AGES radar for infectious diseases - 25.01.2024

The AGES Radar for Infectious Diseases is published monthly. The aim is to provide the interested public with a quick overview of current infectious diseases in Austria and the world. The diseases are briefly described, the current situation is described and, where appropriate and possible, the risk is assessed. Links lead to more detailed information. The "Topic of the month" takes a closer look at one aspect of infectious diseases.

Situation in Austria

Respiratory diseases occur more frequently during the cold season, including COVID-19, influenza and RSV. These diseases are monitored via various systems, such as the Diagnostic Influenza Network Austria (DINÖ), the ILI (Influenza-like Illness) sentinel system and the Austrian RSV Network (ÖRSN). The situation in hospitals is recorded via the SARI (Severe Acute Respiratory Illness) dashboard.

Summary: After peaking in December, COVID-19 hospital admissions and SARS-CoV-2 signals in wastewater have declined. RSV and influenza cases in sentinel surveillance have been rising for several weeks. Both waves are later in the year and currently less pronounced than in the 2022/23 season.

The measures familiar from the pandemic can help to slow down the spread of respiratory infections: hand hygiene, suitable masks in appropriate environments and avoiding contact if you have symptoms.

In wastewater monitoring, the SARS-CoV-2 virus concentration measured in December was higher than ever before. Following a peak in December, the DINÖ has also recorded a decline in SARS-CoV-2-positive samples.

The number of COVID-19 admissions to hospitals has risen steadily since September and peaked in mid-December. Since then, inpatient hospital admissions have been falling again. There were 692 admissions to normal wards in the first week of January, while admissions to intensive care units fell from 48 to 24 over the turn of the year (as at 25 January 2024).

Austrian laboratories send SARS-CoV-2 samples to AGES for sequencing. The results of the sequencing are regularly published on the AGES website in the COVID-19 profile. The dominant variant for several weeks is JN.1, daughter line of BA.2.86.

In Austria, free COVID-19 vaccination is possible for everyone from the age of 6 months and is generally recommended for everyone from the age of 12 years. Further information on COVID-19 vaccination can be found in the current vaccination plan Austria 2023/2024 (Chapter E - COVID-19) dated 05.09.2023.

Coronavirus - AGES

Influenza-positive samples are being reported via the DINÖ with a clear upward trend (exception: Christmas holidays). The influenza subtype A(H1N1)pdm09 is currently predominant. The estimated number of influenza and influenza-like illnesses is shown on the AGES website. There was a significant increase in these illnesses up to the end of December. There was a slump in the figures at the turn of the year, which is probably due to the Christmas holidays.

Hospital admissions have risen sharply since December; in week 01, 250 people with influenza were admitted to a normal ward. In comparison: four weeks earlier, there were 62 influenza admissions (as at 25/01/2024).

Details on the last influenza seasons can be found in the AGES Radar from 05/10/2023.

The influenza vaccination is generally recommended from the age of 6 months according to the Austrian Vaccination Plan 2023/2024. All people living in Austria can be vaccinated against influenza as part of the "Public Influenza Vaccination Programme", including in the surgeries of registered doctors. The vaccination is free of charge for children and young people up to the age of 18 and certain groups of people, for example people with prescription fee exemptions and people living in retirement and nursing homes. For people aged 18 and over, it is available for a co-payment of €7.

Details on how citizens can take advantage of the vaccination can be found at

A Canadian study assessed the effectiveness of this year's influenza vaccination as high. The circulating viruses correspond to the virus strains contained in the 2023/24 vaccinations. The effectiveness was estimated at 61% for influenza A(H1N1), 49% for influenza A(H3N2) and 75% for influenza B.

Influenza - AGES

In calendar week (CW) 41, an RSV-positive sample was registered in the sentinel network (DINÖ) for the first time in the 2023/24 winter season. In recent weeks, the number of RSV infections has steadily increased (exception: Christmas holidays).

Hospital admissions to normal wards have increased over the turn of the year: from 138 in the penultimate week of December to 249 in the first week of January (as of 25 January 2024). The majority of admitted patients are infants and toddlers aged 0 to 4 years.

The respiratory syncytial virus, RSV for short, triggers respiratory diseases. The RSV season in Austria usually begins in November and lasts until April. Infants, young children and people over the age of 60 have an increased risk of contracting RSV.

Since autumn 2023, two vaccines have been available in Austria to prevent RSV-triggered lower respiratory tract diseases in adults. Both vaccines are authorised from the age of 60 and are generally recommended as a single dose in accordance with current national recommendations. In addition, one of the two vaccines, Abrysvo, is authorised for pregnant women for the passive protection of newborns.

Details on RSV vaccination can be found at: Vaccination plan Austria 2023/2024 (


In mid-January, a regional vocational school in Styria and the associated apprentice house had to close temporarily due to numerous cases of gastrointestinal illnesses. Testing of several samples revealed that the illnesses were caused by the highly contagious norovirus. Four other outbreaks in retirement homes in January 2024 were also traced back to norovirus.

Noroviruses are considered one of the most common causes of virus-related infections of the gastrointestinal tract worldwide. It is transmitted via faeces or vomit, either directly from person to person or via contaminated objects, water and food. Inadequate hand hygiene is often the reason for the spread of the virus. Mussels are a common cause of norovirus outbreaks worldwide, as they can filter noroviruses out of faecally contaminated seawater. Noroviruses are very contagious, even small amounts of 10 to 100 virus particles can lead to illness. This often begins after just a few hours with severe vomiting and diarrhoea.

Norovirus infections occur more frequently in the winter months (see chart). There were a total of 2,130 confirmed norovirus cases in 2023. In 2024, 276 norovirus cases have been reported so far (as at 23/01/2024, 12:00).

In neighbouring Germany, the trend is comparable to Austria: an increase in norovirus cases has been observed since November. The numbers have also been very high in the USA and the UK since December, and the peak of the 2023/24 season appears to have been reached in both countries.

In the case of a norovirus infection, the symptoms usually stop on their own after 48 hours. To avoid dehydration, it is important to drink plenty of water or tea. Special electrolyte mixtures from the pharmacy can compensate for both fluid and mineral salt loss.

The most important measure to prevent a norovirus infection is to wash your hands thoroughly, especially after using the toilet and before handling food.

Following the temporary switch to distance learning and the cleaning of the entire school building in Styria, regular school operations resumed on 15 January 2024.

You can find more information in the Norovirus folder.

Norovirus - AGES

At the end of the 2023 annual statistics, a total of 2,768 cases of pertussis were reported (as at 23 January 2024). This continues the upward trend that was already observed before the pandemic, with over 350 cases already reported in January 2024 (as of 23 January 2024).

Higher pertussis case numbers than in the previous year were also observed in other European countries in 2023. More details can be found in the AGES Radar of 30 November 2023.

Pertussis is a highly contagious, notifiable infectious disease of the respiratory tract. This disease can lead to severe courses and deaths, especially in infants and young children.

In Austria, the number of cases of pertussis rose steadily in the years before the COVID-19 pandemic. While 579 cases were reported nationwide in 2015, this figure had already risen to 2,233 in 2019. In 2020, 2021 and 2022, the number of pertussis cases in Austria fell sharply due to the preventive measures against COVID-19. The current rise in case numbers is partly due to low pertussis vaccination coverage rates(ECDC) during the pandemic years. According to WHO data, Austria has a suboptimal vaccination coverage rate for 1-year-olds of 84%(WHO, as of 2022).

Vaccination against whooping cough is the best protective measure against severe cases(ECDC). The pertussis vaccination is included in the free childhood vaccination programme and is usually administered as part of the quadruple or sixfold vaccination (diphtheria, tetanus, pertussis, poliomyelitis ± Haemophilus influenzae B and hepatitis B). After basic immunisation in infancy, it should be boosted for the first time in early school age and then at regular intervals throughout life. You can find more information on this in the Vaccination Plan Austria 2023/2024 and "Fact check: Whooping cough. Vaccination protects!"(Whooping cough fact check).

Whooping cough (pertussis) - AGES

As of 18 January 2024, a total of 24 people with an outbreak strain of Salmonella Strathcona have been reported in six federal states: Upper Austria (4), Lower Austria (7), Vienna (4), Styria (7), Carinthia (1) and Salzburg (1). The cases were registered by the National Reference Centre for Salmonella from August 2023 to December 2023. Four of the 24 cases were hospitalised. No deaths were reported. The last case fell ill in mid-December 2023, and no new cases have been reported in the last three weeks. This made it the largest outbreak of foodborne illness in Austria in 2023.

Salmonella is a bacterium that can cause diarrhoea; salmonellosis is usually food-borne and is also rarely caused by contact with reptiles, for example. In Austria, salmonella is the second most common cause of diarrhoea.

The outbreak affected several countries, the source is being sought as part of an international investigation and is suspected to be outside Austria. AGES Infectious Diseases Epidemiology was commissioned to investigate the outbreak in Austria and is working closely with the local health authorities and food inspectorates of the affected provinces. The infected persons were interviewed by telephone about the food they had eaten in the week before the outbreak. This information provides clues to finding the source of the outbreak. This clarification is still in progress.

To prevent infection with salmonella, clean handling of food is recommended: Food, especially meat, poultry, eggs or pasta with cream filling, should be boiled well. Raw poultry meat should not be washed after unpacking. After handling raw poultry meat, it is essential to wash your hands thoroughly before starting other kitchen tasks. All work surfaces and utensils that have been in contact with raw poultry meat, other raw meat or raw eggs should be cleaned with washing-up liquid and hot water.

Salmonella - AGES

International outbreaks

At the end of 2023, respiratory diseases were circulating at a very high level in Europe and the USA. Due to the high number of infections with respiratory diseases, a decree was issued in Spain at the beginning of January making masks compulsory again in doctors' surgeries and hospitals. Hospitals in several states in the USA also introduced mask-wearing rules at the turn of the year. The number of people seeking healthcare due to a respiratory illness is still very high or rising in most of the USA in mid-January(CDC, as of 19 January 2024).

Respiratory diseases also continue to circulate at a high level in most European countries after the turn of the year. Influenza is currently the most common. Influenza activity remains high, while SARS-CoV-2 and RSV are declining in most countries.

The high level of circulating respiratory diseases is also reflected in hospital admissions, intensive care unit occupancy and deaths. The European Mortality Monitoring Programme (EuroMoMo) records a significantly increased mortality level for the second week in 2024.

The currently reported SARS-CoV-2 figures do not accurately reflect the infection situation, as the number of tests and reports has decreased worldwide.

SARS-COV-2 variants

Currently, neither the WHO nor the ECDC has a Variant of Concern (VOC), so no virus variant has been categorised as a cause for concern.

BA.2.86 was upgraded to a Variant of Interest (VOI) by the WHO and ECDC at the end of November, as it has numerous mutations and has been constantly increasing worldwide. BA.2.86 is now the most common lineage. In Europe, BA.2.86 circulates at an average of 88 % (as of 19/01/2024).

JN.1 is a sublineage of BA.2.86 and accounts for the majority of this variant. On 19 December, the WHO itself upgraded this subline to a VOI as it is spreading rapidly. So far, JN.1 is not considered more dangerous than other variants, which is why the WHO considers the risk it poses to be low. However, due to its rapid spread, it increases the burden of respiratory diseases in many countries.

Worldwide, JN.1 was the most frequently detected VOI with 65.5% of all sequences in the last week of 2023. JN.1 also accounts for the largest proportion of BA.2.86 (74 of 87 in week 1) and a large proportion of the total samples (74 of 104 in week 1) in the AGES samples in the last week (as of 23 January 2024).

The sequencing level is low worldwide.

More detailed information on the international variant situation can be found at Coronavirus - AGES

The global cholera case numbers for 2023 have once again exceeded those of the previous year. In total, more than 667,000 cholera cases and 4,000 deaths were reported worldwide in 2023 up to 15 December, almost 200,000 more confirmed cholera cases than in 2022, according to the WHO situation report published on 11 January 2024.

Cholera is a diarrhoeal disease caused by toxin-producing strains of the pathogen Vibrio cholerae. It is transmitted via human faeces that contaminate water and food. Human-to-human transmission is rare, but with proper treatment and sufficient intake of clean water and electrolytes, the disease is usually mild and mortality is low. In disaster areas, there is often no adequate supply and cholera can therefore lead to death, especially in children. The establishment of a stable drinking water supply, hygiene and the fight against poverty are the most effective means of combating cholera outbreaks.

The WHO has already classified the global resurgence of cholera as a public health emergency of the highest order at the beginning of 2023, after the number of cholera cases more than doubled worldwide from 2021 to 2022. Details can be found in the AGES-Radar 05.10.2023.

Between 01.01.2023 and 15.12.2023, 30 countries reported cases of cholera or acute watery diarrhoea. Africa is the most affected WHO region with 17 reporting countries. The main causes are inadequate and overloaded sewage systems. Increased rainfall in the rainy season from October to April in south-east Africa leads to contamination of drinking water with wastewater. There are also population movements due to flooding: poor hygiene standards in the refugee camps favour the spread of cholera.

Vaccination is available and is primarily recommended for disaster and relief operations.

For travellers, the risk of infection is considered low by the ECDC, even if it could occasionally happen that a case is brought into the EU. No cholera toxin-producing vibrios have been identified in the Austrian national reference laboratory for cholera in the past three years.

WHO report: Multi-country outbreak of cholera, External situation report #10 - 11 January 2024 (

Cholera - AGES

Topic of the month

Recently, numerous media outlets in Austria reported that Pamela Rendi-Wagner has applied for a top European job: The former SPÖ party chairwoman wants to take over as head of the ECDC. This European Union agency is tasked with containing and improving the fight against communicable diseases. Current and emerging risks are to be recognised, assessed and communicated in good time.

Despite the pandemic, the ECDC has not been very much in the public eye; many may have heard of this organisation for the first time in connection with Rendi-Wagner's application. Its American counterpart, the CDC, is also better known in the healthcare sector - its recommendations and studies were regularly heard of during the pandemic years. One reason for this is that the ECDC's work has so far been primarily aimed at experts. Only since 2023 has it also increasingly addressed the public directly. In addition to its scientific work, it supports national organisations with information material in numerous languages and helps with transnational campaigns. One example of this is the European Immunisation Information Portal.

Tasks, goals and history

The ECDC collects data on infectious diseases and outbreaks from the EU/EEA countries, evaluates them and promotes the exchange - not only of data, but above all of national organisations. AGES is part of this network: we supply the data on infectious diseases from Austria to the ECDC, work together scientifically and jointly train the future public health experts. Structured international training programmes continuously raise the scientific level in dealing with public health issues in all member countries.

AGES is represented as a training partner with both lecturers and trainee scientists: In the EPIET and EUPHEM programmes, the Institute of Infection Epidemiology and the Institute of Medical Microbiology and Hygiene are important partners. In addition, the organisation awards scholarships, organises training courses and runs a virtual academy for continuing education.

In 2005, the ECDC began its work on behalf of the European Union with the aim of improving the prevention and control of communicable diseases in Europe. It is based in Solna in the province of Stockholm, just north of the Swedish capital. German doctor Andrea Ammon has headed the ECDC since 2017. In addition to coordinating the national organisations, the ECDC provides the Commission of the European Union with scientific advice. It supports outbreak preparedness and advises on the response to outbreaks. Globally, it works closely with the WHO.

You can find a more detailed overview of the individual tasks here.

In response to the COVID-19 pandemic, the ECDC was given the mandate to form a multinational expert group if necessary, which is quickly available to the EU Commission or the member states. This "Health Emergency Task Force" is put together on a situation-specific basis and can perform different tasks depending on what the situation requires: Clarifying risks, identifying new pathogens, establishing standardised procedures or advising decision-makers. In principle, such teams can provide support worldwide; as an EU organisation, member states have priority. The teams are recruited from ECDC experts, from the EPIET and EUPHEM training programmes and from experts from the respective countries.

The networks of specialists

Cooperation between the member states works via topic-specific networks (NFP - National Focal Points or OCP - Operational Contact Points). This creates separate networks in which the information from the ECDC is passed on to the member states and a targeted exchange between the specialists can take place. Most of these networks have at least annual meetings so that people know each other personally and good communication is established. The representatives of the countries sit either in the respective ministries or in the public health organisations. AGES also provides many of the NFPs and is represented in the ECDC Advisory Forum.

ECDC website


The WHO certified Cape Verde as a "malaria-free country" in January 2024. This certification is granted when a country can prove that it has broken the continuous transmission of indigenous malaria by Anopheles mosquitoes and that this condition has persisted for three years. A prevention plan is also required to prevent reintroduction. Worldwide, 43 countries have received this certification.

Like other European countries, the UK is experiencing a setback in the fight against measles. In 2016, the WHO declared the region measles-free, but in 2023 there were 209 confirmed measles cases between January and the end of November. More recent data suggests over 170 measles cases in the West Midlands alone between December 2023 and mid-January 2024. The health authorities have therefore declared the measles outbreak a "national event" and warned against under-vaccination. In order to prevent measles in the sense of nationwide community protection, the vaccination coverage rate for the first two doses would have to reach at least 95%. This target has not been achieved in the UK in recent years. This has led to a steady increase in the number of people who are susceptible to infection, increasing the likelihood of outbreaks.

Following the COVID-19 pandemic and in view of the vaccination coverage rate in many countries, the ECDC expects a further increase in measles cases in Europe and worldwide. The WHO Regional Office for Europe drew attention to the enormous increase in measles cases on 23 January: According to the WHO, 30 times as many measles cases were registered in the region between January and October 2023 than in the entire previous year. Kazakhstan and Russia are mainly affected, with more than 10,000 cases each.

The best prevention against measles is vaccination. In Austria, a total of two vaccine doses are generally recommended from the age of 9 months (a joint vaccine with mumps and rubella). Vaccination is free of charge regardless of age, and missing vaccinations should be made up for at any age.

Measles - AGES

COVID-19 vaccinations reduced the number of deaths across Europe by 57%. Translated into absolute figures, this equates to around 1.4 million lives saved by over 25-year-olds. This is according to a WHO study published on 13 January 2024, which estimated the number of lives saved by COVID-19 vaccination. The focus was on vaccination programmes in the WHO Europe region between December 2020 and March 2023.

In Austria, the number of lives saved by the COVID-19 vaccination is 24,859. The vaccination had the greatest impact on people over 60 years of age, this age group accounted for 96% of the lives saved across Europe. The third vaccination saved the most lives at 721,122.

Technical term epidemiology

Every month, we present a technical term from the field of infectious disease epidemiology. This time there are three terms, as they belong together thematically:

Endemic, epidemic and pandemic

The RKI's specialist dictionary "Infection Protection and Infection Epidemiology" defines endemic as the "permanent (indefinite) occurrence of a disease or pathogen in a specific area or population". The disease is "native" to a certain geographical region and occurs there permanently. For example, malaria is endemic in certain countries of the world and the disease regularly causes new cases there, which means that in this temporal and spatial situation, many people are infected at the same time, which is the normal state of affairs. This does not mean that this number is always constant; fluctuations can also occur here. Fluctuations in the number of cases can occur, for example, due to seasonal influences or changes in the immune status or age structure of the population.

In contrast, an epidemic is when "compared to the initial situation, certain cases of illness with a uniform cause occur more frequently." An epidemic refers to the sudden and above-average occurrence of a disease in a geographically limited region or in a specific population group. An example of an epidemic is the annual increase in cases of influenza in the winter months. The increase in cases rises rapidly but only for a limited time and is confined to a specific geographical area.

A pandemic is defined as a new "but temporary, worldwide spread of an infectious disease with high numbers of cases and, as a rule, a severe course of disease". The definition makes it clear that a pandemic is basically an emergency situation. The World Health Organisation (WHO) defines a pandemic as the global emergence of a new disease that spreads rapidly across different countries and continents, infecting a significant number of people. A pandemic can occur when a novel pathogen spreads to which the population has little or no immunity and when there is sustained person-to-person transmission. A pandemic refers not only to the geographical spread, but also to the extent of the disease that jeopardises the normal operation of healthcare systems. It is important to have pandemic plans in place for different types of pathogens, with the aim of limiting the impact on public health and mitigating the economic consequences.


The next AGES-Radar will be published on 29 February 2024.

Last updated: 25.01.2024

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