Lassa fever: A patient in the UK has died of the virus but what is it and how dangerous is it?

A person in the UK has died after contracting Lassa fever, health officials have said.

Two cases were announced earlier this week with a third individual under investigation. The UK Health Security Agency (UKHSA) confirmed on Friday that the third case was Lassa fever and the patient had died.

The cases are within the same family and are linked to recent travel to west Africa. They are the first cases identified in the UK since 2009.

The patient was being treated by Bedfordshire Hospitals NHS Foundation Trust.

A spokesperson said: "We confirm the sad death of a patient at our trust, who had confirmed Lassa fever. We send our deepest condolences to their family at this difficult time.

"We will continue to support the patient’s family and our staff and are working closely with colleagues from the UK Health Security Agency to undertake a robust contact tracing exercise".

One of the cases has recovered, while the other will receive specialist care at the Royal Free London NHS Foundation Trust.

Lassa fever is a viral illness caused by Lassa virus which occurs mostly in countries in west Africa, including Nigeria, Sierra Leone, Mali, Liberia and Guinea. It’s transmitted to humans mainly through food or household items contaminated by infected rats’ urine and faeces.

The most common symptoms include gradual onset of fever, malaise and general weakness, according to the World Health Organisation (WHO), and this can progress to headaches, vomiting and diarrhoea.

Various degrees of deafness also occur in 25 per cent of recovered patients, although for half of this group, it will return after one to three months.

In the most severe cases, facial swelling, fluid in the lungs, bleeding from the mouth, nose, vagina or gastrointestinal tract,