Ebola virus disease, D.R. Congo, Uganda
On 15 May 2026, the DRC declared its 17th Ebola outbreak caused by the Bundibugyo virus, with Uganda simultaneously reporting an imported case. WHO declared a Public Health Emergency of International Concern (PHEIC) on 16 May. Per 24 May, 867 suspected cases and 204 deaths have been reported, with transmission now spanning three provinces (Ituri, North Kivu, South Kivu). The presumed origin is Mongbwalu, a high-traffic mining zone, with onward spread to Rwampara and Bunia via care-seeking. Four healthcare workers have died. A US surgeon infected during a procedure was evacuated to Berlin. Uganda's two imported cases in Kampala have no documented local transmission yet. Response is hampered by armed conflict in Ituri, low contact-follow-up, unsafe burials, and porous borders with Uganda and South Sudan. No licensed vaccine or therapeutic exists for BDBV. WHO assesses national risk as very high, regional as high, global as low.
Hantavirus disease, ex-cruise ship, global update
The global case total in the MV Hondius cruise ship outbreak now stands at 12, including three deaths. A 12th hantavirus case was confirmed after a crew member tested positive, the WHO announced on Friday. The crew member had disembarked in Tenerife but was repatriated to the Netherlands, where the person has been in isolation. All confirmed and probable cases remain limited to ship passengers and crew. The MV Hondius is currently docked in Rotterdam undergoing sanitation. Identification of additional cases is still possible given the long Andes hantavirus incubation period (up to six weeks). EU/EEA population risk remains very low.
Measles, Global updates
The ECDC reports continued measles transmission across the EU/EEA and globally. In March 2026, 12 of 30 reporting countries notified 172 cases, led by Bulgaria, Italy, Spain, France, and Germany. Between April 2025 and March 2026, 3,607 cases were reported, predominantly in unvaccinated infants under one year, with five deaths. Active outbreaks persist in Bulgaria, France, and Portugal, with notable totals in Spain (118), Germany (82), Latvia (49), and England (542). A cluster in Spain (Murcia) linked to Alcantarilla now totals twelve cases. The picture is more severe globally. Bangladesh reports 8,067 confirmed cases and 481 deaths since mid-March. The Americas account for 18,088 cases, concentrated in Mexico (10,049), Guatemala, the US, and Canada. Japan has already exceeded its 2025 total. Peru declared a health emergency over 231 confirmed and 115 suspected cases, mostly in Puno. In Africa, 22 Member States recorded 96,455 cases (3,463 confirmed) and 633 deaths in 2026 (CFR 0.7%), with 496 new cases since 3 May across six countries.
Chikungunya, Mauritius and French Guiana
In Mauritius, an ongoing outbreak has surpassed 3,300 cases in 2026, as of 18 May. This marks a substantial increase from the 735 cases reported by 1 April, which noted rapid transmission across several districts. In French Guiana, 249 autochthonous cases have been identified, with case numbers increasing weekly. Most cases were detected in the Littoral ouest sector on the western side, near the Suriname border, which entered the 'epidemic' phase on 23 April. the outbreak's highest alert level. The identified strain shows close genetic relationship with recent sequences from Cuba and Brazil
West Nile virus disease, Europe and USA
The 2026 WNV season is opening earlier than expected on both sides of the Atlantic. In Italy, the first human case of the year has been reported in the province of Oristano, southwestern Sardinia. Oristano is a recognised hotspot. Italy reported multiple WNV cases and two deaths in 2025, with cases spanning Lazio, northern regions, and Sardinia. In the United States, the first case of WNV with neuroinvasive disease has been reported in resident of Harris County, Texas. Tennessee has also reported early-season detection. For context, there have been 976 total West Nile cases reported in Texas during the last five years, with 106 deaths. The early appearance in both regions signals heightened transmission risk and warrants intensified surveillance.
D.R. Congo declared its 17th Ebola outbreak on 15 May 2026 (Bundibugyo virus); WHO declared a Public Health Emergency of International Concern. As of 24 May, 867 suspected cases and 204 deaths span Ituri, North and South Kivu, with two imported cases in Uganda and no licensed vaccine. The cruise ship hantavirus outbreak has reached 12 cases including three deaths; the ship is docked in Rotterdam and EU/EEA risk remains very low. Measles transmission continues across the EU/EEA, with 3,607 cases (April 2025–March 2026), with outbreaks in Bulgaria, France, Portugal, and Spain. Globally, Bangladesh recorded 8,067 cases and 481 deaths, the Americas 18,088, and Africa 96,455 across 22 countries; Peru declared a health emergency over a measles outbreak involving 231 cases. The first West Nile Virus cases in 2026 were reported in Italy and the United States. Mauritius has surpassed 3,300 chikungunya cases, and French Guiana reports 249 autochthonous cases.
The ESCMID-AUMC Epi Alert, a strategic collaboration between the ESCMID Emerging Infections Subcommittee and the Center of Tropical Medicine and Travel Medicine of Amsterdam University Medical Center (AUMC) that integrates expertise and resources to advance emerging infectious diseases surveillance and intelligence sharing. This collaboration integrates ESCMID's extensive international network and emerging infections expertise with AUMC's proven surveillance capabilities, led by Dr. Abraham Goorhuis and the AUMC team and other collaborators form European Institutions.
The Epi Alert aims to be a weekly publication. The briefings are curated by infectious disease specialists prioritising data from trusted sources (such as Beacon, H-Radar, Outbreaknews, WHO, ECDC, CDC) based on potential impact, geographic region and urgency/relevancy to clinical practice. It aims to provide concise summaries for busy healthcare professionals with direct links for further investigation and transparency.
This integrated collaboration represents a significant milestone in ESCMID's commitment to emerging infections preparedness, strengthening our collective capacity to detect, analyse, and respond to infectious disease threats through international cooperation.
Disclaimer: The information in this epi-alert is a weekly summary of the information that is available on the internet, mainly the websites of Beacon, H-Radar, Outbreaknews, WHO, ECDC, CDC, and others. For this summary, we consider issues that are most relevant to the ESCMID members involved in clinical patient care. Therefore, this report is not comprehensive, but we strive to include all major global issues in this report on a weekly basis.
21 May 2026
This document provides an ESCMID Emerging Infections Subcommittee situation update on the 2026 Ebola Bundibugyo outbreak in the Democratic Republic of the Congo and Uganda. Its purpose is to inform healthcare professionals, microbiologists, public health authorities, and ESCMID members about the current epidemiological situation, major clinical and public health challenges, regional and international risks, and recommended preparedness measures. The document also highlights the importance of surveillance, infection prevention, healthcare worker protection, laboratory readiness, and international coordination while emphasising the urgent need for research and development of vaccines, diagnostics, and therapeutics for non-Zaire ebolaviruses.
Update - 06 May 2026
ESCMID EIS Day 3 update report
05 May 2026
This Situation Report, provides a concise overview of a suspected cluster of hantavirus pulmonary syndrome (HPS) identified aboard a cruise vessel originating from Argentina. As of 04 May 2026, preliminary information from WHO and UN sources indicates a small number of severe respiratory cases, including fatalities, with one laboratory-confirmed hantavirus infection and several additional suspected cases.
The purpose of this report is to inform ESCMID members of the evolving situation, summarise the current epidemiological understanding, and highlight key clinical and public health considerations. While rodent-associated exposure remains the leading hypothesis, investigations are ongoing, and important uncertainties persist regarding the exact transmission dynamics, viral strain, and extent of risk.
Given the potential severity of HPS and the confined setting of a cruise vessel, this event underscores the importance of vigilance, rapid risk assessment, and continued monitoring.
Disclaimer: The information contained in this document reflects what was available as of 04 May 2026, 5 pm (CEST) and may be updated as further relevant information becomes available; the situation remains ongoing.
Nipah virus is a highly pathogenic zoonotic virus that can be transmitted to humans through fruit bats, contaminated food, or close human-to-human contact, and is associated with severe encephalitis and high case-fatality rates. In January 2026, Nipah virus disease was reported in eastern India, with two confirmed cases identified among healthcare workers at a single hospital in West Bengal. This represents the seventh documented outbreak in India and the third reported in the state. According to an official update issued on 27 January 2026 by the Ministry of Health and Family Welfare of India, both cases were laboratory confirmed at the National Institute for Virology. A total of 196 contacts were identified, traced, monitored, and tested; all remain asymptomatic and have tested negative, with no additional cases detected to date, indicating no evidence of community transmission. Prompt and comprehensive public health measures, including enhanced surveillance, laboratory testing, and coordinated field investigations, have been implemented by national and state authorities, and the situation remains under close monitoring. While importation into Europe via infected travellers cannot be entirely excluded, the absence of Pteropus fruit bats in Europe limits the risk of onward transmission. No additional measures beyond monitoring, information sharing, and traveller advisories are expected at this stage.
On 14 November 2025, Ethiopia confirmed its first outbreak of Marburg virus disease (MVD) in the South Omo Zone, Southern Ethiopia. This outbreak represents a significant epidemiological shift: Ethiopia has never previously reported MVD. Genetic sequencing suggests the strain is closely related to East African lineages, pointing to a regional reservoir. Laboratory testing identified Marburg virus in samples from a cluster of suspected haemorrhagic fever cases. To date, 10 cases have been reported, including five fatalities (CFR 50%), two among healthcare workers, highlighting the risk of nosocomial transmission. A total of 57 suspected cases have been investigated, including four in the past 24 hours.
The recent re-emergence of avian influenza (H5N1) in parts of Asia, including isolated human cases in Cambodia and India, highlights the need for continued vigilance. While sustained human-to-human transmission has not been observed, the current situation warrants close monitoring. Strengthening surveillance, improving poultry vaccination strategies, and promoting regional One Health collaborations can support risk assessment and management, including early containment efforts.
Since the previous update on 05 May 2025, and as of 12 May 2025, nine new MERS-CoV cases—including two deaths—have been reported by health authorities in Saudi Arabia, bringing the total number of cases this year to ten.
Seven of the recent cases were part of the same cluster in Riyadh, including one patient with no history of contact with camels and six healthcare workers who acquired nosocomial infections from that patient in early May.
The risk of sustained human-to-human transmission in Europe remains very low. However, the current MERS-CoV situation is concerning, as this rise in cases comes just two weeks ahead of the Mecca pilgrimage—a period typically associated with high international travel.
Since April 2012, and as of 12 May 2025, a total of 2,638 confirmed MERS cases—including 957 deaths—have been reported globally.
A Marburg virus disease (MVD) outbreak is evolving in Rwanda, East Africa. As of 07 October 2024, over 40 confirmed MVD cases have been reported, mainly in healthcare facilities in Kigali, with many healthcare workers affected. This outbreak represents a spread from known endemic areas to urban settings, including nosocomial transmission in Kigali hospitals. While outbreaks are typically limited to remote areas, this one spans across Rwanda, with potential for satellite cases and further spread. No vaccines or treatments are currently available.
This compilation includes the latest news, publications, and resources, covering recent developments such as vaccine distribution in Africa and WHO policy updates. It provides links to '2022-2024 Mpox Outbreak: Global Trends,' which features interactive dashboards and epidemiological data. This update offers a brief overview of the developments of the mpox situation for healthcare professionals, researchers, and policymakers.
As of August 2024, the world is facing a significant mpox outbreak, primarily affecting countries in Central and East Africa, particularly the Democratic Republic of the Congo (DRC) and neighbouring countries, with cases reported across several regions. The outbreak is characterised by the sustained human-to-human transmission of the clade I monkeypox virus (MPXV).
This commentary provides up-to-date, evidence-based information on mpox (formerly known as monkeypox) for healthcare professionals, researchers, and public health officials.
Andes hantavirus outbreak on a cruise ship - an ESCMID Emerging Infections Subcommittee rapid assessment
Marta Mora-Rillo, Nitin Gupta, Effrossyni Gkrania-Klotsas, Jan Felix Drexler, Pikka Jokelainen, Sotirios Tsiodras, Galadriel Pellejero-Sagastizabal, Aleksandra Barac1, Jose-Ramon Pano-Pardo,∙ F-Xavier Lescure,∙ Martin P. Grobusch
Past, present and future of dengue in Europe
Jan Felix Drexler, Anna-Bella Failloux, Didier Fontenille, Thomas Jaenisch, Jolyon M. Medlock, Xavier N. de Lamballerie, F. Xavier Lescure, Sotirios Tsiodras, Martin P. Grobusch
Endemic avian influenza landscape in Asia: sustained zoonotic risks
Nitin Gupta, Martin P Grobusch, Jan Felix Drexler, José Ramón Paño-Pardo, Galadriel Pellejero-Sagastizabal, Sotirios Tsiodras, Aleksandra Barac, F-Xavier Lescure, Pikka Jokelainen for the Emerging Infectious Subcommittee, European Society of Clinical Microbiology and Infectious Disease
Yellow fever in South America in 2025: a concerning increase, but a true resurgence?
Aleksandra Barac, Nitin Gupta, Pikka Jokelainen , Sotirios Tsiodras, Marta Mora-Rillo, Effrossyni Gkrania-Klotsas, José Ramón Paño-Pardo, Casandra Bulescu, Galadriel Pellejero-Sagastizabal, Abraham Goorhuis, Maria Paquita Garcia Mendoza, Jacob Van der Ende, François-Xavier Lescure, Martin P Grobusch, Jan Felix Drexler
Delayed correct diagnoses in emerging disease outbreaks: historical patterns and lessons for contemporary responses
Galadriel Pellejero-Sagastizábal, Casandra Bulescu, Nitin Gupta, Pikka Jokelainen, Effrossyni Gkrania-Klotsas, Aleksandra Barac, Abraham Goorhuis, Shevin T Jacob, Selidji T Agnandji, Francine Ntoumi, Marta Mora-Rillo, José Ramón Paño-Pardo, F-Xavier Lescure, Martin P Grobusch
Is a human highly pathogenic avian influenza A H5N1 pandemic inevitable?
Effrossyni Gkrania-Klotsas, Pikka Jokelainen, Anne L Wyllie, Nitin Gupta, Aleksandra Barac, José Ramón Paño-Pardo, Marta Mora-Rillo, Martin P Grobusch, Charles B Holmes, Marion Koopmans, Francois-Xavier Lescure
Marburg virus disease outbreak in Rwanda, 2024'-author's response
Martin P Grobusch, Galadriel Pellejero-Sagastizábal, Pikka Jokelainen, F-Xavier Lescure, Marta Mora-Rillo, Nitin Gupta
Marburg virus disease outbreak in Rwanda, 2024
Martin P Grobusch, Pikka Jokelainen, Anne L Wyllie, Nitin Gupta, José Ramón Paño-Pardo, Aleksandra Barac, Casandra Bulescu, Galadriel Pellejero-Sagastizábal, Abraham Goorhuis, F-Xavier Lescure, Effrossyni Gkrania-Klotsas, Marta Mora-Rillo
Poliomyelitis in Gaza
Nitin Gupta, Martin P Grobusch, Pikka Jokelainen, Anne L Wyllie, Aleksandra Barac, Marta Mora-Rillo, Effrossyni Gkrania-Klotsas, Galadriel Pellejero-Sagastizabal, José Ramón Paño-Pardo, Erwin Duizer, François-Xavier Lescure
Complex mpox situation, 2024
Pikka Jokelainen, Anne L Wyllie, Nitin Gupta, Aleksandra Barac, Effrossyni Gkrania-Klotsas, Casandra Bulescu, José Ramón Paño-Pardo, Marta Mora-Rillo, Martin P Grobusch, F-Xavier Lescure