The Nigeria Centre for Disease Control and Prevention (NCDC) has reported 6,704 suspected Lassa fever cases and 162 deaths across 125 Local Government Areas in 28 states within the first 23 weeks of 2024.

By Aaior K Comfort

From these suspected cases, 911 have been confirmed from January to June 9, 2024, according to the NCDC’s Lassa fever situation report released on its website on Friday.

Lassa fever, as explained by the World Health Organisation, is an acute viral haemorrhagic illness caused by the Lassa virus, part of the arenavirus family. Humans typically contract the virus through exposure to food or household items contaminated with urine or feces from infected Mastomys rats, a rodent species endemic to parts of West Africa.

The NCDC noted a case fatality rate (CFR) of 17.8% in 2024, which is slightly higher than the 17.1% CFR for the same period in 2023.

“In total for 2024, 28 states have reported at least one confirmed case across 125 Local Government Areas. Sixty-five percent of all confirmed Lassa fever cases were from Ondo, Edo, and Bauchi states, with Ondo reporting 25%, Edo 22%, and Bauchi 18%. The remaining 35% of cases came from 25 other states with confirmed cases,” the report stated.

The predominant age group affected is 21-30 years, with a range from 1 to 98 years and a median age of 32 years. The gender distribution for confirmed cases is equal, with a male-to-female ratio of 1:1. Additionally, 33 healthcare workers have been infected with the virus.

Lassa fever is endemic in several West African countries, including Benin, Ghana, Guinea, Liberia, Mali, Sierra Leone, Togo, and Nigeria, and potentially exists in other West African regions as well.

Person-to-person transmission and laboratory infections can occur, particularly in healthcare settings lacking adequate infection prevention and control measures. The overall case-fatality rate is about 1%, but it rises to approximately 15% among hospitalized patients with severe Lassa fever. Early supportive care with rehydration and symptomatic treatment can improve survival outcomes.

Around 80% of individuals infected with the Lassa virus show no symptoms. However, one in five infections leads to severe disease, impacting several organs such as the liver, spleen, and kidneys.