Volume 96, Issue 4
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645



The multimammate mouse () is the reservoir for Lassa virus (LASV). Zoonotic transmission occurs when humans are directly or indirectly exposed to fluids of the multimammate mouse, such as urine, saliva, and blood. Housing characteristics and domestic organization affect rodent density in and around households and villages, and are likely to be a risk factor for Lassa fever in humans where the reservoir exists. We use semi-structured interviews ( = 51), a quantitative survey ( = 429), direct observations, and a rodent ecology study to provide new insights into how the organization of domestic spaces brings together humans and rodents and creates pathways for infection in rural settlements in Bo District, Sierra Leone. Rodents were frequently reported inside houses (92.4% of respondents), in which we predominantly trapped (57% of trapped rodents) and (38% of trapped rodents). Building design and materials provide hiding and nesting places for rodents and lead to close proximity with humans. Patterns of contact are both unintentional and intentional and research participants reported high levels of contact with rodents (34.2% of respondents) and rodent fluids (52.8% of respondents). Rodents are also perceived as a serious threat to food security. These results present detailed knowledge about how humans live with and come into contact with rodents, including the LASV reservoir. Our results argue for further collaborative research in housing and environmental modification such as ceiling construction, food storage, and sanitation as prevention against zoonotic LASV transmission.

[open-access] This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.


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  1. Fichet-Calvet E, Rogers DJ, , 2009. Risk maps of Lassa fever in West Africa. PLoS Negl Trop Dis 3: e388.[Crossref] [Google Scholar]
  2. Gunther S, Lenz O, , 2004. Lassa virus. Crit Rev Clin Lab Sci 41: 339390.[Crossref] [Google Scholar]
  3. McCormick JB, Fisher-Hoch SP, , 2002. Lassa fever. Curr Top Microbiol Immunol 262: 75109. [Google Scholar]
  4. Olayemi A, Cadar D, Magassouba N, Obadare A, Kourouma F, Oyeyiola A, Fasogbon S, Igbokwe J, Rieger T, Bockholt S, Jerome H, Schmidt-Chanasit J, Garigliany M, Lorenzen S, Igbahenah F, Fichet JN, Ortsega D, Omilabu S, Gunther S, Fichet-Calvet E, , 2016. New hosts of the Lassa virus. Sci Rep 6: 25280.[Crossref] [Google Scholar]
  5. McCormick JB, Saluzzo JF, Dodet B, , 1999. Lassa fever. , eds. Emergence and Control of Rodent-borne Viral Diseases. Paris: Elsevier, 177195. [Google Scholar]
  6. Ogbu O, Ajuluchukwu E, Uneke CJ, , 2007. Lassa fever in West African sub-region: an overview. J Vector Borne Dis 44: 111. [Google Scholar]
  7. Walker DH, Wulff H, Lange JV, Murphy FA, , 1975. Comparative pathology of Lassa virus infection in moneys, guinea-pigs, and Mastomys natalensis . Bull World Health Organ 52: 523534. [Google Scholar]
  8. Stephenson EH, Larson EW, Dominik JW, , 1984. Effect of environmental factors on aerosol-induced Lassa virus infection. J Med Virol 14: 295303.[Crossref] [Google Scholar]
  9. Lo Iacono G, Cunningham AA, Fichet-Calvet E, Garry RF, Grant DS, Khan SH, Leach M, Moses LM, Schieffelin JS, Shaffer JG, Webb CT, Wood JL, , 2015. Using modelling to disentangle the relative contributions of zoonotic and anthroponotic transmission: the case of Lassa fever. PLoS Negl Trop Dis 9: e3398.[Crossref] [Google Scholar]
  10. Bonner PC, Schmidt WP, Belmain SR, Oshin B, Baglole D, Borchert M, , 2007. Poor housing quality increases risk of rodent infestation and Lassa fever in refugee camps of Sierra Leone. Am J Trop Med Hyg 77: 169175. [Google Scholar]
  11. Ter Meulen J, Lukashevich I, Sidibe K, Inapogui A, Marx M, Dorlemann A, Yansane ML, Koulemou K, Chang-Claude J, Schmitz H, , 1996. Hunting of peridomestic rodents and consumption of their meat as possible risk factors for rodent-to-human transmission of Lassa virus in the Republic of Guinea. Am J Trop Med Hyg 55: 661666. [Google Scholar]
  12. Kernéis S, Koivogui L, Magassouba N, Koulemou K, Lewis R, Aplogan A, Grais RF, Guerin PJ, Fichet-Calvet E, , 2009. Prevalence and risk factors of Lassa seropositivity in inhabitants of the forest region of Guinea: a cross-sectional study. PLoS Negl Trop Dis 3: e548.[Crossref] [Google Scholar]
  13. Bonwitt J, Kelly AH, Ansumana R, Agbla S, Sahr F, Saez AM, Borchert M, Kock R, Fichet-Calvet E, , 2016. Rat-atouille: a mixed method study to characterize rodent hunting and consumption in the context of Lassa fever. EcoHealth 13: 234247.[Crossref] [Google Scholar]
  14. Center for Disease Control and Prevention, 2014. Lassa Fever Prevention. Available at: http://www.cdc.gov/vhf/lassa/prevention/index.html. Accessed March 2016. [Google Scholar]
  15. Brown H, Kelly AH, Mari Saez A, Fichet-Calvet E, Ansumana R, Bonwitt J, Magassouba N, Sahr F, Borchert M, , 2015. Extending the “social”: anthropological contributions to the study of viral haemorrhagic fevers. PLoS Negl Trop Dis 9: e0003651.[Crossref] [Google Scholar]
  16. Lecompte E, Fichet-Calvet E, Daffis S, Koulemou K, Sylla O, Kourouma F, Dore A, Soropogui B, Aniskin V, Allali B, Kouassi Kan S, Lalis A, Koivogui L, Gunther S, Denys C, ter Meulen J, , 2006. Mastomys natalensis and Lassa fever, West Africa. Emerg Infect Dis 12: 19711974.[Crossref] [Google Scholar]
  17. Leski TA, Stockelman MG, Moses LM, Park M, Stenger DA, Ansumana R, Bausch DG, Lin B, , 2015. Sequence variability and geographic distribution of Lassa virus, Sierra Leone. Emerg Infect Dis 21: 609618.[Crossref] [Google Scholar]
  18. Safronetz D, Sogoba N, Lopez JE, Maiga O, Dahlstrom E, Zivcec M, Feldmann F, Haddock E, Fischer RJ, Anderson JM, Munster VJ, Branco L, Garry R, Porcella SF, Schwan TG, Feldmann H, , 2013. Geographic distribution and genetic characterization of Lassa virus in sub-Saharan Mali. PLoS Negl Trop Dis 7: e2582.[Crossref] [Google Scholar]
  19. Fichet-Calvet E, Lecompte E, Koivogui L, Soropogui B, Dore A, Kourouma F, Sylla O, Daffis S, Koulemou K, Ter Meulen J, , 2007. Fluctuation of abundance and Lassa virus prevalence in Mastomys natalensis in Guinea, West Africa. Vector Borne Zoonotic Dis 7: 119128.[Crossref] [Google Scholar]
  20. Fichet-Calvet E, Audenaert L, Barrière P, Verheyen E, , 2009. Diversity, dynamics and reproduction in a community of small mammals in Upper Guinea, with emphasis on pygmy mice ecology. Afr J Ecol 48: 600614. [Google Scholar]
  21. Fichet-Calvet E, Lecompte E, Veyrunes F, Barriere P, Nicolas V, Koulemou K, , 2009. Diversity and dynamics in a community of small mammals in coastal Guinea, West Africa. Belg J Zool 139: 93102. [Google Scholar]
  22. Monath TP, Newhouse VF, Kemp GE, Setzer HW, Cacciapuoti A, , 1974. Lassa virus isolation from Mastomys natalensis rodents during an epidemic in Sierra Leone. Science 185: 263265.[Crossref] [Google Scholar]
  23. Isaacson M, , 1975. The ecology of Praomys (Mastomys) natalensis in southern Africa. Bull World Health Organ 52: 629636. [Google Scholar]
  24. Ochei O, Abjejegah C, Okoh EC, Abah SO, , 2014. Housing factors and transmission of Lassa fever in a rural area of south Nigeria. General Health and Medical Sciences 1: 1520. [Google Scholar]
  25. Moses LM, Kargbo K, Koninga J, Robert W, Lungay V, Fionnie R, Kanneh L, Bangura J, Garry RF, Bausch DG, , 2009. Household predictors of abundance of the Lassa virus reservoir, Mastomys natalensis, in the Eastern Province of Sierra Leone. 58th annual meeting of the American Society of Tropical Medicine and Hygiene. Washington, DC, November 18–22, 2009. [Google Scholar]
  26. Demby AH, Inapogui A, Kargbo K, Koninga J, Kourouma K, Kanu J, Coulibaly M, Wagoner KD, Ksiazek TG, Peters CJ, Rollin PE, Bausch DG, , 2001. Lassa fever in Guinea: II. Distribution and prevalence of Lassa virus infection in small mammals. Vector Borne Zoonotic Dis 1: 283297.[Crossref] [Google Scholar]
  27. Kelly JD, Barrie MB, Ross RA, Temple BA, Moses LM, Bausch DG, , 2013. Housing equity for health equity: a rights-based approach to the control of Lassa fever in post-war Sierra Leone. BMC Int Health Hum Rights 13: 2.[Crossref] [Google Scholar]
  28. Keenlyside RA, McCormick JB, Webb PA, Smith E, Elliot L, Johnson KM, , 1983. Case-control study of Mastomy natalensis and humans in Lassa virus-infected households in Sierra Leone. Am J Trop Med Hyg 32: 829837. [Google Scholar]
  29. Yalley-Ogunro JE, Frame JD, Hanson AP, , 1984. Endemic Lassa fever in Liberia. VI. Village serological surveys for evidence of Lassa virus activity in Lofa County, Liberia. Trans R Soc Trop Med Hyg 78: 764770.[Crossref] [Google Scholar]
  30. Sierra Leone Statistics Thomas AC, , 2010. Population profile of Bo district and Bo town 2004 Census Publication Series: Number 4. , ed. Population and Housing Census of Sierra Leone. Freetown, Sierra Leone: Sierra Leone Union for Population Studies. [Google Scholar]
  31. Sierra Leone Statistics Thomas AC, , 2007. Population profile of Sierra Leone 2004 Census Publication Series: Number 4. , ed. Population and Housing Census of Sierra Leone. Freetown, Sierra Leone: Sierra Leone Union for Population Studies. [Google Scholar]
  32. WHO, 2008. Module 7: The EPI coverage survey. Training for mid-level managers (MLM)—WHO/IVB/08.07. CH-1211 Geneva 27, Switzerland: Expanded Programme on Immunization of the Department of Immunization, Vaccines and Biologicals. [Google Scholar]
  33. Mills JN, Yates TL, Childs J, Parmenter RR, Ksiazek TG, Rollin PE, Peters CJ, , 1995. Guidelines for working with rodents potentially infected with hantavirus. J Mammal 76: 716722.[Crossref] [Google Scholar]
  34. Fichet-Calvet E, Johnson N, , 2014. Lassa fever: a rodent-human interaction. , ed. The Role of Animals in Emerging Viral Diseases. Boston, MA: Academic Press, 89123.[Crossref] [Google Scholar]
  35. Lecompte E, Brouat C, Duplantier JM, Galan M, Granjon L, Loiseau A, Mouline K, Cosson JF, , 2005. Molecular identification of four cryptic species of Mastomys (Rodentia, Murinae). Biochem Syst Ecol 33: 681689.[Crossref] [Google Scholar]
  36. Merlin, 2002. Lassa Fever KAP survey——Report. London, United Kingdom: Merlin. [Google Scholar]
  37. Masi E, Pino FA, Santos M d GS, Genehr L, Albuquerque JOM, Bancher AM, Alves JCM, , 2010. Socioeconomic and environmental risk factors for urban rodent infestation in Sao Paulo, Brazil. J Pest Sci 83: 231241.[Crossref] [Google Scholar]
  38. Promkerd P, Khoprasert Y, Virathavone P, Thoummabouth M, Sirisak O, Jakel T, , 2008. Factors explaining the abundance of rodents in the city of Luang Prabang, Lao PDR, as revealed by field and household surveys. Integr Zool 3: 1120.[Crossref] [Google Scholar]
  39. McCormick JB, Webb PA, Krebs JW, Johnson KM, Smith ES, , 1987. A prospective study of the epidemiology and ecology of Lassa fever. J Infect Dis 155: 437444.[Crossref] [Google Scholar]
  40. Sagripanti JL, Lytle CD, , 2011. Sensitivity to ultraviolet radiation of Lassa, vaccinia, and Ebola viruses dried on surfaces. Arch Virol 156: 489494.[Crossref] [Google Scholar]
  41. Monath TP, , 1975. Lassa fever: review of epidemiology and epizootiology. Bull World Health Organ 52: 577592. [Google Scholar]
  42. Borremans B, Vossen R, Becker-Ziaja B, Gryseels S, Hughes N, Van Gestel M, Van Houtte N, Gunther S, Leirs H, , 2015. Shedding dynamics of Morogoro virus, an African arenavirus closely related to Lassa virus, in its natural reservoir host Mastomys natalensis . Sci Rep 5: 10445.[Crossref] [Google Scholar]
  43. Whisson DA, Quinn JH, Collins KC, , 2007. Home range and movements of roof rats (Rattus rattus) in an old-growth Riparian forest, California. J Mammal 88: 589594.[Crossref] [Google Scholar]
  44. Foster S, King C, Patty B, Miller S, , 2011. Tree-climbing capabilities of Norway and ship rats. NZ J Zool 38: 285296.[Crossref] [Google Scholar]
  45. Feng AYT, Himsworth CG, , 2013. The secret life of the city rat: a review of the ecology of urban Norway and black rats (Rattus norvegicus and Rattus rattus). Urban Ecosyst 17: 149162.[Crossref] [Google Scholar]
  46. Fichet-Calvet E, Koulemou K, Koivogui L, Soropogui B, Sylla O, Lecompte E, Daffis S, Kouadio A, Kouassi Kan S, Akoua-Koffi C, Denys C, ter Meulen J, , 2005. Spatial distribution of commensal rodents in regions with high and low Lassa fever prevalence in Guinea. Belg J Zool 135 (Suppl): 6367. [Google Scholar]
  47. Fichet-Calvet E, Lecompte E, Koivogui L, Daffis S, ter Meulen J, , 2008. Reproductive characteristics of Mastomys natalensis and Lassa virus prevalence in Guinea, West Africa. Vector Borne Zoonotic Dis 8: 4148.[Crossref] [Google Scholar]
  48. Gratz NG, , 1997. The burden of rodent-borne diseases in Africa south of the Sahara. Belg J Zool 127: 7184. [Google Scholar]
  49. Han BA, Schmidt JP, Bowden SE, Drake JM, , 2015. Rodent reservoirs of future zoonotic diseases. Proc Natl Acad Sci USA 112: 70397044.[Crossref] [Google Scholar]
  50. Wolfe ND, Dunavan CP, Diamond J, , 2007. Origins of major human infectious diseases. Nature 447: 279283.[Crossref] [Google Scholar]
  51. Eisen RJ, Enscore RE, Atiku LA, Zielinski-Gutierrez E, Mpanga JT, Kajik E, Andama V, Mungujakisa C, Tibo E, MacMillan K, Borchert JN, Gage KL, , 2013. Evidence that rodent control strategies ought to be improved to enhance food security and reduce the risk of rodent-borne illnesses within subsistence farming villages in the plague-endemic West Nile region, Uganda. Int J Pest Manage 59: 259270.[Crossref] [Google Scholar]
  52. Coeurdassier M, Riols R, Decors A, Mionnet A, David F, Quintaine T, Truchetet D, Scheifler R, Giraudoux P, , 2014. Unintentional wildlife poisoning and proposals for sustainable management of rodents. Conserv Biol 28: 315321.[Crossref] [Google Scholar]
  53. Brown PR, Yee N, Singleton GR, Kenney AJ, Htwe NM, Myint M, Aye T, , 2008. Farmers' knowledge, attitudes, and practices for rodent management in Myanmar. Int J Pest Manage 54: 6976.[Crossref] [Google Scholar]
  54. World Bank, 2014. World Development Indicators: Sierra Leone. Available at: http://data.worldbank.org/country/sierra-leone. Accessed June 2014. [Google Scholar]
  55. Fichet-Calvet E, Olschlager S, Strecker T, Koivogui L, Becker-Ziaja B, Camara AB, Soropogui B, Magassouba N, Gunther S, , 2016. Spatial and temporal evolution of Lassa virus in the natural host population in Upper Guinea. Sci Rep 6: 21977.[Crossref] [Google Scholar]
  56. Glass GE, Johnson JS, Hodenbach GA, Disalvo CLJ, Peters CJ, Childs JE, Mills JN, , 1997. Experimental evaluation of rodent exclusion methods to reduce hantavirus transmission to humans in rural housing. Am J Trop Med Hyg 56: 359364. [Google Scholar]
  57. Hopkins AS, Whitetail-Eagle J, Corneli AL, Person B, Ettestad PJ, Dimenna M, Norstog J, Creswell J, Khan AS, Olson JG, Cavallaro KF, Bryan RT, Cheek JE, Begay B, Hoddenbach GA, Ksiazek TG, Mills JN, , 2002. Experimental evaluation of rodent exclusion methods to reduce hantavirus transmission to residents in a native American Community in New Mexico. Vector Borne Zoonotic Dis 2: 6168.[Crossref] [Google Scholar]

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  • Received : 17 Aug 2016
  • Accepted : 12 Dec 2016
  • Published online : 06 Feb 2017

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