May 28, 2026 Author : Saraiva da Cunha (Infectious Diseases ) Hantavirus is the original and best-known name of a group of more than fifty virus species whose genus is currently designated Orthohantavirus . The Hantaviruses found in Europe and Asia are distinct from those found on the American continent. The natural hosts of Hantaviruses are mainly rodent species, in which they do not cause disease. Only Hantaviruses transmitted by rodents (through excreta and saliva) are associated with human disease. Human infections are uncommon and are almost always related to contexts of rodent exposure. They vary in severity, from no symptoms at all to severe disease with high mortality. Rodent control, together with the adoption of behaviors and personal protective measures to avoid contact with their excreta or saliva, is the main way to prevent Hantavirus infections. The number of hantavirus infection cases reported annually in Europe over the last 15 years has ranged between about 1,700 and 5,000, with Finland and Germany reporting the highest numbers of cases. During this period, Portugal has never reported cases of hantavirus infection. It is believed that the variation and geographical distribution of cases in Europe is related to climatic factors, forest and agricultural characteristics, and their relationship with the abundance of rodent populations and human interaction. How are Hantaviruses transmitted to humans? Most often, human infection is indirect : By inhalation of particles of feces, urine, or saliva from infected rodents in the air, which occurs mainly in enclosed and poorly ventilated spaces where rodents are or have been present. Typical spaces with these characteristics include warehouses, storage rooms, garages, among others. Ingestion of water or food contaminated with feces, urine, or saliva of infected rodents. Direct infection is also possible: When feces, urine, or saliva from infected rodents come into contact with wounds in skin or mucous membranes; Through bites or scratches from infected rats. Person-to-person transmission has only been documented for one species of Hantavirus - the Andes virus - which exists in some regions of South America, and requires close and prolonged contact. Do Hantaviruses cause different diseases? Two main clinical presentations are known, related to the virus species involved and the geographical region: Hemorrhagic fever with renal syndrome and epidemic nephropathy, in Europe and Asia. Hantavirus cardiopulmonary syndrome, in American continent. In Europe, hantavirus infections are mainly caused by the Puumala virus, followed in importance by the Dobrava virus and occasionally by the Seoul and Tula viruses. Symptoms of Hantavirus infection The initial symptoms of Hantavirus infection are common to the different disease presentations and are non-specific. They occur in many other illnesses, and resemble those of severe influenza : High fever; Chills; Intense fatigue; Muscle pain and headaches; Nausea, vomiting, and abdominal pain. Hemorrhagic fever with renal syndrome Occurs mainly in Europe and Asia and is notifiable disease in Europe. It primarily affects the kidneys and the circulatory system. The incubation period ranges from 10 days to six weeks. Initially, there may be high fever, severe headaches, muscle pain, and intense lower back pain. Facial redness and signs of bleeding in the skin and mucous membranes may sometimes be visible. In the most severe cases, the disease progresses to hypotension, significant internal bleeding, and acute kidney failure. The hospitalization rate of confirmed cases in Europe is 30%-50%. Mortality varies with the virus involved: it may reach 10%-15% in Asia due to more aggressive species and is generally below 1% in Europe in cases associated with the Puumala virus. Epidemic nephropathy is a milder form of this presentation. It is mainly caused by the Puumala virus and occurs in Europe. Hantavirus cardiopulmonary syndrome Predominates in the American continent and is mainly caused by Sin Nombre virus and Andes virus. It is a severe respiratory disease that mainly affects the lungs but also the heart. It has an incubation period of one to six weeks. The disease can worsen within a few days, with severe respiratory distress and shortness of breath due to fluid accumulation in the lungs. The most critical cases require intensive care and are life-threatening, with a mortality rate that can reach 50%. Diagnosis and treatment Given the rarity of hantavirus infections, in the early stage of the disease suspicion may only arise based on occupational context or patient history, particularly when there is a report of likely exposure to rodents. Definitive diagnosis of hantavirus infection requires laboratory confirmation , carried out through tests aimed at identifying: Antibodies against hantavirus; Virus genetic material. There is no specific antiviral treatment for these infections. Treatment focuses on symptom relief and supportive care to allow the body to recover. In more severe cases, admission to intensive care may be required. Prevention of Hantavirus infections There is currently no vaccine against Hantavirus. Prevention is based on measures that reduce the likelihood of contact with rodents or with their feces, urine, and saliva. People involved in agricultural and outdoor activities are at higher risk. General rodent control measures: In homes and other buildings, pay particular attention to areas where food is stored or handled, as these are especially attractive to rodents; Keep spaces tidy and clean, particularly free of easily accessible food or waste; Store food properly; Securely contain and do not accumulate garbage; Maintain buildings in good condition, taking care to repair cracks in walls, ceilings, and floors and other defects that provide shelter and nesting conditions; Install bait and traps in appropriate locations; Be alert to signs of rodent presence. Reinforce protective measures when in places where rodents may be present , particularly during cleaning operations: Wear rubber gloves and a protective mask; Ventilate spaces; Pre-moisten (with water and a disinfectant) areas that need to be swept to reduce dust formation; Do not handle rodents if found; if possible, use a pest control service for removal; Wash hands thoroughly after carrying out cleaning tasks. When engaging in outdoor activities, avoid areas where rodents may be present. In campsites, keep food and beverages in tightly sealed containers and avoid sleeping directly on the ground. Following the Andes hantavirus outbreak associated with the cruise ship MV Hondius , the Directorate-General of Health issued Standard 001/2026 recommending procedures for the management of contacts with confirmed or suspected cases. Sources European Centre for Disease Prevention and Control. Factsheet on Orthohantavirus infections . European Centre for Disease Prevention and Control: Surveillance atlas of infectious diseases . Vial PA, Ferrés M, Vial C, et al. Hantavirus in humans: a review of clinical aspects and management. Lancet Infect Dis 2023;23:e371-82. World Health Organization. Hantavírus . Meet the infectious diseases clinical team from Hospital da Luz network. The content published in the Health Guide is intended for the general public and is provided for informational and educational purposes only. It does not replace individual medical assessment, diagnosis, or personalized clinical advice from a qualified healthcare professional. The content is produced or reviewed by physicians and other healthcare professionals at Hospital da Luz and is based on the knowledge available at the time of publication or the most recent update, as indicated at the beginning of each item.
