WHO Identifies Andes Hantavirus Strain in MV Hondius Cruise Ship Outbreak

Health officials are tracking a hantavirus outbreak that began on the MV Hondius cruise ship, with growing attention on the Andes virus, a rare South American strain.

The World Health Organization identified the virus from the ship, which has caused around eight cases and three deaths as of May 11, as the Andes strain.

Unlike most hantaviruses, which spread from rodents to humans, the Andes strain can transmit from person to person, raising concerns about potential outbreaks.

"The Andes strain has been increasing recently as rodents migrate north toward Buenos Aires in hot, wet climate conditions," Dr. Marc Siegel, Fox News senior medical analyst, told Fox News Digital. "It is predominately a rodent virus – current sequencing shows no mutations so far."

The virus is endemic primarily in Argentina, Chile and parts of southern South America, according to the Centers for Disease Control and Prevention. It is carried mainly by the long-tailed pygmy rice rat.

The Andes strain often leads to hantavirus pulmonary syndrome, a severe condition, Siegel said.

Hantavirus pulmonary syndrome is a rare respiratory disease that fills the lungs with fluid and impairs breathing. It can turn life-threatening quickly, with 38 percent of patients who develop respiratory symptoms dying, per the CDC.

Early symptoms include fatigue, fever and muscle aches. About half of patients also have headaches, dizziness, chills and abdominal issues such as nausea, vomiting and diarrhea, the CDC said.

Symptoms usually start four to 42 days after exposure. In most cases, only symptomatic people spread the virus to others.

Person-to-person spread of Andes virus remains rare, despite its capability, Siegel said. There is no treatment or vaccine. The U.S. Army Medical Research Institute of Infectious Diseases is developing monoclonal antibodies, and an mRNA vaccine is in progress.

Patients receive supportive care, including rest, hydration and symptom-relief medications.

Health experts say the Andes virus spreads far less efficiently than measles, influenza or COVID. The CDC assesses overall risk to the American public and travelers as extremely low.

"Andes virus testing is limited to people who have relevant symptoms and exposure history," the agency stated. "If you think you had contact with a person with Andes virus and are experiencing symptoms, contact a medical professional or your state or local health department immediately."