Trend and Descriptive Epidemiology of Lassa Fever in Ebonyi State, 2018 - 2022

Adanna Ezenwa-Ahanene, Alex Ekwueme Federal University Teaching Hospital, Nigeria
Ayo Adebowale, University of Ibadan
A T Salawu, University of Ibadan
Benson Agwu, Alex Ekwueme Federal University Teaching Hospital, Abakaliki

Lassa fever (LF) emergence in Nigeria is a significant public health concern, with Ebonyi state in the South-Eastern zone reporting a high burden. This study aimed to investigate the trend and descriptive epidemiology of LF in the state. This study utilized data from the state Integrated Disease Surveillance and Response (IDSR) system for (2018-2022). A total of 1578 cases were reported, with 300 laboratory-confirmed. An additive time series assessed the trend and seasonality in order to ascertain the quarter in which the disease peaked. Projected values were determined using the identified fitted model among linear, quadratic, cubic and exponential models (a0.05). Mean age was 29.4 ± 17.8 years, showing a seasonal trend across the years. Quadratic model provided the best fit for prediction (R2 = 98.4%, P-value <0.05). Predicted cases for year 2023 were highest in 1st quarter, 123 and 3rd quarter, 42, while seasonality index was +70.76 and -9.09 respectively. Reported cases followed a declining trend (slope= -0.1363). Farmers were 70% less likely to die from LF compared to the unemployed (aOR:0.3, CI: 0.17-0.83). Adequate preparedness to mitigate the spread of the disease during its the peak is recommended. Keywords: Lassa fever, Time Series Analysis, Seasonality, Ebonyi State

Keywords: Health and Morbidity, Population projections, forecasts, and estimations, Data and Methods, Spatial Demography

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