AGES Radar for Infectious Diseases – 18 June 2026
Summary
Since December 2025, an outbreak of salmonella has been observed in several European countries; Austria has so far recorded six confirmed cases.
West Nile virus surveillance began in Europe and Austria at the end of May and the beginning of June respectively.
The Ebola outbreak in the Democratic Republic of the Congo (DRC) and Uganda is continuing, with 676 confirmed cases in the DRC to date.
To mark World Food Safety Day, this month’s topic focuses on Listeria, the pathogen that causes listeriosis. Listeriosis is less common than other foodborne illnesses, but can have serious consequences, particularly for pregnant women and their unborn babies.
In the news: Two ‘giant ticks’ have been reported in Austria to date. A study involving AGES colleagues has detected the Alongshan virus in Austrian ticks. The annual reports of the National Reference Centres for Salmonella, Yersinia and Neisseria gonorrhoeae, as well as the National Rabies Advisory Centre, have been published. The AGES Epimap has gone live; this is an interactive tool that transparently displays the situation regarding animal diseases in Austria.
A multinational outbreak involving Salmonella enterica serovar Stanley (sequence type ST2045) has been under observation since December 2025. Several European countries are affected, including Austria, which has so far reported six confirmed cases. The cases form part of a closely related genetic cluster that has been detected in several countries, strongly suggesting a common source of infection.
The fact that new cases continue to be identified indicates ongoing exposure. As of 5 June 2026, 83 confirmed cases had been recorded across Europe, with onset of illness between December 2025 and mid-May 2026. In addition, there are 24 further, as yet unsequenced cases with a possible link to the outbreak.
From an epidemiological perspective, the disproportionately high number of cases among children and young adults is notable, suggesting specific patterns of exposure or consumption. Chicken-flavoured instant noodles and other processed products containing chicken are currently being discussed as possible sources of infection. In some cases, it has been reported that instant noodles were consumed without being properly prepared – that is, uncooked and with only the accompanying seasoning mix added. As these are not ready-to-eat foods, a lack of heating may increase the risk of infection. However, a clear source has not yet been identified for all cases.
The ECDC classifies the risk to the general public as very low. For children and young adults, the risk is assessed as low, provided that preparation instructions are strictly followed. Nevertheless, due to the continued reporting of cases and the clearly defined genetic cluster, there remains a need for action. In Austria, the investigation is being carried out by AGES on behalf of the Ministry of Health, in close coordination at both national and European level.
At EU level, the investigations are being coordinated by the ECDC and EFSA; a joint Rapid Outbreak Assessment is in preparation, with publication scheduled for 1 July. In parallel, the situation is being continuously monitored from both an epidemiological and molecular perspective.
From the beginning of June to the end of November, AGES publishes weekly updates on its website regarding West Nile virus (WNV) surveillance. No human cases have been recorded in Austria so far this season. WNV has not yet been detected in horses or birds either.
The ECDC’s (European Centre for Disease Prevention and Control) seasonal reporting on human West Nile virus cases in Europe began at the end of May. The first confirmed case of the year was reported in North Macedonia in early June; this remains the only case in Europe to date. (ECDC, as at 12 June 202)
Following the record year of 2024, which saw a total of 34 locally acquired and three imported WNV infections, only one imported case of WNV in humans was recorded in Austria in 2025.
In Austria, WNV is mainly transmitted by mosquitoes of the genus Culex. 80% of infections are asymptomatic; 20% of infected patients exhibit flu-like symptoms, including a sudden, high fever (West Nile fever), muscle pain, headaches and gastrointestinal symptoms. The most dangerous form is the neuroinvasive form of WNV disease, which primarily affects older people and occurs in less than 1% of those infected. This can lead, amongst other things, to encephalitis with possible permanent damage, and in some cases to fatal outcomes. The proportion of cases with a neuroinvasive course among registered WNV infections is significantly higher, as many WNV infections with a mild course go undiagnosed and unreported.
The Ebola outbreak in the Democratic Republic of the Congo (DRC) and Uganda is continuing. A total of 676 confirmed cases have been reported in the DRC, including 136 deaths (WHO, as at 10 June 2026). The outbreak remains centred in Ituri Province, in the north-east of the country. The neighbouring provinces of North Kivu and South Kivu are also affected. The scale of the outbreak is likely to be greater than currently recorded, both in terms of confirmed cases and geographical spread.
In Uganda, 19 confirmed cases, including two deaths, have been recorded. The outbreak in Uganda is demonstrably linked to that in the DRC, with 14 directly imported cases and five instances of secondary transmission to contacts and healthcare workers. Uganda has not reported any new cases in the last six days. (WHO, as at 11 June 2026).
As of 11 June 2026, 820 contacts had been identified; of these, 394 have completed the 21-day monitoring period, whilst 409 are currently under active surveillance.
The outbreak is caused by the Bundibugyo virus. There are currently no authorised vaccines or specific treatments available for this variant of the Ebola virus. Following a recommendation by a WHO expert group, two medicines and a post-exposure prophylaxis are now to be tested in clinical trials for efficacy and safety. A protocol for conducting these clinical trials has been submitted and is currently being reviewed by the ethics committee and the authorities in the affected countries. Widespread use outside such trials is not currently recommended.
Containing the outbreak continues to prove difficult, partly because it is taking place in a conflict-ridden environment. Security issues, attacks on healthcare facilities and high population mobility in the region are complicating the situation. Some countries, including the USA, Canada and Tunisia, have introduced entry controls and health checks for travellers from high-risk countries.
The WHO assesses the risk for the DRC as very high, and for Uganda and neighbouring countries as high. The likelihood of transmission within the EU or the EEA is considered very low, as mathematical models suggest that the probability of an imported case can be estimated as very low. Furthermore, in the unlikely event of such a case occurring, it would be quickly identified and isolated, and further control measures would be implemented immediately to prevent the virus from spreading.
At the end of May, a 19-year-old Caritas employee in Austria showed symptoms of illness following her return from Uganda, leading to a suspected case of Ebola. However, this was subsequently ruled out promptly. The AGES podcast ‘Courage to Take Risks – In Context: Ebola’ explains how the specific case was handled and which other factors, apart from the medical ones, play an important role.
The Austrian Ministry of Foreign Affairs is warning against travel to the DRC; a level 4 (out of 4) travel warning is in place for the whole country.
The AGES Infectious Diseases Radar dated 21 May 2026 reported on the early stages of this Ebola outbreak.
Updates from the WHO on the Ebola outbreak can be found at: Disease Outbreak News – Bundibugyo virus
As in the last two years, we are once again reporting this year, to mark World Food Safety Day, on food safety and the common causes of foodborne illness. The classic pathogens are: Campylobacter, Salmonella and Listeria. On 23 May 2024, we covered Campylobacter in our ‘Topic of the Month’ section, and on 12 June 2025, we looked at Salmonella. To round off the series, this year we are focusing on Listeria.
The underestimated cause of death among foodborne infections
Listeriosis is, in principle, a foodborne illness. The pathogen Listeria monocytogenes can be found in the environment, in soil and in water. Animals and humans can carry the pathogen without falling ill, but symptomatic cases can also occur. Symptoms range from diarrhoea, severe headaches, high fever, nausea and vomiting to encephalitis, meningitis or sepsis (blood poisoning). The incubation period varies depending on the clinical presentation: for gastrointestinal symptoms, it is usually a few hours up to six days; in more severe cases, it is generally longer, ranging from several days to weeks.
Under the Epidemic Diseases Act of 1950, listeriosis is classified as a notifiable disease. This applies to both foodborne cases and invasive forms of the disease. Compared with campylobacteriosis and salmonellosis, listeriosis occurs much less frequently. In 2025, there were 7,155 cases of campylobacteriosis and 1,541 cases of human (non-typhoidal) salmonellosis. During the same period, only 32 cases of listeriosis were reported. However, the disease is generally more severe. In 2024, Listeria accounted for the highest proportion of hospital admissions and deaths among foodborne infections reported in the EU. Around 70% of those affected required hospitalisation, and approximately 8% of cases were fatal. An infection during pregnancy can have serious consequences for the unborn child. If a pregnant woman contracts listeriosis, this can lead to premature birth, severe damage to the unborn child and even stillbirth. In older people and those with weakened immune systems, Listeria can spread to the bloodstream and even the meninges, becoming life-threatening.
Listeria is often found in unheated foods, such as raw milk cheeses, smoked salmon and minced pork, or in pre-packaged salads.
Product recalls and recall management in the digital age
Food companies are legally obliged to monitor the safety and quality of their products themselves through internal controls based on the so-called HACCP (Hazard Analysis and Critical Control Points) concept. If food companies identify potential health risks in a food product, they must act swiftly. Affected products are withdrawn from the market and the public is informed of the recall. The aim is to reach consumers as quickly as possible and to prevent food that is harmful to health from being consumed.
Thanks to increasing digitalisation, recall information can now be disseminated much more quickly and widely than was possible just a few years ago. In Austria, AGES publishes the latest product warnings and recalls on its website. In addition, AGES’s product warning app for Android and Apple devices provides timely information free of charge. The Ministry of Consumer Protection and consumer portals also provide up-to-date recall information.
A recall notice usually contains a detailed description of the affected product, details of the best-before or use-by dates, batch numbers, points of sale, and information about the potential health risk. Product photos may also be published to make identification easier. Anyone who has an affected product at home should follow the instructions in the recall notice. In most cases, products can be returned to the shop even without a receipt. The purchase price is usually refunded or the product replaced.
Ready-to-eat foods: a risk category?
Are new dietary trends also changing the risk profile for Listeria? In recent years, the consumption of ‘ready-to-eat’ foods (RTE foods), which can be bought in supermarkets, has risen sharply. As sales of RTE foods have increased, so too have the number of recalls involving these products. Contamination levels remain low in most categories. In its 2024 Zoonoses Report, the EFSA states that only 0% to 6.6% of samples tested positive overall. The highest incidence rates were reported for ‘fermented sausage products’ (6.6 per cent), fish (2.9 per cent), hard cheese (1.6 per cent) and ‘other ready-to-eat products’ (1.6 per cent). Although detection rates are low overall, ready-to-eat foods pose a particular risk, as they are usually not reheated or washed before consumption.
Refrigeration alone is not a guarantee of safety
Refrigerating food is important, particularly to prevent the growth of bacteria. However, Listeria can also multiply at fridge temperatures, albeit more slowly, so simply refrigerating food is not always sufficient. Ideally, a fridge should be set to 5 °C or below. Unlike many other pathogens, Listeria can survive at fridge temperatures as low as 4 °C.
It is therefore important to: buy fresh produce whenever possible, wash fruit and vegetables thoroughly, and use up food from the fridge quickly. Even ready-to-eat salad should be washed again. Pack food well to avoid cross-contamination and eat it as soon as possible.
To kill Listeria, heat food to over 70 °C for at least two minutes.
As the bacteria can accumulate in the fridge, it is important to clean it thoroughly on a regular basis. Listeria can also survive on kitchen towels and cloths. It is therefore necessary to dry towels thoroughly and wash them regularly at a high temperature, as well as to change cloths and sponges regularly.
A new risk due to an ageing population?
As well as pregnant women and newborns, immunocompromised individuals are particularly at risk. Whilst an infection often causes only mild symptoms in healthy adults, it can take a severe course in people with a weakened immune system.
Due to demographic trends and rising life expectancy, the number of older people in the population is increasing. As older people are more frequently affected by chronic conditions and their immune systems weaken with age, the risk of severe listeriosis also rises.
An ageing society could therefore mean that listeriosis remains a significant public health challenge in the future. This makes it all the more important to adhere to hygiene measures, handle (high-risk) foods with care, and provide targeted information to groups of people who are particularly at risk.
Two Hyalomma ticks (‘giant ticks’) have already been reported this season. One tick was found on a horse, sent to AGES and analysed in the laboratory. Tests for Crimean-Congo haemorrhagic fever virus (CCHFV) and rickettsiae were negative. The second tick was confirmed as Hyalomma sp. on the basis of a photograph submitted, but was no longer available at the time of the AGES’s response and could therefore not be examined further.
If you suspect the presence of a Hyalomma tick (“giant tick”), please send a photograph to zecken@ages.at and keep the tick until you receive a response from AGES, so that any necessary further investigations can be carried out. Ticks that have not yet engorged – i.e. are still ‘flat’ – can be secured to a sheet of paper on one side using adhesive tape. Ticks that have already fed on blood can be stored in containers, e.g. small glass jars, small plastic boxes, screw-top containers, etc.
Here you will find all the information you need on reporting and handing in ticks you have found: Tick Information – AGES
By handing in ticks, you are supporting our EU projects OH SURVector and RAISE, which contribute to a better understanding of the distribution of tick species and their potential pathogens.
A study published in *The Lancet* in early June 2026, involving AGES colleagues Georg Duscher, Anna-Margarita Schötta and Mateusz Markowicz, has detected widespread circulation of the Alongshan virus (ALSV) in Austrian tick populations. Analysis of archived samples shows that the virus has been circulating in Austria since at least 2005 and has therefore been established for over two decades. The detection rate in ticks is a median of 1.2 %.
Serological tests, using antibody detection, provide the first evidence of past infections in humans in Austria. The virus itself could not be detected in any of the patient samples. Phylogenetic analyses confirm that the virus detected in ticks belongs to a European viral lineage and persists regionally in tick populations.
The results underscore the importance of continuous surveillance and of including the Alongshan virus in the differential diagnosis for patients following a tick bite.
The Alongshan virus was first discovered in China in 2017 in patients with symptoms similar to those of TBE virus infection. It is still unclear whether the virus variant circulating in Europe can also cause disease in humans.
On 10 June 2026, the 2025 Annual Report of the National Reference Centre for Gonococci was published.
In 2025, 535 samples from 513 patients tested positive for gonococci by culture at the National Reference Centre for Gonococci. These samples were submitted in all four quarters and originated from all nine Austrian federal states. The majority of the strains were isolated from urethral swabs (swabs taken from the urethra).
Gonorrhoea is usually treated with the antibiotic ceftriaxone, which remains the standard therapy. However, in Austria, one isolate showing resistance to ceftriaxone was detected for the first time in 2022 and again in 2025. These pathogens also showed resistance to other antibiotics such as cefixime, ciprofloxacin, tetracycline and azithromycin, and were therefore classified as ‘extensively drug-resistant’ (XDR).
Apart from this XDR isolate, all samples tested at the Reference Centre for Gonococci in 2025 were susceptible to ceftriaxone. With regard to azithromycin, 10.6 % of the isolates showed reduced susceptibility, defined as a minimum inhibitory concentration (MIC) of over 1 mg/L and thus above the epidemiological cut-off (ECOFF). Resistance rates to tetracycline and penicillin stood at 81.8 % and 28.6 %, respectively, in 2025.
Gonorrhoea, colloquially known as ‘the clap’, is caused by the bacterium Neisseria gonorrhoeae. Gonorrhoea is the second most common bacterial sexually transmitted infection after chlamydial infections. Transmission occurs through direct mucosal contact with infectious secretions; it can therefore occur during all forms of sexual intercourse (vaginal, oral and anal) or during childbirth from an infected mother to her child.
The most important preventive measure to avoid infection is the consistent and correct use of condoms during sexual contact, as well as adhering to ‘safer sex’ guidelines. There are no specific vaccines to protect against gonorrhoea.
The 2025 annual report of the National Reference Centre for Yersinia was published at the end of May.
In 2025, a slight decrease in the number of human primary isolates submitted was recorded compared with the previous year. A total of 202 human primary isolates were submitted, of which 89 were classified as pathogenic and 110 as apathogenic; in three cases, other bacterial species (Citrobacter and Kluyvera) were identified. The incidence of yersiniosis cases culture-confirmed by the Reference Centre stood at 0.97 per 100,000 inhabitants in 2025, which was slightly below the previous year’s level.
Among the pathogenic isolates, Yersinia enterocolitica continued to predominate (88 out of 89 isolates), whilst Y. pseudotuberculosis was detected only once. Of the pathogenic Y. enterocolitica isolates, 11 were resistant to amoxicillin/clavulanic acid. As in previous years, all pathogenic isolates showed resistance to ampicillin.
On 15 June 2026, the 2025 Annual Report of the National Reference Centre for Salmonella (NRZS) was published.
In 2025, a 10.1% increase in the number of human primary isolates submitted was recorded compared with the previous year. Overall, Salmonella (S.) Enteritidis was the most common serotype (42.0%). The frequent occurrence of S. Strathcona, which has been recurring since 2011, continued in 2025. For the first time, the outbreak strain was detected in Italian organic cherry tomatoes, which had long been suspected as a source of infection.
For humans, food of animal origin represents the most significant source of infection for salmonellosis. In 2025, 1,541 primary human Salmonella isolates (from 1,538 patients/infected individuals) were submitted to the NRZS. This translates to an annual incidence of 16.7 per 100,000 inhabitants for Austria as a whole. A region-specific analysis of the incidence shows that the annual incidence rates in the regions of Burgenland (22.5), Upper Austria (21.1), Salzburg (20.2), Lower Austria (17.5) and Tyrol (17.2) are higher than the figure for Austria as a whole. In Vienna (16.5), Styria (13.1) and in Vorarlberg and Carinthia (9.5 each), the annual incidence rates are below this figure.
The proportion of multi-drug-resistant isolates stood at 12.7%. High-level resistance to ciprofloxacin and resistance to third-generation cephalosporins (cefotaxime, ceftazidime) occurred only sporadically.
On 15 June 2026, the 2025 Annual Report of the National Rabies Advisory Centre was published.
Since 2005, the Institute for Medical Microbiology and Hygiene at AGES Vienna has served as the central national rabies advisory centre. It provides telephone support to healthcare professionals and members of the public in deciding on the need for post-exposure prophylaxis.
In 2025, no suspected cases or confirmed cases of human rabies were recorded. Last year, the Rabies Advisory Centre carried out a total of 954 telephone consultations, of which 638 were with members of the public and 316 with healthcare professionals.
At the National Reference Laboratory for Rabies, a total of 405 animals were tested for rabies, with foxes (68 samples) and bats (244 samples) being the most common species. A total of 22 animals that had previously bitten a human were tested. Most of these were dogs and cats: 10 dogs, 7 cats, 3 bats, 1 fox and 1 squirrel. All results were negative.
Publication of Epimap
On 11 June 2026, the AGES Epimap went live – an interactive tool that transparently displays the spread of animal diseases in Austria and across the EU. The Epimap is freely accessible to everyone at AGES Animal Disease Maps – AGES.
The data is sourced from the official European animal disease reporting system (ADIS) and is updated every morning on working days. The Epimap shows current outbreaks and includes data dating back to 2014. This also allows longer-term trends to be visualised. Analyses and maps can be generated and saved as required. You can also find the Epimap in a number of fact sheets on the AGES website.
Epimap was developed as part of the RAISE project and makes an important contribution to integrated One Health surveillance by making animal health data transparently accessible and supporting links to human health issues. It serves as a prototype application for the One Health surveillance platform currently under development, into which the visualisations of animal diseases will also be incorporated. In addition to this visualisation, the platform will utilise further representations and data links to improve the health of humans, animals, plants and the environment.
Case figures for notifiable diseases under the Epidemic Diseases Act; the figures shown are for the previous month and, for the period from the start of the year to the end of the previous month, the figures for the current year, the previous year, and the median for the last five years for comparison (Epidemiological Reporting System, as at 17 June 2026).
a Diseases are assessed in accordance with the case definition. The figures show diseases for which a case definition exists, with the exception of transmissible spongiform encephalopathies. As a rule, confirmed and probable cases are counted. Changes may still occur as a result of late reports or subsequent entries.
b Bacterial and viral food poisoning, in accordance with the Epidemics Act.
c Invasive bacterial disease, in accordance with the Epidemics Act.
d Includes only cases of pneumonia.
e Due to the lack of a case definition prior to 2025, only cases from 2025 onwards are shown; the median is also calculated only from 2025 onwards.
f Mpox has been a notifiable disease since 2022; the median is calculated only for the years in which it is a notifiable disease.
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Last updated: 22.05.2026
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