As health officials frantically try to pinpoint the location of passengers from the hantavirus-stricken MV Hondius, fears are mounting that the deadly rat virus could soon reach Britain.
At the time of writing, three passengers travelling on the luxury cruise ship have died, two cases have been confirmed and a further five suspected cases have been identified.
However, many people are unaware that hantavirus is already in the UK.
Official guidance released by the UKHSA yesterday confirmed that hantaviruses are carried by our native rodents – notably wild mice and voles.
There are also cases of hantavirus diagnosed in pet rats, but this is the Seoul strain which is not transmissible person-to-person.
In the UK, hantavirus infections in humans tend to occur in places where people and rodents coexist, most commonly in rural, agricultural settings. People can come into contact with the virus when they come into contact where rodents might have nested, such as sheds, barns and in holiday homes.
Since 2012, there have only been 11 confirmed human cases of Seoul hantavirus infection in the UK, with nine linked to pet rats or rats bred for reptile feeding.
Read on for everything you need to know about hantavirus in the UK and the necessary precautions you can take to keep you and your loved ones safe.
Hantaviruses are spread to humans via inhalation of or contact with infected rodent faeces, urine and saliva
Location matters
Hantaviruses are present in rodents such as rats, mice and voles.
The type of hantavirus you could be exposed to is dependent on which species of rodents inhabit the area in which you live.
In the UK, we have the ‘Seoul virus’, which is carried by brown rats and sometimes seen in pet rats.
In humans, this strain attacks the kidneys – rather than the lungs – and if it goes untreated can cause internal bleeding and organ failure. However, it has a much higher survival rate than the ‘New World’ strains of the virus found in the Americas.
Poorly passengers on-board the MV Hondius have the Andes strain which is ‘endemic’ in Argentina and particularly common in long-tailed pygmy rice rats.
Whilst only the Andes virus can spread from human-to-human, rodents remain the primary culprits for transmission.
People who work, play or live in spaces where rats and mice are present most at risk of infection.
Could the Andes hantavirus strain infect British rodents?
Dr Michael Head, an expert in public health research and epidemiology from the University of Southampton, told The Pharmacist that theoretically, infected rats from Argentina could reach British shores and interact with our native rodents.
‘Rats are mobile. They can get on planes and boats and go to other continents. So, there is a theoretical risk,’ he explained.
‘[But] the risk of the Andes virus becoming imported and sustained in the UK is extremely low I would think.
‘It would need to establish as host in the rats here, and it might also need some kind of competitive advantage to outweigh the Seoul hantavirus in order to become the dominant strain.
‘So, the risk to somebody based in the UK, is as close to zero as it gets.’
Don’t take risks – wear a mask
When the virus makes the jump from rodents to humans, it’s often because people have inhaled the viral spores present in contaminated faeces or urine.
It’s not only wild rodents who might carry hantavirus.
If a pet rat or mouse has it, it is possible to become unwell when cleaning their cage, as dried urine and faecal matter can become airborne when disturbed.
‘The mice shed the virus in feces and urine,’ Dr Chris Smith, a consultant virologist from the University of Cambridge told the Telegraph.
‘When people clear it up, the viral particles become airborne and are breathed in, causing hantavirus pulmonary syndrome.’
As such, experts recommend spraying any droppings, nests or signs of infestations with water before thoroughly cleaning and disinfecting the area.
For the same reason, protective clothing including a mask and goggles should be worn.
This is because the virus can also enter humans via the nose, eyes and mouth.
US officials confirmed that Ms Arakawa died from hantavirus pulmonary syndrome
‘People are usually infected by hantavirus by breathing in dust from contaminated areas such as sheds and garages, or by direct contact with rodents or their waste’, Declan Lismore, Superintendent Pharmacist at Chemist4U said.
This was the tragic fate of Betsy Arakawa, 65, wife of Oscar-winning actor Gene Hackman. US officials confirmed that Ms Arakawa died from a respiratory illness linked to the virus.
An environmental assessment of the property took place a week after the couple were found dead in February last year, with an investigation team discovering nests and rodents in the outbuildings of their remote home.
They found rodent droppings, a live rodent, dead rodent and rodent nests in three garages just 45 metres from the main house. Rodents were also spotted in two abandoned vehicles and farming machinery in the grounds of the property.
Traps had been set and the house itself was ‘clean with no signs of rodent activity’.
Medical investigators concluded that Ms Arakawa contracted hantavirus pulmonary syndrome (HPS), a life-threatening lung condition which can lead to sudden death.
In its early stages, it can cause fatigue, muscles aches and fever – symptoms which are easily mistaken for the flu.
Around half of patients will also experience headache, dizziness, chills and gastrointestinal issues such as nausea, vomiting, diarrhoea and abdominal pain.
Four to ten days after this initial phase, more distinct and severe symptoms appear.
These include coughing and shortness of breath. Some patients may also experience tightness in the chest, as the lungs fill with fluid.
Around 40 per cent of patients who experience these symptoms will die from respiratory complications.
Dr Smith added that rodents who are infected are infected for life – but animals don’t tend to show symptoms.
It is more common in wild rodents, who can pick up the virus in breeding areas.
Repeat exposure makes infection more likely
Experts believe routine exposure to the virus makes infection more likely.
‘You need to be frequently infected before you get the disease,’ Prof Malcom Bennet, an infectious diseases specialist at the University of Nottingham, explains.
‘The more constant your exposure, the more likely you are to become infected. It’s like Covid – if you’re with lots of people who have it, you’ll get it.’
And whilst it’s unlikely you’ll catch hantavirus from drinking from a can an infected mouse has scurried over, the deadly virus can still crop up in some innocent-seeming places.
The Andes strain of hantavirus can be spread through kissing, sharing drinks or coughs and sneezes, experts have said.
A lab report published in esteemed medical journal The Lancet suggested that infectious particles are present in the saliva, urine, and mucus of patients struck down by the Andes virus – particularly when patients are symptom-free.
Professor Marcela Ferres, who headed up the research, said previous outbreaks have been linked to sharing straws.
Because the virus is present in the saliva and the space around the teeth it can also be spread through coughing, sneezing and kissing.
But experts maintain the risk of human transmission is still very low for people who have not been in contact with an infected person.
Until the latest outbreak, experts believed it was very unlikely that hantaviruses could spread between humans.
Now, while it appears the virus can spread between people in close proximity, experts say people should not be worried about it turning into the next pandemic.
In an update on 7 May, Dr Maria Van Kerkhove from the WHO stressed it was not the start of a pandemic.
She said: ‘This is not Covid, this is not influenza, it spreads very, very differently.’
A third Briton has now been diagnosed with suspected hantavirus linked to the cruise ship outbreak, health officials have said.
