Lassa Fever Resurgence: The Nigeria Perspective

Abstract

Lassa fever (LF) is one of the chronic, zoonotic, viral haemorrhagic diseases that is caused Lassa virus, belonging to the family of arenaviruses, a member of the family Arenaviridaer. The Lassa virus was described in the year 1950s, but was not named until 1969. The first case of Lassa fever was recorded in Nigeria, there have been several outbreaks across other West African nations such as Sierra Leone, Togo, Benin Republic, Guinea, Liberia, Ghana, and Mali. Of all viral hemorrhagic fevers (VHF) exported to the Europe and America, Lassa fever ranks the highest. In light of the current resurgence of Lassa fever in Nigeria, Lassa fever cases in the country has risen to 857, with 167 deaths recorded from the disease between January and July 2022. Ondo has 30% of the confirmed cases, followed by Edo with 26% and Bauchi with 14%. Lassa fever comprising of Lassa, Junin, Lujo, Guanarito, and Machupo. The Filoviridae comprising of Ebola and Marburg viruses, and the Bunyaviridae is made up of Rify Vaey Fever and Crimean Congo haemorrhagic fever. Animal to human transmission is caused by contact with droplets from Natal Multimammate rat or the African rat (Mastomys natalensis), while human-to-human transmission occurs through contact with infected fluid from an infected person. The incubation period of Lassa fever ranges between 6–21 days and is accompanied with the clinical symptoms such as gradual slight fever, malaise and general weakness, followed by serious symptoms like abdominal, chest, and muscle pains, cough, headache, sore throat, nausea, shock, swelling of the face, diarrhea, and frequent vomiting. More severe cases result to bleeding and eventually death. It can be prevented by avoiding areas endemic with the host animal, observing proper hygiene, and the use of proper personal protective equipment for health workers. No specific treatment is available for Lassa fever infection, although ribavirin has been suggested to be effective when administered at the onset of infection.