A hantavirus outbreak aboard the MV Hondius cruise ship has killed three passengers and sickened at least four others, worrying health experts.
People most often contract the rare but deadly disease from the feces, urine or saliva of infected rodents, but the World Health Organization insisted Tuesday that no rodents have been found on the liner.
Now, scientists are looking at one particularly worrisome potential cause of transmission.
“The situation is particularly concerning given that it appears that this is likely the Andean strain of hantavirus,” Donna A. Patterson, a professor in the Department of History, Political Science, Philosophy and Law Studies at Delaware State University, told The Post.
“In the right conditions, often in close quarters, it can spread from human to human,” she added.
The Dutch cruise liner departed from Argentina — one location where the Andes strain is found, along with Chile — on March 20 for its weeks-long voyage to Antarctica, but has remained stranded off the coast of West Africa since Monday.
With a mortality rate of up to 40% from this particular strain, the dilemma of quarantine in a tight, confined space such as the 353-foot-long ship is raising concerns.
How long is the quarantine for hantavirus?
It’s important to figure out the source of the infections to determine quarantine measures.
“If passengers were exposed during shore excursions, it’s possible multiple individuals were infected at the same time and are now presenting symptoms at different points within the incubation window,” Dr. Raymond Alvarez, an immunologist, virologist and CEO of Ichor Biologics, told The Post.
“That’s a more contained scenario.”
If the initial infections happened onboard, the chances of continuing transmission are higher and “require more aggressive containment measures,” Alvarez said.
On average, the quarantine timeline for hantavirus is three to four weeks, though this can vary as the incubation period lasts “about two weeks, with patients showing symptoms generally from about a week but as long as a month,” according to Patterson.
According to Alvarez, the isolation period can last four to five weeks as a precaution to monitor exposed individuals and prevent further spread.
The latter end of this timeline was also recommended by Jill Roberts, a molecular epidemiology expert with the University of South Florida College of Public Health in Tampa.
“The virus has a long incubation period,” she told The Post.
The downsides to isolation
While quarantine is generally recommended to prevent additional spread, there are unique problems in a cruise ship environment.
“Given the design of cruise ships, including close quarters and opportunities for re-circulated air, this could lead to more passengers potentially becoming infected,” Patterson explained.
She added that “the longer they are on the ship, the higher the odds of infection.”
There’s also only so much isolation that can be done to contain the virus until the source is identified.
“Keeping the passengers isolated helps to keep a close watch on their medical condition but may not be doing much to prevent the spread of illness,” Dr. Carrie Horn, chief medical officer at National Jewish Health, told The Post.
“If the epidemiology team can better understand how and where the patients were infected in the first place, they may not need to quarantine all of the passengers for very long,” Horn added.
Could the virus spread from the ship?
The ship is stranded in the Atlantic Ocean, but there are proposed plans to dock in Spain’s Canary Islands for medical evaluation.
Bringing the passengers on land could mean further contamination if protocols are not executed carefully.
“In order to safely disembark and protect local populations at the site of disembarkation, there needs to be a site to isolate and quarantine passengers as needed to ensure that the outbreak does not spread further,” Patterson said
While the origins of the virus and the ship’s fate are still unknown, experts say there’s no reason for the general public to panic.
“They could have picked it up anywhere — I don’t think it came from the ship,” physician Zaid Fadul previously told The Post, with other experts agreeing the outbreak likely came from rodents.
“The most likely situation is that people traveling from South America came in contact with infected rodents’ dropping in this part of the world,” Giulia Gallo, a virus researcher with the Pirbright Institute in the UK, told Science Media Centre.
Beyond waiting for further information from health officials, those on board can continue good hygiene practices to prevent illness.
“The best thing they can do to stay safe is to minimize risk of other infections,” said Horn. “Things like good handwashing, especially before eating or after being in crowded areas, are important.”
