Written by Morgan Michalkiewicz, MPH

Hantavirus is a group of viruses carried primarily by rodents. It can cause serious illness in humans. Although infections are rare, they can lead to severe disease and, in some cases, death. Early symptoms often resemble common respiratory or viral illnesses (like influenza). However, infection can quickly worsen and require urgent medical care.^1,2

 In the United States, hantavirus is most often associated with exposure in Western states, while different forms of the virus are more common globally. Hantaviruses are responsible for two main types of diseases: hantavirus pulmonary syndrome (HPS) and hemorrhagic fever with renal syndrome (HFRS). HPS is primarily seen in North, Central, and South America, while HFRS is more common in Europe and Asia. Both HPS and HFRS can be severe and require hospitalization.^1,2

How Infection Happens and Where Risk Begins

Most hantavirus infections begin through contact with infected rodents or their environments. The virus usually spreads when people inhale particles that have been contaminated with rodent urine, droppings, or saliva or when they touch contaminated surfaces and then touch their face or open skin.^1,2,3 

Risk is highest in enclosed or poorly ventilated spaces where rodents have been present, such as cabins, sheds, garages, or storage areas. Activities like cleaning after long periods of vacancy or disturbing rodent nesting materials can increase exposure risk if proper precautions are not used.^1,2,3

Person-to-Person Spread and the Ongoing 2026 Outbreak

In general, hantaviruses do not spread between people. However, a rare strain known as Andes virus (ANDV) has been associated with limited person-to-person transmission.⁴ Even in these cases, spread is uncommon.

Media attention in the spring of 2026 has focused on an outbreak involving Andes virus on a cruise ship carrying 147 passengers and crew. As of May 18, 2026, 11 cases have been identified (eight laboratory-confirmed and three suspected). There have been three deaths. One previously identified case has since tested negative upon retesting. The patient who had been in critical condition is now showing signs of improvement, while the remaining identified cases have reported mild symptoms and are quarantining.⁵ Public health agencies are closely monitoring the situation. While human-to-human transmission is being investigated, it has not been confirmed, and most hantavirus infections still occur through rodent exposure.

Symptoms and Disease Progression 

Early symptoms may resemble the flu (influenza) and may include fever, fatigue, muscle aches, chills, headache, and sometimes nausea or abdominal discomfort.^1,2 Because these symptoms are common across many illnesses, it can be challenging to diagnose a hantavirus infection early.

In more severe cases, illness can progress rapidly:

• With HPS, symptoms may worsen to include coughing, shortness of breath, and chest tightness. This is caused by fluid buildup in the lungs.  
• With HFRS, patients may develop low blood pressure, bleeding complications, or kidney dysfunction. 

Both HPS and HFRS can become life-threatening without prompt medical attention.^1,2

Treatment and Prevention

There is currently no specific antiviral treatment or vaccine for hantavirus. Care is supportive and may include oxygen therapy, fluid management, and intensive care in severe cases.^1,2 Early medical attention can improve outcomes.

Prevention remains the most effective strategy in avoiding hantavirus. Key steps include sealing homes and buildings to prevent rodent entry, storing food in rodent-proof containers, and safely cleaning areas with rodent droppings. Do not sweep or vacuum dry materials that could contain droppings or nesting materials. This may allow the virus to get into the air around you.

Instead, contaminated areas should be disinfected carefully, ideally while wearing protective equipment such as gloves and masks.^1,2,3

Path Forward

Hantavirus remains a rare infection, but its severity makes awareness important. Most cases are linked to rodent exposure rather than human-to-human spread. The overall risk of hantavirus to the public remains low. Continued attention to prevention, especially in environments where rodent exposure is possible, is key in reducing infection risk and protecting community health. 

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Sources 
1. About hantavirus. Centers for Disease Control and Prevention. May 13, 2024. Accessed May 5, 2026. https://www.cdc.gov/hantavirus/about/index.html

2. Hantavirus. World Health Organization. May 6, 2026. Accessed May 7, 2026. https://www.who.int/news-room/fact-sheets/detail/hantavirus

3. Hantavirus prevention. Centers for Disease Control and Prevention. May 13, 2024. Accessed May 5, 2026. https://www.cdc.gov/hantavirus/prevention/index.html

4. Hantavirus-associated cluster of illness on a cruise ship: ECDC assessment and recommendations. European Centre for Disease Prevention and Control. May 6, 2026. 
Accessed May 7, 2026. https://www.ecdc.europa.eu/en/publications-data/hantavirus-associated-cluster-illness-cruise-ship-ecdc-assessment-and

5. Hantavirus cluster linked to cruise ship travel, multi-country. World Health Organization. May 13, 2026. Accessed May 15, 2026. https://www.who.int/emergencies/disease-outbreak-news/item/2026-DON601