As multiple Americans who were onboard the cruise ship at the center of a hantavirus outbreak return to the U.S., with at least one testing positive and another showing symptoms, which signs are health experts looking for?
Hantavirus symptoms aren’t exactly unique – at least to start, health officials told reporters Monday.
“We’re going to expect to see people have symptoms. That’s just, you know, if you think in any given week or month, how many times do you experience some level of nasal congestion or upset stomach or something? We’re being very, very liberal in how we’re framing symptoms and monitoring for symptoms here,” Dr. Brendan Jackson, acting director of the Division of High Consequence Pathogens and Pathology with the U.S. Centers for Disease Control and Prevention, said. “And so that’s how the system is working. It doesn’t necessarily mean just because someone has symptoms that they’re going to end up having this illness.”
The CDC notes that “typically, people are only infectious while they have symptoms.” But the particular strain of hantavirus believed to be behind the current outbreak is known as the Andes virus, which can mirror flu-like symptoms to start.
According to the CDC, early symptoms of the virus can look similar to many other illnesses, with symptoms like fatigue, fever and muscle aches, particularly in large muscle groups like the thighs, hips, back, and sometimes shoulders.
In addition to those, however, about half of patients also experience:
- Headaches
- Dizziness
- Chills
- Abdominal problems, like nausea, vomiting, diarrhea, and abdominal pain
After these early symptoms, later stages of the virus can bring more serious concerns, the CDC noted.
Four to 10 days in, patients might experience things like coughing, shortness of breath, tightness in their chest and fluid in their lungs.
An infection can rapidly progress and become life-threatening.
Symptoms of hantavirus pulmonary syndrome usually show between one and eight weeks after contact with an infected rodent. As the infection progresses, patients might experience tightness in the chest, as the lungs fill with fluid.
“HPS can be deadly. Thirty-eight percent of people who develop respiratory symptoms may die from the disease,” the CDC reported.
The other syndrome caused by hantavirus — known as hemorrhagic fever with renal syndrome, which can cause bleeding, high fever, and kidney failure — usually develops within a week or two after exposure.
Death rates vary by which hantavirus causes the illness. Hantavirus pulmonary syndrome is fatal in about 35% of people infected, while the death rate for hemorrhagic fever with renal syndrome varies from 1% to 15% of patients, according to the CDC.
The passengers landed in Omaha about 1:30 a.m. CT via a State Department plane after the ship anchored in the Canary Islands Sunday. Personnel in full-body protective gear and breathing masks had escorted the travelers from ship to shore in Tenerife in an effort that was continuing Monday.
One of the 17 American passengers evacuated from the ship and flown to Nebraska tested “mildly” positive but was not showing any symptoms, and another had mild symptoms, U.S. health officials said late Sunday. The two traveled in the plane’s biocontainment units “out of an abundance of caution,” HHS said.
“One passenger will be transported to the Nebraska Biocontainment Unit upon arrival, while other passengers will go to the National Quarantine Unit for assessment and monitoring,” Kayla Thomas, a spokesperson for the Nebraska Medicine hospital that will help care for the passengers, said. “The passenger who is going to the Biocontainment Unit tested positive for the virus but does not have symptoms.”
State and local health officials in the U.S. are also monitoring at least eight passengers who disembarked on April 24 and returned home.
So what happens next?
Health experts said there’s a possibility any asymptomatic passengers in Nebraska could move home to finish their quarantine.
“The passengers that are all in the sort of assessment phase, they’re going to be here for at least a few days while we do assessments and then coordination from what happens next,” Jackson said. “They certainly have the option to stay here for the entire 42-day period, if that’s just the safest and most effective option for them. There’s going to be an individualized decision plan for them to determine if it makes more sense for them to complete their 42-day monitoring at home. And there’s going to be a couple of things that go into to to that decision. First and foremost, do they remain symptom free? But then also, do they have all the structures and support to be able to be continue that period at home, making sure that that they can, be able to isolate in a separate part of structure from anybody else, make sure that they can contact their health department, get tested if necessary, if they develop symptoms or if they need a higher level of medical care that that’s available to them. So there’s a range of structures that need to be in place before anyone would be transferred to their their home. And that would be done in close coordination with the health departments in the states that would be receiving them.”
Hantaviruses have been around for centuries and are thought to exist around the world. The disease gained renewed attention last year after the late actor Gene Hackman‘s wife, Betsy Arakawa, died from a hantavirus infection in New Mexico.
In the U.S., federal health officials began tracking the virus after a 1993 outbreak in the Four Corners region — the area where Arizona, Colorado, New Mexico and Utah meet. It was an astute physician with the Indian Health Service who first noticed a pattern of deaths among young patients.
The virus usually spreads when people inhale contaminated residue of rodent droppings. But the Andes virus may be able to spread between people in rare cases. Because of this, health officials are taking extra precautions with passengers returning to their home countries.
Most U.S. cases are in Western states. New Mexico and Arizona are hot spots, likely because the odds are greater for mouse-human encounters in rural areas.
COVID-19 spreads much more easily than hantavirus, sometimes even from people who are symptom-free — which made the virus extremely difficult to contain when the pandemic broke out in 2020. Hantavirus is harder to get, though potentially more dangerous once someone is sick.
“There are a lot of unknowns here. But as was mentioned earlier, it seems that with hantavirus, this specific Andes, that this can be transmitted person to person, but it typically does require very close contact and typically when those individuals are symptomatic,” Dr. Angela Hewlett, medical director of the Nebraska Bio Containment Unit, said Monday. “Now again, recognizing that like I said, although this is you know, there are some unknowns. And this is not a not a new virus. This is not the scenario that we encountered with Covid where we had a brand new brand new virus. So there is some information, known about Andes virus. And we’re still fortunate to at least have that. But again, these this will be an ongoing assessment.”
