Hantavirus: How scared should I be?

As news of an outbreak of hantavirus aboard a cruise ship continues to make headlines, many travellers may feel nervous ahead of their holidays.

The World Health Organisation (WHO) said yesterday there had been six confirmed hantavirus cases linked to MV Hondius. It added that a worldwide total of eight cases, including three deaths, had been reported – with one previous suspected case being reclassified after testing negative for hantavirus.

With this in mind, how dangerous is Hantavirus and should we be worried?

The WHO states that Hantaviruses are a group of viruses carried by rodents that can cause severe disease in humans.

People usually get infected through contact with infected rodents or their urine, droppings or saliva. Infection with hantaviruses can cause a range of illnesses, including severe disease and death – although the virus can vary in severity and geographical location play a role.

In the Americas, severe infections have led to hantavirus cardiopulmonary syndrome (HCPS) which affects the lungs and heart. In Europe and Asia, hantaviruses have been known to cause haemorrhagic fever with renal syndrome (HFRS) affecting the kidneys and blood vessels.

Hantavirus infections are relatively uncommon globally but are associated with a case fatality rate of 1–15% in Asia and Europe and up to 50% in the Americas.

The UK Health Security Agency (UKHSA) has stressed that the overall risk to the British public remains very low.

In a recent statement, Dr Meera Chand, deputy director for Epidemic and Emerging Infections at UKHSA, said: “Our thoughts are with all those affected by the hantavirus outbreak onboard the MV Hondius. It’s important to reassure people that the risk to the general public remains very low.

“We are standing up arrangements to support, isolate and monitor British nationals from the ship on their return to the UK and we are contact tracing anyone who may have been in contact with the ship or the hantavirus cases to limit the risk of onward transmission.”

The WHO states that in humans, symptoms can begin from one to eight weeks after exposure and typically include:

In HCPS (more commonly seen in the Americas) the disease may progress rapidly to cough, shortness of breath, accumulation of fluid in the lungs and shock.

In HFRS (more often seen in Europe and Asia) later stages may include low blood pressure, bleeding disorders and kidney failure.

The WHO states: “Early diagnosis of hantavirus infection can be challenging because early symptoms are common with other febrile or respiratory illnesses, such as influenza, COVID-19, viral pneumonia, leptospirosis, dengue or sepsis.

“A careful patient history is therefore essential, with particular attention to possible rodent exposure, occupational and environmental risks, travel history, and contact with known cases in areas where hantaviruses are present.”

The WHO states that there is no licenced specific antiviral treatment or vaccine for hantavirus infection. The WHO states: “Early access to intensive care, when clinically indicated, improves outcomes, particularly for patients with hantavirus cardiopulmonary syndrome.”

Preventing hantavirus infection depends primarily on reducing contacts between people and rodents. Effective measures include:

During outbreaks or when cases are suspected, early identification and isolation of cases, monitoring of close contacts, and application of standard infection prevention measures are important to limit further spread.

The UKHSA states: “None of the British nationals on board MV Hondius are currently reporting symptoms, but they are being closely monitored.

“Further checks will be carried out by medical staff of all passengers and crew on board before they disembark. British Passengers and ship crew not displaying any symptoms of hantavirus will be escorted by UK government staff to an airport and a chartered flight will fly them back to the UK.

“Infection prevention and control measures will be in place throughout the journey. Passengers, crew and medical teams boarding the flight will wear personal protective equipment such as face masks while journeying from Tenerife and during transit to facilities at Arrowe Park Hospital. Risk to the public in the UK will remain very low.”

For the latest UKHSA guidance on Hantavirus cases, see here.