30 January 2009
Imported case of Lassa fever in the United Kingdom
The Health Protection Agency (HPA) has confirmed that a patient, who returned to the United Kingdom from Nigeria on 6 January 2009, is currently being treated for Lassa fever . This is an isolated case which poses no risk to the general public.
The patient was admitted to hospital on 8 January where testing for a wide range of infectious diseases was undertaken. A diagnosis of Lassa fever was made on the 22 January. The patient was then transferred to the high security infectious diseases unit at the Royal Free Hospital in London.
Lassa fever is an acute viral haemorrhagic fever caused by Lassa virus, a member of the arenavirus family. It is endemic in Guinea, Liberia, Nigeria and Sierra Leone. Evidence of infection has also been found in the neighbouring countries of Mali and Senegal.
Lassa fever is most commonly transmitted to humans following contamination of broken skin or mucous membranes with the urine or droppings of rats that live around homes in rural areas of endemic countries. Person to person transmission can occur after direct contact with the bodily fluids of persons who have Lassa fever.
There is no vaccine available to protect against Lassa fever. The risk of Lassa fever in tourists is extremely low.
Prior to this most recent case there have been six cases of Lassa fever imported into the UK since 1976, with no onward transmission of infection . These cases were in high risk individuals such as those working in the medical or aid sectors. Travellers to endemic countries should avoid contact with rodents. Healthcare workers should use personal protection measures when caring for persons suspected to have Lassa fever.
The HPA is helping to identify hospital staff who may have been involved in the care of this patient and who came into contact with their bodily fluids. Hospital patients and visitors are not at risk, and this case poses no threat to the general public.
Health professionals who require further information on this imported case can contact the Duty Doctor at the HPA on 020 8200 4400.
1. Health Protection Agency. Case of Lassa fever in specialist unit in London. 23 January 2009. [Accessed 28 January 2009]. Available at http://www.hpa.org.uk/webw/HPAweb&HPAwebStandard/HPA
2. Health Protection Agency. Lassa fever – questions and answers. [Accessed 28 January 2009]. Available at http://www.hpa.org.uk/webw/HPAweb&HPAwebStandard/HPA