2026 Current Hantavirus Situation
Page originally published 5/21/2026.
Local, state, national, and global public health partners are working together to assess and care for people who were aboard the MV Hondius, a cruise ship that experienced an outbreak of Andes hantavirus.
While California residents were aboard the MV Hondius cruise ship, none have developed symptoms and they remain under close monitoring. The California Department of Public Health (CDPH) reports the risk to the general public remains extremely low. Unlike influenza and COVID-19, years of experience in South America have shown that this Andes hantavirus only rarely spreads between people. Health partners will continue to coordinate closely to monitor the situation and provide support.
On this page:
Since California residents were on board the cruise ship, what is the state or local plan to monitor the situation?
The state and the local health jurisdiction where the cruise ship passengers reside are working to assess and clinically monitor the travelers. The Centers for Disease Control and Prevention (CDC) worked closely with other U.S. government agencies and international partners to bring Americans on the ship home as quickly and as safely as possible.
If most hantaviruses do not spread from person-to-person, what happened on the cruise ship?
The hantavirus cases on the MV Hondius cruise ship were caused by a type of hantavirus called Andes virus. The Andes virus is limited to southern South America. Although rare, the Andes virus is the only type of hantavirus that has been documented to spread from person-to-person.
Where can I learn more about Andes virus, including symptoms, how it spreads, and how it can be prevented?
For information on:
- Andes virus, visit the CDC’s Andes Virus.
- Hantavirus, including the Sin Nombre type which more commonly causes disease in southwestern U.S. states, including California, visit the County of San Diego’s Hantavirus.
I’ve heard that there is hantavirus already in San Diego County, where can I learn more about that?
As of May 13, 2026, CDPH reports there are currently no cases of Andes hantavirus disease in California or in California residents, nor in U.S. residents.
Cases of hantavirus are rare. Since 2000, there have only been four (4) cases of hantavirus among San Diego County residents. These were all the Sin Nombre type of the virus. Three of the four (3/4) cases were infected while traveling.
What is the County doing to monitor hantavirus locally?
In San Diego, deer mice are the main carriers of hantavirus. They are found mostly in rural areas, the desert, and the mountains. Mice that commonly live with humans are house mice and do not carry hantavirus.
The Vector Control Program routinely collects blood samples from wild mice to test for hantavirus.
- If positive results are found, the public – including affected communities – are informed by direct outreach and press releases to take precautions to lower risk of exposure.
- See Hantavirus Activity in San Diego County for results of routine testing.
County of San Diego
- What is Hantavirus? (Video)
- Health Alert: Hantavirus Among Cruise Ship Passengers (California Health Alert Network San Diego – May 12, 2026)
- Hantavirus (Epidemiology and Immunization Services Branch)
- Hantavirus (Vector Control Program)
California Department of Public Health
- Andes Hantavirus Update: No Cases in California (May 13, 2026)
- CDPH Confirms Four Californians Being Monitored for Andes hantavirus Exposure Related to Cruise Ship (May 11, 2026)
- CDPH Aware of California Passengers Exposed to Andes Hantavirus Outbreak on International Cruise Ship (May 8, 2026)
Centers for Disease Control and Prevention
Call the Epidemiology Unit at (619) 692-8499, or send an e-mail, for more information.
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