The flu outbreak in Austria has come to an end. Since the beginning of March, only isolated cases of influenza A have been detected. Influenza B continues to be absent, whilst influenza C has been detected in isolated cases. The AGES wastewater monitoring programme now shows no further evidence of influenza viruses.

The influenza detections were almost exclusively of influenza A, subtypes A(H3N2) and A(H1N1). Influenza B was detected in only 1% of all samples.

Hospital admissions for influenza have been declining since the start of the year: at the beginning of January, 863 admissions per week were recorded in general wards; by the end of March, this figure had fallen to just 10. As corrections and late reports are to be expected on an ongoing basis, the data may still change. 

In most countries of the European Union and the European Economic Area (EU/EEA), influenza circulation is low and continues to decline across all age groups. The influenza subtypes A(H1)pdm09 and A(H3) are detected with equal frequency.

The best preventive measure against severe influenza is the annual flu vaccination. In Austria, vaccination against influenza (true flu) is recommended from the age of 6 months and is available free of charge to all age groups under the public vaccination programme. Vaccination is particularly important for people at risk of severe illness and their close contacts/household members, as well as for those who are at increased risk of infection due to their circumstances (including pregnant women) or occupation. A nasal vaccine is available specifically for children. Ideally, the influenza vaccination should be administered in mid-October or November, before the flu season begins. Details can be found at www.impfen.gv.at/influenza and in the current Austrian Vaccination Schedule 2025/2026.

In episode 003 – Influenza & Co: How do I navigate the flu season safely? of the AGES podcast “Mut zum Risiko”, infectious disease epidemiologist Fiona Költringer explains what the flu is all about and how best to protect yourself against it. 

Flu - AGES

Following a peak at the end of February, the number of respiratory syncytial virus (RSV) cases detected by the sentinel surveillance system has fallen significantly in recent weeks. However, the proportion of samples testing positive for RSV remained above 10% at the beginning of April. Hospital admissions for RSV infections have been declining since mid-February. At the end of March, 121 admissions to general wards were recorded per week. In wastewater, the proportion of samples with detectable results is decreasing.

In the rest of the EU and the EEA, RSV circulation is elevated but appears to be generally declining. As in Austria, children under five continue to account for the majority of hospital admissions. 

Children under five years of age and people over 65 are at particularly high risk of developing severe RSV infection. Therefore, the RSV vaccine is recommended for adults aged 60 and over. There is currently no authorised RSV vaccine for children in the sense of active immunisation. However, monoclonal antibodies are available for passive immunisation: Beyfortus (nirsevimab) is authorised and recommended for the prevention of lower respiratory tract RSV disease in newborns, infants and young children during their first RSV season, as well as in children up to 24 months of age who remain susceptible to severe RSV disease during their second RSV season. Beyfortus is available under the free childhood vaccination programme funded by the federal government, the Länder and social insurance; immunisations were recommended for the 2025/26 season until 15 April 2026. A vaccination for pregnant women is also authorised for the passive immunisation of children. The RSV vaccination is recommended for adults aged 60 and over, as well as for people aged 18 and over who are at increased risk, to protect the vaccinated person against RSV infections/illnesses.

Further information on the vaccinations is available at impfen.gv.at/impfungen/rsv and in the current 2025/2026 vaccination schedule. 

RSV - AGES

In early April, there were very few, if any, samples testing positive for SARS-CoV-2 in the Sentinel system. The viral load in wastewater remains consistently low.

The number of hospital admissions due to severe acute respiratory infections caused by COVID-19 has been falling steadily since the start of the year. At the end of March, 26 admissions to general wards were recorded – compared with 334 at the end of December.

In the EU and the EEA, SARS-CoV-2 is circulating at low levels across all age groups, with only a few hospitalisations being reported.

There is currently increased media coverage of the BA.3.2 variant (‘Circadia’). A WHO report from December 2025 assesses the overall risk of the variant as low. BA.3.2 shows differences from previous Omicron variants; however, phenotypic studies indicate, among other things, reduced infectivity and a moderate reproduction rate compared to other variants. There is currently no evidence that BA.3.2 poses a risk to public health; currently authorised vaccines continue to offer protection against severe disease progression.

The COVID-19 vaccine is available free of charge in Austria and, according to the current Austrian vaccination schedule, is primarily recommended in the autumn for anyone aged 12 and over who wishes to reduce the risk of a potentially severe course of the disease. A recent study by Viennese scientists demonstrated the clear benefits of the COVID-19 vaccination for older people. The mRNA vaccines showed a protection rate of approximately 80% among residents aged over 85 in a care home.

Further information on the vaccination and its indications can be found in the Austrian Vaccination Schedule 2025/2026.

Coronavirus - AGES

A case of subacute sclerosing panencephalitis (SSPE), the most severe form of measles, was reported in Vienna in February. This late complication, which usually develops several years after the initial infection and causes the brain to literally disintegrate, has a grim prognosis, with the condition almost always proving fatal. Unfortunately, the patient in question, a 9-year-old boy, has since passed away.

The risk of developing SSPE is significantly highest among people who contracted measles as infants or young children. This makes it all the more important to protect these age groups in particular, from the age of 9 months, through timely vaccination in accordance with the Austrian immunisation schedule. Younger children can only be protected from the disease through herd immunity – that is, by achieving high vaccination coverage in the other age groups. In this respect, it is particularly important that the environment of infants is also consistently protected against measles.

This tragic case had likely been infected years ago in a country where, due to difficult circumstances, unrestricted access to vaccinations and the achievement of high vaccination coverage were temporarily no longer possible. In Austria, such barriers do not exist. A measles vaccination is available free of charge for all age groups – including adults – as part of the childhood vaccination programme and is offered at many vaccination centres. Two doses are recommended from the age of 9. 

Further details can be found at impfen.gv.at/impfungen/masern-mumps-roteln or in the Austrian Immunisation Schedule 2025/2026. 

Measles - AGES

On 25 March 2026, the Italian Ministry of Health reported a confirmed case of avian influenza A(H9N2) in a person in the Lombardy region. This is the first recorded human case of avian influenza of the A(H9N2) subtype in the EU or the EEA. The infection occurred in Senegal, where the patient had previously been staying. Upon arrival in Italy, he visited the A&E department with a fever and a cough and was treated in hospital. The patient has underlying health conditions that weaken the immune system. The Italian authorities have carried out contact tracing to identify and control any potential transmission to other people. No direct contact with animals, wildlife or rural environments has been identified. Nor has any contact with symptomatic or confirmed human cases been reported. Further epidemiological investigations into the source of infection are ongoing. Epidemiological and microbiological investigations have been initiated and the situation continues to be monitored.

Since 1998, 195 human cases of A(H9N2) have been reported worldwide in 10 countries in Asia and Africa, of which only two were fatal. The ECDC assesses the risk to the general population in Europe from A(H9N2) in connection with this case in Italy as very low.

The subtype A(H5N1) is currently the main strain circulating in European wild birds and poultry. Detections of A(H5N1) in European birds are now declining again. In the autumn and winter of 2025/2026, the highest circulation of avian influenza in waterfowl in five years was recorded. In Austria, regions classified as having a ‘significantly increased risk’ of avian influenza were downgraded to ‘increased risk’ at the beginning of April. The mandatory housing order has therefore been lifted, although certain requirements must still be met. Further information can be found in the latest Animal Disease Radar.

In episode 10: ‘The chickens aren’t laughing – bird flu in the spotlight’ of the AGES podcast ‘Mut zum Risiko’, expert Irene Zimpernik explains the virus and the disease and provides recommendations for poultry farmers and the general public. Among other things, dead wild birds should not be touched and must be reported immediately.

In March 2026, the UK Health Security Agency reported an outbreak of meningococcal disease in Kent, England. The initial report on 15 March 2026 recorded 13 cases of people infected with meningococcal disease and two deaths. The number rose in the days leading up to 1 April, with a total of 21 cases eventually identified. Young adults were primarily affected. It is believed that the meningococcal infection was transmitted in a nightclub and subsequently spread within this age group. To curb further spread, vaccination campaigns were carried out and antibiotics were distributed. This recent outbreak highlights the importance of vaccination. In the United Kingdom, the meningococcal B vaccine has only been included in the national immunisation programme since 2015, so many people over the age of 10 have not been vaccinated. 

Meningococci (Neisseria meningitidis) are divided into different serogroups; in Austria, group B is the most common. Cases fell sharply, particularly in 2020 and 2021, due to COVID-19 measures. Since then, however, the number of cases has risen again. Nevertheless, in 2025 the annual number of cases remained consistently below 40 per year. Meningococcal disease can occur at any age, but it is more commonly observed in infants, young children and adolescents.

In Austria, the vaccine against group B meningococcal disease has been available since 2014 and is recommended for all children and adolescents as early as possible from the age of two months to provide individual protection against invasive group B meningococcal disease. The vaccine is not included in the free vaccination programme. Catch-up vaccinations are recommended up to the age of 25, but are also possible for older adults (for example, where there is a specific indication according to the Austrian vaccination schedule) and can contribute to individual protection. 

Vaccination against other serogroups (A, C, W, Y) is recommended in Austria from the age of 1, is available free of charge from the age of 10 to the age of 13, and is a chargeable vaccination for adults where there is a specific indication (e.g. including travel vaccination). Further information can be found in the Austrian Immunisation Schedule 2025/26. 

Meningococci are transmitted from person to person via droplet infection. They can colonise the nasopharynx of healthy individuals. In some cases, they can penetrate the mucous membranes and lead to severe infections (invasive disease). Meningococcal meningitis and meningococcal sepsis are particularly feared. Meningitis causes a general (severe) feeling of illness with high fever, severe headaches and neck stiffness; the disease can take a fulminant course. If the pathogens pass from the bloodstream into the tissue, haemorrhages can lead to a typical pinpoint “rash”. In the AGES Radar of 26 September 2024, we reported in detail on this disease to mark World Meningitis Day.

Meningococci - AGES

In March 2026, the laboratory in Basel-Stadt reported the detection of the dengue virus (serotype 4) in an Asian tiger mosquito from the region. This is the first detection north of the Alps. The sample examined came from a pool of tiger mosquitoes caught as early as 2024, but was not finally analysed until 2025 and published in early 2026. This finding provides important evidence that the dengue virus was already present in mosquitoes in Central Europe in 2024.

The Asian tiger mosquito is established in 369 regions across 16 European countries. In recent years, there have been repeated cases of autochthonous dengue virus infections in humans in countries including France, Italy, Spain and Croatia. These occurred predominantly seasonally during the warmer months. 

No autochthonous dengue virus cases have yet been reported in Austria. However, the Asian tiger mosquito has already established itself in some regions of Austria. Due to the geographical proximity to affected regions, the control of the tiger mosquito in Austria is becoming increasingly important. The hotspots for the tiger mosquito in Austria are cities such as Vienna, Graz and Linz. This year, the city of Graz is placing greater emphasis on the so-called Sterile Insect Technique (SIT). SIT involves releasing sterile male tiger mosquitoes, which mate with females. The resulting eggs are non-viable, thereby reducing the population in the long term. Following a pilot project in 2025, the number of sterile mosquitoes released is set to increase significantly in 2026 in order to specifically reduce the tiger mosquito population. You can find more information on mosquitoes and what each individual can do to curb their spread under Tips for avoiding tiger mosquitoes – AGES.

Dengue – AGES

Vaccinations are among the most effective and cost-efficient measures for preventing disease and have played a key role in significantly curbing diseases such as diphtheria and polio. Thanks to the smallpox vaccine, smallpox was declared eradicated worldwide in 1980. 

Despite their track record in the fight against infectious diseases, this very success is proving to be the greatest obstacle to vaccination: most people are no longer aware of the dangerous course of many highly contagious diseases and their potentially severe consequences, and consequently underestimate them. Thanks to vaccination, some vaccine-preventable diseases are no longer as common, particularly in Europe. However, due to globalisation and high population mobility, they could re-emerge at any time.

Despite the proven efficacy and safety of authorised vaccines, willingness to be vaccinated is declining in some sections of the population. A UNICEF report from 2023 shows that the perception of the importance of childhood vaccinations has declined in 52 out of 55 countries since the COVID-19 pandemic. A Eurobarometer survey on Europeans’ attitudes towards vaccinations found that 48% (incorrectly) believe that vaccinations can often lead to serious side effects; 38% think that vaccinations cause the very diseases they are designed to protect against.

Uncertainty surrounding vaccination or vaccine scepticism can stem from a variety of reasons: whether it be a lack of trust in the safety and efficacy of vaccines or in the healthcare system; a misjudgement of the potential risks of infectious diseases; or limited access to vaccines.

Factors that can fuel vaccine scepticism include false and misleading information and deceptive representations circulating online. A study on misinformation and disinformation on social media (Facebook, TikTok, etc.) revealed that health-related topics are particularly frequently affected. Above all, misleading representations – which do not necessarily contain outright falsehoods but reinforce incorrect beliefs – can further fuel uncertainties surrounding vaccinations. 

But how should we deal with vaccine hesitancy? This has been and is currently being investigated in a number of research projects, including the European VAX-TRUST study, which examined between 2021 and 2024 why parents were hesitant to vaccinate their children.

In most cases, uncertainty stems from personal concerns; many people simply have questions. When dealing with this, the first step is to listen actively, ask questions and find out what lies behind the concerns. Transparent, open and personal communication is key in these conversations. One approach is the so-called ‘motivational interview’: an empathetic, respectful conversation between a healthcare professional and the vaccine recipient, in which concerns are acknowledged and appropriate information is provided. 

A study involving more than a million people in the United Kingdom found that two-thirds of those who expressed reservations about vaccination during the COVID-19 pandemic went on to get vaccinated later. Most reservations about COVID-19 vaccines or vaccination were based on specific concerns that can be dispelled and successfully overcome through the availability of information.

Doctors, particularly GPs, are the most trusted source of information on vaccinations for the Austrian population. In the February 2022 Eurobarometer survey, 65% of Austrians surveyed also stated that they trusted healthcare professionals, doctors and pharmacists the most when it came to information on COVID-19 vaccinations.

A 2023 study by the Centre for Health Policy Research (https://pmc.ncbi.nlm.nih.gov/articles/PMC10755181/Übersichtarbeit) showed that consistent and clear recommendations from a trusted healthcare professional, who addresses misconceptions and emphasises the benefits, were strongly associated with an increase in vaccinations during pregnancy; especially when the conversations took place in person. 

The JitsuVAX project developed tools to help tackle misinformation regarding vaccinations. These can be used by healthcare professionals and are also helpful for discussions among friends, acquaintances or within the family.

Institutions such as the ECDC regularly offer webinars for healthcare professionals; for example, one on the topic of ‘From hesitancy to acceptance, using empathy to respond to vaccination misinformation’ will take place on 21 April 2026.

How to speak to a vaccine sceptic: research reveals what works

On 23 March 2026, a symposium on current challenges and developments in the field of tuberculosis was held at the Josephinum in Vienna to mark World Tuberculosis Day. The event focused on clinical case studies, new therapeutic approaches and international case reports, as well as epidemiological issues. An overview of the epidemiological situation in Austria was presented, supplemented by insights into the cluster analysis of mycobacteria. In addition, the results of the evaluations of the tuberculosis screening programme were presented, providing an insight into current tuberculosis screening practices in Austria. Overall, the symposium thus made a significant contribution to the further development of tuberculosis prevention and treatment.

The Campylobacter Alert Annual Report 2025 was published in April. The annual incidence was 77.8 cases per 100,000 inhabitants, compared with 74.6 in 2024, representing an increase of 4.3%.
Most cases occurred during the summer months. Children under the age of 5 and young adults were particularly affected. The highest incidence rates were recorded in Burgenland and Salzburg, whilst the lowest incidence was in Carinthia. Whilst a decline in reported cases was recorded in Vorarlberg, Tyrol and Styria, the remaining federal states, with the exception of Upper Austria, saw an increase in incidence compared to the previous year.

Unchanged high resistance rates were observed for the fluoroquinolone and tetracycline classes of antibiotics; the resistance situation for macrolides remains favourable. More detailed information can be found in the annual Austrian resistance report AURES.  

The most likely source of infection is often raw or undercooked poultry meat, particularly chicken, in which the bacteria under investigation are frequently detected. However, Campylobacter is also found in other contaminated foods, such as unpasteurised milk.

Campylobacter - AGES
  

The annual report on the nationwide pathogen monitoring of mosquitoes for 2025 was published in March. The monitoring is carried out as part of the ‘OH SURVector’ project and serves to monitor the West Nile virus (WNV) and other pathogens in mosquitoes.

From May to October 2025, traps were set up twice a month at 69 locations. A total of 6,146 mosquitoes were caught, significantly fewer than in the previous year. This can be attributed to the weather conditions in the summer of 2025, which were unfavourable for the development of many mosquito species. The partner countries of the OH SURVector project, where mosquito monitoring programmes are carried out (the Czech Republic, Slovakia, Hungary), also describe 2025 as a year with very low mosquito numbers.

Most of the mosquitoes identified belonged to the species Cx. pipiens/torrentium, the main vector of WNV in Europe. The mosquitoes were grouped into 1,313 pools and analysed. WNV or any other pathogen could not be detected in any of these pools.
 

The 2025 annual report, ‘Ovitrap Monitoring of Non-native Mosquito Species in Austria’, was published in March. The Austria-wide mosquito monitoring programme using Ovitraps (‘egg traps’) makes it possible to record the occurrence and spread of non-native and potentially invasive mosquito species in Austria. These traps are set up at various locations throughout Austria from early May to late October.

In 2025, a total of 6,594 samples were collected; eggs of container-breeding mosquitoes of the genus Aedes were detected in 1,622 of these samples (24.6%). This means that the proportion of positive samples is below the level of previous years (comparison with 2024: 30.4%).

The distribution of the tiger mosquito (Ae. albopictus) in Austria in 2025 was similar to that of previous years. This species is already established in large parts of Vienna, Graz and Linz, where it also occurs locally in large numbers. The geographical spread of the tiger mosquito has increased significantly in these three cities over recent years. 

The Japanese bush mosquito (Ae. japonicus) can now be found in all Austrian federal states and is particularly widespread in the south and south-west. This species will no longer be eradicable in Austria.

The Korean bush mosquito (Ae. koreicus) has so far only been found sporadically and could not be detected at all in 2025. 

The 2025 Meningococcal Annual Report was published in April. Over the course of the year, 31 laboratory-confirmed cases of meningococcal disease were recorded in Austria. This corresponds to an incidence of 0.3 per 100,000 people. 

In 25 of these N. meningitidis cases, the serogroup could be determined: 44% belonged to serogroup B, whilst 40% were classified as serogroup Y. 

In addition, the bacteria were tested for resistance to the antibiotics penicillin, ceftriaxone, rifampicin and ciprofloxacin. No resistance was detected.
 

Number of cases of notifiable diseases under the Epidemics 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 15 April 2026).

^a Diseases are assessed in accordance with the case definition. Diseases for which a case definition exists are shown, with the exception of transmissible spongiform encephalopathies. As a rule, confirmed and probable cases are counted. Changes may still occur due to late reporting 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 involving 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.