Why the hantavirus outbreak is different from Covid-19
Health experts, including the Director-General of the World Health Organization, have stressed that the situation is fundamentally different from the Covid-19 pandemic.
An outbreak of hantavirus infections aboard the cruise ship MV Hondius has raised concern among health authorities, but public health experts say the virus differs fundamentally from Covid-19 in ways that make sustained global spread highly unlikely.
What happened on the MV Hondius?
As of 12 May 2026, 11 infections have been confirmed among passengers and crew on the MV Hondius, with three deaths reported, including a Dutch couple and a German tourist, says Al Jazeera.
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Investigators believe the infected individuals were likely exposed before boarding the vessel, most probably in Argentina, where hantaviruses are endemic.
Following the detection of the cases, 94 people were repatriated to 20 countries and placed under quarantine as part of international containment measures.
What is hantavirus?
Hantavirus refers to a family of viruses carried primarily by infected rodents and transmitted to humans through exposure to contaminated urine, saliva, or droppings. Infection typically occurs when dried particles become airborne and are inhaled.
The disease presents mainly in two forms:
- Hantavirus Pulmonary Syndrome (HPS), which primarily affects the lungs and has an estimated fatality rate of around 40%
- Haemorrhagic Fever with Renal Syndrome (HFRS), which affects the kidneys and has a fatality rate ranging from 1% to 15%
The strain identified in the cruise ship outbreak is the Andes strain hantavirus, which is notable because it is the only known hantavirus variant capable of limited human-to-human transmission, typically requiring prolonged close contact.
How it differs from Covid-19
Health experts, including the Director-General of the World Health Organization, have stressed that the situation is fundamentally different from the Covid-19 pandemic.
They emphasise that this is "not another Covid" due to key biological differences:
- Transmission route: Covid-19 spreads efficiently through respiratory droplets and aerosols in the upper respiratory tract. Hantaviruses primarily infect deep lung tissue and are usually transmitted via rodent exposure, with minimal viral presence in expelled droplets.
- Replication and incubation: Covid-19 is a positive-sense RNA virus that begins replicating immediately after infection and typically incubates within 2-14 days. Hantavirus is a negative-sense RNA virus requiring an additional replication step and has an incubation period of one to eight weeks.
- Human-to-human spread: Sustained transmission of hantavirus between people is extremely rare and typically requires close, prolonged contact, unlike Covid-19, which spreads efficiently in casual settings.
Containment measures and risk assessment
Health authorities have placed exposed individuals under medical observation and imposed quarantine periods of up to six weeks for asymptomatic contacts.
Because the Andes strain is linked to rodent reservoirs that are not established in Europe, officials do not expect sustained transmission beyond isolated clusters linked to the exposure event.
Experts assess that the biological constraints of hantavirus transmission make a large-scale pandemic highly unlikely, even in the context of international travel.
