This week’s Epi Alert highlights continued vector-borne and viral haemorrhagic fever activity across Europe and Africa. West Nile virus transmission is expanding across Europe, with over 1,000 locally acquired cases, while locally acquired dengue clusters have been reported in France and Italy and an imported case of Crimean-Congo haemorrhagic fever is being treated in Vienna. In Africa, Namibia is experiencing an unusually large malaria surge with over 122,000 cases, while the Bundibugyo Ebola outbreak in the Democratic Republic of the Congo continues to expand, with more than 6,300 confirmed cases and 3,000 deaths across six provinces.
West Nile virus disease, Europe
West Nile virus (WNV) transmission continues to expand across Europe, with 1,086 locally acquired human cases reported in 15 countries during the 2026 transmission season as of 3 September. Italy has reported the highest number of cases (516), followed by Greece (284), Spain (88), Romania (56) and North Macedonia (55). Overall, 144 areas have reported locally acquired human WNV infections, including 20 areas affected for the first time during the latest reporting week. The geographic expansion of transmission underscores continued seasonal WNV activity across Europe and the importance of ongoing surveillance and measures to protect blood and other substances-of-human-origin supplies.
Crimean-Congo hemorrhagic fever, Austria
A confirmed case of Crimean-Congo hemorrhagic fever is being treated in isolation at the Favoriten Clinic in Vienna. The patient, who is currently in stable condition, developed symptoms following a stay in the Middle East, where the infection is assessed to have occurred. The individual sought prompt medical attention and is receiving specialized infectious disease care.
Malaria, Africa
Namibia is experiencing a surge in malaria cases in 2026 that exceeds typical endemic patterns. As of 3 September 2026, over 122,000 cases and 122 deaths have been reported. The increase is occurring during the seasonal transmission peak and is driven in part by favorable environmental conditions and a gap in Indoor Residual Spraying (IRS) coverage.
Ebola virus disease, D.R. Congo
The Bundibugyo virus disease outbreak continues to expand in the Democratic Republic of the Congo, with 6,342 confirmed cases and 3,072 deaths reported as of 2 September 2026. Transmission now affects 60 health zones across six provinces, with Ituri remaining the epicentre, accounting for more than 5,000 cases. The outbreak continues amid significant humanitarian and security challenges,. No licensed vaccines or specific therapeutics are available for Bundibugyo virus disease, although several vaccine candidates are under development; DRC has initiated vaccination of frontline workers with Ervebo under WHO emergency guidance regarding its potential cross-protection. Uganda, which reported 20 confirmed cases and two deaths linked to the outbreak, has meanwhile been declared free of the outbreak following 42 days without a new confirmed case.
Dengue, France and Italy
Local dengue transmission has been reported in France and Italy during the 2026 transmission season, with eight locally acquired cases reported as of 2 September: five in France and three in Italy. Italy reported locally acquired dengue for the first time this season, with two active clusters identified in Alliste, Lecce (two cases) and Piombino, Livorno (one case). France has reported four clusters comprising five cases, of which two remain active, in Sète and Marseille.
Per September, 15 European countries have reported 1086 locally acquired human cases of WNV infection.
Confirmed imported case following a stay in the Middle East, currently isolated in stable condition.
Two teenagers hospitalized with confirmed meningitis B; close contacts offered prophylactic antibiotics.
Multi-island outbreak with over 400 hospitalisations on Faial Island; laboratory-confirmed on two islands.
81 cases linked to contaminated pumpkin seeds across 10 regions; product recall initiated.
Hillsborough County identified as the epicenter of locally acquired transmission, with increasing case numbers.
Outbreak with 13 suspected human cases, two deaths, and 20 dead animals in Grand'Anse.
Elevated case fatality and geographic expansion reported in 2025-2026, with suspected human-to-human transmission.
First reported local cluster linked to raw freshwater fish in Zhengzhou, a low-prevalence area.
Nine-year-old boy in critical condition after contracting Naegleria fowleri at Kursi Beach.
20 diagnosed cases, including one death, with infected mosquitoes detected in four regional councils.
Over 65,000 suspected cases reported nationwide by August 2026 amid the rainy season.
Two cases reported in hunters in the Luangwa Valley of Eastern Province.
Over 122,000 cases and 122 deaths reported by 3 September amid an IRS coverage gap.
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.