ITV News Health Editor Emily Morgan analyses the cases
A patient in the UK has died from a confirmed case of Lassa fever, the UK Health Security Agency (UKHSA) has said.
The patient died in Bedfordshire. No further details confirming their name or age have yet been released.
In a statement, the UKHSA said the confirmed case of Lassa fever brought the total cases of the potentially fatal disease in the UK to three following the discovery of two cases in East England on Wednesday.
The statement said: “We are contacting the individuals who have had close contact with the cases prior to confirmation of their infection, to provide appropriate assessment, support and advice. The risk to the general public remains very low.”
A Bedfordshire Hospitals NHS Foundation Trust 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.”
All three of the confirmed UK cases are understood to be linked to recent travel to West Africa.
Prior to the recent infections, eight cases had been identified in the UK since 1980.
The cases are the first of the disease to be confirmed in the UK since 2009.
What is Lassa fever?
According to the World Health Organization (WHO), Lassa fever is an animal-borne acute viral haemorrhagic illness caused by the Lassa virus which is known to be endemic in parts of West Africa.
About 80% of people infected with Lassa virus have no symptoms. Most people will make a full recovery - although severe illness can occur.
Th symptoms start as a fever with aches and pains, and can progress to a headache, vomiting and diarrhoea. Severe cases can cause victims to bleed from the mouth and nose.
One in five infections result in severe disease where the virus affects several organs such as the liver, spleen and kidneys, says the WHO.
Humans usually become infected with the virus through exposure to food or household items that are contaminated with the urine or faeces of infected by Mastomys rats.
Like Ebola, the virus can also be spread through contact with the bodily fluids of a sick person, but it does not spread easily between humans.
The WHO says there is no epidemiological evidence supporting airborne spread from person to person.
The organisation's website says: "Person-to-person infections and laboratory transmission can also occur, particularly in health care settings in the absence of adequate infection prevention and control measures."
"Lassa fever is known to be endemic in Benin, Ghana, Guinea, Liberia, Mali, Sierra Leone, Togo and Nigeria, but probably exists in other West African countries as well," the WHO adds.
The overall case fatality rate is 1%. The figure rises to around 15% among patients who are hospitalised with severe clinical presentation of Lassa fever, says the WHO.
It is "essential" patients are diagnosed promptly and receive rehydration and symptomatic treatment to improve survival chances.