Conference Abstract | Volume 8, Abstract ELIC2025321 (Oral 102) | Published: 14 Aug 2025
1Jhpiego-Abuja, Nigeria, 2National Lassa Fever Technical Working Group- Abuja, Nigeria, 3Nigeria Centre for Disease Control and Prevention- Abuja, Nigeria
&Corresponding author: Favour Makava Adeniji, Jhpiego, Abuja, FCT, Nigeria, Email: Favour.Makava@jhpiego.org
Received: 11 Apr 2025, Accepted: 09 Jul 2025, Published: 28 Mar 2025
Domain: Infectious Disease Epidemiology
Keywords: Lassa fever, Contact tracing, Surveillance, Nigeria, Outbreak response, public health
©Favour Makava Adeniji 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: Favour Makava Adeniji et al., Assessing the effectiveness of Lassa fever contact tracing in Nigeria, 2020-2024: A five-year trend analysis. Journal of Interventional Epidemiology and Public Health. 2025;8(ConfProc5):000102. https://doi.org/10.37432/JIEPH-CONFPRO5-00102
Lassa fever remains a major public health challenge in Nigeria. Effective contact tracing is essential for early case identification, timely isolation, and outbreak containment. However, its implementation has faced notable challenges. This study analyzed five years (2020–2024) of national surveillance data to evaluate the performance of contact tracing and its role in detecting secondary Lassa fever cases, with the goal of informing future strategies.
A retrospective descriptive analysis was conducted using Microsoft Excel on data from Nigeria Centre for Disease Control (NCDC) Lassa fever situation reports (2020–2024). The population included all contacts listed from confirmed cases. Key indicators assessed were: number of confirmed cases, contacts listed, contacts completing follow-up, symptomatic contacts, confirmed secondary cases, and contacts lost to follow-up. Descriptive statistics were applied to observe performance trends and implementation gaps.
Between 2020 and 2024, there were 5,297 confirmed Lassa fever cases and 25,929 contacts listed. Of these, 24,824 (95.7%) completed follow-up. A total of 492 (1.9%) developed symptoms, and 199 (0.77%) were confirmed positive. While follow-up completion improved reaching zero losses in 2023 contact positivity rates remained consistently low and declined over the years. Losses to follow-up re-emerged in 2024, reflecting ongoing operational challenges and limiting the overall effectiveness of detecting secondary transmission.
Despite high follow-up completion, Lassa fever contact tracing in Nigeria shows limited success in identifying symptomatic and positive secondary cases, a critical gap for public health. Urgent implementation of targeted interventions, enhanced surveillance training, are crucial to strengthen contact tracing and reduce Lassa fever transmission.
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