The latest news about "hantavirus" cases has once again brought back fears of unknown viruses and new pandemics. Speculation has appeared on social media, and the term sounds threatening – but the real data show a different picture: this is a serious but relatively rare zoonotic infection, with a clearly known source, methods of transmission, and preventive measures.
What is "hantavirus" actually?
"Hantaviruses" are a group of RNA viruses from the "Hantaviridae" family, which are transmitted mainly from rodents to humans and cause so-called natural focal diseases.
There are over 20 known species of hantaviruses capable of causing severe lung or kidney diseases in humans – from hemorrhagic fever with renal syndrome (HFRS) in Europe and Asia to hantavirus pulmonary syndrome (HPS) in the Americas.
What is specific about these viruses is that they are not transmitted by airborne droplets between people, as in the case of the flu or COVID-19, but are closely linked to their natural "reservoir" – wild and synanthropic rodents such as field mice, rats, etc.
In these animals, the infection runs chronically without killing them, and the virus is shed through urine, saliva, and feces – this is exactly the key to human infection in natural and rural areas.
How does a person get infected and why are we not talking about easy spread
The main route of infection with hantavirus is contact with secretions shed by infected rodents – urine, feces, or saliva – or inhalation of dust particles contaminated with them.
This can happen, for example, when cleaning a rural attic, farm building, abandoned shack, or while working in the field or in forest areas where there are many murine rodents.
In an urban environment, the risk is significantly lower and is most often associated with poor sanitary conditions and a highly elevated population of rats or mice.
Unlike respiratory viruses, human-to-human transmission is extremely rare with hantaviruses – isolated cases have been described in certain regions and with specific strains, but mass spread between people is not observed. This is one of the reasons experts emphasize that "hantavirus is not a second COVID-19".
Symptoms: from flu-like manifestations to severe forms
The incubation period for hantavirus infections is usually between 1 and 8 weeks after contact with the virus, which makes it difficult to link the specific exposure to the onset of complaints.
Initial symptoms often resemble the flu: high fever, severe fatigue, headache, muscle pain – especially in large muscle groups (thighs, back, shoulders) – chills, and sometimes nausea, vomiting, diarrhea, and abdominal pain.
In pulmonary forms – "hantavirus pulmonary syndrome" – symptoms can worsen sharply after a few days: coughing, shortness of breath, a feeling of tightness in the chest appear, and the lungs begin to fill with fluid. This leads to severe respiratory failure and requires intensive care. Mortality for HPS in some regions is estimated between 38% and 50% of diagnosed cases.
In renal forms – "hemorrhagic fever with renal syndrome" – there is a sudden onset, severe headache, back and abdominal pain, high fever, and in more severe cases – impaired kidney function, reduced urine output, and a risk of kidney failure.
How widespread is the hantavirus around the world?
Hantavirus infections have been known for decades in various regions of the world – Asia, Europe, North and South America – and are considered typical "natural focal" diseases, i.e., linked to specific geographical zones and rodent populations.
In Russia, for example, approximately up to 7,000 cases of hantavirus infections are diagnosed annually – mainly hemorrhagic fever with renal syndrome – especially in areas with high populations of field mice and other reservoir species.
In the USA, hantavirus pulmonary syndrome remains a rare but severe infection – hundreds of cases have been described since the 90s, with several dozen people affected in certain years, often associated with contact with mice in rural homes or camping areas.
It is important to emphasize that despite high mortality in some forms, the total number of hantavirus infection cases globally remains low, and there is no data on a global mass spread comparable to the flu or COVID-19.
Hantavirus and Bulgaria: is there a reason for panic?
Bulgarian virologists and infectious disease specialists emphasize that "we have hantaviruses in Bulgaria, just as in Europe," but the risk of epidemic spread in our country is assessed as low.
According to data from health authorities for recent years, isolated cases are registered in Bulgaria annually: in 2024 – two people affected, in 2025 – about five, and for the current year, there are no confirmed new cases so far.
Specialists add that this is not a "new" or "unknown" virus, but an infection known to doctors for a long time and observed mainly during the spring and summer, when field mice and forest rodents are most active in search of food and have more frequent contact with humans.
Bulgarian infectious disease specialists explain that the disease in our country usually runs in a spectrum – from milder forms with flu-like symptoms to more severe ones, in which the kidneys or lungs are affected, but the health system has experience and resources for the diagnosis and treatment of such cases.
Can hantavirus trigger a new pandemic?
Despite the alarming headlines surrounding recent cases of hantavirus infection on a cruise ship in the Atlantic, epidemiologists are unanimous: the potential of hantaviruses for a global pandemic is much lower than that of coronaviruses.
The reasons are several: the virus is closely linked to its natural reservoir (rodents), there is no stable human-to-human transmission, it requires specific conditions for infection (contact with secretions from rodents), and it spreads more slowly, without mass "hidden" transmission between people.
The case with the cruise liner, where some of the passengers and crew developed severe symptoms and deaths were reported, is a serious incident, but it remains localized and does not fundamentally change the epidemiological assessment of hantaviruses.
Bulgarian specialists also emphasize that there is no reason to expect a scenario similar to COVID-19: "there is no danger of epidemic spread of the virus" in our country, provided basic hygiene and sanitary measures are followed and there is adequate control over rodent populations.
How to protect ourselves: practical tips
Prevention for hantaviruses is aimed at avoiding contact with rodents and their secretions, especially in rural and forest areas.
Health authorities and medical institutions recommend:
- avoiding the cleaning of rooms with traces of mice and rats without protective gloves and a mask;
- not sweeping or shaking out dry feces and nests – instead, moisten them with a disinfectant or bleach solution and clean them carefully;
- not touching dead rodents with bare hands; use gloves if necessary and dispose of carcasses in sealed bags;
- limiting nesting places for rodents around homes and farm buildings – by cleaning up trash, stored materials, and food;
- when camping, hunting, or working in the forest, keep food in closed containers, do not leave residues that attract rodents, and avoid sleeping directly on the ground in places with visible traces of mice.
When to seek medical help?
Doctors advise seeking medical help if there is a combination of high fever, severe fatigue, muscle and abdominal pain, headache, chills, and the appearance of shortness of breath or tightness in the chest – especially if a person has recently been in contact with rural or forest areas with many rodents.
Early hospitalization and observation are key, as the condition in severe forms can worsen quickly and require intensive care, including oxygen therapy and kidney function support.
The good news is that modern medicine has experience in the treatment and supportive therapy for hantavirus infections, and early recognition of symptoms significantly improves the patient's prognosis.
Ultimately, "hantavirus" is not a mysterious enemy, but a well-described zoonotic pathogen with clear transmission routes and specific prevention measures.
The real risk for the general public remains low if basic hygiene rules are followed and control over rodent populations is maintained – but awareness and attention, especially in rural and forest areas, are of critical importance.