San Mateo County health authorities have recently identified two new hantavirus exposure cases associated with travel activities: one involving a passenger from the MV Hondius cruise ship and another linked to a traveler passing through San Francisco International Airport (SFO). These incidents are unusual for the Bay Area and have triggered increased surveillance and public health alerts to mitigate any further spread.

Both individuals were exposed in environments with known rodent presence, the primary reservoirs of hantavirus, raising concerns about potential contamination in cruise ship cabins and airport terminals.

Health officials recommend that travelers and residents stay alert for symptoms indicative of hantavirus pulmonary syndrome (HPS), which can include fever, muscle pain, and breathing difficulties. Preventive actions advised include:

• Thoroughly disinfecting travel accommodations, especially cabins and airport waiting areas.
• Avoiding contact with rodent droppings, urine, or nesting sites.
• Promptly consulting healthcare providers if symptoms arise within 1 to 5 weeks after potential exposure.

Investigations by public health officials have linked the two hantavirus cases to specific travel-related exposures. The traveler passing through SFO likely contracted the virus either before or during their time at the airport, while the MV Hondius passenger’s infection is believed to stem from rodent activity near the ship’s docking area.

Both patients are currently under medical supervision, and contact tracing efforts are underway to prevent additional infections. This development underscores the importance of vigilance in public spaces, especially those frequented by travelers.

Highlights from the investigation include:

• Evidence suggests the SFO traveler’s exposure occurred in or around airport facilities.
• Rodent infestations near the cruise ship’s berth are suspected as the source for the MV Hondius passenger.
• Collaboration between local health departments and transportation authorities is ongoing to enhance awareness and implement preventive strategies.

Hantavirus is primarily transmitted when individuals inhale airborne particles contaminated with virus-laden rodent droppings, urine, or nesting materials. People living or working in areas with significant rodent activity-such as rural homes, farms, or even cruise ships docked in ports-are at heightened risk.

In the recent Bay Area cases, exposure likely occurred due to close contact with rodent-infested environments combined with confined spaces aboard the cruise ship and within airport terminals. While person-to-person transmission is exceedingly rare and limited to specific hantavirus strains, it remains a possibility in isolated cases.

Early recognition of symptoms is vital. Initial signs often appear suddenly and may include:

• High fever and muscle soreness
• Extreme tiredness and headaches
• Chills and lightheadedness
• Progressive shortness of breath as the illness advances

Prompt medical intervention is crucial since hantavirus can rapidly escalate to severe respiratory failure. Preventive strategies emphasize sealing homes against rodent intrusion and using protective gear when cleaning potentially contaminated areas.

Individuals traveling or embarking on cruises should exercise caution to minimize hantavirus exposure, particularly in outdoor or enclosed spaces where rodents may be present. The virus spreads mainly through contact with infected rodent saliva, urine, or feces, and inhalation of contaminated dust particles.

To safeguard health, travelers should avoid disturbing rodent nests, wear protective gloves and masks when cleaning potentially contaminated areas, and wash hands thoroughly after outdoor activities or contact with surfaces that might harbor the virus.

Recommended safety measures include:

• Inspecting and sealing gaps or holes in cabins, tents, or storage spaces to prevent rodent entry.
• Storing food securely and disposing of garbage properly to deter rodents.
• Maintaining cleanliness in living and recreational areas, especially when docked at ports or during shore excursions.
• Seeking immediate medical evaluation if symptoms such as fever, muscle pain, or breathing difficulties develop after travel.