Conference Abstract | Volume 8, Abstract ELIC2025213 (Poster 047) | Published: 31 Jul 2025
Fara Raymond Koundouno1,2,&, Giuditta. Annibaldis1, Karifa Kourouma1,2, Tamba Elie Millimouno1,2, Fernand M’bemba Tolno1,2, Faya Moriba Kamano1,2, Saa Lucien Millimouno1,2, Hugo Soubrier1, Mette Hinrichs1, Nfaly Magassouba3, Ralf Krumkamp1, Stephan Günther1, Sophie Duraffour1
1Bernhard Nocht-Institute for Tropical Medicine, Hamburg, Germany, 2Laboratoire des Fièvres Hémorragiques Virales de Guéckédou (LFHV-GKD), Guéckédou, Guinea, 3Université Gamal Abdel Nasser, Conakry, Guinea (UCANC)
&Corresponding author: Fara Raymond Koundouno, Bernhard Nocht-Institute for Tropical Medicine, Hamburg, Germany. Email: raymond.koundouno@bnitm.de
Received: 30 Apr 2025, Accepted: 09 Jul 2025, Published: 31 Jul 2025
Domain: Infectious Disease Epidemiology
Keywords: Seroprevalence, Lassa fever, risk factors, Guinea, community engagement
©Fara Raymond Koundouno 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: Fara Raymond Koundouno et al., REALISE: A two-year study tracking Lassa fever seroprevalence and contributing risk factors in Guinea’s Gueckedou region. Journal of Interventional Epidemiology and Public Health. 2025;8(ConfProc5):00191. https://doi.org/10.37432/JIEPH-CONFPRO5-00191
Lassa virus (LASV), the cause of Lassa fever (LF), is endemic in Guinea. Although the detection of acute LF cases is rising in the country, data on LASV seroprevalence at the community level remain limited. The REALISE study aims to address this gap by assessing LASV seroprevalence and associated risk factors across four sites in the Gueckedou region, with active engagement of local communities.
A 2-year longitudinal study (2021-2023) involved 500 participants from three rural and one urban sites, which were selected based on previous laboratory surveillance data from the region. Community engagement began six months prior to sampling. Blood samples and questionnaires were collected at study start (T0), 12 months (T2), 18 months (T3), and 24 months (T4). Serological tests (PANADEA Diagnostics) for immunoglobulin G (IgG) and M (IgM) against LASV nucleoprotein (NP) were performed. IgM-positivity indicated recent infection, and real-time RT-PCR (altona Diagnostics) was done on these samples.
Of the 500 participants enrolled at T0, 13% were lost to follow-up at T4. At T0, anti-NP IgG prevalence was of 83.4% in rural areas in contrast to 63.2% in urban areas. At T4, anti-NP IgG increased in both rural and urban areas to 88.5% and 64.9%, respectively. Anti-NP IgM ranged from 0.3% to 1.7% across all sites and follow up time points. All RT-PCR tests on IgM positive samples were negative, and no participant reported illness. Analyses are currently ongoing to explore LF risk factors.
Participants from rural areas exhibit the highest LASV seroprevalence rates as compared to those from urban areas, likely due to rodent reservoirs presence. Seroconversions indicate ongoing exposure and highlight the need for further research on LF. Our findings promote community-centered research and support the global Lassa vaccine strategy
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