Related Experiment Video
Updated: Oct 22, 2025

A Method of Trigonometric Modelling of Seasonal Variation Demonstrated with Multiple Sclerosis Relapse Data
Published on: December 9, 2015
52 Years of Lassa Fever Outbreaks in Nigeria, 1969-2020: An Epidemiologic Analysis of the Temporal and Spatial Trends
Dennis E Agbonlahor1, George O Akpede2, Christian T Happi3
1Department of Medical Laboratory Science, College of Medical Sciences, Edo State University, Uzairue, Edo State, Nigeria and Lahor Research Laboratories and Medical Centre, Benin City, Edo State, Nigeria.
Abstract:
The year 2020 made 52 years since the first report of Lassa fever (LF) outbreaks from Nigeria, but what progress has been made in its control? We sought to answer this through an epidemiologic analysis of the temporal and spatial trends of the outbreaks from 1969 to 2020. The analysis showed an overall strengthening of the outbreaks, hallmarked by the change from irregular to regular annual and from limited local to nationwide outbreaks, while there was a sharp contrast between the upward trend in case numbers and downward trend in case fatality. Pending the availability of effective vaccines, greater effort is required to reverse the upward trend in case numbers and sustain the downward trend in case fatality. We discuss the factors associated with the observed trends as well as the prerequisites for further improvements.
Related Concept Videos
Patterns of Fever
Steps in Outbreak Investigation
Statistical Methods for Analyzing Epidemiological Data
Prevalence and Incidence
Prevalence indicates the proportion of individuals in a population who have a specific disease or health...
Causality in Epidemiology
Principles of Disease Surveillance

