In this month of April, the world once again quietly uttered a word that evokes fear: outbreak. This time, the protagonist was not a coronavirus, but the hantavirus, specifically the Andes strain, detected aboard the expedition cruise ship MV Hondius while sailing through the South Atlantic. The ship had left Ushuaia (Argentina) on April 1 with passengers and crew of various nationalities, and during the voyage cases of infection began to be detected that left at least three dead and triggered an international health response.
The news came loaded with pandemic echoes: evacuations, quarantines, contact tracing in multiple countries. Social networks did the rest. According to verifiers at VerificaRTVE and Newtral, false content circulated that included claims about border closures, non-existent vaccines, and the reuse of images from previous health crises—especially the COVID-19 pandemic—to falsely illustrate the situation.
In this climate of uncertainty, the question gains strength: are we facing a new COVID?
Key differences between hantavirus and COVID-19
Experts emphasize that, despite the concern generated by a hantavirus outbreak, the risk of an epidemic like COVID-19 is significantly low.
“This is not another COVID,” declared the in vogue director of the World Health Organization (WHO), Dr. Tedros Adhanom Ghebreyesus, to CBS Records data.
Hantavirus and SARS-CoV-2 are profoundly different pathogens, and confusing them is not only a scientific error, but a risk to public health. Hantavirus is less contagious than COVID-19, requiring prolonged physical contact for transmission. Unlike COVID-19, which spreads easily through the air, hantavirus is commonly distributed by rodents in dry climates.
Comparing the risk and spread of both, Dr. Céline Gounder, medical correspondent for CBS Records data and infectious disease specialist, is resounding: COVID-19 resembles a “forest fire,” while the hantavirus is classified as a “wet trunk,” which implies a lower capacity to spread.
Transmission of hantaviruses to humans occurs through contact with contaminated urine, excrement or saliva from infected rodents; Infection can also occur from rodent bites, although it is less common. In other words, to become infected with hantavirus, in most cases you have to be in direct contact with rodents or their waste. Very little—only some cases of the Andes strain—is transmitted person to person, after a prolonged period of contact and by exchange of body fluids.
The contrast with COVID-19 is dramatic. An epidemiologist even pointed out that, if it had been COVID, there would have been more than 100 infected people on the ship; However, despite the fact that the outbreak occurred in a closed space, those affected were initially only eight. COVID-19 is significantly more contagious because people spread the coronavirus before they have symptoms and can be contagious without knowing they are sick.
Hantavirus: an ancient virus, not an unknown enemy
COVID-19 was caused by a new virus, unknown to science, and researchers learned about its spread as the pandemic progressed. While hantaviruses, on the other hand, have been known for decades, which means there is much more research available to treat patients and prevent the spread of infections.
Recent hantaviruses circulate in the Americas and can cause hantavirus pulmonary syndrome (HPSS). In December 2025, the Pan American Health Organization (PAHO) issued an epidemiological alert after observing an increase in cases in endemic countries, particularly in the Southern Cone. Therefore, it is not an emerging pathogen or an unexpected mutation: it is a virus that has been behaving predictably in well-defined populations and regions for decades.
Incubation period and health response
The incubation period for the Andes variant hantavirus, which caused the recent outbreak, can extend from two to six weeks.
This gives health officials more time to plan their response to the outbreak compared to the short incubation period of COVID-19.
More lethal mortality, but with less scope
Here emerges what is perhaps the most striking paradox of this comparison: the hantavirus kills more frequently than COVID-19, but infects many fewer people. In the Americas, hantavirus can cause hantavirus cardiopulmonary syndrome (HCPS), a severe respiratory disease, with a case fatality rate of up to 50%. The mortality rate for COVID-19 in the United States was approximately 1%, while the Andean hantavirus has a mortality rate of up to 39.8%.
However, this lethality does not translate into a massive impact because the virus simply does not reach as many people. In 2025, eight countries reported 229 confirmed cases and 59 deaths. So far in 2026, until epidemiological week 15, 94 cases and 13 deaths have been reported throughout the region. For a scale reference: COVID-19 infected hundreds of millions of people around the world in a matter of months.
Similar symptoms, different origin
Both viruses share certain clinical manifestations that can confuse patients and doctors themselves in early stages. Symptoms usually begin one to eight weeks after exposure and include fever, headache, muscle aches, and gastrointestinal symptoms such as abdominal pain, nausea, or vomiting. In the case of hantavirus pulmonary syndrome, the disease can progress rapidly to cough, shortness of breath, fluid buildup in the lungs, and shock.
Early diagnosis of hantavirus infection can be complicated, since the initial symptoms are common to other febrile or respiratory diseases, such as influenza, COVID-19, viral pneumonia, leptospirosis, dengue or sepsis.
Vaccines and treatments
Currently, there is no approved universal vaccine against hantavirus nor a specific antiviral capable of completely curing it. Treatment is mainly based on intensive support and early care to avoid respiratory or cardiac complications.
With COVID-19, the situation evolved differently: much more advanced vaccines, antiviral treatments and hospital protocols were developed after the pandemic, which considerably reduced the risk of death in vulnerable patients.
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