Covid-19 had a lower mortality rate. Hantaviruses have a mortality rate of 1% to 15%, while the Andes variant can reach up to 50%. But severe symptoms help identify and isolate cases more quickly… says Italian infectious disease doctor Fabrizio Pregliasco
Following the alarm raised by the Hantavirus outbreak on the MV Hondius cruise ship and concerns about the spread of the Andes version, Italian infectious disease doctor Fabrizio Pregliasco has given an interview to the Italian newspaper Corriere della Sera, where he explains what Hantaviruses are, how they are transmitted and what the main differences are with Covid-19. The Director of the School of Specialization in Hygiene and Preventive Medicine at the State University of Milan also talks about the real risk of spread, the use of masks, travel and the preventive measures that should be followed.
What are hantaviruses?
Hantaviruses are zoonotic viruses, i.e., directly or indirectly transmissible between animals and humans, which naturally infect rodents and occasionally are transmitted to humans. To date, the possibility of transmission from one person to another has only been documented for the Andes virus, spread mainly in Argentina and Chile, which is also the one that caused the outbreak on the MV Hondius ship.
Is the explosion on the ship a positive or negative thing?
The ship is home to people from 23 nationalities, which has involved various health authorities. Furthermore, it allows for easier control of people. However, its ‘perimeter’ is not so impenetrable: as we have seen, some passengers disembarked when the evolutionary stage of the virus was not yet clear.
What does the activation of risk procedures by the Ministry of Health mean?
The aim is to prevent the spread of the Andean variant of Hantavirus by tracing people who disembarked the ship before the virus was detected, as well as by reconstructing the chain of contacts, including indirect ones, such as four tourists who passed through Rome and were on the same flight as the woman who later died. It is important to have rapid control, as in the case of a fire.
What does the 2025-2029 pandemic plan foresee?
It aims to be more comprehensive, as it includes more pathogens. Previous documents were mainly about seasonal flu. From this perspective, Covid-19 has been a big lesson.
Could the Andean virus outbreak spread further?
Yes, because the incubation period can last 6 to 8 weeks. Some passengers may still be at risk. Even asymptomatic people can transmit the virus, although they usually have a low viral load. However, the risk of a global pandemic is low: we are not facing another Covid-19.
What are the differences with Covid-19?
The Andes virus is transmitted only through close and prolonged contact or through inhalation of urine, feces or saliva of infected rodents. While Covid-19 is much more contagious and spreads through the respiratory tract, mainly through droplets and air.
Why do hantaviruses have a higher mortality rate?
It’s true: Covid-19 had a lower mortality rate. Hantaviruses have a mortality rate of 1% to 15%, while the Andes variant can reach up to 50%. But severe symptoms help identify and isolate cases more quickly.
How serious are the infections?
They range from asymptomatic cases to mild symptoms such as headache, fever, nausea, vomiting, diarrhea, and muscle aches. There are then three main forms: hemorrhagic fever with renal syndrome (Europe and Asia), epidemic nephropathy (Europe), and pulmonary syndrome (America).
Is there a treatment or vaccine?
There is no specific antiviral treatment or vaccine. Treatment is supportive and focuses on clinical monitoring. In the event of a hypothetical pandemic, an mRNA vaccine could be developed in 10-12 months.
How can the spread be prevented?
By reducing contact with rodents: good hygiene, hand washing, covering the respiratory tract, storing food in closed containers, sealing openings in buildings, and avoiding dry cleaning of contaminated areas to avoid spreading viral particles into the air.
Should masks be used?
No, it is not necessary, unless you are in an environment where there may be rodents.
What should travelers to South America know?
There are no current restrictions. It is only recommended to monitor the official information of the Italian Foreign Ministry ‘Viaggiare Sicuri’ and avoid high-risk areas such as waste dumps.
What should those who have booked cruises know?
Hygiene measures will be further strengthened. In general, travel by plane, ferry or train is considered safe at this time.