Summary
In this month's topic, we explain the background to Mpox and why the WHO has declared an international emergency for the second time in two years.
As of 27 August 2024, 10,374 cases of whooping cough have been reported in Austria. More than every third infant affected was treated in hospital.
Since July, cases of West Nile fever have been detected in Austria in which the infection occurred in Austria.
An increase in SARS-CoV-2 is still being observed in wastewater and in the sentinel system.
New measles cases are still being reported sporadically in Austria, totalling 497 this year.
Internationally, we provide updates on the outbreaks of avian influenza in the USA and the Oropouche virus.
The annual reports on botulism, polio, salmonella and food-borne outbreaks are published at the same time as this radar.
The first cases of West Nile fever this year were registered in Austria in July 2024; as of 27 August, eleven human infections had been confirmed. Only adults in eastern Austria were affected.
Six of these cases were identified during routine testing of donated blood from blood donors. Some cases were diagnosed and hospitalised due to neurological symptoms. Two cases are imported.
West Nile virus (WNV) is transmitted by mosquitoes of the genus Culex.
As part of a surveillance programme carried out by AGES, traps were set up throughout Austria and also specifically in gardens of some of the cases. The virus has not yet been detected in the several thousand mosquitoes already caught this year and tested for WNV.
In addition to Austria, eleven other European countries have reported cases of West Nile fever. ECDC calls on all countries to monitor the safety of blood donations, observes the development and maintains an up-to-date dashboard.
There is no authorised vaccine for humans. As a preventive measure, attempts should be made to avoid gel bites (long clothing, use of repellents).
SARS-CoV-2 activity continues to increase in Austria.
Since June, there has been an increase in SARS-CoV-2 concentrations in Austrian wastewater. The positivity rate in the sentinel samples of SARS-CoV-2 monitoring in Austria has been above 10% since calendar week 26, reaching almost 25% in mid-August. The positivity rate indicates how many of the samples recorded in the system from patients with acute respiratory infections test positive for SARS-CoV-2. There has been a slight increase in inpatient hospital admissions in recent weeks, albeit still at a low level.
The current trend in European countries is mixed. While an increase in SARS-CoV-2 activity continues to be observed in some countries, others are reporting decreasing trends. The overall impact of rising SARS-CoV-2 activity on hospitalisations and mortality has been low. (As of 27/08/2024)
The BA.2.86 variant and its sublines, including KP.3, currently dominate worldwide. The KP.3.1.1 and LB.1 variants classified by the WHO as "Variants under monitoring" (VUM) are showing particularly strong growth. The European Centre for Disease Prevention and Control (ECDC) does not believe that KP.3 has an impact on the severity of infection or the effectiveness of the vaccine.
The situation is being closely monitored by European countries. It is currently not considered to be a cause for concern.
Due to the increasing SARS-CoV-2 activity, wearing a mask is recommended if close contact with many people indoors cannot be avoided, e.g. at the airport or on an aeroplane.
The vaccine adapted to the JN.1 variant has arrived in Austria and can be ordered and vaccinated by vaccination centres. A single vaccination is recommended for all persons aged 12 and over, especially for people at risk and people aged 60 and over. Details on COVID-19 vaccination can be found in the updated recommendation from 18.07.2024.
Vaccination plan Austria (sozialministerium.at)
Pertussis numbers have risen massively in Austria and many European countries in 2024, even in countries with high vaccination coverage rates. We presented details on this in the AGES Radar from 28/03/2024.
While 2,791 cases were reported in Austria in the previous year as a whole, there have already been 10,374 cases of pertussis this year (as of 27 August 2024).
Almost 40% of patients under the age of one were admitted to hospital, across all age groups it was 6.2% (as of 21 August 2024). Pertussis is not just a childhood disease; it can also cause severe suffering in adults. There is a relevant risk of hospitalisation in the 60+ age group.
The vaccination is included in the free vaccination programme for children in Austria. The primary purpose of the vaccination is to protect infants and young children from a severe course and death. Basic immunisation in infants should be refreshed at primary school age, preferably when they start school. To maintain immunisation protection, the vaccination should be boostered regularly, every ten years up to the age of 60 and every five years from the age of 60. The pertussis vaccination is recommended for everyone.
In order to protect infants in the first months of life, pregnant women in particular are advised to be vaccinated in the last trimester of pregnancy , regardless of the interval between the last pertussis vaccination. This gives newborn babies protection through maternal antibodies.
Further information on the pertussis vaccination can be found in the vaccination plan Austria 2023/2024 version 2.0 (sozialministerium.at).
Whooping cough (pertussis) - AGES
In 2024, 497 cases of measles have been registered so far. AGES updates the data here on a weekly basis. The number of new infections has been low for several weeks, but cases must still be expected. Many of the new cases have been imported from other European countries.
Information on the measles-mumps-rubella vaccination can be found in the Austria 2023/2024 vaccination plan (sozialministerium.at).
On 25 March 2024, an outbreak of A(H5N1) avian influenza was reported for the first time in dairy cows in several US states. This was the first time these avian influenza viruses were found in cows.
In April 2024, the CDC confirmed infection with the A(H5N1) virus in a person who had contact with dairy cows in Texas. This was the first confirmed case of transmission of the A(H5N1) virus from mammals to humans.
Since then, the virus has been detected in 191 dairy cow herds in 13 US states (as of 27/08/2024). The H5N1 virus has also been detected in poultry farms. In connection with the outbreaks in dairy cows and poultry, there have been a total of ten confirmed transmissions to humans, workers on the respective affected farms in recent months. We have reported in detail in the past four issues of the AGES Radar.
Between March and 10 August 2024, at least 4,500 people with contact to dairy cows and/or poultry were monitored in the USA and at least 230 people were tested for the influenza A virus. Since the AGES radar of 25 July 2024 , no further human cases of influenza A(H5N1) have been reported in the USA.
In random tests of dairy products in US retail stores, viral RNA was detected in some samples, but no live viruses. The existing pasteurisation methods appear to inactivate the virus effectively.
There are no reported outbreaks of avian influenza in cattle or virus detection in dairy products in Europe.
Avian influenza is notifiable in Austria and is monitored. In order to correctly classify the rare event of a human infection with avian influenza as quickly as possible, doctors are advised to ask patients with unclear or flu-like symptoms about contact with birds or other animals in the last two weeks.
Further information on avian influenza in Austria can be found in the Animal Disease Radar.
H5 Bird Flu: Current Situation | Bird Flu | CDC
Current H5N1 Bird Flu Situation in Dairy Cows | Bird Flu | CDC
After Italy recorded the first imported case of Oropouche in Europe in June, the number of cases imported into Europe has increased significantly. As of 9 August 2020, the ECDC recorded a total of 19 cases of orpouche in three countries: Spain (12), Italy (5) and Germany (2). Eighteen of the infected people had returned from a trip to Cuba and one from Brazil.
OROV circulates in Central and South America, and was previously mainly found in the Amazon basin. This year, OROV cases are rising sharply, even in regions that were previously unaffected, including Bolivia and Cuba. This is being exacerbated by changes in the ecosystem and climate change. At the same time, improved laboratory capacities and increased awareness are ensuring that more cases can be recognised.
By the end of July, 8,078 cases of oropouche had been confirmed in the WHO region of the Americas (comprising all countries on the American continent). Brazil is particularly affected and in July also recorded the first official oropouche deaths since the virus was discovered. In addition, an increasing number of miscarriages, stillbirths and cases of neurological defects in newborns born to mothers with Oropouche infection have been reported since June. The Pan American Health Organisation (PAHO) therefore upgraded the epidemiological risk level from moderate to high in August. The member states have been called upon to step up surveillance of the virus and rely more on laboratory diagnoses so that cases can be better identified. The WHO also considers the risk to be high at regional level.
Whether vertical transmission occurs, i.e. infection of the unborn child while still in the womb, is currently being investigated and has not yet been confirmed.
The ECDC currently estimates the risk of OROV infection for people travelling to South and Central America or the Caribbean as moderate. The risk increases for those who visit heavily affected areas, particularly in the northern states of Brazil or the Amazon region, and/or for those who do not take adequate personal protective measures. Measures such as using insect repellent, wearing long clothing and sleeping under a mosquito net treated with insect repellent are essential to reduce the risk of bites and therefore infection.
The vectors of the Oropouche virus are not found in Europe. The risk of locally acquired OROV disease in the EU/EEA is considered low by the ECDC .
More details on Oropouche can be found in the AGES-Radar of 27/06/2024 and in the AGES-Radar of 25/07/2024.
Threat assessment brief: Oropouche virus disease cases imported to the European Union (europa.eu)
Oropouche virus disease - Region of the Americas (who.int)
Mysterious Oropouche virus is spreading: what you should know (nature.com)
RKI - Archive 2024 - Epidemiological Bulletin 31/2024
Due to rising Mpox case numbers in several African countries, triggered by the Mpox virus clade Ib, the WHO declared a public health emergency of international concern for Mpox on 14 August 2024. The Democratic Republic of the Congo (DRC) is particularly affected by the increase in cases.
In August, the first Mpox clade I cases outside Africa were detected in Sweden and Thailand . These are imported cases; the infected persons had previously stayed in the region of Africa where the Mpox outbreak is currently being recorded.
As of 27 August 2024, no case of Mpox clade I has been registered in Austria. Ten clade II Mpox cases have been reported so far in 2024 (AGES, as of 27/08/2024)
"Monkeypox" does not come from monkeys
"Monkeypox" or "monkeypox" is a misnomer. The natural hosts of the Mpox virus (MPXV) are mainly small, forest-dwelling rodents, such as African chipmunks, dormice or Gambian giant hamster rats. The name "monkeypox" was coined in 1958 when a Danish laboratory first discovered the virus in Asian monkeys. Primates - and therefore also humans - are false hosts of MPXV. In 2015, the WHO published "best practice" guidelines for naming new infectious diseases. These guidelines advise against naming infectious diseases after geographical locations, personal names or animals. In order to reduce and avoid misinterpretation, stigmatisation and racism, among other things, the name "Monkeypox" or "monkeypox", which has been used since the discovery of the virus, was changed to "Mpox" by the WHO in November 2022.
Health emergency with international implications
The "public health emergency of international concern" (PHEIC) declared by the WHO on 14 August 2024 is already the second in two years in relation to Mpox. In 2022, the WHO declared a PHEIC due to a transnational Mpox outbreak that affected Europe in particular. This was lifted again in May 2023.
The PHEIC is the WHO's highest alert level. It is declared when a disease outbreak is considered serious and unusual, has the potential to spread across borders and is likely to require international action to contain it. The COVID-19 outbreak was also classified as such at the beginning of 2020. By declaring a PHEIC, the WHO is calling on countries around the world to work together and provide resources to improve surveillance of the virus, treat infected people and stop the outbreak of the disease.
Current outbreak - what is different?
The current Mpox outbreak differs in some aspects from the one two years ago.
The international Mpox outbreak in 2022/2023 was caused by MPXV clade II and mainly affected men who have sex with men (MSM). Sexual contact was the main transmission route in this outbreak. The death rate was lower than in the current outbreak. Through intensive and targeted public health efforts and the development of natural immunity, the outbreak was finally brought under control.(RKI) While 132 Mpox clade II cases were registered in Austria by the end of July 2022, there were only ten in the same period this year.
The current outbreak, which is currently still largely confined to Africa, is based on MPXV clades Ia and Ib. Exactly how clades Ia and Ib are transmitted is not yet fully understood. Both sexual contact and close contact, e.g. in healthcare facilities or within the household, appear to play a role. Unlike the outbreak in 2022/2023, children are also affected in the current outbreak. They have the highest probability of dying from Mpox. Clade Ib first appeared in the DRC in 2023 and has been spreading rapidly ever since. Although genetic sequencing is not available for all countries, the new variant (clade 1b) has already been confirmed in Rwanda, Uganda and Kenya(ECDC). In 2024 alone, 20,720 cases and 582 deaths were reported from 13 African countries. The DRC is particularly affected with 19,667 cases and 575 deaths.(Africa CDC, as of 23/08/2024)
Outside Africa, only two clade I Mpox cases have been detected so far. These were one person in Sweden and another in Thailand who had been infected during a stay in the region of Africa where the current outbreak is taking place.
According to the ECDC, it is very likely that more imported Mpox cases of MPXV clade I will occur in the EU/EEA. Provided that imported cases are diagnosed quickly and control measures are implemented, the ECDC estimates the likelihood of further transmissions in Europe to be very low.
Spread and containment
There are various reasons why there is currently such a large Mpox outbreak. These include the declining immune protection provided by the smallpox vaccination. The smallpox vaccination offers cross-protection against Mpox, but according to the WHO, immunity is only given to people aged 42 years or older. After smallpox was eradicated in 1980, vaccination programmes were discontinued and there was no longer any natural exposure to smallpox.
Mpox, however, is not a new disease. Since the first human case was detected in the DRC in 1970, there have been repeated regional outbreaks based on animal-to-human transmission. From 2017, Nigeria reported human-to-human transmission, largely through sexual contact. Between 2018 and 2021, there were also isolated cases of Mpox in the UK, USA, Singapore and Israel. Since the spread of clade II in numerous industrialised countries in 2022, intensive investment has been made in research on the topic for the first time. More scientific studies have been published in two years than in half a century.
The European Commission is currently coordinating the procurement and donation of 215,000 doses of vaccine to support the African CDC in combating the Mpox outbreak in the affected countries in Africa. The vaccine manufacturer Bavarian Nordic and the African CDC are in talks regarding a technology transfer that will enable African manufacturers to produce the vaccine themselves.
A vaccine is available in Austria, but is currently only recommended by the National Immunisation Committee (NIG) for people at risk.
WHO Director-General declares mpox outbreak a public health emergency of international concern
The Resurgence of Mpox in Africa | Global Health | JAMA | JAMA Network
A study published in "The Lancet Respiratory Medicine" in August analysed how many lives were saved in the WHO European Region between December 2020 and March 2023 by vaccinating adults. Co-authors from Austria were Bernhard Benka, from AGES, and Monika Redlberger-Fritz from the Medical University of Vienna.
Countries in the WHO European Region that were able to provide complete data were included in this retrospective observational study. This was the case for 34 out of 54 countries. Six age groups of 25 years and older were considered.
In the 34 countries with complete data, COVID-19 vaccinations reduced deaths by 59%. Converted into absolute figures, this represents around 1.6 million lives saved. The over-60s accounted for the largest share. Most lives were saved with the first booster and during the Omikron wave, which emphasises the importance of regularly updating vaccination protection for at-risk groups.
A study published in August 2024 investigated three prolonged outbreaks of Pseudomonas aeruginosa in a hospital in Upper Austria between 2017 and 2023. The first author was AGES employee Adriana Cabal.
In spring 2022, an increased number of Pseudomonas aeruginosa infections were detected in a hospital in Upper Austria. Whole genome sequencing enabled the identification of three elongated clusters, which were recognised as three different outbreaks.
Antibiotic-resistant P. aeruginosa normally spread through biofilms in the water pipes and are found in every hospital, so their occurrence is not unusual. The hygiene controls implemented by the hospital as well as increased hand hygiene, disinfection and isolation of patients were quickly implemented as control measures. As a result, no further cases occurred and the outbreaks were successfully declared over.
The study emphasises the importance of genomic surveillance and the successful implementation of control and prevention measures in the management of such infections.
The AGES Annual Report 2023 on botulism was published on 29 August 2024.
Last year, two cases of human botulism were documented by the National Reference Centre for Botulism in Austria. Botulism is caused by a neurotoxin (nerve poison) that is primarily produced by the bacterium Clostridium botulinum. This botulinum neurotoxin is considered the most toxic of all naturally occurring substances.
In December 2023, a 41-year-old man was admitted to hospital with symptoms typical of botulism, such as difficulty swallowing and double vision. Botulinum neurotoxin gene B was detected in a stool sample. The source of the infection could not be identified, and the symptoms improved with intensive medical treatment.
The second case - a 34-year-old woman who had been administered intra-gastric botulinum neurotoxin A in Turkey to lose weight - was part of an international outbreak of botulism in which 34 people fell ill after such procedures. Cases of botulism caused by medical interventions (iatrogenic) are not notifiable in Austria.
The AGES Annual Report 2023 on Salmonella was published on 29 August 2024.
In 2023, 1,218 human salmonella first isolates were submitted to the National Reference Centre. The increase in the total number of first isolates submitted corresponds to an increase of 4.5% compared to 2022.
Overall, Salmonella (S.) Enteritidis was the most common serotype (45.1%).
There were several outbreaks linked to the consumption of Polish chicken meat in 2023, including one death. Austria was also involved in a transnational outbreak in which Italian organic cherry tomatoes on the vine are suspected to be the source of infection. Several travel-associated outbreaks were also identified.
The proportion of multi-resistant isolates was 12.0%. High-level resistance to ciprofloxacin and resistance to third-generation cephalosporins (cefotaxime, ceftazidime) occurred only sporadically (<1%).
The AGES Annual Report 2023 of the National Reference Centre for Polioviruses (NRZP) was published on 29.08.2024.
One of the main tasks of the reference centre is to carry out nationwide surveillance of cases of acute flaccid paralysis (AFP). No enteroviruses were detected in the stool samples from the two AFP cases reported in 2023.
In addition, a total of 19,387 samples were tested for enteroviruses in 2023 using virus isolation or molecular biological methods. Poliovirus was not detected in any sample.
The WHO European Region has been polio-free for over 20 years as of 2023.
A foodborne outbreak (LMbKA) is defined as two or more incidents of infection caused by the consumption of the same food or a food from the same food business operator.
In 2023, a total of 42 foodborne outbreaks were reported in Austria, 14 more than in the previous year. Of these, 222 people were affected. Thirty-eight people had to be hospitalised and there was one death. The number of outbreaks continued to rise compared to previous years. Salmonella spp. caused the most outbreaks (21), followed by Campylobacter spp.(12 outbreaks). Five outbreaks were caused by Shiga toxin-producing E. coli (STEC) and one each by Listeria monocytogenes and Yersinia enterocolitica. Two outbreaks were attributed to noroviruses.
In twelve outbreaks, it was possible to establish strong evidence between the outbreak cases and food or a food company. Since 2009, almost 50% of outbreaks with strong evidence have been linked to poultry products (meat and eggs). For these outbreaks, private households are the most common places where the affected persons became infected.
Sixteen outbreaks were associated with stays abroad.
The incubation period is the time between the ingestion or penetration of a pathogen and the appearance of the first symptoms of a disease. The incubation period can vary greatly for some diseases, which is why it is usually given as a significant range; in the case of Mpox, for example, the first symptoms appear 1-21 days after contact with the infectious agent.
Some pathogens can be passed on again within the incubation period. This means that the infected person is already contagious even before the first symptoms appear. The incubation period is an important epidemiological parameter; it influences the speed at which a pathogen spreads and consequently also the measures used to slow down the spread, such as quarantine rules.
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.
How is the AGES radar for infectious diseases compiled?
Who: The radar is a co-operation between the AGES divisions "Public Health" and Risk Communication.
What: Outbreaks and situation assessments of infectious diseases:
- National: Based on data from the Epidemiological Reporting System (EMS), outbreak investigation and regular reports from AGES and the reference laboratories
- International: Based on structured research
- Topic of the week (annual planning)
- Reports on scientific publications and events
Further sources:
Acute infectious respiratory diseases occur more frequently in 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.
Austrian laboratories send SARS-CoV-2 samples to AGES for sequencing. The sequencing results are regularly published on the AGES website.
For the international reports, health organisations (WHO, ECDC, CDC, ...) specialist media, international press, newsletters and social media are monitored on a route-by-route basis.
For infectious diseases in Austria, the situation is assessed by AGES experts, as well as for international outbreaks for which no WHO or ECDC assessment is available.
Disclaimer: The topics are selected according to editorial criteria, there is no claim to completeness.
Suggestions and questions to:wima@ages.at
As the response to enquiries is also coordinated between all parties involved (knowledge management, INFE, risk communication), please be patient. A reply will be sent within one week.
Last updated: 29.08.2024
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