Hantavirus strikes a cruise ship: A ‘perfect storm’ or a warning sign?

The journey was marketed to explorers willing to go “to the edges of the map”, from Antarctica to some of the world’s most remote islands.

This would be a tempting trip for adventure-minded tourists; More than spa trips and lounging by the pool, it’s a chance to see sights that few people have ever seen.

But this call of the wild was among the factors that ultimately made the MV Hondius the epicenter of the deadly hantavirus outbreak, the first on a modern cruise ship. There have been 11 cases linked to the outbreak so far. Three people died and two people are in intensive care.

The incident, which included several disturbing echoes of the beginning of the COVID-19 pandemic, has raised concerns and questions. The most important of these: Was this a strange event or a sign of things to come?

Infectious diseases specialist at UC San Francisco, Dr. “I think it’s both,” said Peter Chin-Hong.

Hantavirus was a previously unknown disease. It is typically spread through exposure to the urine and feces of infected rodents, is extremely difficult to diagnose, and has no established antiviral treatment. Relatively recently, it was conclusively identified in 1978 in a rodent near the Hantan River in South Korea, eventually explaining the mysterious cause of “Korean hemorrhagic fever” that infected thousands of United Nations soldiers during the Korean War.

Although rare, the disease has attracted attention in the United States for decades due to its incredibly high case fatality rate of up to 50% among strains circulating in the Americas.

Western Hemisphere strains of hantavirus are so deadly because they can attack the lungs and cause them to leak. The strains circulating in Asia and Europe, where hantavirus is more common and generally less deadly, attack the kidneys.

Severely ill patients can only be treated by connecting them to life support machines that directly add oxygen to their blood.

Despite its severity, the disease’s overall impact in America remained muted for two main reasons. First, most strains of hantavirus do not spread directly from person to person. Second, many people will not come into contact with rodents that carry the virus during their daily lives.

But crowd-pleasing trips like those on the MV Hondius blur the second line. The ice-reinforced ship, which was launched in 2019, offered passengers opportunities for “maximum contact with the nature and wildlife you’ve ever traveled to see,” according to its operator, Oceanwide Expeditions.

“The broader pattern is certainly not random,” Chin-Hong said, “and it means more exploration tourism visiting remote areas.” He added that climate change is also increasing the scope of some infectious diseases.

“The hantavirus on a cruise ship is unprecedented and reflects the perfect storm of an expedition in a remote area, potential environmental exposure during a short trip, and the ability of hantavirus (this particular Andes virus) to pass from person to person,” he said.

Andes virus, which circulates in Argentina and Chile and spreads mostly among long-tailed pygmy rice mice, is the only type of hantavirus known to be transmitted from person to person.

This type of interpersonal spread had previously occurred in a deadly outbreak in Argentina. From November 2018 to February 2019, the Andean virus infected 34 people there and killed 11, according to one report. to work In the New England Journal of Medicine.

MV Hondius had 149 passengers and staff on board when the ship opened to the public. announced It was stated that three of its passengers died. One of 18 US citizens on board traveller He initially tested positive for hantavirus abroad but also tested negative; Dr. D., incident manager for the Centers for Disease Control and Prevention’s hantavirus response. A follow-up test is currently being conducted in the United States, with results expected in a day or two, David Fitter said in a briefing with reporters on Wednesday.

This patient, who is not ill, is being monitored in the biocontainment unit at the University of Nebraska Medical Center.

Five California residents were potentially exposed to the virus; four on a cruise ship and the fifth while on a plane with an infected person in South Africa. All five were asymptomatic and appeared healthy, the California Department of Public Health said Wednesday.

Most infected people do not actually spread the Andean virus, Chin-Hong said. But some become “super spreaders,” infecting others at extraordinary rates.

That’s what happened in 2018-19. The medical journal study found that a single person contracted the Andean virus from a rodent, and that the outbreak was spread mainly by three infected people attending crowded social events; this included a birthday party and the funeral of one of the hantavirus victims.

In the case of MV Hondius, the first person thought to have contracted hantavirus was a Dutch man who was likely exposed to rodents. bird watching before boarding the ship for its transatlantic voyage, according to authorities. He spent the previous three months traveling to Argentina, Chile and Uruguay, the World Health Organization said. The man boarded the ship on April 1, developed symptoms on April 6, and died on board on April 11.

“At this time, this person is thought to be an ornithologist. visiting a garbage dump, Kaiser Permanente Southern California’s regional infectious diseases physician, Dr. Elizabeth Hudson is where many rare birds gather and are exposed to a rodent in the dump.

He said that based on this, the realities of sea travel emerged.

“Cruise ships, unfortunately, are the perfect environment for the spread of infectious diseases,” said Hudson. “There is a population of people living together in a relatively small, enclosed space, and most people spend the majority of their time indoors eating and socializing. This means that if there is an infection that can easily spread from person to person, the nature of the cruise ship allows this to happen more easily.”

It can also be difficult to isolate sick people on a cruise ship. The doctor of the MV Hondius and another crew member working as a guide also contracted hantavirus. Symptoms people reported included gastrointestinal illness, fever, general malaise, pneumonia, fatigue, aches and respiratory symptoms.

Health experts say the hantavirus outbreak is not expected to spread widely. Unlike COVID-19, Andean virus is much more difficult to transmit from person to person.

In past outbreaks of the Andean virus, steps such as isolating sick people and asking those who were not sick but exposed to the virus to stay away from others ended the outbreaks.

It can take up to six weeks from the time a person is exposed to the virus to the onset of illness. This “takes us back to June 21,” WHO Director-General Tedros Adhanom Ghebreyesus said at a press conference on Tuesday. “The WHO recommendation is that active monitoring should be carried out in a designated quarantine facility or at home for 42 days from last exposure.”

A Californian who was aboard the MV Hondius but abandoned ship before the hantavirus outbreak was discovered has returned to his home in Santa Clara County and remains healthy. California Department of Public Health director Dr. According to Erica Pan, this person is asked to limit traveling outside the home for a 42-day period to see if they are sick.

Another Californian from Sacramento County also returned home after sitting a few seats away from a hantavirus-infected passenger who had briefly traveled on a flight from South Africa to the Netherlands before being asked to get off the plane due to illness. The Californian remains in good health but is also asked to limit his activities with others.

“They should not share their bed with another person. … They should not attend social events and visit crowded places,” Pan said.

The other two Californians aboard the MV Hondius are healthy and are being observed at the University of Nebraska Medical Center’s National Quarantine Unit, the only federally funded quarantine unit in the United States. Thirteen others are being observed here, with two at Emory University in Atlanta.

The California Department of Public Health said it doesn’t know when Californians in Nebraska will return home.

A fifth state resident potentially exposed to hantavirus has been found, California health officials said Wednesday. This person left the cruise ship, returned briefly to California, then left for additional travel; Moreover, all of this happened before the epidemic was announced.

The individual, who remained healthy, is now on the remote Pitcairn Islands in the South Pacific Ocean, halfway between Peru and New Zealand.

Despite concerns about this latest outbreak, Andean virus is thought to be a poor candidate to be the next outbreak. Part of what makes COVID spread so easily is that people can infect others even if they are not personally experiencing symptoms.

With COVID, people can get sick by breathing in aerosolized viral particles that circulate around and are pushed throughout the room by an air conditioning vent.

With the Andean virus, by contrast, people likely need to be symptomatic to spread the disease.

Chin-Hong said the 2018-19 Andean virus outbreak in Argentina showed that close contact, including “sitting very close” to a sick person, was necessary for transmission.

Those most at risk of catching hantavirus from another person have “direct exposure to bodily fluids,” Pan said.

First case in the USA Andean virus The incident actually occurred in January 2018 with a woman staying in cabins and youth hostels in the Andes region of Argentina and Chile. Although he took two commercial flights in the US before he became ill and was hospitalized in Delaware, he did not infect anyone else after he returned. He eventually recovered at home.

Even more morbid, the Andean virus is too lethal to spread rapidly in a pandemic situation, health experts say.

So why are we seeing this epidemic now?

Hantavirus appears to be expanding its range in Argentina. A. report A report published in December stated that the spread of hantavirus in this country was moving southward.

“This redistribution reflects either ecological shifts affecting rodent reservoir populations, increased human intrusion into previously untouched habitats, or improved surveillance detecting cases in areas where historical awareness was lower,” said the report published by the Biothreats Emergence, Analysis and Communications Network, or BEACON, based at Boston University’s Center for Emerging Infectious Diseases.

From mid-June to early November, the country had 23 confirmed cases, with nine deaths. No human-to-human transmission was reported during this time.

another one report suggested that changing temperatures and precipitation also affected the spread of hantavirus in Argentina.

Another well-documented example of this phenomenon is the rise of dengue fever viruses spread by mosquitoes in Argentina. Rising temperatures make the climate more conducive to transmission. to work he suggested.

“Climate change has definitely had an impact on Argentina,” Chin-Hong said. “As the weather gets warmer, you potentially have more mice.”