An exceptionally large Cyclospora outbreak in the United States of America (USA) has been under investigation since 22 June 2026. As of 10 August 2026, 13,895 laboratory-confirmed, domestically acquired cases of cyclosporiasis had been reported. By way of comparison, around 3,000 to 4,000 cases of cyclosporiasis are normally recorded in the US over the course of a whole year. 

In addition to the 13,895 official cases, more than 10,000 further cases are under investigation; these have not yet been laboratory-confirmed or require further testing, for example to rule out infection acquired whilst travelling abroad. In Michigan, two deaths from cyclosporiasis were confirmed on 30 July.

Cyclosporiasis is a diarrhoeal disease caused by the microscopic parasite Cyclospora. Infection occurs primarily through food or water contaminated with human faeces. Common symptoms include watery diarrhoea, abdominal cramps, nausea and fatigue. If left untreated, the condition can lead to dehydration and serious complications. These symptoms can last for up to a month, and in some cases even longer. The symptoms appear to subside, only to return once or several times. The parasite lives in the human gut and is excreted in the stools within a resilient shell. This enables it to survive on fresh produce and makes it difficult to remove by simply rinsing or using conventional disinfectants.
 
The information available so far suggests that lettuce or leafy vegetables may be a possible source of this outbreak in the US. However, other foods cannot currently be completely ruled out as the cause. Investigations by the US Centres for Disease Control and Prevention (CDC), the US Food and Drug Administration (FDA) and health authorities in several states are still ongoing. 

Investigations to date highlight how difficult it is to identify the cause; tracing the outbreak is proving complicated for several reasons. Among other things, this is due to the long incubation period. Symptoms may sometimes not appear until more than two weeks after consuming contaminated food. At this stage of the case history interview, it is often difficult for those affected to remember exactly what they ate. Furthermore, the pathogen is difficult to detect in the laboratory, as the parasites are very small and often present only in small numbers. Complex supply chains also make traceability more difficult: food can be distributed to many retailers and catering establishments before a cluster of cases is noticed. Furthermore, due to budget cuts last year, the CDC has reduced its staff and programmes, which makes efficient outbreak investigation even more difficult. It is currently estimated that there is a six-week delay between the onset of symptoms and a report being made to the CDC. A further rise in cases is expected.

On 17 July 2026, the US food producer Taylor Farms initiated a voluntary recall of iceberg lettuce sourced from central Mexico. Mexican authorities have so far been unable to detect any traces of Cyclospora in lettuce and water samples taken from the affected production facility. In Mexico itself, 33 cases of cyclosporiasis have been reported to date. The Mexican health authority has stated that the identified cases are not classified as an active outbreak. Further information on the individual cases and whether there is a link to the US outbreak is not currently available.

In the UK, health authorities have observed a significant rise in cyclosporiasis cases in 2026. Between 30 April and 15 July, 67 cases were recorded in the UK. Most infections are currently linked to travel to Mexico, mainly Cancún. 

In Austria, cyclosporiasis is primarily relevant as a travel-related illness. The disease is rare in Austria and is not a notifiable disease. Anyone who develops persistent diarrhoea following a stay in the US, Mexico or in subtropical or tropical countries should seek medical advice and have the condition investigated. 

You can find out more on this topic at:
‘Explosive diarrhoea’ outbreak grips US: how researchers are hunting its source | Nature
Episode 216 Cyclospora: Explosive Diarrhoea Everywhere – This Podcast Will Kill You
 

In the Ebola outbreak caused by the Bundibugyo virus in the Democratic Republic of the Congo (DRC), case numbers in the DRC have risen dramatically once again since the last edition of AGES-Radar on 16 July 2026.

As of 11 August 2026, 4,381 cases of Bundibugyo virus disease (BVD – Bundibugyo Virus Disease) and 2,011 deaths had been recorded in the DRC – 2,370 and 1,257 more, respectively, than four weeks ago. This corresponds to a case fatality rate of approximately 46 per cent. To date, 869 patients confirmed to have contracted the disease have recovered. (ECDC, as at 11 August 2026)

As discussed in the previous issue, the outbreak is taking place in a highly complex humanitarian context. Despite ongoing control measures, the epidemic continues to spread, with an upward trend. The current Ebola epidemic demonstrates once again that gender considerations are central to effective outbreak control. Due to their social role in the DRC as healthcare workers, carers and key figures within families and communities, women are exposed to a particularly high risk of infection. As in previous outbreaks, they account for the majority of those affected in the current outbreak. Although they have a very good understanding of the socio-cultural and local circumstances, women remain significantly under-represented in leadership and decision-making structures involved in outbreak response. Women face additional health and social burdens: During past Ebola outbreaks, a marked decline in antenatal care and obstetric services in healthcare facilities was observed. The proportion of hospital births fell by up to 40 per cent, resulting in a rise in maternal mortality. Furthermore, existing inequalities are exacerbated and gender-based violence is on the rise. Many women continue to undertake caregiving and burial duties under high-risk conditions and often with inadequate protection.

In Uganda, the situation has eased. On 28 July, the Ugandan Ministry of Health declared the Ebola outbreak in the country to be over, after 42 days without any new locally transmitted cases being confirmed. The last confirmed case was discharged from hospital on 16 June 2026. The most recent imported case was discharged from a treatment centre on 16 July following two negative test results.

The case confirmed in France – a doctor who had returned from a humanitarian mission – has recovered. He was discharged from hospital on 4 July 2026 following two consecutive negative PCR test results. No secondary transmission was detected. All five flight contacts, as well as the contacts recorded by the DRK, remained symptom-free during the 21-day follow-up period. As of 1 August 2026, France has not reported any further confirmed cases of BVD over a period of 28 days since the patient’s discharge.

The Austrian Ministry of Foreign Affairs continues to advise against travel to the DRC. A Level 4 (out of 4) travel warning applies to the entire country. The risk of infection for the general population in the European Union or the European Economic Area (EU or EEA) is assessed as very low. 

The AGES podcast ‘The Courage to Take Risks – In Context: Ebola’ explains how a suspected case of Ebola was handled in Austria and which factors, apart from the medical aspects, play an important role.

Regular updates on the outbreak in the DRC can be found at:

BMASGPK – Ebola
WHO Disease Outbreak News – Ebola Disease
ECDC Surveillance and Updates – Ebola Disease Outbreak
 

With 47,026 confirmed cases of measles, including 48 deaths, the Pan American Health Organisation (PAHO – Pan American Health Organisation) recorded five times as many cases between the start of the year and 26 July 2026 as in the same period the previous year. Most cases were reported from Guatemala, Mexico, the USA and Canada. In the WHO Region of the Americas,

measles cases had already risen 32-fold in 2025 compared with the previous year, with 14,891 cases and 29 deaths. This dramatic development risks undoing years of hard work in a region that, back in 2016, became the first in the world to achieve the goal of measles elimination and was free from endemic measles.

Although slightly downward trends are now being observed in some of the affected countries due to control measures implemented, the situation remains a cause for concern. Outbreaks are continuing, with cases emerging in new geographical areas. The overall risk in the WHO Region of the Americas is assessed as ‘very high’; significant vaccination gaps, amongst other factors, contribute to this risk assessment. Only a third of the countries in the Region have reached the threshold of 95 per cent for the first dose of the measles, mumps and rubella (MMR) vaccine; for the second dose, the figure is just 20 per cent of countries. Vaccination coverage is declining, whilst the proportion of susceptible population groups is increasing. This is caused by a complex interplay of insufficient funding, structural weaknesses in the health system, geopolitical crises and growing vaccine hesitancy.  Particularly following natural disasters such as the severe earthquake in Venezuela in June or the current situation in Colombia, the risk of major measles outbreaks with high rates of complications is once again significantly increased.  Although vaccine donations have already been provisionally delivered to Venezuela and no confirmed cases of measles have been reported so far, this risk remains.

The measles virus is currently circulating at high levels again in several regions worldwide, thereby increasing the likelihood of imported cases. This can lead to a resurgence of measles, particularly where vaccination coverage is insufficient, even in countries where the disease had previously been eliminated.  For example, at the start of the year, several countries in Europe lost their ‘measles-free’ status after case numbers had risen sharply in recent years, including Austria (as reported in the AGES Radar issue of 13 February 2026). 

So far this year, eight confirmed cases of measles have been reported in Austria, seven of which were imported (as at 12 August 2026). The most recent case reported in Austria had contracted the infection in Mexico.

The most effective preventive measure to protect against measles infection is vaccination. It is particularly important to check your vaccination status and, if necessary, ensure your vaccinations are up to date, especially before travelling. The MMR combination vaccine is generally recommended from the age of 9 months and should, in any case, be administered before children start attending communal facilities such as crèches, nurseries or schools. The MMR vaccination is available free of charge in Austria for all age groups and is available at vaccination centres, including numerous public vaccination centres. Two doses are required; the interval between them depends on when the first dose was administered. Missed vaccinations can and should be caught up on at any age. Further details can be found at impfen.gv.at/impfungen/masern or in the Austrian Immunisation Schedule 2025/2026.
 

As water temperatures rise, infections caused by so-called non-cholera vibrios could also become more common in Europe. These bacteria occur naturally in warm, slightly salty or brackish waters and can cause, amongst other things, wound infections, ear infections or gastrointestinal symptoms in humans. In Austria, too, vibrio bacteria are regularly detected in water bodies, particularly during hot summers.

To monitor developments more effectively, AGES, as the National Reference Centre for Vibrio cholerae, is carrying out intensified surveillance of these infections in Austria at the initiative of the European Centre for Disease Prevention and Control (ECDC). To this end, GPs and laboratories have been informed and asked to raise awareness and submit samples. Although not all bathing lakes in Austria are currently routinely tested for vibrios as part of bathing water monitoring, selected bodies of water are being specifically analysed for the presence of these bacteria within the framework of scientific collaborations.

The aim is to better track the spread of Vibrio infections in Europe. As these diseases are not notifiable in all countries, it is assumed that the figures are underreported. At the same time, climate change and warmer waters are creating increasingly favourable conditions for the proliferation of these bacteria.

To this end, the ECDC provides the Vibrio Viewer, an interactive map that highlights areas with an increased risk of Vibrio bacteria occurring. The data collected helps to identify changes at an early stage and to implement targeted measures to protect the population. Despite the observed increase, Vibrio infections remain rare overall.

Non-cholera Vibrio species – AGES
 

The United Nations (UN) has warned of a resurgence of the global HIV epidemic. This is due to declining international funding for HIV prevention and care. According to UNAIDS, international funding for HIV fell by 18 per cent in 2025, from 8.8 billion US dollars to 7.3 billion US dollars, reaching its lowest level in almost two decades.

Although new infections and AIDS-related deaths worldwide are at their lowest level in over 30 years, the progress made so far is at risk. In 2025, around 1.2 million people worldwide became newly infected with HIV, and some 570,000 people died as a result of AIDS. Countries in sub-Saharan Africa are

particularly affected, where prevention services have in some cases been severely curtailed. Around 80 per cent of funding for prevention measures came from international development cooperation.

Declining international aid is also leading to delays in supply chains and shortages of antiretroviral medicines in the countries most severely affected. If people living with HIV are unable to take their medication regularly or have to interrupt their treatment due to a lack of medicines, their viral load may rise again, facilitating the emergence and spread of resistant HIV variants.

Legal and social barriers further complicate the fight against HIV. Worldwide, 66 countries criminalise same-sex relationships, 14 countries criminalise transgender people, 168 states criminalise sex work and 152 criminalise the possession of small amounts of drugs. It is precisely these groups of people who are at high risk of becoming infected with HIV. Fear of prosecution or discrimination can lead to people not accessing HIV services.

UNAIDS believes that the global goal of ending AIDS as a public health threat by 2030 is at risk.
 

The 2025 annual report of the National Reference Centre for Listeriosis was published in early July.

Listeriosis remained a rare infectious disease in 2025. A total of 32 human cases of invasive listeriosis were reported via the Epidemiological Reporting System (EMS), corresponding to an incidence of 0.35 cases per 100,000 inhabitants. The National Reference Centre (NRZ) for Listeriosis verified 27 human cases of invasive listeriosis. The discrepancy between the case figures in the EMS and those confirmed by the NRZ is due to the fact that, in five cases, the diagnosis was based solely on molecular biology and therefore no isolate was available for further investigation. Five deaths were documented, although it was not determined whether the cause of death was directly related to listeriosis. One case was pregnancy-associated. In this instance, Listeria monocytogenes was detected in the newborn, whilst no positive detection could be made in the mother.

In 2025, two clusters were identified. One cluster was linked to an international outbreak in Germany, which was traced to contaminated herring products. In addition, further cases emerged from the cluster that had already been identified in 2024. AGES had already been commissioned to investigate this cluster back in 2024. Sausage and meat products are suspected as the possible source of infection.

Listeria – AGES
 

At the end of July, the 2025 annual report of the National Reference Centre for Escherichia coli, including verotoxin-producing E. coli (VTEC), was published. 

In 2025, a total of 2,491 samples were analysed, comprising 2,343 human samples, 132 food samples and 16 interlaboratory test samples.

VTEC was detected in 1,199 stool samples and one urine sample. Antibodies against E. coli O157 were detected in four serum samples. In total, 1,204 VTEC-positive human samples were processed at the National Reference Centre in 2025.

In 2025, 984 cases of VTEC-related illness and 3 deaths were reported in Austria (EMS, as at 28 April 2026). The incidence of VTEC-related cases in Austria in 2025 was 10.7 per 100,000 people. In 12 cases, haemolytic uraemic syndrome (HUS) occurred as a post-infectious complication, with half of these cases occurring in children aged 0–4 years. This corresponds to an incidence of 1.4 HUS cases per 100,000 children. Seven VTEC outbreaks
were recorded, as well as 12 family clusters, each with 2 to 3 cases.  

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 12 August 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 as a result of 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 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.