Additional Coverage:
Health Officials Investigate Hantavirus Outbreak Linked to Cruise Ship MV Hondius
Health authorities continue to probe a hantavirus outbreak associated with the expedition cruise ship MV Hondius, raising concerns about the virus’s presence in the United States.
The ship, which was voyaging from Argentina across the Atlantic, has reported at least eight hantavirus cases among passengers, including three fatalities, according to the World Health Organization and subsequent health reports.
Several U.S. states, including Texas, Virginia, Georgia, Arizona, and California, are now monitoring residents who recently returned from the MV Hondius to track potential infections.
Hantavirus Overview and U.S. Context
Historically, hantavirus infections in the U.S. number between 800 and 900 cases, a figure corroborated by CDC data showing 890 reported cases from 1993 through 2023. Most cases occur west of the Mississippi River and are linked to exposure to rodent droppings and urine, explained Dr. Luis Marcos, professor of medicine at Stony Brook Medicine.
The most prevalent strain in the U.S., Sin Nombre virus, is primarily contracted by inhaling particles contaminated by rodent excreta. Human-to-human transmission is exceedingly rare and has only been documented with the Andean hantavirus strain from South America – the strain implicated in the current cruise ship outbreak.
Outbreak Details and Transmission Insights
The outbreak reportedly began with a couple who contracted the virus during travel in Argentina before boarding the ship. They were asymptomatic during the virus’s incubation period, which can range from one to four weeks.
Symptoms of hantavirus infection often mimic flu or COVID-19, including fever and muscle aches. While some individuals experience mild illness, others can develop hantavirus pulmonary syndrome (HPS), a severe condition where fluid accumulates in the lungs, carrying a mortality rate between 30% and 60%.
Dr. Marcos emphasized that close, sustained contact is generally required for human-to-human transmission of the Andean virus, making the risk of widespread spread lower than that of respiratory viruses like COVID-19 or influenza.
Preventive Measures and Outlook
Due to hantavirus’s lengthy incubation period-potentially up to 56 days-quarantine measures for exposed individuals may last several weeks. Currently, there are no antiviral treatments or vaccines available in the U.S., though several vaccine candidates are in development.
Supportive hospital care remains the primary intervention for severe cases, including ventilator support when lung function is compromised.
Dr. Marcos expressed confidence that the outbreak will subside within weeks and assessed the risk of a hantavirus pandemic as very low, given its limited transmission efficiency compared to other viruses.
To reduce risk, he advises wearing gloves and masks when cleaning areas with potential rodent exposure, ensuring good ventilation, and practicing frequent hand hygiene.
Health officials continue to monitor the situation closely as investigations proceed.