Lassa fever is an acute viral haemorrhagic illness, infecting only eight cases so far in the UK since 1980
Health chiefs on Sunday confirmed the first death from Lassa fever in the UK, the third case to be identified in the UK in the last few days.
All three cases of the potentially fatal disease are understood to be linked to recent travel to West Africa, said UK Health Security Agency.
Dr Michael Head, senior research fellow in Global Health at the University of Southampton, said: “Lassa fever is a serious infection, but is nothing like as infectious as Covid-19. Previous studies have estimated the R number of Lassa to be roughly between 1.0 and 1.6.”
One hospital in England has declared a major incident, which comes after testing a drive for staff in hospitals treating Lassa fever cases to put on personal protective equipment (PPE).
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Lassa fever is an acute viral haemorrhagic illness, belonging to the virus family Arenaviridae, that lasts between two and 21 days, according to the World Health Organization (WHO).
The virus, for which there is no approved vaccine, is known to be endemic in Benin, Ghana, Guinea, Liberia, Mali, Sierra Leone, and Nigeria.
But it also probably exists in other West African countries as well.
UKHSA 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.”
Prior to the three recent cases, 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.
Meanwhile, UKHSA told the PA news agency that four people have now died from the virus in the UK since 2000.
One died in 2000, two died in 2009 and the fourth death was confirmed on Friday.
In November 2019, three British nationals were brought back to the UK from Sierra Leone for medical assessment after coming into close contact with two people diagnosed with Lassa fever.
However, no Lassa fever cases were ultimately confirmed.
Most people with Lassa fever, whose symptoms are similar to Ebola, will make a full recovery – although severe illness can occur.
After starting as a fever with aches and pains, the symptoms can progress to headache, vomiting and diarrhea.
Severe cases can cause victims to bleed from the mouth and nose.
Humans can contract Lassa fever from eating food that has been tainted by the urine or faeces of rodents.
The virus, like Ebola, can also be spread through contact with the bodily fluids of a sick person, but it does not spread easily between humans.
According to the World Health Organization, there is no epidemiological evidence supporting airborne spread from person to person.