Rhys Parry/ The University of Queensland/ The Conversation
For many individuals, information of a virus outbreak on a cruise ship instantly brings again reminiscences of COVID spreading when the Ruby Princess docked in Sydney in March 2020. Of the passengers and crew who disembarked, 575 had COVID. The virus then unfold to the neighborhood.
So it’s comprehensible that persons are involved that passengers from the MV Hondius have to be quarantined after potential publicity to Andes virus, a rodent-borne hantavirus.
Nevertheless, the comparability with COVID solely goes up to now. Andes virus is critical, and authorities are proper to reply cautiously. However consultants, together with these from the World Health Organization, observe it doesn’t have the traits wanted to grow to be “the following COVID”.
As of Might 11, European well being authorities have reported 9 circumstances linked to the cruise ship, together with seven confirmed and two possible circumstances. Three deaths have been reported.
5 Australians and one New Zealander are being repatriated to Australia for quarantine and monitoring. The passengers will initially quarantine on the Centre for Nationwide Resilience close to RAAF Base Pearce in Western Australia.
Right here’s what you have to find out about Andes virus, the danger of transmission, and the way it’s completely different from the virus that brought on COVID.
How do hantaviruses unfold?
Hantaviruses are a gaggle of viruses often carried by mice, rats, and different rodents. Persons are mostly contaminated after inhaling tiny particles of contaminated rodent urine, droppings or saliva.
Most hantaviruses usually are not recognized to unfold between folks. Andes virus is the exception. After the preliminary spillover from contaminated rodents, it’s the only hantavirus with well-documented person-to-person transmission.
However that doesn’t imply it spreads simply between folks. Additional human-to-human unfold is unusual, however it might probably happen in close-contact settings equivalent to households, amongst caregivers, throughout intimate contact, or after extended publicity in crowded or poorly ventilated indoor areas.
That may be very completely different from SARS-CoV-2, the virus that causes COVID. SARS-CoV-2 spreads very effectively via the air. Individuals might infect others earlier than they even realised they have been sick.
Early estimates suggested every individual contaminated with SARS-CoV-2 handed the virus to roughly two or extra others, on common, in populations who had by no means encountered it earlier than.
Andes virus can cause onward human-to-human transmission, however requires an ideal storm of situations: symptomatic folks in crowded, poorly ventilated areas with shut contact over time. This was the case on the MV Hondius.
This distinction in transmission potential is why SARS-CoV-2 brought on a pandemic and Andes virus has solely produced contained outbreaks.
What are the signs of Andes virus?
Early signs of Andes virus an infection can seem like many different sicknesses, together with fever, headache, muscle aches, nausea and fatigue.
In some folks, an infection can progress to hantavirus pulmonary syndrome, a life-threatening situation by which respiratory turns into tough.
How lengthy after contact are you able to get signs?
The WHO recommends that folks uncovered to Andes virus monitor for signs for 42 days after their final potential publicity.
This displays the outer restrict of the time between an infection and symptom onset. It doesn’t imply persons are infectious for 42 days.
Australian authorities have introduced that the returning passengers will initially spend three weeks in quarantine, with additional monitoring preparations to comply with.
Melbourne’s Doherty Institute will undertake the testing utilizing polymerase chain response (PCR), which detects the virus’s genetic materials, and blood-based antibody testing, often known as serology.
A damaging check early after publicity is helpful, however not at all times definitive. If the virus continues to be incubating, there might not but be sufficient viral genetic materials or antibody response to detect.
How does the virus progress?
The lengthy incubation interval displays how Andes virus progresses, in comparison with SARS-CoV-2.
COVID signs usually seem inside days as a result of the virus replicates quickly within the respiratory system.
Andes virus progresses in another way. Extreme illness is linked to blood-vessel dysfunction and inflammatory responses. The respiratory issues related to the complication hantavirus pulmonary syndrome aren’t attributable to the virus immediately destroying lung tissue, however by the immune system’s delayed response. This causes fluid to leak into the lungs and makes respiratory tough.
How lethal is it?
Fatality rates range considerably between hantavirus species.
European and Asian hantaviruses usually trigger dying in lower than 1–15% of circumstances, whereas hantavirus pulmonary syndrome from American strains, together with Andes virus, can attain as much as 50%.
For context, in 2025, eight international locations throughout the Americas reported 229 hantavirus circumstances and 59 deaths. These are extreme infections, however they continue to be uncommon occasions.
A virus doesn’t grow to be a pandemic just because it’s lethal.
Can Andes virus be handled?
There is no such thing as a particular antiviral drug for Andes virus. Health care for infected people focuses on shut monitoring, supporting their respiratory and managing problems to the guts and kidneys.
There is no such thing as a licensed vaccine to forestall Andes virus.
Nevertheless, there may be additionally excellent news in how shortly the scientific response has come collectively after this outbreak began. Swiss laboratories collaborated shortly to sequence the complete genetic code of the virus from one affected person and made it publicly out there inside days.
This gave researchers around the globe a reference to match different circumstances towards. This may assist sooner affirmation of suspected circumstances, whereas serving to public well being groups determine which circumstances are linked to the outbreak and who wants monitoring or isolation.
Backside line
The intuition to see one other COVID in each viral outbreak is comprehensible however, on this case, deceptive.
The Andes virus is harmful to these contaminated, but it surely isn’t an excellent candidate for pandemic unfold. It incubates slowly, usually spreads via shut contact, and transmission seems most effective when persons are symptomatic.
It’s essential to get the Andes virus below management, but it surely’s not a pandemic menace like COVID.
Rhys Parry, Analysis Fellow, Virology, The University of Queensland
This text is republished from The Conversation below a Inventive Commons license. Learn the original article.
