ReliefWeb

A. Situation analysis

Description of the disaster

Lassa Fever is an acute viral illness and a viral haemorrhagic fever (VHF). The causative agent is a single-stranded ribonucleic acid (RNA) virus in the family arenaviridae, the Lassa virus. This zoonotic disease is associated with high morbidity and mortality, transmitted by the multi-mammate rat (mastomys natalensis), one of the most common rats in equatorial Africa. The disease was first discovered in a town called Lassa in Borno State, Nigeria in 1969. In the past, Lassa fever cases and outbreaks have been reported in Nigeria, Sierra Leone, Liberia, Ghana, Benin, Mali and Guinea. Once a mastomys rat is infected by the Lassa virus, the excreta of the rat, both urine and faeces, will contain high quantities of virus potential to transmit the virus from the rat to humans. Humans become infected from direct contact with the urine and faeces of the rat which contains the virus, through touching soiled objects, eating contaminated food, or exposure to open cuts or sores. Secondary transmission from person to person can occur following exposure to the virus in the blood, tissue, urine, faeces or other bodily secretions of an infected individual. Hospital-acquired (nosocomial) transmission from person to person are not uncommon, and importantly can occur if appropriate Personal Protective Equipment (PPE) is not worn when managing suspected cases.

Lassa Fever is an epidemic-prone disease for immediate notification on the Integrated Disease Surveillance and Response (IDSR) platform in Nigeria. The actual incidence rate in Nigeria is unknown, but case fatality rates range from 3% to 42% (and over the last two years has remained between 20% and 25%). Historically, outbreaks occur during the dry season (November to April); however, in recent years, cases have also occurred during the rainy season. Lassa fever importation into non-endemic countries has occurred in the UK, USA, and Germany, amongst others.

On 24 January 2020, a Lassa Fever outbreak in Nigeria was declared by the Nigeria Centre for Disease Control (NCDC); the nodal agency for epidemic monitoring and surveillance. In a parallel response, the multi-stakeholder National Emergency Operations Centre (EoC) was activated on 24 January in 8 states, including the Federal Capital Territory. These EoCs were set up to monitor and coordinate the response.

The Nigerian Red Cross Society (NRCS) received support from IFRC through this DREF operation, launched for CHF 284,572 in February 2020 to support Government actions to curb the outbreak in the areas of hygiene promotion, active case finding, contact tracing, vector control and psychosocial support in the target six states (Ondo, Edo, Bauchi, Ebonyi, Taraba & Kano) based on the incidence of confirmed cases. Operation lasted three months.

The number of affected people (suspected and confirmed) was higher this year than previous cyclical Lassa Fever outbreaks. In the Epidemiological Week (EW) 4 (20-26 January 2020), the Sitrep issued by the NCDC, showed 689 suspected cases since the first week of January 2020, out of which 258 were confirmed positive. The number of deaths reported from Lassa Fever is 41 with a case fatality rate of 15.9%. A comparison of this data with that of the same period in 2019 shows that the outbreak in 2020 is more alarming, fast and widespread. Indeed, since the beginning of 2020, infection incidence has been reported in 19 states. These include Ondo, Edo, Ebonyi, Enugu, Kano, Borno, Nasarawa, Kogi, Rivers, Abia, Adamawa, Benue, Kaduna, Delta, Taraba, Plateau, Bauchi, Osun and Ogun states.