Lassa fever in Nigeria: Update 1

The Nigeria Centre for Disease Control and Prevention (NCDC) reports continued occurrence of Lassa fever across Nigeria in 2024. From 1 January 2024 to 11 February 2024 there were 411 confirmed cases, including 72 deaths. A further 2122 suspected cases were also reported.

Lassa fever cases have been reported in 32 states, with 65% of all confirmed Lassa fever cases reported from Ondo, Edo, and Bauchi states.

Lassa fever is a type of viral haemorrhagic fever (VHF) endemic in parts of West Africa. Lassa virus is transmitted via the urine or droppings from infected rodents (Mastomys rats). Transmission can also occur via body fluids of infected people.

Advice for Travellers

The risk to travellers becoming infected or developing Lassa fever is extremely low, unless living in conditions of poor sanitation and overcrowding in rural areas where these rodents are usually found.

Travellers to known Lassa fever outbreak areas must be made aware of the risk of infection and transmission routes of Lassa virus which is most commonly through:

• ingesting or breathing in tiny particles in the air if it has been contaminated with infected rodent excretions, for example during cleaning activities such as sweeping
• touching objects soiled with infected rat excretions, and infecting open cuts or sores
• eating food which has been contaminated with rat excretions

Medical personnel travelling to work in an outbreak region must follow strict infection prevention control guidance.

Travellers returning from a Lassa fever outbreak area should seek rapid medical attention by contacting NHS 24 (Scotland) or NHS 111 (rest of UK) for advice prior to attending UK medical facilities if they develop fever and have:

• returned to the UK within 21 days from a region or area with a known outbreak of Lassa fever
• had contact with individuals infected with a VHF

For further information, see the TRAVAX Viral Haemorrhagic Fever page.