Hantavirus “is not a new covid,” the World Health Organization stresses.
Although the crisis on the cruise ship MV Hondius, which will sail for the Netherlands today, has raised lively concerns, rekindling memories of the 2020 coronavirus pandemic, there are many differences between the two diseases, experts say. What are they?
Accidental
Covid-19 is an infectious, viral disease caused by the Sars-CoV-2 coronavirus, which emerged in China in late 2019. Was it transmitted from animals to humans in the Wuhan market, or did it come from a science lab in the city, from a mutant virus that was being experimented on? Both hypotheses have been put forward, but most scientists support the former.
This virus was isolated in early January 2020, and on 11 March 2020 the World Health Organization announced that the Covid-19 outbreak was now designated a “pandemic”. The death toll was in the millions (up to 20, according to the WHO) and the pandemic caused repeated shocks to the global economy.
Hantavirus, whose name comes from the Korean River Hadan, after the first outbreak was recorded there during the Korean War (1950-53), is a virus that is present on all continents, but particularly in Asia and Europe. Scientists are monitoring the zones where it is endemic.
Transmission and symptoms
Hantaviruses are transmitted to humans mainly through the urine, faeces and saliva of infected rodents. The main mode of transmission is inhalation of contaminated fecal dust.
The only one of the 30 strains of hantavirus known to be transmitted from human to human is the Andean strain, which was found in the sick passengers on the cruise ship. The incubation period ranges from one to six weeks. In contrast, in Covid-19, the first symptoms appear on average 7-10 days after infection.
Although human-to-human transmission of Andean chantavirus is via the respiratory tract, special conditions are required to contract it: close contact, confusion or vulnerability of the person exposed to it, explained Virgini Souvage of the Institut Pasteur, the head of the National Reference Centre for Chantaviruses in France.
According to the Pasteur Institute, “the period of transmission with the highest risk” for chantavirus is the one before symptoms appear. The people most at risk are those who have very close contact with the patient (e.g. through sexual intercourse) or are with them in enclosed spaces (bedroom, car).
Hantaviruses in the Americas can cause respiratory and cardiac distress, as well as hemorrhagic fevers, but Covid-19 is exclusively a respiratory disease that can cause fever, cough, shortness of breath, headache, body aches, fatigue, diarrhea, loss of sense of smell and taste.
Higher mortality, lower risk of pandemic
A virus that would kill “50% of the population would decimate the world very quickly, but that would deprive it of the ability to spread,” said Raul Gonsales Itig, a biologist at the National Scientific Research Agency of Argentina, a country that recorded 11 deaths from chantavirus between 2018-19. Andean chantavirus mortality is approaching 40% and “death occurs quickly,” he explained, stressing that “isolating patients without delay breaks the chain of transmission.”
“Everything happens faster: a single person transmits it, ten become infected and, without proper treatment, die That is why the risk of a pandemic of hantavirus is much lower,” he summarized. In contrast, Covid-19 infected thousands of people before the deaths began to pile up.
Treatments, vaccines
There is no specific treatment or vaccine for chantavirus, infectious disease specialist Vincent Ronin told Agence France-Presse.
But “the sooner the disease is diagnosed, the better the prognosis” for sufferers, Chauvasse explained. If someone develops severe pulmonary symptoms, it is necessary to receive respiratory assistance, for example to be intubated. If they have kidney failure, they may need dialysis.
In Covid-19, treatment consists of treating the symptoms (e.g. with paracetamol) but in some susceptible people it may be necessary to give antivirals.
As for vaccines, trials have been done for some strains of chantavirus but their effectiveness for all types has not yet been proven, Ronen said.
Vaccines were developed for Covid-19 in record time, in the middle of the pandemic. Their effectiveness and safety have since been documented, based on the billions of vaccinations given around the world.
