At least six passengers from the MV Hondius cruise ship have tested positive for the Andes strain of hantavirus. Of the 18 Americans who were on board and are now in quarantine facilities in the U.S., at least three are being closely watched for possible infection.<\/p>\n\n\n\n
The latest confirmed cases are all among people who had direct contact with other patients who were on the ship, although concerns about how easily \u2014 or not \u2014 the Andes strain spreads are growing. Andes is the only type of hantavirus that can pass from person to person.<\/p>\n\n\n\n
It has been assumed that the virus is contagious only if someone is in close contact with someone who\u2019s having symptoms. Some experts now suggest it\u2019s possible it may be more contagious than thought.<\/p>\n\n\n\n
\u201cWhat we\u2019re hearing now, including from the doctors who were on the ship, is that at least a few people contracted it without that long, prolonged exposure that we\u2019ve always assumed,\u201d Dr. Ashish Jha, a senior fellow at Harvard University\u2019s Kennedy School, told NBC\u2019s \u201cTODAY\u201d show on Monday.<\/p>\n\n\n\n
Dr. Brendan Jackson, acting director of the high-consequence pathogens and pathology division at the Centers for Disease Control and Prevention, said in an interview Monday that the close quarters of the cruise ship environment seem to be key in this outbreak.<\/p>\n\n\n\n
Cruise ships are notorious for infectious disease outbreaks because they bring together a wide variety of people and stick them in close quarters for days or even weeks \u2014 repeatedly sharing high-touch areas like buffets.<\/p>\n\n\n\n
\u201cThat is definitely different than how we live most of the time,\u201d Jackson said.<\/p>\n\n\n\n
Hantavirus is so rare that spread on cruise ships was unheard of until three Hondius passengers were confirmed to have died from the Andes strain this month.<\/p>\n\n\n\n
There\u2019s no evidence to suggest the Andes strain has changed to make it more infectious, Jackson said.<\/p>\n\n\n\n
While experts maintain that the risk of hantavirus\u2019 spreading widely is extremely low, they say there\u2019s still much to learn about the virus and how it infects people.<\/p>\n\n\n\n
How does hantavirus spread from person to person?<\/strong><\/p>\n\n\n\n Only one of the dozens of hantavirus strains is known to spread among people: the Andes strain. That\u2019s what sickened at least six people who were on the Hondius, and it is suspected in at least two more cases.<\/p>\n\n\n\n The Andes strain doesn\u2019t spread easily, Jackson said. \u201cWhen it does, it typically involves household members that are doing things like sharing beds or sharing eating utensils or having contact with body fluids,\u201d he said.<\/p>\n\n\n\n Dr. David Fitter, head of the CDC\u2019s Division of Global Migration Health, said at a media briefing Monday at Emory University Hospital in Atlanta, where two passengers are under observation: \u201cThis is very different than a respiratory virus. It\u2019s very difficult to spread.\u201d<\/p>\n\n\n\n It\u2019s also possible that the virus can spread between people if they\u2019re physically close to one another for an extended period of time. The CDC tends to define that as being within 6 feet of another person for longer than 15 minutes, Jackson said earlier Monday at a media briefing at the Nebraska Biocontainment Unit in Omaha, where most of the U.S. passengers from the ship were taken for observation.<\/p>\n\n\n\n \u201cThere\u2019s nothing magical about 6 feet. It\u2019s not a force field, but it\u2019s a rough number that gives us a sense of how close somebody has been,\u201d he said. \u201cIt\u2019s a fairly conservative approach given the evidence we have so far about how this virus has spread in the past.\u201d<\/p>\n\n\n\n Most people with hantavirus, including the Andes strain, become infected after having breathed in or otherwise ingested particles from the urine or droppings from rodents that carry the virus. Just 2% to 5% of all Andes cases are estimated to stem from person-to-person transmission.<\/p>\n\n\n\n Large outbreaks are extremely rare. There was one documented \u201csuperspreader\u201d outbreak in Argentina in 2018. Thirty-four people were sickened after several people with hantavirus attended a variety of social events, including a birthday party. Eleven people died.<\/p>\n\n\n\n Can infected people spread hantavirus before they have symptoms?<\/strong><\/p>\n\n\n\n Jackson said there\u2019s no documented evidence that infected people can spread the virus if they don\u2019t have any symptoms, like coughing or sneezing.<\/p>\n\n\n\n That doesn\u2019t mean asymptomatic spread is impossible.<\/p>\n\n\n\n Dr. Rachael Lee, chief health care epidemiologist at the University of Alabama at Birmingham, said the problem with hantavirus is that patients are identified only when they\u2019re sick enough to be hospitalized. \u201cWhat we don\u2019t have good data on is how many people are potentially exposed and then just develop antibodies,\u201d Lee said. \u201cWe don\u2019t really know too much about transmission from one person to the next.\u201d<\/p>\n\n\n\n Hantavirus is unlike more infectious viruses, like the flu and Covid, because it tends to settle deeper in the lungs, rather than in the upper airways, said Dr. Nicole Iovine, the chief epidemiologist and an infectious disease expert at the University of Florida Health\u2019s Shands Hospital.<\/p>\n\n\n\n \u201cThat\u2019s one of the things that would limit the spread of the Andes virus,\u201d she said, \u201cbecause it\u2019s not in your throat or your nose.\u201d<\/p>\n\n\n\n It\u2019s also why hantavirus can be dangerous, with a fatality rate of up to 50%. The virus can inflame blood vessels, making it difficult for a person to get enough oxygen.<\/p>\n\n\n\n Jackson of the CDC acknowledged that there\u2019s a lot more to learn about hantavirus.<\/p>\n\n\n\n \u201cIt\u2019s important to remember that we\u2019re very early in this outbreak,\u201d he told NBC News. \u201cThe risk to the public is very, very low at this time, but that doesn\u2019t mean we\u2019re letting our guard down.\u201d<\/p>\n\n\n\n