Two cases of rare rat-borne Lassa fever found in UK

Two cases of the rare rat-borne Lassa fever have been found in England, with a further “probable” case being investigated.

The UK Health Security Agency (UKHSA) said the cases which have been identified are within the same family in the east of England and are linked to recent travel to west Africa.

Lassa Fever is an illness caused by the Lassa virus, which usually infects people through exposure to food or household items that have been contaminated with the urine or faeces of infected rats. The virus can also be spread through infected bodily fluids.

Most people with the Lassa Fever will make a full recovery, the UKHSA said, however severe illness may occur in some individuals.

The illness is a viral haemorrhagic fever which means it can affect multiple organs in the body and may be accompanied by hemorrhage or bleeding, according to the United States’ Centres for Disease Control and Prevention (CDC).

People living areas of west Africa with high populations of rodents are most at risk of Lassa fever, UKHSA said. It added cases which occur elsewhere are “almost exclusively in people who work in endemic areas in high-risk occupations such as medical or other aid workers.”

One of the cases identified has recovered while the other is being treated at the Royal Free London Foundation Trust. The third probable case is being treated at Bedfordshire Hospitals Foundation Trust.

Dr Susan Hopkins, chief medical advisor at UKHSA said: “Cases of Lassa fever are rare in the UK and it does not spread easily between people. The overall risk to the public is very low. 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 UKHSA and the NHS have well established and robust infection control procedures for dealing with cases of imported infectious disease and these will be reinforced.”

Prior to the new cases there have been just eight reported in the UK since 1980, with the most recent two in 2009.

Dr Sir Michael Jacobs, consultant in infectious diseases at the Royal Free London, said: “The Royal Free Hospital is a specialist centre for treating patients with viral haemorrhagic fevers, including Lassa fever. Our secure unit is run by a highly-trained and experienced team of doctors, nurses, therapists and laboratory staff and is designed to ensure our staff can safely treat patients with these kind of infections.”