In February 2025, public health agencies in Germany and the United Kingdom (UK) reported four cases of domestically acquired cholera caused by consumption of holy water imported from Ethiopia, and a further three cases in travellers to Ethiopia. Multidrug-resistant Vibrio cholerae O1, linked to recent outbreaks in Eastern and Middle Africa, was detected in clinical specimens and the holy water. In cholera-endemic regions, visitors should drink potable water and should not bring bottled water back from their travels.

After the introduction of the dengue vaccination in spring 2023, 48 cases of dengue infection with a dengue vaccination history were registered between September 2023 and December 2024 among 2079 German travellers with dengue infection returning from abroad.

Introduction:West Nile virus (WNV) is an arthropod-borne virus (arbovirus). It circulates in an enzootic cycle between ornithophilic mosquitoes as vectors and different avian species as reservoir hosts and/or for amplification but humans can be infected as accidental hosts. Since 2019, autochthonous mosquito-borne WNV infections in humans were reported in Germany indicating a continuous circulation in the affected areas. The animal and human infections were initially restricted to Central-East Germany in the first years. This article provides an update to the WNV epidemiology in Germany from 2022 to 2024. Methods:Analysis was based on surveillance data and confirmatory testing for human and animal cases of WNV in Germany from 2022 to 2024. Results:Since 2022, a slight annual spread became visible, which intensified in 2024 and caused numerous infections in northwest Germany, particularly among animals. Altogether, 80 confirmed human WNV infections were identified in 2022-2024, mostly among blood donors. Transfusion safety is maintained by donor deferral or testing of donations using nucleic acid amplification techniques (NAT) after a stay in an affected area. The vast majority of blood establishments test all donations during the transmission season in Germany from June to the end of November. In this way, roughly 2.2 million donations are screened annually, by that contributing significantly to WNV surveillance. Conclusion:Confirmation of initially reactive screening tests is still a challenge as other flaviviruses, especially Usutu virus, are co-circulating. Specific NAT or next-generation sequencing are necessary for discrimination. To fully understand the WNV epidemic, combined results of human and veterinary surveillance including results of sequencing are needed. A One health approach is essential to identify affected areas and to ensure transfusion safety and public health.

Human Borna disease virus 1 (BoDV-1) encephalitis is characterized by rapid clinical progression, an absence of a causal therapy and an extremely high case fatality rate. Here, we discuss prevention options through a hypothetical vaccine focusing on epidemiological features.

Background Enteric fevers (EF) are caused by infections with Salmonella Typhi (STY) or Salmonella Paratyphi (SP) A-C (except the SPB enteric pathovar) and exhibit increasing antimicrobial resistance (AMR). Notification is mandatory in Germany. Aim To describe characteristics and trends of notified EF cases in Germany. Methods We analysed German EF notifications 2001–2023 fulfilling the case definition. We calculated numbers of imported EF cases per 100,000 air travellers by country of exposure 2012–2023. Results In 2001–2023, 2,670 confirmed EF cases were notified: 56% (1,498/2,670) STY, 44% (1,172/2,670) SP, with seasonal peaks in April–May and August–September. Aside from years with COVID-19-related travel restrictions, STY notifications were stable, while SP notifications decreased. Median age of EF cases was 26 years (range: 0–93) and 55% (1,458/2,663) were male. Of cases with information, 93% (2,491/2,670) had fever, 71% (1,906/2,670) diarrhoea, 78% (2,033/2,607) were hospitalised (STY: 85% (1,234/1,459) vs SP: 70% (799/1,148), p < 0.001) and four died (two STY, one SPA, one SPB). Of STY cases, 7% (88/1,221) reported vaccination. Overall, 86% (2,251/2,613) of cases acquired EF abroad, most commonly in India, Pakistan and Türkiye. Ciprofloxacin resistance was reported for 50/59 STY and 16/18 SPA cases and cefotaxime resistance for 10/57 STY cases (exposure: Pakistan (9/10), India (1/10)) with information since 2017. We also report outbreaks and incidence among travellers. Conclusions Most cases were imported and had high hospitalisation rates and AMR. Typhoid vaccination was underutilised, highlighting that additional ways to reach at-risk travellers with information and vaccination offers are needed.

Borna disease virus 1 (BoDV-1) is the causative agent of Borna disease, a fatal neurologic disorder of domestic mammals and humans, resulting from spill-over infection from its natural reservoir host, the bicolored white-toothed shrew (Crocidura leucodon). The known BoDV-1-endemic area is remarkably restricted to parts of Germany, Austria, Switzerland and Liechtenstein. To gain comprehensive data on its occurrence, we analysed diagnostic material from suspected BoDV-1-induced encephalitis cases based on clinical and/or histopathological diagnosis. BoDV-1 infection was confirmed by RT-qPCR in 207 domestic mammals, 28 humans and seven wild shrews. Thereby, this study markedly raises the number of published laboratory-confirmed human BoDV-1 infections and provides a first comprehensive summary. Generation of 136 new BoDV-1 genome sequences from animals and humans facilitated an in-depth phylogeographic analysis, allowing for the definition of risk areas for zoonotic BoDV-1 transmission and facilitating the assessment of geographical infection sources. Consistent with the low mobility of its reservoir host, BoDV-1 sequences showed a remarkable geographic association, with individual phylogenetic clades occupying distinct areas. The closest genetic relatives of most human-derived BoDV-1 sequences were located at distances of less than 40 km, indicating that spill-over transmission from the natural reservoir usually occurs in the patient´s home region.

In February 2023, German public health authorities reported two dengue cases (one confirmed, one probable) and four possible cases who travelled to Ibiza, Spain, in late summer/autumn 2022; the infection was probably acquired through mosquito bites. Case 1 visited Ibiza over 1 week in late August with two familial companions; all three developed symptoms the day after returning home. Only Case 1 was tested; dengue virus (DENV) infection was confirmed by presence of NS1 antigen and IgM antibodies. Case 2 travelled to Ibiza with two familial companions for 1 week in early October, and stayed in the same town as Case 1. Case 2 showed symptoms on the day of return, and the familial companions 1 day before and 3 days after return; Case 2 tested positive for DENV IgM. The most probable source case had symptom onset in mid-August, and travelled to a dengue-endemic country prior to a stay in the same municipality of Ibiza for 20 days, until the end of August. Dengue diagnosis was probable based on positive DENV IgM. Aedes albopictus, a competent vector for dengue, has been present in Ibiza since 2014. This is the first report of a local dengue transmission event on Ibiza.

Background: Autochthonous human West Nile virus (WNV) infections were notified in the infectious disease surveillance system in Germany in 2018 for the first time and every year since then. Since clinically apparent infections are infrequent, we conducted two studies to investigate subclinical infections of this emerging disease in Germany in 2019 to detect infections not visible to surveillance based on symptomatic infections: limited-scope blood donor testing and a serosurvey among employees at two Berlin zoos with a history of demonstrated WNV infections in animals. Methods: For the zoo study, employees of the two zoos in Berlin were invited to participate in the study in late 2019. Blood samples were drawn and tested for the presence of antibodies (immunoglobulin M [IgM] and immunoglobulin G [IgG]) against WNV, and two other flaviviruses present in Germany: Usutu virus and Tick-borne encephalitis virus (TBEV). For the study in blood donors, four blood establishments with collection sites in regions with documented WNV-infected animals in 2018 and 2019 participated in the study. All donations in these regions were tested for WNV genome from July to November 2019. Results: In the enzyme-linked immunosorbent assay, none of the 70 tested zoo employees were WNV IgM-positive, 8 were WNV IgG-positive, additional 2 participants had equivocal results. All 10 were negative in the virus neutralization test (VNT) for WNV, but positive in the VNT for TBEV. None of the 4273 samples from blood donors tested in areas with WNV-infected animals was positive for WNV-RNA. Conclusion: Our results indicate that WNV circulation in Germany, though clearly documented in animals in 2019, apparently affected very few humans. Still areas with WNV-positive animals remain risk areas for human infection as well.

PURPOSE:The emerging zoonotic Borna disease virus 1 (BoDV-1) and the variegated squirrel bornavirus 1 (VSBV-1) cause severe and fatal human encephalitis in Germany. We conducted the first systematic clinical analysis of acute, molecularly confirmed fatal bornavirus encephalitis cases comprising 21 BoDV-1 and four VSBV-1 patients to identify options for better diagnosis and timely treatment. METHODS:Analyses were based on medical records and, for BoDV-1, on additional medical interviews with patients' relatives. RESULTS:Disease onset was unspecific, often with fever and headache, inconsistently mixed with early fluctuating neurological symptoms, all rapidly leading to severe encephalopathy and progressive vigilance decline. Very shortly after seeking the first medical advice (median time interval 2 and 0 days for BoDV-1 and VSBV-1, respectively), all except one patient were hospitalised upon manifest neurological symptoms (median 10 and 16 days respectively after general symptom onset). Neurological symptoms varied, always progressing to coma and death. BoDV-1 and VSBV-1 patients required ventilation a median of three and five days, and died a median of 32 and 72 days, after hospitalisation. Death occurred mostly after supportive treatment cessation at different points in time based on poor prognosis. Disease duration therefore showed a wide, incomparable range. CONCLUSION:The extremely rapid progression is the most obvious clinical characteristic of bornavirus encephalitis and the timeframe for diagnosis and targeted therapy is very short. Therefore, our results demand an early clinical suspicion based on symptomatology, epidemiology, imaging, and laboratory findings, followed by prompt virological testing as a prerequisite for any potentially effective treatment.

Dengue virus (DENV) infections after exposure in Egypt increased in Germany in 2023, with 36 cases vs zero to eight in 2017 to 2022. Over 90% of the patients had stayed on the Red Sea Coast (mostly Hurghada), almost 50% in private residences. Case numbers increased more strongly than traveller numbers. Mosquito control is more difficult in towns than hotel grounds, increasing the risk of infection at private residences. Physicians should consider dengue for unexplained fever after return from Egypt.

In March 2023, 34 associated cases of iatrogenic botulism were detected in Germany (30 cases), Switzerland (two cases), Austria (one case), and France (one case). An alert was rapidly disseminated via European Union networks and communication platforms (Food- and Waterborne Diseases and Zoonoses Network, EpiPulse, Early Warning and Response System) and the International Health Regulation mechanism; the outbreak was investigated in a European collaboration. We traced sources of the botulism outbreak to treatment of weight loss in Türkiye, involving intragastric injections of botulinum neurotoxin. Cases were traced using a list of patients who had received this treatment. Laboratory investigations of the first 12 German cases confirmed nine cases. The application of innovative and highly sensitive endopeptidase assays was necessary to detect minute traces of botulinum neurotoxin in patient sera. The botulism notification requirement for physicians was essential to detect this outbreak in Germany. The surveillance case definition of botulism should be revisited and inclusion of cases of iatrogenic botulism should be considered as these cases might lack standard laboratory confirmation yet warrant public health action. Any potential risks associated with the use of botulinum neurotoxins in medical procedures need to be carefully balanced with the expected benefits of the procedure.

Borna disease virus 1 (BoDV-1) is the causative agent of Borna disease, a progressive and mostly fatal neurologic disorder of domestic mammals and humans, resulting from spill-over infection from its natural reservoir host, the bicolored white-toothed shrew (Crocidura leucodon). The known BoDV-1 endemic area is remarkably restricted to parts of Germany, Austria, Switzerland and the Principality of Liechtenstein. To gain comprehensive data on the occurrence of BoDV-1, we analysed diagnostic material from suspected fatal BoDV-1-induced encephalitis cases in domestic mammals and humans. BoDV-1 infection was confirmed by RT-qPCR in 207 of 231 domestic mammals (89.6%), 28 of 29 humans (96.6%) and seven shrews, mainly within the known endemic area. By reporting multiple unpublished cases, this study raises the number of published laboratory-confirmed human BoDV-1 infections to 46 and provides a first comprehensive summary. Generation of 136 new complete or partial BoDV 1 genome sequences from animals and humans facilitated an in-depth phylogeographic analysis. Consistent with the low mobility of its reservoir host, BoDV-1 sequences showed a remarkable geographic association, with individual phylogenetic clades occupying distinct and barely overlapping dispersal areas. The closest genetic relatives of most human-derived BoDV-1 sequences were located at distances of less than 40 km from the patient’s residence, indicating that spill-over transmission from the natural reservoir usually occurs in the region of the patient´s residence. In summary, the novel and extended phylogeographic data allow for the definition of risk areas for zoonotic BoDV-1 transmission and facilitate the assessment of geographical sources for individual infection events.

In 2018, Borna Disease Virus 1 (BoDV-1) was confirmed as a human zoonotic pathogen causing rare but fatal encephalitis in Germany. While diagnostic procedures and the clinical picture have been described, epidemiology remains mysterious. Though endemic areas and a natural reservoir host have been identified with the shrew Crocidura leucodon shedding virus in secretions, transmission events, routes and risk factors are unclear. We performed the first comprehensive epidemiological study, combining a large case series with the first case-control study: We interviewed family members of 20 PCR-confirmed BoDV-1 encephalitis cases deceased in 1996-2021 with a standardized questionnaire covering medical history, housing environment, profession, animal contacts, outdoor activities, travel, and nutrition. Cases' median age was 51 (range 11-79) years, 12/20 were female, and 18/20 lived in the federal state of Bavaria in Southeastern Germany. None had a known relevant pre-existing medical condition. None of the interviews yielded a transmission event such as direct shrew contact, but peridomestic shrew presence was confirmed in 13 cases supporting environmental transmission. Residency in rural areas endemic for animal BoDV-1 was the common denominator of all cases. A subsequent individually matched case-control study revealed residence close to nature in a stand-alone location or on the fringe of the settlement as a risk factor for disease in multivariable analysis with an adjusted OR of 10.8 (95% CI 1.3-89.0). Other variables including keeping cats were not associated with disease. Targeted prevention, future post-exposure-prophylaxis, and timely diagnosis remain challenging.

Background: Travellers are generally considered good sentinels for infectious disease surveillance. Aim: To investigate whether health data from travellers arriving from Africa to Europe could provide evidence to support surveillance systems in Africa. Methods: We examined disease occurrence and estimated risk of infection among travellers arriving from Africa to Europe from 2015 to 2019 using surveillance data of arthropod-borne disease cases collected through The European Surveillance System (TESSy) and flight passenger volumes from the International Air Transport Association. Results: Malaria was the most common arthropod-borne disease reported among travellers from Africa, with 34,235 cases. The malaria travellers' infection rate (TIR) was 28.8 cases per 100,000 travellers, which is 36 and 144 times higher than the TIR for dengue and chikungunya, respectively. The malaria TIR was highest among travellers arriving from Central and Western Africa. There were 956 and 161 diagnosed imported cases of dengue and chikungunya, respectively. The highest TIR was among travellers arriving from Central, Eastern and Western Africa for dengue and from Central Africa for chikungunya in this period. Limited numbers of cases of Zika virus disease, West Nile virus infection, Rift Valley fever and yellow fever were reported. Conclusions: Despite some limitations, travellers' health data can efficiently complement local surveillance data in Africa, particularly when the country or region has a sub-optimal surveillance system. The sharing of anonymised traveller health data between regions/continents should be encouraged.

Botulism outbreaks due to commercial products are extremely rare in the European Union. Here we report on the first international outbreak of foodborne botulism caused by commercial salt-cured, dried roach (Rutilus rutilus). Between November and December 2016, an outbreak of six foodborne botulism type E cases from five unrelated households was documented in Germany and Spain. The outbreak involved persons of Russian and Kazakh backgrounds, all consumed unheated salt-cured, dried roach—a snack particularly favored in Easter-European countries. The implicated food batches had been distributed by an international wholesaler and were recalled from Europe-wide outlets of a supermarket chain and other independent retailers. Of interest, and very unlike to other foodborne disease outbreaks which usually involves a single strain or virus variant, different Clostridium botulinum strains and toxin variants could be identified even from a single patient's sample. Foodborne botulism is a rare but potentially life-threatening disease and almost exclusively involves home-made or artisan products and thus, outbreaks are limited to individual or few cases. As a consequence, international outbreaks are the absolute exception and this is the first one within the European Union. Additional cases were likely prevented by a broad product recall, underscoring the importance of timely public health action. Challenges and difficulties on the diagnostic and epidemiological level encountered in the outbreak are highlighted.

Background: Endemic and imported vector- and rodent-borne infectious agents can be linked to high morbidity and mortality. Therefore, vector- and rodent-borne human diseases and the effects of climate change are important public health issues. Methods: For this review, the relevant literature was identified and evaluated according to the thematic aspects and supplemented with an analysis of surveillance data for Germany. Results: Factors such as increasing temperatures, changing precipitation patterns, and human behaviour may influence the epidemiology of vector- and rodent-borne infectious diseases in Germany. Conclusions: The effects of climatic changes on the spread of vector- and rodent-borne infectious diseases need to be further studied in detail and considered in the context of climate adaptation measures.

Following the report of a non-travel-associated clus-ter of monkeypox cases by the United Kingdom in May 2022, 41 countries across the WHO European Region have reported 21,098 cases and two deaths by 23 August 2022. Nowcasting suggests a plateau-ing in case notifications. Most cases (97%) are MSM, with atypical rash-illness presentation. Spread is mainly through close contact during sexual activities. Few cases are reported among women and children. Targeted interventions of at-risk groups are needed to stop further transmission.