Is hantavirus giving you déjà vu? You’re not alone. Ever since the COVID-19 pandemic, news of a deadly infectious disease outbreak can trigger alarm.
Now that the passengers on the hantavirus-stricken cruise ship have returned to their home countries and cases are growing, you may be fearing the worst. Perhaps you’re having flashbacks to early 2020 — being stuck in quarantine, sanitizing groceries, scrolling TikTok.
“COVID PTSD is real,” Dr. Wendy Armstrong, president-elect of of Infectious Disease Society of America, tells TODAY.com.
What’s more, hantavirus can cause severe respiratory illness in humans, with a mortality rate around 40%, and it can take up to eight weeks after exposure to show symptoms, per the U.S. Centers for Disease Control and Prevention.
Fortunately, the current hantavirus outbreak is not COVID 2.0, experts previously told TODAY.com. It’s a serious situation, but the risk to the public is very low, the CDC emphasizes.
Authorities are racing to contain the virus, which primarily spreads to humans from infected rodents.
What’s unusual about the cruise ship outbreak is it involves a rare strain called the Andes virus, the only type of hantavirus known to transmit from human to human (through close contact). Scientists are still investigating how the rare virus spread on the luxury cruise ship.
So far, 11 cases have been identified, including one American in isolation at the National Quarantine Unit in Omaha, Nebraska.
The World Health Organization identified the first passengers infected with hantavirus as a Dutch couple who had traveled in Argentina, where the Andes virus is endemic. Officials suspect the couple was exposed before boarding the MV Hondius. They later died, along with a third passenger.
It’s believed that some person-to-person transmission occurred on the ship, WHO epidemiologist Maria Van Kerkhove said. An estimated 150 people may have been exposed to hantavirus on the ship.
As a result, “it’s possible we might see more cases in the coming weeks” due to the virus’s long incubation period, WHO Director-General Dr. Tedros Adhanom Ghebreyesus told reporters at a briefing on Tuesday.
However, all signs still point to this outbreak being contained, experts say. Here’s what to know.
Will Hantavirus Cause a Lockdown?
“Public health officials are monitoring this situation closely, but there is no indication of a risk that would warrant lockdown measures,” Dr. Mara Jana Broadhurst, associate professor at the University of Nebraska Medical Center and member of the College of American Pathologists, tells TODAY.com.
In a press briefing on Wednesday, the CDC also stressed there are no state or federal quarantine orders in place or plans to introduce them.
Ghebreyesus also said Tuesday that, “at the moment, there is no sign that we are seeing the start of a larger outbreak.”
It’s understandable that people are drawing comparisons to COVID-19, Broadhurst adds, but these are two distinct situations.
How Is Hantavirus Different From COVID?
The 2020 pandemic was caused by a novel virus, SARS-CoV-2. COVID transmits very easily between people through respiratory droplets and aerosols, which “allowed it to spread rapidly worldwide,” says Broadhurst.
The result? Mass infection, surges in hospitalizations and deaths, and overwhelmed hospitals. The lockdown was an emergency measure to stop transmission and “flatten the curve” before treatments or vaccines were widely available.
Hantavirus differs from COVID in a few key ways, which makes a pandemic — and subsequent lockdown — highly unlikely.
First, hantavirus is not new.
We’ve known about hantaviruses for decades, and the CDC started conducting surveillance in 1993 after the deadly “Four Corners” outbreak in the Southwestern U.S.
The Andes virus was first identified in Argentina in 1995. The strain sequenced from passengers looks “quite identical,” without mutations that may increase transmissibility, Armstrong adds.
Second, hantavirus behaves very differently from COVID. It’s a zoonotic virus and primarily spreads to humans through contact with infected rodents or their droppings.
The Andes virus is the only strain capable of spreading from person to person — however, this is still incredibly rare, experts emphasize.
Unlike COVID, the Andes virus does not appear to spread easily between people, with current evidence showing that transmission requires close, prolonged contact with a sick person or their bodily fluids, rather than casual interactions.
“That fundamental difference is why we do not expect this situation to escalate into something like a pandemic or trigger lockdowns,” says Broadhurst.
Exposures have occurred during activities like sleeping in the same bed, intimate contact, or caring for a sick person.
“It’s not the same as COVID, where you can walk into a room and have relatively minimal exposure and get infected,” Armstrong adds.
Due to the nature of the virus, it’s unlikely to cause widespread global transmission.
The largest documented outbreak of the Andes virus, which occurred in 2018 in Argentina, resulted in 34 cases and 11 deaths.
According to a study of the outbreak, the reproduction number — the number of new infections caused by one case — for Andes hantavirus was 2.12 before control measures were enforced, and 0.96 after cases isolated and contacts quarantined, the authors wrote in the New England Journal of Medicine.
Comparatively, the reproduction number for measles, which is actively spreading in the United States and has not led to lockdown orders, is 12–18.
“We are seeing a relatively small number of cases, even though some 150 people were on the ship, which is an ideal enclosed environment, for a prolonged period of time,” Armstrong notes.
The last reason hantavirus is unlike to lead to a lockdown is that health authorities took swift action to contain the outbreak once hantavirus was detected.
“All suspected and confirmed cases have been isolated and managed under strict medical supervision, minimizing any risk of further transmission,” Ghebreyesus said.
The cruise ship cluster could result in additional cases among passengers or their contacts, the experts say, but the outbreak is expected to be contained.
Where Is Hantavirus in the U.S.?
There are currently no confirmed cases of the Andes strain of hantavirus in the U.S., according to the CDC. However, officials have identified at least 36 people across the U.S. who were possibly exposed to it.
These include 18 passengers evacuated from the ship earlier this week: 16 are in quarantine in Nebraska and two are being monitored at Emory University in Atlanta, Georgia.
The American who tested positive has since tested negative and is in good condition, and one adult who had symptoms tested negative.
The WHO recommends individuals quarantine for 42 days from their last exposure. Officials are still trying to determine when the 18 Americans in quarantine can safely go home, NBC News reported.
The other roughly 20 Americans linked to the outbreak include former passengers who left the cruise early in late April (before the outbreak was identified) and individuals who were exposed to infected passengers during air travel. They are staying at home and being monitored, and none are showing symptoms.
Outside of the current outbreak, there are a handful of hantavirus infections in the U.S. every year.
Since 1993, there have been an estimated 890 cases reported total, per the CDC. The last outbreak occurred in 2012, when 10 visitors to Yosemite contracted hantavirus from infected mice.
Hantavirus made headlines last year when it was revealed as the cause of death of Betsy Arakawa, the wife of Gene Hackman.
The primary species of hantavirus in the U.S., known as the Sin Nombre virus, only spreads to humans from infected mice.
The Andes strain is found in South America, mainly in Argentina and Chile. Its natural host, the long-tailed pygmy rice rat, has not been found in the U.S., per the CDC.
Is Hantavirus Spreading?
As of May 14, the WHO has identified nine confirmed hantavirus cases and two suspected cases.
“We are seeing the case count go up, and I am sure that that is also adding to people’s anxiety,” says Armstrong.
However, hantavirus does not appear to be spreading beyond the original cohort of cruise ship passengers, officials say.
“On top of that, there have been no positive tests so far from (people) on the plane that one of the victims took when she was very sick and probably quite contagious,” Armstrong adds.
Of course, the situation could change.
“We may see more cases from the cruise ship passengers over time, but that doesn’t necessarily mean that something has gotten out of our control. It’s not a reason for alarm,” says Armstrong.
Anyone linked to the outbreak who develops symptoms will be isolated and treated immediately, Ghebreyesus said.
In the meantime, there’s no need for the public to panic, experts say.
Hantavirus Symptoms
Hantaviruses can cause two sets of symptoms, depending on the species of virus and where you’re infected.
In the Americas, hantaviruses can cause a severe and often fatal respiratory illness called hantavirus pulmonary syndrome (HPS).
Early on, HPS causes flu-like symptoms such as a fever, muscle aches, and fatigue, as well as diarrhea or vomiting, per the CDC.
After about a week, these can progress to breathing difficulties, fluid in the lungs, and respiratory failure. The fatality rate of HPS is 30-40%, experts note.
In Europe, Asia, and Africa, hantaviruses cause an illness called hemorrhagic fever with renal syndrome (HFRS). This also begins with flu-like symptoms, but can progress to blurry vision, internal bleeding and kidney failure. The fatality rate is lower, about 1-15%.
There is no specific treatment or cure for hantavirus.
You can reduce your risk of getting hantavirus by minimizing exposure to wild rodents and their droppings, the experts note.
At this stage, people in the U.S. do not need to be worried about being exposed to the Andes strain of hantavirus, experts previously told TODAY.com.
This article was originally published on TODAY.com
