A rare virus contracted through exposure to rodents or their faeces has been blamed for the deaths of several tourists on board an international cruise ship.
The WHO has confirmed at least one case of hantavirus on board MV Hondius, sailing the Atlantic Ocean, with five additional suspected cases.
Out of the six people affected, three have died, while one remains in intensive care.
Hantavirus also made headlines after it killed Betsy Arakawa, the wife of late actor Gene Hackman, in February last year.
What is hantavirus?
Hantaviruses are a serious yet rare family of viruses that can cause illness and death.
They cause two syndromes: hantavirus pulmonary syndrome (HPS), which is found in the Western Hemisphere, and haemorrhagic fever with renal syndrome (HFRS), found mostly in Europe and Asia.
HPS affects the lungs, with symptoms including coughing, shortness of breath and chest tightness. The US Centres for Disease Control and Prevention (CDC) estimates 38 per cent of people who develop these respiratory symptoms may die from the disease.
In contrast, HFRS targets the kidneys, potentially causing low blood pressure, internal bleeding and acute kidney failure. While its fatality rate varies by strain, 5 to 15 per cent of cases can prove fatal.
How is hantavirus spread?
According to the CDC, hantavirus is most commonly spread from rodents to people through environmental exposure, rather than from person to person.
The virus circulates when the fresh urine, droppings or nesting materials of an infected rodent are stirred up into the air.
A person can then become infected by breathing in that contaminated air.
Hantavirus can also be transmitted when the saliva, urine or faeces of an infected animal penetrates a person’s cut or wound, or enters their eyes, nose or mouth.
Why are cruise ship outbreaks so common?
Dr Renata Muylaert, from the University of Sydney’s Disease Ecology Lab, says the hantavirus cruise outbreak is “certainly concerning” but “rare”.
She says hantavirus prevention relies on reducing exposure to its natural hosts: rats and mice.
“In enclosed environments such as cruise ship interiors, this means strict rodent control, maintaining very high hygiene standards, and ensuring that food and grain are securely stored to prevent any rodent infestation.”
The hantavirus news is the latest in a long line of cruise ship outbreaks globally, with gastro, COVID and influenza all causing serious illness and death in passengers.
On cruise ships, crowds of people congregate together in confined spaces for extended periods of time, creating an environment ripe for “superspreader events”.
Additionally, a 2021 study found that a person’s risk of contracting a disease such as gastroenteritis was higher on a longer voyage, as they were exposed for more time.
MV Hondius, the vessel at the centre of the hantavirus outbreak, left Argentina on March 20 and was expected to complete its journey on Monday in Cape Verde, a 45-day voyage.
The WHO is undertaking a “full public health risk assessment” and providing support to the remaining passengers on board.
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