People exposed to the deadly rat virus could potentially become super-spreaders, experts have warned, with symptoms taking up to two months to appear after initial exposure.
Currently, two British people are self-isolating at home in the UK after potential exposure to hantavirus on a cruise ship which was sailing from Argentina to Cape Verde.
At present, there are more than 20 Britons still on board the stricken MV Hondius who are expected to return home in the coming days – and face being quarantined for up to eight weeks.
Officials say the risk to the public remains low, but according to research conducted by the US Army Medical Research Institute of Infectious Diseases, the Andes strain – which has been identified as the variant on the ship – can spread rapidly between humans.
Experts don’t know if the outbreak was caused by a rodent contamination on the vessel itself or whether passengers were exposed to the virus before boarding. New reports suggest that some passengers visited a rubbish tip for a birdwatching trip before the ship departed, which might have exposed them to the virus.
If this hypothesis is correct, they wouldn’t have felt unwell until around a week later, by which time the ship would have sailed.
Hantavirus can often lead to two, more serious, illnesses that affect the lungs or kidneys, resulting in organ failure and even death. Both illnesses often start like the flu causing fever, fatigue and muscle aches.
Here, the Daily Mail outlines exactly how long it typically takes for the incurable virus to kill, from initial exposure to deadly complications…
Two British people are self-isolating at home in the UK after potential exposure to hantavirus on a cruise ship struck by the outbreak, the UK Health Security Agency (UKHSA) has said.
How does hantavirus spread?
When the virus makes the jump from rodents to humans, it’s often because contaminated droppings have been stirred up – creating airborne particles which are then breathed in.
But people can also get infected with the virus when saliva, urine, or feces from an infected rodent gets into their eyes, nose or mouth.
While initial symptoms of hantavirus are similar to that of the flu – which is transmitted through airborne droplets when people cough or sneeze – the Andes strain is spread through prolonged contact with someone who has been infected.
It can then be spread from human to human through close contact – such as sharing food, sleeping in the same bed and between sexual partners.
The incubation period
Hantaviruses can take up to eight weeks to cause symptoms of one of two severe illnesses.
In the early stages those infected with the virus may feel more tired than usual, before developing a fever and muscle aches – similar to the flu.
Then, depending on which strain of hantavirus a person is infected with, the disease progresses down one of two routes: hantavirus pulmonary syndrome (HPS) or hemorrhagic fever with renal syndrome (HFRS).
As a rule, the Asian strains develop into the less serious HFRS.
But diagnosing hantavirus in a person who has been infected less than 72 hours is notoriously difficult, with symptoms easily confused with influenza or Covid. Around 30 per cent of people are also thought to be asymptomatic.
Not everyone who is infected will develop serious complications.
Hantavirus pulmonary syndrome: The early symptoms
HPS is a serious and potentially deadly disease that affects the lungs.
Around half of HPS patients will also experience headache, dizziness, chills and gastrointestinal issues such as nausea, vomiting, diarrhoea and abdominal pain as well as the more typical flu-like symptoms.
Hantavirus pulmonary syndrome: Respiratory issues and lung damage
Four to ten days after the initial phase of illness, 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.
Once this happens, patients will need to be intubated to help them breathe.
Around 40 per cent of people who develop respiratory symptoms – requiring urgent medical attention – will die from the disease.
Hemorrhagic Fever with Renal Syndrome: The early symptoms
HRFS is a severe and sometimes deadly disease that affects the kidneys, causing internal bleeding and eventually organ failure.
Symptoms usually develop quicker than HPS, causing intense headaches and abdominal pain within two weeks after exposure.
Symptoms develop suddenly causing fever and chills, nausea and blurred vision. Some patients may also experience flushing of the face, inflammation or redness of the eyes, or a tell-tale butterfly rash on the cheeks.
In rarer cases, symptoms may take up to eight weeks to develop.
Aerial view shows health personnel assisting patients onto a boat from the cruise ship MV Hondius, while stationary off the port of Praia
Hemorrhagic Fever with Renal Syndrome: Kidney failure
As the virus takes hold, patients may experience a drop in blood pressure – causing feelings of lightheadedness, nausea, and confusion – paired with internal bleeding and eventually kidney failure.
When caught at this late stage, patients require urgent medical attention to filter toxins from the body and maintain fluid levels.
HFRS patients will typically be admitted to intensive care, away from other patients to minimise the risk of transmission, and put on dialysis.
This procedure removes waste products from the blood, helping support the normal role of the kidneys.
Treatment and recovery
There is no specific treatment for hantavirus infection – but early medical support can improve survival.
New treatments are now being trialled but currently no widely available vaccines to protect against the virus exist.
However, there are a limited number of vaccines being used in China and South Korea where certain strains are more common.
There are an estimated 150,000 cases of HFRS worldwide each year, primarily in Europe and Asia. More than half of the reported cases typically occur in China.
