| Autor: |
Bangura U; Bernhard Nocht Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Hemorrhagic Fever Reference and Research, Hamburg, Germany., Davis C; MRC-University of Glasgow Centre for Virus Research, Glasgow, UK., Lamin J; Mercy Hospital Research Laboratory, Bo, Sierra Leone., Bangura J; University of Makeni and University of California, Davis One Health Program, Makeni, Sierra Leone., Soropogui B; Laboratoire des Fièvres Hémorragiques en Guinée, Conakry, Guinea., Davison AJ; MRC-University of Glasgow Centre for Virus Research, Glasgow, UK., Nichols J; MRC-University of Glasgow Centre for Virus Research, Glasgow, UK., Vucak M; MRC-University of Glasgow Centre for Virus Research, Glasgow, UK., Dawson M; Mercy Hospital Research Laboratory, Bo, Sierra Leone., Ansumana R; Mercy Hospital Research Laboratory, Bo, Sierra Leone., Sondufu D; Mercy Hospital Research Laboratory, Bo, Sierra Leone., Cadar D; Bernhard Nocht Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Hemorrhagic Fever Reference and Research, Hamburg, Germany., Rieger T; Bernhard Nocht Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Hemorrhagic Fever Reference and Research, Hamburg, Germany., Thomson E; MRC-University of Glasgow Centre for Virus Research, Glasgow, UK., Sahr F; College of Medicine and Allied Health Sciences, University of Sierra Leone, Freetown, Sierra Leone., Magassouba N; Laboratoire des Fièvres Hémorragiques en Guinée, Conakry, Guinea., Ghersi B; One Health Institute, School of Veterinary Medicine, University of California, Davis, Davis, CA, USA., Bird BH; One Health Institute, School of Veterinary Medicine, University of California, Davis, Davis, CA, USA., Fichet-Calvet E; Bernhard Nocht Institute for Tropical Medicine, WHO Collaborating Centre for Arbovirus and Hemorrhagic Fever Reference and Research, Hamburg, Germany. |
| Abstrakt: |
The spread of Lassa virus (LASV) in Guinea, Liberia and Sierra Leone, which together are named the Mano River Union (MRU) area, was examined phylogeographically. To provide a reliable evolutionary scenario, new rodent-derived, whole LASV sequences were included. These were generated by metatranscriptomic next-generation sequencing from rodents sampled between 2003 and 2020 in 21 localities of Guinea and Sierra Leone. An analysis was performed using BEAST to perform continuous phylogeographic inference and EvoLaps v36 to visualize spatio-temporal spread. LASV was identified as expected in its primary host reservoir, the Natal multimammate mouse ( Mastomys natalensis ), and also in two Guinean multimammate mice ( Mastomys erythroleucus ) in northern Sierra Leone and two rusty-bellied brush-furred mice ( Lophuromys sikapusi ) in southern Sierra Leone. This finding is consistent with the latter two species being secondary host reservoirs. The strains in these three species were very closely related in LASV lineage IV. Phylogenetic analysis indicated that the most recent common ancestor of lineage IV existed 316-374 years ago and revealed distinct, well-supported clades from Sierra Leone (Bo, Kabala and Kenema), Guinea (Faranah, Kissidougou-Guekedou and Macenta) and Liberia (Phebe-Ganta). The phylogeographic scenario suggests southern Guinea as the point of origin of LASV in the MRU area, with subsequent spread to towards Mali, Liberia and Sierra Leone at a mean speed of 1.6 to 1.1 km/year. |
