significantly across the Darfur states. In the northern state, 3687 cases and 26 deaths have been reported, with a CFR of 0.7 %. The southern state has recorded 1589 cases and 66 deaths, resulting in a higher CFR of 4.2 %. The central state has reported 682 cases and nine deaths (CFR 1.3 %), while the eastern state has seen 517 cases and 26 deaths, with a notably high CFR of 5%. The western state has reported 17 cases with no associated deaths. There are identified gaps in the surveillance system in Darfur, which may lead to delayed reporting from some areas and no reports in others.

On 4 August 2025, WHO received an International Health Regulations notification from the IHR National Focal Point (NFP) for Israel reporting the declaration of a circulating vaccine-derived poliovirus type 1 (cVDPV1) outbreak in the country. Between February and July 2025, nine genetically related VDPV1 isolates were detected in environmental samples collected from seven sampling sites, four of which are geographically non-overlapping in the Jerusalem district and Central Region. Laboratory analyses and whole-genome sequencing (WGS) indicate that these viruses are genetically linked to each other and to multiple Sabin-like viruses isolated from environmental samples since October 2024. As of 8 August 2025, cVDPV1 has been detected only in environmental samples, with no paralytic cases reported at this stage. However current evidence supports classification of this event as an outbreak of cVDPV1 with sustained community transmission. Prior to this outbreak a Sabin-like type 1 virus (SL1), related to SL1 viruses detected in environmental surveillance, was the cause of an acute flaccid paralysis (AFP) case in an unvaccinated 17-year-old male from Jerusalem that was reported on 23 December 2024 and classified as vaccine-associated paralytic poliomyelitis (VAPP). Israel discontinued routine use of the bivalent oral polio vaccine (bOPV) in March 2025 but continues to administer four doses of inactivated polio vaccine (IPV) as part of the routine immunization schedule up to 12 months of age. The WHO/UNICEF Estimates of National Immunization Coverage for three doses of IPV in 2024 was 98%. However, vaccination coverage in Jerusalem is notably lower and below WHO’s recommended coverage threshold, which is necessary to maintain sufficient population immunity and prevent poliovirus transmission.