HEALTH ADVISORY

County of Santa Clara
Public Health Department

Health Officer
150 W Tasman Drive
San Jose, CA 95134

May 12, 2026

HEALTH ADVISORY: Hantavirus Disease Outbreak Among Passengers of the MV Hondius Ship

To:
All Healthcare Providers

From:

Sarah L. Rudman, MD, MPH
Public Health Officer and Director
County of Santa Clara Public Health Department

and

Monika Roy, MD, MPH
Deputy Public Health Officer
Director, Infectious Disease and Response Branch
County of Santa Clara Public Health Department

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Situational Update

An outbreak of severe respiratory illnesses aboard the MV Hondius, a Dutch flagged cruise ship, was first reported to the WHO on May 2, 2026. As of May 8, WHO has reported a total of eight cases (six confirmed and two probable cases), including three deaths (among two confirmed and one probable case). All six cases have been confirmed as infected with the Andes virus, a species of hantavirus with documented person‑to‑person transmission following prolonged close contact. 

The California Department of Health (CDPH) is currently aware of four California residents linked to this outbreak including a resident of Santa Clara County who has already returned home, two additional cruise ship contacts who are currently repatriated and in a medical facility in Nebraska, and a fourth contact who was not onboard the ship but is a close contact to a case.

The County of Santa Clara Public Health Department (SCC PHD) has been actively monitoring the returned traveler in our county daily and will continue to do so for the duration of the virus’ 42-day incubation period. The individual is currently at home, feeling well, and reporting no symptoms of hantavirus at this time. 

The risk to the general public is considered extremely low at this time. Person to person transmission of Andes virus requires prolonged close contact, individuals are not considered infectious unless symptomatic, and all individuals exposed on the cruise ship are being closely monitored and evaluated.

For additional information about Andes virus, the cruise ship outbreak, or the international, national, state, and local public health responses, please refer to the resource section below.

Actions Requested of Healthcare Providers:

1. Educate patients who may be worried about hantavirus that the risk to the general public is extremely low at this time based on what is known about the virus, its transmission dynamics, and current public health efforts. Emphasize that there are currently no cases of Andes hantavirus in Santa Clara County. Explain that an “exposure” does not mean the person is sick or will get sick, instead, it means they were around a person who was sick and they are being monitored in case they develop symptoms.

2. Include Hantavirus Pulmonary Syndrome (HPS) in the differential diagnosis for an ill person who has compatible symptoms AND who has reported epidemiological risk factors.

SCC PHD will notify healthcare facilities before sending any known symptomatic contacts exposed to the Andes virus to a healthcare facility. Notwithstanding the foregoing, if there are patients with symptoms consistent with Hantavirus Pulmonary Syndrome (HPS) who present to your healthcare facility, assess for epidemiologic risk factors within 42 days of symptom onset. For symptomatic patients without any epidemiologic risk factors, hantavirus infection is unlikely and you should provide reassurance and evaluate for other illnesses. 

Typical symptoms of HPS include:

• Early symptoms (within 4 to 42 days after exposure): Fever, fatigue, headaches, gastrointestinal symptoms, and myalgias (especially in large muscle groups like thighs, hips, back or shoulders.)
• Late symptoms (occur approximately 4 to 10 days after the early symptoms): Respiratory symptoms like coughing and dyspnea. Within 24 hours of initial evaluation, HPS patients can develop hypotension, pulmonary edema, and hypoxia.

Epidemiologic risk factors for Andes virus include at least one of the following:

• 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.

Epidemiologic risk factor for Sin Nombre virus (species of hantavirus found in the western US):

• Exposure to rodent urine/feces/saliva or food that could have been contaminated by rodents.

3. In patients in whom Andes virus infection is suspected, ensure isolation precautions and notify public health.

• Isolation: Place the patient in airborne isolation and use a gown, gloves, eye protection, and an N95 or other higher respirator when entering the patient’s room.
• Public Health Notification: Notify SCC PHD immediately by calling (408) 885-4214 and select option 3. After hours, call (408) 998-3438 and ask to page the Health Officer on call.
• Testing: SCC PHD will help coordinate testing if needed; testing is not recommended for asymptomatic returned travelers or contacts. Assays for hantavirus IgM and IgG antibodies are available through the CDC. A RT-PCR assay is also available through CDPH. Early diagnosis can be difficult and repeat diagnostic testing is often done 72 hours after symptom onset.

4. Work with SCC PHD to transport patients with confirmed or suspected Hantavirus Pulmonary Syndrome (HPS) to a designated healthcare facility with 24-hour ECMO coverage.

• There is no specific treatment for HPS and early supportive care is recommended.
• Patients with suspected HPS can deteriorate rapidly, and in severe cases, extra-corporeal membrane oxygenation (ECMO) can significantly improve survival. Individuals with Andes Virus infection showing signs of HPS should be evaluated as soon as possible at a facility with critical care capacity that can provide extra corporeal membrane oxygenation (ECMO). SCC PHD will assist with coordination of transport and treatment at a previously designated healthcare facility with 24-hour ECMO capability.

Resources: 

1. Andes Virus Outbreak on a Cruise Ship: Current Situation (Centers for Disease Control and Prevention)
2. Clinician Brief: Hantavirus Pulmonary Syndrome (HPS)  (Centers for Disease Control and Prevention)
3. Hantavirus Infection (California Department of Public Health)

References:

1. Health Advisory: 2026 Multi-country Hantavirus Cluster Linked to Cruise Ship (Centers for Disease Control and Prevention)
2. Health Advisory: Hantavirus Disease Outbreak Among Passengers of the MV Hondius Ship (California Department of Public Health)
3. CDPH Aware of California Passengers Exposed to Andes Hantavirus Outbreak on International Cruise Ship (California Department of Public Health)
4. Appendix A: Type and Duration of Precautions Recommended for Selected Infections and Conditions (Centers for Disease Control and Prevention)

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