Hantaviruses are a group of enveloped RNA viruses found worldwide, with various species of mice and rats serving as their reservoirs. Different hantavirus species are relevant to humans depending on the geographical region. In Germany, these are primarily the Puumala virus (PUUV), which is mainly found in the south and west, and the Dobrava-Belgrade virus (DOBV), which occurs in the east and north of the country. Other important virus types include the Sin Nombre virus (SNV), which is prevalent in North America, and the Andes virus (ANDV) in South America [1]. The latter is currently receiving a great deal of media attention due to the recent outbreak linked to the cruise ship ‘Hondius’.
The incubation period for Hantavirus is typically two to four weeks, though in some cases it can be as long as five to 60 days. Many infections are asymptomatic or present with flu-like symptoms, which is why a high number of unreported cases is assumed. Depending on the type of virus, two severe forms of the disease may occur: haemorrhagic fever with renal syndrome (HFRS), which is caused by Asian and European strains, and haemorrhagic fever with renal syndrome (HFRS), which is caused by Asian and European strains. This is usually characterised by an acute onset with fever, headaches, abdominal and back pain, as well as dizziness, drowsiness, and visual disturbances. It often leads to acute kidney failure as the disease progresses. In Germany, the Puumala and Dobrava-Belgrade (Kurkino) viruses usually cause mild illness. The case fatality rate for the Puumala virus is less than 0.1%. For the Dobrava-Belgrade virus (Kurkino type), it is 0.3–0.9%, which is also very low. However, other Dobrava-Belgrade virus (DOBV) variants in the Balkans or Russia can result in a case fatality rate of 10–15%.
Hantavirus pulmonary syndrome (HPS/HCPS), which is caused by American hantavirus strains, is associated with sudden fever, nausea or vomiting, myalgia, weakness and dizziness. Later, cough, shortness of breath, pulmonary oedema and acute respiratory distress syndrome (ARDS) may develop. The case fatality rate for diseases caused by these strains is significantly higher, usually estimated at 25–40% [1].
As there is no cure for the disease, people infected with Hantavirus are treated primarily for their symptoms. After recovering from a hantavirus infection, individuals generally develop long-lasting immunity to that particular type of virus. Currently, there is no approved vaccine against hantaviruses in Germany or most other countries [1].
As the symptoms of hantavirus infection are non-specific and may also occur in other infectious diseases, such as those caused by SARS-CoV-2, influenza or Leptospira, taking a careful medical history and considering possible exposure to hantaviruses is essential. A definitive diagnosis can only be made with laboratory confirmation [1, 5].
Infected rodents shed hantaviruses via their saliva, urine and faeces. The viruses remain infectious in these excretions for several days, even after they have dried out. Humans can become infected in various ways: by inhaling virus-contaminated air (e.g. through stirred-up dust), through skin breaks that come into contact with contaminated dust or soil, or through bites. Infection is also possible via food that has come into contact with the excretions of infected animals [1]. There is an increased risk of infection during activities where people come into contact with rodents – e.g. when clearing out cellars infested with mice, or during agricultural or forestry work. Human-to-human transmission (which is extremely rare) has so far only been documented for the Andes virus and occurs only following close and prolonged contact, particularly in the early phase of the disease when the viral load is particularly high [5]. Human-to-human transmission of European or Asian hantaviruses has not yet been observed [1]; isolation of infected individuals is therefore not necessary for these virus types.
The first passengers to fall ill with the virus on board the “Hondius” were infected in April 2026. After several passengers disembarked on the tropical island of Saint Helena (UK), the cases were linked in early May to the Andes virus. Unlike other hantaviruses, human-to-human transmission of the Andes virus cannot be ruled out in the event of very close contact [2]. The World Health Organization (WHO) was notified and has since been monitoring the international contact tracing of the passengers, all of whom have now been brought ashore. According to the WHO, the situation stabilised by 22 May 2026 [3]. As of 24 May 2026, the European Centre for Disease Prevention and Control (ECDC) had confirmed 10 cases and identified two probable cases of infection, including three fatalities [4]. The ECDC classifies the risk to the general European population from the hantavirus responsible for this outbreak as very low, since the Andes virus spreads less easily than SARS-CoV-2 and its natural rodent host, the rice rat, is not native to Europe. Furthermore, there is no evidence whatsoever that the Andes virus may have mutated.
The best way to protect against infection is to avoid contact with rodent droppings. In Germany, this primarily means avoiding contact with the droppings of bank voles and fire-tailed voles. Rodents should be controlled in areas near residential properties and hygiene rules observed. Dust formation can often be prevented by moistening surfaces; otherwise, respiratory protection and gloves should be worn to reduce the risk of infection. Rodent carcasses and excrement should be moistened with a cleaning agent before disposal [1]. Products with proven limited virucidal efficacy should be used for disinfection, as hantaviruses are sensitive to these formulations due to their enveloped nature. Suitable products include Sterillium® and Sterillium® classic pure for hand disinfection and Sterillium® surface spray for surface disinfection.
Use disinfectants safely. Always read the label and product information before use.
