Lassa fever is rare in the UK. Most people recover quickly. However, it can still be fatal in some cases.
Two cases of Lassa fever have been identified in England, and a further probable case is under investigation, High Conequence Infectious Death Network is involved with their ongoing care."
What is Lassa fever?
According to the World Health Organization, Lassa fever "is endemic in Benin and Ghana, Guinea, Liberia Mali, Sierra Leone, Nigeria, and Sierra Leone." However, it is also likely to exist in other West African countries.
What are the signs?
The WHO states that Lassa fever incubation takes between six and 21 days. When the disease is symptomatic, it usually starts slowly and is marked by fever, weakness and malaise.
A fever can cause headaches, sore throats, muscle pain, chest discomfort, nausea, vomiting and diarrhoea.
The WHO states that severe cases of facial swelling, fluid retention in the lung cavity, bleeding from your mouth, nose or gastrointestinal tract, and low blood pressure can all occur.
Around 80 percent of Lassa-infected people have no symptoms.
According to the WHO, ribavirin is an antiviral drug that can be used to treat Lassa fever. However, it should only be administered early in the disease's course. The current vaccine is not available against the disease.
Do we need to be concerned about the rising number of cases in England
Most people who have Lassa virus will recover quickly. However, it's possible for severe illness to occur and can be fatal in as many as 1% of cases.
Dr Susan Hopkins, UKHSA's chief medical advisor, stated that Lassa fever cases are very rare in the UK, and does not easily spread between people.
"The public's overall risk is very low. We are reaching out to those who were in close contact with these cases before confirmation of infection. This will allow us to provide the appropriate assessment, support, and advice.
"The NHS and UKHSA have robust and well-established infection control procedures to deal with cases of imported infectious diseases. These will be strengthened."
Dr. Sir Michael Jacobs is a consultant in infectious diseases at Royal Free Hospital in Hampstead, North London. He said that the Royal Free Hospital was a specialist center for patients with viral haemorrhagic fevers including Lassa fever.
"Our secure unit is managed by highly-trained and experienced nurses, doctors, therapists, and laboratory staff. It is equipped to safely treat these types of infections by our staff."