Conference Abstract | Volume 8, Abstract ELIC2025186 (Oral 006) | Published: 10 Aug 2025
David Simons1,2,3,&, Ravi Goyal4, Umaru Bangura5,6, Rory Gibb2,7, Ben Rushton8, Dianah Sondufu6, Joyce Lamin9, James Koninga9, Momoh Jimmy9, Mike Dawson6, Joseph Lahai6, Rashid Ansumana6, Elisabeth Fichet-Calvet5, Richard Kock1, Deborah Watson-Jones3,10, Kate Jones2,7
1Centre for Emerging, Endemic and Exotic Diseases, The Royal Veterinary College, London, United Kingdom, 2Centre for Biodiversity and Environment Research, Department of Genetics, Evolution and Environment, University College London, London, United Kingdom, 3Department of Clinical Research, London School of Hygiene and Tropical Medicine, London, United Kingdom, 4Department of Medicine, University of California, San Diego, USA, 5Implementation Research, Zoonoses control, Bernard-Nocht Institute for Tropical Medicine, Hamburg, Germany, 6Njala University, Bo, Sierra Leone, 7People & Nature Lab, UCL East, Department of Genetics, Evolution and Environment, University College London, London, United Kingdom, 8Panadea Diagnostics GmbH, Hamburg, Germany, 9Kenema Government Hospital, Kenema, Sierra Leone, 10Mwanza Intervention Trials Unit, National Institute for Medical Research, Mwanza, Tanzania
&Corresponding author: David Simons, The Royal Veterinary College, Royal College Street, London, United Kingdom. Email: dzs6259@psu.edu
Received: 18 May 2025, Accepted: 09 Jul 2025, Published: 10 Aug 2025
Domain: Infectious Disease Epidemiology
Keywords: Rodent-associated zoonoses, Mastomys natalensis, disease ecology, transmission networks, land use, Sierra Leone
©David Simons 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: David Simons et al., Contact networks of small mammals highlight potential transmission foci of Lassa mammarenavirus. Journal of Interventional Epidemiology and Public Health. 2025;8(ConfProc5):006. https://doi.org/10.37432/jieph-confpro5-00006
Lassa fever, caused by Mammarenavirus lassaense (LASV), is an endemic zoonosis in several West African countries. Human infections primarily arise from rodent-to-human transmission, with Mastomys natalensis, a synanthropic species, serving as the principal reservoir. In Sierra Leone, small-mammal communities vary across land use gradients, potentially shaping LASV transmission risk in human populations. However, the extent to which anthropogenic environments facilitate small-mammal interactions conducive to viral transmission remains poorly understood.
We conducted small-mammal sampling over 43,266 trap nights, detecting 684 rodents and shrews in the LASV-endemic Eastern Province of Sierra Leone. To assess potential for within- and between-species transmission, we constructed space-sharing networks based on co-trapping within species-specific radii informed by home range estimates. These networks approximated shared space use rather than direct interaction, allowing comparison of potential encounter patterns across habitats.
Small-mammal communities in agricultural settings had greater species richness and were more connected than those in villages and forests, although overall space-sharing rates did not differ substantially. Network topology varied by land use, with greater modularity in village networks. Notably, space sharing among M. natalensis individuals was more frequent in agricultural settings than in villages, suggesting that land use may modulate opportunities for intra-specific viral transmission. LASV seroprevalence across the small-mammal community was 5.7%, with antibodies detected in nine species. We found no major differences in seroprevalence by land use or network complexity.
Menu