A suspected hantavirus outbreak aboard a cruise ship has resulted in three deaths and seven other individuals falling ill. The World Health Organization (WHO) has confirmed that detailed investigations are underway, including extensive laboratory testing and epidemiological studies to understand the virus's spread. Sequencing of the virus from the current outbreak is also ongoing.
What is Hantavirus?
Hantavirus is primarily spread through contact with rodents or their urine, saliva, or droppings. The virus becomes particularly dangerous when contaminated material is disturbed and becomes airborne, posing a risk of inhalation. People are typically exposed to hantavirus around homes, cabins, or sheds, especially when cleaning enclosed spaces with poor ventilation or entering areas where mouse droppings are present. The WHO notes that while rare, hantaviruses may spread between people.
The US Centers for Disease Control and Prevention (CDC) began tracking the virus after a 1993 outbreak in the Four Corners region, where Arizona, Colorado, New Mexico, and Utah meet. A doctor with the Indian Health Service first noticed a pattern of deaths among young patients, according to Dr. Michelle Harkins, a pulmonologist at the University of New Mexico Health Sciences Center who has studied the disease for years. Most US cases occur in Western states, with New Mexico and Arizona being hotspots, likely due to greater odds of mouse-human encounters in rural areas.
Symptoms of Hantavirus
An infection can rapidly progress and become life-threatening. Early symptoms may include fever, chills, muscle aches, and headache. "Early in the illness, you really may not be able to tell the difference between hantavirus and having the flu," said Dr. Sonja Bartolome of UT Southwestern Medical Center in Dallas. Symptoms of hantavirus pulmonary syndrome usually appear one to eight weeks after contact with an infected rodent. As the infection progresses, patients may experience chest tightness as the lungs fill with fluid. The other syndrome caused by hantavirus—hemorrhagic fever with renal syndrome—typically develops within a week or two after exposure.
Death rates vary depending on the specific hantavirus. Hantavirus pulmonary syndrome is fatal in nearly 40% of infected individuals, while the death rate for hemorrhagic fever with renal syndrome ranges from 1% to 15%, according to the CDC.
How to Prevent Hantavirus
There is no specific treatment or cure, but early medical attention can increase survival chances. Despite years of research, Dr. Harkins noted that many questions remain unanswered, including why the disease can be mild for some people and severe for others, and how antibodies develop. Researchers have been following patients over long periods in hopes of finding a treatment. "A lot of mysteries," she said, emphasizing that rodent exposure is a key factor. The best way to avoid the germ is to minimize contact with rodents and their droppings. Use protective gloves and a bleach solution for cleaning up droppings. Public health experts caution against sweeping or vacuuming, which can cause the virus to become airborne.
