Conference Abstract | Volume 8, Abstract ELIC202580 (Poster 096) | Published: 18 Aug 2025
Stephen Eghelakpo Akar1,2,3,&, William Nwachukwu3, Sunbo Oludare Adewuyi1, Anthony Agbakizua Ahumibe1,2, Iniobong Akanimo3, Oyeladun Okunromade3, Olajumoke Babatunde3, Chikwe Ihekweazu4, Mami Hitachi2, Kentaro Kato2, Yuki Takamatsu5, Kenji Hirayama6, Satoshi Kaneko2
1Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan, 2Department of Eco-epidemiology, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan,3Nigeria Centre for Disease Control and Prevention, Abuja, Nigeria, 4WHO Hub for Pandemic and Epidemic Intelligence, Berlin, Germany, 5Department of Virology, Institute of Tropical Medicine, Nagasaki University, Nagasaki, Japan, 6School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
&Corresponding author: Stephen Eghelakpo Akar, Graduate School of Biomedical Sciences, Nagasaki University, Nagasaki, Japan. Email: steve.eghelakpo.akar@gmail.com
Received: 25 May 2025, Accepted: 09 Jul 2025, Published: 18 Aug 2025
Domain: Infectious Disease Epidemiology
Keywords: Lassa fever, epidemiology, viral positivity, predictors, Nigeria
©Stephen Eghelakpo Akar et al. Journal of Interventional Epidemiology and Public Health (ISSN: 2664-2824). This is an Open Access article distributed under the terms of the Creative Commons Attribution International 4.0 License (https://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Cite this article: Stephen Eghelakpo Akar et al., Socio-demographic, climatic, ecological and clinical predictors of Lassa fever virus positivity in Nigeria: Analysis of multi-year national surveillance data, 2018-2021. Journal of Interventional Epidemiology and Public Health. 2025;8(ConfProc5):00096 https://doi.org/10.37432/JIEPH-CONFPRO5-00240
Lassa fever, a re-emerging zoonotic viral hemorrhagic disease caused by the LASV remains a major public health concern in Nigeria. Effective prevention and control of LF is dependent on addressing potential drivers of LASV transmission across the human-environment-animal interface. We therefore describe the epidemiological profile, trend, seasonality, and factors associated with LASV positivity in Nigeria from 2018 to 2021.
Between January 2017 and December 2021 Nigeria recorded a total of 20167 suspected LF cases with an overall viral positivity of 16.3%. Cases were mostly males (56.0%) with a median age of 30.0 (IQR: 20.0-42.0) years, seen mostly in the South-south geo-political (49.0%), temperate-humid climatic (72.0%), and in the Lowland rainforest ecological zones (69.6%). Predictors of LASV positivity were the first (aOR=2.86, 95% CI: 2.42-3.41), third (aOR=1.41, 95% CI: 1.12-1.77), and fourth (aOR=1.77, 95% CI: 1.44-2.18) quarters of the year; the temperate climatic zones (aOR= 1.44, 95% CI: 1.16-1.78); the Jos Plateau (aOR= 1..66, 95% CI: 1.36-2.03), Derived Savannah (aOR= 1.44, 95% CI: 1.15-1.81), and Guinea Savannah (aOR= 2.65, 95% CI: 2.08-3.35) ecological zones; male sex (aOR= 1.23, 95% CI: 1.12-1.35); age group 15-44 (aOR= 1.33, 95% CI: 1.13-1.58) and 45-59 years (aOR= 1.34, 95% CI: 1.10-1.63); and artisan or trader (aOR= 1.17, 95% CI: 1.01-1.36). Clinical predictors were abdominal pain (aOR= 1.49, 95% CI: 1.33-1.66); anorexia (aOR= 1.56, 95% CI: 1.32-1.84); chest pain (aOR= 1.40, 95% CI: 1.16-1.67); diarrhea (aOR= 1.19, 95% CI: 1.01-1.40); fatigue (aOR= 1.25, 95% CI: 1.10-1.40); fever (aOR= 1.15, 95% CI: 1.02-1.30); muscle pain (aOR= 1.55, 95% CI: 1.20-2.00); nausea (aOR= 1.33, 95% CI: 1.09-1.62); vomiting (aOR= 2.25, 95% CI: 1.99-2.54); confused or disoriented (aOR= 2.61, 95% CI: 1.60-4.25); malaise (aOR: 1.60, 95% CI: 1.24-2.06).
Menu