At a glance
Distributed via the CDC Health Alert Network
Summary
The Centers for Disease Control and Prevention (CDC) is issuing this Health Alert Network (HAN) Health Advisory to inform clinicians and health departments about a new cluster of hantavirus disease cases caused by infection with Andes virus. Hantavirus disease can cause severe illness and can be fatal. Clinicians should be aware of the potential for imported cases, although the risk of broad spread to the United States is considered extremely unlikely at this time. As a precaution, this Health Advisory summarizes CDC's recommendations for U.S. public health departments, clinical laboratories, and healthcare workers about hantavirus disease case identification, testing, and biosafety considerations in clinical laboratories.
Background
On May 2, 2026, the World Health Organization (WHO) was notified of a cluster of severe acute respiratory illness (SARI) among passengers and crew of a cruise ship in the Atlantic Ocean. The cluster included two deaths and one critically ill passenger, whose laboratory tests confirmed hantavirus. On May 6, 2026, WHO confirmed that the type of hantavirus responsible for this outbreak is the Andes virus. As of May 8, 2026, WHO has reported eight cases (six confirmed and two suspected), including three deaths. Investigations are ongoing to assess exposure risk of all Americans passengers on the cruise ship or who may have been exposed to an infected cruise ship passenger on an aircraft.
The cruise ship departed from Ushuaia, Argentina, on April 1, 2026, and traveled across the South Atlantic Ocean, stopping at several remote locations, including Antarctica, South Georgia Island, Tristan da Cunha, Saint Helena, and Ascension Island. It carried 147 people (86 passengers and 61 crew) from 23 different countries. The extent of their contact with wildlife before or during the expedition is unknown.
CDC is working with partners (federal government, state and local and international) on safely repatriating American passengers from the cruise ship to a facility in Nebraska with specialized medical capabilities. On May 7, 2026, CDC sent a team to meet the cruise ship in the Canary Islands, Spain following travel from Cape Verde. The team is prepared to assess exposure risk among U.S. passengers and determine appropriate monitoring measures.
CDC is also coordinating with international partners to align public health guidance and has already issued health guidance to affected Americans via the State Department. The risk to the public's health in theUnited States is considered extremely low at this time. As a precaution, CDC is working to increase awareness of the outbreak among travelers, public health agencies, laboratories, and healthcare professionals nationwide.
Hantavirus pulmonary syndrome
Hantaviruses are a group of viruses that can cause severe illness and death. They are most commonly transmitted (spread) to humans through contact with infected rodents (e.g., urine, droppings, saliva). Rarely, infection can occur from rodent bites or scratches. From 1993 through 2023, a total of 890 laboratory-confirmed cases of hantavirus were reported in the United States.
In the Americas, hantaviruses can cause hantavirus pulmonary syndrome (HPS), a severe and potentially deadly disease that affects the lungs. HPS can be life-threatening. Among patients who have severe respiratory symptoms, the case fatality rate has been estimated at approximately 38%.
Andes virus, confirmed as the cause of this hantavirus outbreak, is the only type of hantavirus that has been documented to spread from person-to-person. Although rare, spread between people has typically required close, prolonged contact with a symptomatic person. This could include direct physical contact, prolonged time spent in close or enclosed spaces, and exposure to the infected person's saliva, respiratory secretions, or other body fluids (e.g., kissing, sharing utensils, handling contaminated bedding).
Symptoms of HPS caused by Andes virus usually appear within 4-42 days after exposure. Early symptoms can include fever, fatigue, and muscle aches, especially in large muscle groups like the thighs, hips, back, or shoulders. Early symptoms such as fever, headache, muscle aches, nausea, and fatigue can be easily confused with influenza or other viral illnesses. About half of all HPS patients have experienced headaches, dizziness, chills, and gastrointestinal symptoms, including nausea, vomiting, diarrhea, and abdominal pain. Late symptoms of HPS appear approximately 4-10 days after the initial phase of illness and can include coughing, shortness of breath, and chest tightness Individuals are generally only infectious while symptomatic.
Early diagnosis of HPS can be difficult, especially within the first 72 hours of symptoms, before the virus can be accurately detected in body secretions and excretions. Repeat diagnostic testing is often done 72 hours after symptom onset. CLIA assays for detection of New World hantavirus IgM and IgG antibodies are available at CDC, some state public health laboratories, and Quest Diagnostics.
For questions or concerns about submitting a specimen, please contact your state or local health department or CDC's Emergency Operations Center at 770-488-7100.
No specific treatment is recommended for hantavirus infection; early supportive care is critical even before the diagnosis is confirmed. Patients with suspected HPS can deteriorate rapidly, and delayed care reduces the chance of survival. In severe cases, extra-corporeal membrane oxygenation (ECMO) can significantly improve survival (up to ~80%) if started early. Usually, the critical phase of disease is fairly short, and survivors can recover quickly.
Recommendations for Healthcare Providers
- Be prepared to follow CDC's guidance under Appendix A: Type and Duration of Precautions Recommended for Selected Infections and Conditions | Infection Control | CDC.
- In healthcare settings, for patients with suspected or confirmed Andes virus infection, CDC recommends patient placement in an airborne infection isolation room and the use of a gown, gloves, eye protection, and an N95 or higher-level respirator when entering the patient's room.
- Include HPS in the differential diagnosis for an ill person who has compatible symptoms AND who has reported epidemiological risk factors, including at least one of the following, within the 42 days before symptoms onset:
- Had direct physical contact, or spent time in close or enclosed spaces, with a symptomatic person with confirmed or suspected Andes virus infection or with any objects contaminated by their body fluids.
- Had exposure to an infected person's saliva, respiratory secretions, or other body fluids (e.g., kissing, sharing utensils, handling contaminated bedding).
- Experienced a breach in infection prevention and control precautions that resulted in potential contact with body fluids of a patient with suspected or confirmed Andes virus infection.
- Consider and perform diagnostic testing for more common illnesses as well, such as COVID-19, influenza, and other common causes of gastrointestinal and febrile illnesses in an acutely ill patient with epidemiological risk factors and compatible symptoms.
References
- World Health Organization (WHO). Disease Outbreak News: Hantavirus cluster linked to cruise ship travel, Multi-country. May 8, 2026. https://www.who.int/emergencies/disease-outbreak-news/item/2026-DON599
- Complete sequence of Orthohantavirus andesense virus: Swiss resident 2026. May 7, 2026. https://virological.org/t/complete-sequence-of-orthohantavirus-andesense-virus-swiss-resident-2026/1023
- World Health Organization (WHO). Disease Outbreak News: Hantavirus cluster linked to cruise ship travel, Multi-country. May 4, 2026. https://www.who.int/emergencies/disease-outbreak-news/item/2026-DON599
- Martínez VP, Valeria, Di Paola N, Alonso DO, et al. "Super-Spreaders" and Person-to-Person Transmission of Andes Virus in Argentina. New England Journal of Medicine. 383. 2230-2241. 10.1056/NEJMoa2009040. 2020; 383(23):2230-2241. https://doi.org/10.1056/nejmoa2009040. PMID:33264545.