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a dna vaccine delivered by dermal electroporation fully protects cynomolgus macaques against lassa fever.lassa virus (lasv) is an ambisense rna virus in the arenaviridae family and is the etiological agent of lassa fever, a severe hemorrhagic disease endemic to west and central africa. 1,2 there are no us food and drug administration (fda)-licensed vaccines available to prevent lassa fever. 1,2 in our previous studies, we developed a gene-optimized dna vaccine that encodes the glycoprotein precursor gene of lasv (josiah strain) and demonstrated that 3 vaccinations accompanied by dermal electroporat ...201729045192
understanding the cryptic nature of lassa fever in west africa.lassa fever (lf) is increasingly recognized by global health institutions as an important rodent-borne disease with severe impacts on some of west africa's poorest communities. however, our knowledge of lf ecology, epidemiology and distribution is limited, which presents barriers to both short-term disease forecasting and prediction of long-term impacts of environmental change on lassa virus (lasv) zoonotic transmission dynamics. here, we synthesize current knowledge to show that extrapolations ...201728875769
movement patterns of small rodents in lassa fever-endemic villages in guinea.the natal multimammate mouse (mastomys natalensis) is the reservoir host of lassa arenavirus, the etiological agent of lassa fever in humans. because there exists no vaccine for human use, rodent control and adjusting human behavior are currently considered to be the only options for lassa fever control. in order to develop efficient rodent control programs, more information about the host's ecology is needed. in this study, we investigated the spatial behavior of m. natalensis and other small r ...201829572697
natural history of aerosol induced lassa fever in non‑human primates.lassa virus (lasv), an arenavirus causing lassa fever, is endemic to west africa with up to 300,000 cases and between 5000 and 10,000 deaths per year. rarely seen in the united states, lassa virus is a cdc category a biological agent inasmuch deliberate aerosol exposure can have high mortality rates compared to naturally acquired infection. with the need for an animal model, specific countermeasures remain elusive as there is no fda-approved vaccine. this natural history of aerosolized lassa vir ...202032485952
quadrivalent vesiculovax vaccine protects nonhuman primates from viral-induced hemorrhagic fever and death.recent occurrences of filoviruses and the arenavirus lassa virus (lasv) in overlapping endemic areas of africa highlight the need for a prophylactic vaccine that would confer protection against all of these viruses that cause lethal hemorrhagic fever (hf). we developed a quadrivalent formulation of vesiculovax that contains recombinant vesicular stomatitis virus (rvsv) vectors expressing filovirus glycoproteins and that also contains a rvsv vector expressing the glycoprotein of a lineage iv stra ...202031820871
vaccines inducing immunity to lassa virus glycoprotein and nucleoprotein protect macaques after a single shot.lassa fever is a major threat in western africa. the large number of people living at risk for this disease calls for the development of a vaccine against lassa virus (lasv). we generated live-attenuated lasv vaccines based on measles virus and mopeia virus platforms and expressing different lasv antigens, with the aim to develop a vaccine able to protect after a single shot. we compared the efficacy of these vaccines against lasv in cynomolgus monkeys. the vaccines were well tolerated and prote ...201931578242
antibody therapy for lassa fever.serum from convalescent lassa fever patients was previously shown to be ineffective as a source of protective antibodies in some early studies. subsequently, monoclonal antibodies (mabs) to the lassa virus (lasv) glycoprotein produced by memory b cells of west african patients who survived lassa fever were identified. development of mabs as potential lassa immunotherapeutics was facilitated by structural studies and mutational analyses that identified protective epitopes on the prefusion form of ...201931401518
immunogenicity of a protective intradermal dna vaccine against lassa virus in cynomolgus macaques.lassa virus (lasv) is a hemorrhagic fever virus of the arenaviridae family with high rates of mortality and co-morbidities, including chronic seizures and permanent bilateral or unilateral deafness. lasv is endemic in west africa and lassa fever accounts for 10-16% of hospitalizations annually in parts of sierra leone and liberia according to the cdc. an ongoing outbreak in nigeria has resulted in 144 deaths in 568 cases confirmed as lasv as of november 2018, with many more suspected, highlighti ...201931071008
immune-mediated systemic vasculitis as the proposed cause of sudden-onset sensorineural hearing loss following lassa virus exposure in cynomolgus macaques.lassa virus (lasv) causes a severe, often fatal hemorrhagic disease in regions in africa where the disease is endemic, and approximately 30% of patients develop sudden-onset sensorineural hearing loss after recovering from acute disease. the causal mechanism of hearing loss in lasv-infected patients remains elusive. here, we report findings after closely examining the chronic disease experienced by surviving macaques assigned to lasv exposure control groups in two different studies. all nonhuman ...201830377282
virulent infection of outbred hartley guinea pigs with recombinant pichinde virus as a surrogate small animal model for human lassa fever.arenaviruses, such as lassa virus (lasv), can cause severe and fatal hemorrhagic fevers (e.g., lassa fever, lf) in humans with no vaccines or therapeutics. research on arenavirus-induced hemorrhagic fevers (ahfs) has been hampered by the highly virulent nature of these viral pathogens, which require high biocontainment laboratory, and the lack of an immune-competent small animal model that can recapitulate ahf disease and pathological features. guinea pig infected with pichinde virus (picv), an ...202032799623
pichinde virus infection of outbred hartley guinea pigs as a surrogate animal model for human lassa fever: histopathological and immunohistochemical analyses.lassa virus (lasv) is a mammarenavirus (arenavirus) that causes zoonotic infection in humans that can lead to fatal hemorrhagic lassa fever (lf) disease. currently, there are no fda-approved vaccines or therapeutics against lasv. development of treatments against lf and other related arenavirus-induced hemorrhagic fevers (ahfs) requires relevant animal models that can recapitulate clinical and pathological features of ahf diseases in humans. laboratory mice are generally resistant to lasv infect ...202032708789
households as hotspots of lassa fever? assessing the spatial distribution of lassa virus-infected rodents in rural villages of guinea.the natal multimammate mouse (mastomys natalensis) is the reservoir host of lassa virus (lasv), an arenavirus that causes lassa haemorrhagic fever in humans in west africa. while previous studies suggest that spillover risk is focal within rural villages due to the spatial behaviour of the rodents, the level of clustering was never specifically assessed. nevertheless, detailed information on the spatial distribution of infected rodents would be highly valuable to optimize lasv-control campaigns, ...202032459576
population structure of lassa mammarenavirus in west africa.lassa mammarenavirus (lasv) is the etiologic agent of lassa fever. in endemic regions in west africa, lasv genetic diversity tends to cluster by geographic area. seven lasv lineages are recognized, but the role of viral genetic determinants on disease presentation in humans is uncertain. we investigated the geographic structure and distribution of lasv in west africa. we found strong spatial clustering of lasv populations, with two major east-west and north-south diversity gradients. analysis of ...202032294960
structural insight into arenavirus replication machinery.arenaviruses can cause severe haemorrhagic fever and neurological diseases in humans and other animals, exemplified by lassa mammarenavirus, machupo mammarenavirus and lymphocytic choriomeningitis virus, posing great threats to public health1-4. these viruses encode a large multi-domain rna-dependent rna polymerase for transcription and replication of the viral genome5. viral polymerases are one of the leading antiviral therapeutic targets. however, the structure of arenavirus polymerase is not ...202032214249
determining ancestry between rodent- and human-derived virus sequences in endemic foci: towards a more integral molecular epidemiology of lassa fever within west africa.lassa fever is a viral hemorrhagic illness responsible for thousands of human deaths in west africa yearly. rodents are known as natural reservoirs of the causative lassa mammarenavirus (lasv) while humans are regarded as incidental, spill-over hosts. analysis of genetic sequences continues to add to our understanding of the evolutionary history, emergence patterns, and the epidemiology of lasv. hitherto, the source of data in such investigations has mainly comprised human clinical samples. pres ...202032046182
adenoviral vector-based vaccine is fully protective against lethal lassa fever challenge in hartley guinea pigs.lassa virus (lasv), the causative agent of lassa fever (lf), was first identified in 1969. since then, outbreaks in the endemic countries of nigeria, liberia, and sierra leone occur on an annual basis resulting in a case-fatality rate of 15-70% in hospitalized patients. there is currently no licensed vaccine and there are limited animal models to test vaccine efficacy. an estimated 37.7 million people are at risk of contracting lasv; therefore, there is an urgent need for the development of a sa ...201931561999
animal models for lassa virus infection.in humans, lassa virus infection can result in disease with hemorrhagic manifestations and high fatality rates. there are no approved treatments or vaccines available and the inherent danger of studying lassa virus means it can only be studied in high containment labs (bsl4). under these conditions, mouse models are becoming an important instrument in the study of lassa virus infection, disease and host responses. while guinea pigs and non-human primates are the critical components in assessing ...201931442921
vaccine platforms for the prevention of lassa fever.lassa fever is an acute viral haemorrhagic illness caused by lassa virus (lasv), which is endemic throughout much of west africa. the virus primarily circulates in the mastomys natalensis reservoir and is transmitted to humans through contact with infectious rodents or their secretions; human-to-human transmission is documented as well. with the exception of dengue fever, lasv has the highest human impact of any haemorrhagic fever virus. on-going outbreaks in nigeria have resulted in unprecedent ...201931026485
evaluation of rodent control to fight lassa fever based on field data and mathematical modelling.the natal multimammate mouse (mastomys natalensis) is the reservoir host of lassa virus, an arenavirus that causes lassa haemorrhagic fever in humans in west africa. because no vaccine exists and therapeutic options are limited, preventing infection through rodent control and human behavioural measures is currently considered to be the only option. in order to assess the efficacy of rodent control, we performed a 4-year field experiment in rural upper guinea and developed a mathematical model to ...201931007139
lassa virus diversity and feasibility for universal prophylactic vaccine.lassa virus (lasv) is a highly prevalent mammarenavirus in west africa and is maintained in nature in a persistently infected rodent host, mastomys natalensis, which is widely spread in sub-saharan africa. lasv infection of humans can cause lassa fever (lf), a disease associated with high morbidity and significant mortality. recent evidence indicates an lasv expansion outside its traditional endemic areas. in 2017, the world health organization (who) included lasv in top-priority pathogens and r ...201930774934
multiple dna viruses identified in multimammate mouse (mastomys natalensis) populations from across regions of sub-saharan africa.the multimammate mouse (mastomys natalensis; m. natalensis) serves as the main reservoir for the zoonotic arenavirus lassa virus (lasv), and this has led to considerable investigation into the distribution of lasv and other related arenaviruses in this host species. in contrast to the situation with arenaviruses, the presence of other viruses in m. natalensis remains largely unexplored. in this study, herpesviruses and polyomaviruses were identified and partially characterized by pcr methods, se ...202032754877
widespread arenavirus occurrence and seroprevalence in small mammals, nigeria.lassa fever, killing thousands of people annually, is the most reported viral zoonotic disease in nigeria. recently, different rodent species carrying diverse lineages of the lassa virus (lasv) in addition to a novel mobala-like genetic sequence were detected within the country. here, screening 906 small mammal specimens from 11 localities for igg antibodies and incorporating previous pcr detection data involving the same populations, we further describe arenavirus prevalence across nigeria in r ...201830005641
three arenaviruses in three subspecific natal multimammate mouse taxa in tanzania: same host specificity, but different spatial genetic structure?mastomys natalensis is widespread in sub-saharan africa and hosts several arenavirus species, including the pathogenic zoonotic lassa virus in west africa. mitochondrial lineages sub-divide the range of m. natalensis and have been associated with cryptic structure within the species. to test specificity of arenaviruses to hosts carrying these lineages, we screened 1772 m. natalensis in a large area of tanzania where three mitochondrial lineages meet. we detected fifty-two individuals that were p ...202033033629
bayesian estimation of lassa virus epidemiological parameters: implications for spillover prevention using wildlife vaccination.lassa virus is a significant burden on human health throughout its endemic region in west africa, with most human infections the result of spillover from the primary rodent reservoir of the virus, the natal multimammate mouse, m. natalensis. here we develop a bayesian methodology for estimating epidemiological parameters of lassa virus within its rodent reservoir and for generating probabilistic predictions for the efficacy of rodent vaccination programs. our approach uses approximate bayesian c ...202032956349
density dependence and persistence of morogoro arenavirus transmission in a fluctuating population of its reservoir host.a key aim in wildlife disease ecology is to understand how host and parasite characteristics influence parasite transmission and persistence. variation in host population density can have strong impacts on transmission and outbreaks, and theory predicts particular transmission-density patterns depending on how parasites are transmitted between individuals. here, we present the results of a study on the dynamics of morogoro arenavirus in a population of multimammate mice (mastomys natalensis). th ...202031545505
development and evaluation of a one-step quantitative rt-pcr assay for detection of lassa virus.lassa fever is a severe viral hemorrhagic illness caused by lassa virus. based on estimates, the number of lasv infections ranges from 300,000 to 500,000 cases in endemic areas with a fatality rate of 1%. development of fast and sensitive tools for the control and prevention of lassa virus infection as well as for clinical diagnostics of lassa fever are crucial. here we reported development and evaluation of a one-step quantitative rt-qpcr assay for the lassa virus detection - lasv-fl. this assa ...201931170468
rodent control to fight lassa fever: evaluation and lessons learned from a 4-year study in upper guinea.lassa fever is a viral haemorrhagic fever caused by an arenavirus. the disease is endemic in west african countries, including guinea. the rodents mastomys natalensis and mastomys erythroleucus have been identified as lassa virus reservoirs in guinea. in the absence of a vaccine, rodent control and human behavioural changes are the only options to prevent lassa fever in highly endemic areas. we performed a 4 year intervention based on chemical rodent control, utilizing anticoagulant rodenticides ...201830399142
lassa virus antigen distribution and inflammation in the ear of infected strain 13/n guinea pigs.sudden-onset sensorineuronal hearing loss (snhl) is reported in approximately one-third of survivors of lassa fever (lf) and remains the most prominent cause of lassa virus (lasv)-associated morbidity in convalescence. using a guinea pig model of lf, and incorporating animals from lasv vaccine trials, we investigated viral antigen distribution and histopathology in the ear of infected animals to elucidate the pathogenesis of hearing loss associated with lasv infection. antigen was detected only ...202032898586
a lassa virus live-attenuated vaccine candidate based on rearrangement of the intergenic region.lassa virus (lasv) poses a significant public health problem within the regions of lassa fever endemicity in western africa. lasv infects several hundred thousand individuals yearly, and a considerable number of lassa fever cases are associated with high morbidity and lethality. no approved lasv vaccine is available, and current therapy is limited to an off-label usage of ribavirin that is only partially effective and associated with significant side effects. the impact of lassa fever on human h ...202032209677
a lassa fever live-attenuated vaccine based on codon deoptimization of the viral glycoprotein gene.lassa virus (lasv) is endemic in western africa and is estimated to infect hundreds of thousands of individuals annually. a considerable number of these infections result in lassa fever (lf), which is associated with significant morbidity and a case-fatality rate as high as 69% among hospitalized confirmed patients. u.s. food and drug administration-approved lf vaccines are not available. current antiviral treatment is limited to off-label use of a nucleoside analogue, ribavirin, that is only pa ...202032098811
lethal infection of lassa virus isolated from a human clinical sample in outbred guinea pigs without adaptation.lassa virus (lasv), a member of the family arenaviridae, is the causative agent of lassa fever. lassa virus is endemic in west african countries, such as nigeria, guinea, liberia, and sierra leone, and causes outbreaks annually. lassa fever onset begins with "flu-like" symptoms and may develop into lethal hemorrhagic disease in severe cases. although lassa virus is one of the most alarming pathogens from a public health perspective, there are few licensed vaccines or therapeutics against lassa f ...201931554720
a vaccine based on recombinant modified vaccinia ankara containing the nucleoprotein from lassa virus protects against disease progression in a guinea pig model.lassa fever remains the most imported viral haemorrhagic fever in europe and is responsible for 5000 deaths per year throughout western africa. there is no vaccine and treatment is often ineffective. we have developed a vaccine based on modified vaccinia ankara expressing the nucleoprotein from lassa virus (mvalassanp). this study investigated the immunogenicity (in mice) and efficacy (in guinea pigs) of the mvalassanp vaccine as a prime/boost or single vaccination regime. elisa and elispot assa ...201931331770
protection from lethal lassa disease can be achieved both before and after virus exposure by administration of single-cycle replicating lassa virus replicon particles.lassa fever is a frequently severe human disease that is endemic to several countries in west africa. to date, no licensed vaccines are available to prevent lassa virus (lasv) infection, even though lassa fever is thought to be an important disease contributing to mortality and both acute and chronic morbidity. we have previously described a vaccine candidate composed of single-cycle lasv replicon particles (vrps) and a stable cell line for their production. here, we refine the genetic compositi ...201931152662
lassa virus targeting of anterior uvea and endothelium of cornea and conjunctiva in eye of guinea pig model.lassa virus (lasv), a hemorrhagic fever virus endemic to west africa, causes conjunctivitis in patients with acute disease. to examine ocular manifestations of lasv, we histologically examined eyes from infected guinea pigs. in fatal disease, lasv immunostaining was most prominent in the anterior uvea, especially in the filtration angle, ciliary body, and iris and in and around vessels in the bulbar conjunctiva and peripheral cornea, where it co-localized with an endothelial marker (platelet end ...201931002065
a recombinant vesicular stomatitis-based lassa fever vaccine elicits rapid and long-term protection from lethal lassa virus infection in guinea pigs.the world health organization has identified lassa virus (lasv) as one of the top five pathogens to cause a severe outbreak in the near future. this study assesses the ability of a leading vaccine candidate, recombinant vesicular stomatitis virus expressing lasv glycoprotein (vsvδg/lasvgpc), and its ability to induce rapid and long-term immunity to lethal guinea pig-adapted lasv (gpa-lasv). outbred guinea pigs were vaccinated with a single dose of vsvδg/lasvgpc followed by a lethal challenge of ...201930774999
persistence of lassa virus associated with severe systemic arteritis in convalescing guinea pigs (cavia porcellus).lassa fever (lf) survivors develop various clinical manifestations including polyserositis, myalgia, epididymitis, and hearing loss weeks to months after recovery from acute infection. we demonstrate a systemic lymphoplasmacytic and histiocytic arteritis and periarteritis in guinea pigs more than 2 months after recovery from acute lassa virus (lasv) infection. lasv was detected in the arterial tunica media smooth muscle cells by immunohistochemistry, in situ hybridization, and transmission elect ...201930517671
non-neutralizing antibodies elicited by recombinant lassa-rabies vaccine are critical for protection against lassa fever.lassa fever (lf), caused by lassa virus (lasv), is a viral hemorrhagic fever for which no approved vaccine or potent antiviral treatment is available. lf is a who priority disease and, together with rabies, a major health burden in west africa. here we present the development and characterization of an inactivated recombinant lasv and rabies vaccine candidate (lassarab) that expresses a codon-optimized lasv glycoprotein (cogpc) and is adjuvanted by a tlr-4 agonist (gla-se). lassarab elicits last ...201830310067
the s genome segment is sufficient to maintain pathogenicity in intra-clade lassa virus reassortants in a guinea pig model.genome reassortment in lassa virus (lasv) has been reported in nature, but phenotypic consequences of this phenomenon are not well described. here we characterize, both in vitro and in vivo, reassortment between 2 lasv strains: the prototypic 1976 josiah strain and a more recently isolated 2015 liberian strain. in vitro analysis showed that although cis- and trans-acting elements of viral rna synthesis were compatible between strains, reassortants demonstrated different levels of viral replicati ...201830050872
use of a scalable replicon-particle vaccine to protect against lethal lassa virus infection in the guinea pig model.lassa fever is a viral zoonosis that can be transmitted from person to person, especially in the hospital setting. the disease is endemic to several countries in west africa and can be a major contributor to morbidity and mortality in affected areas. there are no approved vaccines to prevent lassa virus infection. in this work, we present a vaccine candidate that combines the scalability and efficacy benefits of a live vaccine with the safety benefits of single-cycle replication. the system cons ...201829800368
comparative genomic characterization of the multimammate mouse mastomys coucha.mastomys are the most widespread african rodent and carriers of various diseases such as the plague or lassa virus. in addition, mastomys have rapidly gained a large number of mammary glands. here, we generated a genome, variome, and transcriptomes for mastomys coucha. as mastomys diverged at similar times from mouse and rat, we demonstrate their utility as a comparative genomic tool for these commonly used animal models. furthermore, we identified over 500 mastomys accelerated regions, often re ...201931424545
lassa virus in pygmy mice, benin, 2016-2017.lassa virus has been identified in 3 pygmy mice, mus baoulei, in central benin. the glycoprotein and nucleoprotein sequences cluster with the togo strain. these mice may be a new reservoir for lassa virus in ghana, togo, and benin.201931365854
phylogeography of lassa virus in nigeria.lassa virus is genetically diverse with several lineages circulating in west africa. this study aimed at describing the sequence variability of lassa virus across nigeria and inferring its spatiotemporal evolution. we sequenced and isolated 77 lassa virus strains from 16 nigerian states. the final data set, including previous works, comprised metadata and sequences of 219 unique strains sampled between 1969 and 2018 in 22 states. most of this data originated from lassa fever patients diagnosed a ...201931413134
adjuvant formulated virus-like particles expressing native-like forms of the lassa virus envelope surface glycoprotein are immunogenic and induce antibodies with broadly neutralizing activity.lassa mammarenavirus (lasv) is a rodent-borne arenavirus endemic to several west african countries. it is the causative agent of human lassa fever, an acute viral hemorrhagic fever disease. to date, no therapeutics or vaccines against lasv have obtained regulatory approval. polyclonal neutralizing antibodies derived from hyperimmunized animals may offer a useful strategy for prophylactic and therapeutic intervention to combat human lasv infections. the lasv envelope surface glycoprotein complex ...202032802410
host-driven phosphorylation appears to regulate the budding activity of the lassa virus matrix protein.lassa mammarenavirus (lasv) is an enveloped rna virus that can cause lassa fever, an acute hemorrhagic fever syndrome associated with significant morbidity and high rates of fatality in endemic regions of western africa. the arenavirus matrix protein z has several functions during the virus life cycle, including coordinating viral assembly, driving the release of new virus particles, regulating viral polymerase activity, and antagonizing the host antiviral response. there is limited knowledge re ...201830544850
experimental morogoro virus infection in its natural host, mastomys natalensis.natural hosts of most arenaviruses are rodents. the human-pathogenic lassa virus and several non-pathogenic arenaviruses such as morogoro virus (morv) share the same host species, namely mastomys natalensis (m. natalensis). in this study, we investigated the history of infection and virus transmission within the natural host population. to this end, we infected m. natalensis at different ages with morv and measured the health status of the animals, virus load in blood and organs, the development ...202134067011
lassa virus vaccine candidate ml29 generates truncated viral rnas which contribute to interfering activity and attenuation.defective interfering particles (dips) are naturally occurring products during virus replication in infected cells. dips contain defective viral genomes (dvgs) and interfere with replication and propagation of their corresponding standard viral genomes by competing for viral and cellular resources, as well as promoting innate immune antiviral responses. consequently, for many different viruses, including mammarenaviruses, dips play key roles in the outcome of infection. due to their ability to b ...202133573250
chadox1-vectored lassa fever vaccine elicits a robust cellular and humoral immune response and protects guinea pigs against lethal lassa virus challenge.lassa virus (lasv) infects hundreds of thousands of individuals each year, highlighting the need for the accelerated development of preventive, diagnostic, and therapeutic interventions. to date, no vaccine has been licensed for lasv. chadox1-lassa-gpc is a chimpanzee adenovirus-vectored vaccine encoding the josiah strain lasv glycoprotein precursor (gpc) gene. in the following study, we show that chadox1-lassa-gpc is immunogenic, inducing robust t-cell and antibody responses in mice. furthermor ...202133654106
a single-shot lassa vaccine induces long-term immunity and protects cynomolgus monkeys against heterologous strains.a safe and protective lassa virus vaccine is crucially needed in western africa to stem the recurrent outbreaks of lassa virus infections in nigeria and the emergence of lassa virus in previously unaffected countries, such as benin and togo. major challenges in developing a lassa virus vaccine include the high diversity of circulating strains and their reemergence from 1 year to another. to address each of these challenges, we immunized cynomolgus monkeys with a measles virus vector expressing t ...202134108251
tetravalent rabies-vectored filovirus and lassa fever vaccine induces long-term immunity in nonhuman primates.the objective of this study is to evaluate the immunogenicity of adjuvanted monovalent rabies virus-based vaccine candidates against ebola virus (filorab1), sudan virus (filorab2), marburg virus (filorab3), lassa virus (lassarab1), and combined trivalent vaccine candidate (filorab1-3) and tetravalent vaccine candidate (filorab1-3 and lassarab) in nonhuman primates.202133421072
systemic viral spreading and defective host responses are associated with fatal lassa fever in macaques.lassa virus (lasv) is endemic in west africa and induces a viral hemorrhagic fever (vhf) with up to 30% lethality among clinical cases. the mechanisms involved in control of lassa fever or, in contrast, the ensuing catastrophic illness and death are poorly understood. we used the cynomolgus monkey model to reproduce the human disease with asymptomatic to mild or fatal disease. after initial replication at the inoculation site, lasv reached the secondary lymphoid organs. lasv did not spread furth ...202133398113
mastomys natalensis has a cellular immune response profile distinct from laboratory mice.the multimammate mouse (mastomys natalensis; m. natalensis) has been identified as a major reservoir for multiple human pathogens including lassa virus (lasv), leishmania spp., yersinia spp., and borrelia spp. although m. natalensis are related to well-characterized mouse and rat species commonly used in laboratory models, there is an absence of established assays and reagents to study the host immune responses of m. natalensis. as a result, there are major limitations to our understanding of im ...202133922222
epidemiology of lassa fever.lassa fever (lf) is a lethal hemorrhagic disease primarily concentrated in the tropical savannah regions of nigeria and the mano river union countries of sierra leone, liberia, and guinea. endemic hotspots within these countries have had recurrent exposure to lassa virus (lasv) via continual spillover from the host reservoir mastomys natalensis. increased trade and travel throughout the region have spread the virus to previously unexposed countries, including ghana, benin, mali, and côte d'ivoir ...202133861373
establishment of a genetically confirmed breeding colony of mastomys natalensis from wild-caught founders from west africa.mastomys natalensis are a ubiquitous and often dominant rodent across sub-saharan africa. importantly, they are a natural reservoir for microbial pathogens including lassa virus (lasv), the etiological agent of lassa fever in humans. lassa-infected rodents have been documented across west africa and coincide with regions where annual outbreaks occur. zoonotic transmission to humans most often occurs directly from infected rodents. little is known about lasv infection kinetics and transmissibilit ...202133807214
hunting and consumption of rodents by children in the lassa fever endemic area of faranah, guinea.as a consequence of the ebola outbreak, human-animal contact has gained importance for zoonotic transmission surveillance. in faranah (upper guinea), daily life is intertwined with rodents, such as the natal multimammate mouse, mastomys natalensis; a reservoir for lassa virus (lasv). however, this contact is rarely perceived as a health risk by residents, although lassa fever (lf) is known to be endemic to this region. conversely, these observations remain a great concern for global health agend ...202133730025
ecology of lassa virus.individuals living in endemic hotspots of lassa fever have recurrent exposure to lassa virus (lasv) via spillover from the primary host reservoir mastomys natalensis. despite m. natalensis being broadly distributed across sub-saharan africa, lassa fever is only found in west africa. in recent years, new lasv reservoirs have been identified. erudition of rodent habitats, reproduction and fecundity, movement patterns, and spatial preferences are essential to institute preventative measures against ...202133564902
hematology and clinical chemistry reference ranges for laboratory-bred natal multimammate mice (mastomys natalensis).laboratory-controlled physiological data for the multimammate rat (mastomys natalensis) are scarce, despite this species being a known reservoir and vector for zoonotic viruses, including the highly pathogenic lassa virus, as well as other arenaviruses and many species of bacteria. for this reason, m. natalensis is an important rodent for the study of host-virus interactions within laboratory settings. herein, we provide basic blood parameters for age- and sex-distributed animals in regards to b ...202133513733
lassa virus circulation in small mammal populations in bo district, sierra leone.lassa fever is a viral hemorrhagic fever caused by the lassa virus lasv, which was first isolated in the rodent mastomys natalensis in 1974 in kenema, sierra leone. as little is known about the abundance and the presence of lasv in rodents living in the bo area, we carried out a small mammal longitudinal population survey. a standardized trapping session was performed in various habitats and seasons in six villages over two years (2014-2016) and samples collected were tested for arenavirus igg a ...202133466234
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