Seroprevalence of anti-Lassa Virus IgG antibodies in three districts of Sierra Leone: A cross-sectional, population-based study.

Background: Lassa virus (LASV), the cause of the acute viral hemorrhagic illness Lassa fever (LF), is endemic in West Africa. Infections in humans occur mainly after exposure to infected excrement or urine of the rodent-host, Mastomys natalensis. The prevalence of exposure to LASV in Sierra Leone is crudely estimated and largely unknown.

Local disease-ecosystem-livelihood dynamics: reflections from comparative case studies in Africa.

This article explores the implications for human health of local interactions between disease, ecosystems and livelihoods. Five interdisciplinary case studies addressed zoonotic diseases in African settings: Rift Valley fever (RVF) in Kenya, human African trypanosomiasis in Zambia and Zimbabwe, Lassa fever in Sierra Leone and henipaviruses in Ghana. Each explored how ecological changes and human-ecosystem interactions affect pathogen dynamics and hence the likelihood of zoonotic spillover and transmission, and how socially differentiated peoples' interactions with ecosystems and animals affect their exposure to disease.

Genomic surveillance elucidates Ebola virus origin and transmission during the 2014 outbreak.

In its largest outbreak, Ebola virus disease is spreading through Guinea, Liberia, Sierra Leone, and Nigeria. We sequenced 99 Ebola virus genomes from 78 patients in Sierra Leone to ~2000× coverage. We observed a rapid accumulation of interhost and intrahost genetic variation, allowing us to characterize patterns of viral transmission over the initial weeks of the epidemic.

Lassa fever in Guinea: II. Distribution and prevalence of Lassa virus infection in small mammals.

Rodents of the genus Mastomys form the reservoir for Lassa virus (LV), an arenavirus that causes a potentially severe hemorrhagic illness, Lassa fever (LF). Although Mastomys rodents exist throughout sub-Saharan Africa, areas of human LF appear to be quite focal. The distribution of small mammals and LV-infected Mastomys has been assessed in only a few countries.