| biological species in praomys (mastomys) natalensis (smith), a rodent carrier of lassa virus and bubonic plague in africa. | plague has been known from countries surrounding rhodesia from as early as 1935, but was first reported from rhodesia in 1974. part of our investigation of the complex ecosystem involving yersinia pestis is critical assessment of the evolutionary status of natural populations belonging to formal, taxonomic species of implicated rodents. we present data on chromosomal and hemoglobin variation in sympatric populations and laboratory produced hybrids that give unequivocal evidence for at least two ... | 1978 | 677375 |
| lassa virus isolation from mastomys natalensis rodents during an epidemic in sierra leone. | lassa fever is a severe febrile illness of man, first recognized in west africa in 1969. during an epidemic in sierra leone, lassa virus was isolated for the first time from wild rodents of mastomys natalensis. a high prevalence of infected mastomys was found in houses occupied by patients with lassa fever. the data presented provide the first demonstration of an extra-human cycle of lassa virus transmission and suggest that rodent control may be an effective method of limiting the disease. | 1974 | 4833828 |
| the binding of staphylococcal protein a by the sera of different animal species. | the capacity of purified immunoglobulin or serum to bind (125i)-labeled staphylococcal protein a (spa) was measured by means of an immunofiltration assay that facilitated the examination of large numbers of sera and required only a minute quantity of each. sera from 80 species, including humans, laboratory animals, domestic animals, and a variety of african mammals were examined. a wide interspecies variation in the spa-binding capacity of serum immunoglobulins was confirmed. only small variatio ... | 1982 | 7061862 |
| imported lassa fever--new jersey, 2004. | lassa fever is an acute viral illness caused by lassa virus, which is hosted by rodents in the mastomys natalensis species complex and rarely imported to countries outside of those areas in africa where the disease is endemic. lassa fever is characterized by fever, muscle aches, sore throat, nausea, vomiting, and chest and abdominal pain. approximately 15%-20% of patients hospitalized for lassa fever die from the illness; however, approximately 80% of human infections with lassa virus are mild o ... | 2004 | 15457145 |
| recovery of a lassa-related arenavirus in zimbabwe. | immunofluorescent antibodies to "mozambique" virus, a close relative of lassa virus, were found in 11 of 55 mastomys natalensis and 1 of 13 aethomys chrysophilus rodents captured near que que and chiredzi, zimbabwe. six strains of mozambique virus, identified by use of specific monoclonal antibodies to the agent, were recovered from visceral tissues of m. natalensis rodents. all mastomys having virus or antibodies to this agent were of the chromosomal form 2n = 32 (m. natalensis). these data ext ... | 1981 | 7034562 |
| case-control study of mastomys natalensis and humans in lassa virus-infected households in sierra leone. | lassa virus infection and antibodies were studied in households where lassa fever cases occurred, and compared to those in nearest neighbor houses and "far" houses located across the village from case houses. seventy-nine percent of all rodents caught in the houses were mastomys, the natural reservoir of lassa virus. rodent infection was not randomly distributed, but rather focal. thirty-nine percent of the mastomys in case houses were viremic, compared to 3.7% in control houses. human antibody ... | 1983 | 6881432 |
| a prospective study of the epidemiology and ecology of lassa fever. | in studies of lassa fever in sierra leone, the prevalence of human antibody to lassa virus ranged from 8% to 52%. mastomys natalensis, the reservoir of lassa virus, constituted 50%-60% of the rodents captured in houses but only 10%-20% of those captured in surrounding agriculture and bush areas (chi 2 = 90.2, p less than 10(-6), df = 1), a finding suggesting that houses are the most-important location for transmission of lassa virus. viral infection of mastomys from houses ranged from 0% to 80%. ... | 1987 | 3805771 |
| lassa virus infection in mastomys natalensis in sierra leone. gross and microscopic findings in infected and uninfected animals. | pathological examinations of 28 wild-caught mastomys natalensis from sierra leone, 14 of which were positive for lassa virus by tissue culture, are reported. the high frequency of neoplastic and degenerative diseases observed among older animals in closed colonies of m. natalensis were not observed in the wild animals studied. this is probably a reflection of the age distribution of the study population, since the life expectancy of wild mastomys is less than a year. inflammatory lesions were no ... | 1975 | 1085221 |
| the ecology of praomys (mastomys) natalensis in southern africa. | the only non-human host of lassa virus so far identified is the multimammate mouse, praomys (mastomys) natalensis, but its precise role in the natural lassa fever cycle remains to be determined. this species is also an important link in the plague cycle in southern africa and is one of the commonest rodents of africa. it is a prolific breeder and can be kept and bred easily in captivity. it is thus an excellent laboratory animal, although it needs to be handled with care because it is aggressive ... | 1975 | 1085218 |
| recent isolations of lassa virus from nigerian rodents. | rodents were trapped in the benue-plateau and north-eastern states of nigeria where lassa fever had been reported in previous years. eight lassa virus strains were isolated from tissues and blood of rodents identified in the field as being of 3 different species: mastomys natalensis, rattus rattus, and mus minutoides. all the infected rodents were collected in village habitats. these isolations indicate the presence of lassa virus in wild rodents in nigeria during periods when no human infection ... | 1975 | 1085216 |
| lassa fever (arenaviruses) as a public health problem. | two "new" virus infections, marburg and lassa fever, now constitute diseases of public health importance in several countries of africa, especially west africa. lassa fever has an insidious onset, is initially difficult to diagnose, has "nonspecific" clinical symptoms which have been confused with yellow fever and typhoid, shows evidence of persistent infection, is tremendously contagious, has a high mortality rate, and in particular exhibits unusual nosocomial propensity. it has also been shown ... | 1976 | 1026322 |
| comparative pathology of lassa virus infection in monkeys, guinea-pigs, and mastomys natalensis. | experimental lassa virus infections of squirrel monkeys, guinea-pigs, and the african multimammate rat, mastomys natalensis, were studied virologically and pathologically. in the monkeys, early viral lymphoreticulotropism, hepatotropism, nephrotropism, and viraemia were noted. at the time of death, viral titres in nearly all target organs were associated with necrotic changes: splenic lymphoid necrosis, renal tubular necrosis, myocarditis, arteritis, and hepatocytic regeneration. in convalescent ... | 1975 | 821625 |
| lassa fever: review of epidemiology and epizootiology. | the basic ecology of lassa fever appears to involve enzootic transmission of virus in commensal populations of a single murine species, mastomys natalensis. virus may spill over from the rodent cycle to man by various routes. secondary spread between humans may occur within domiciliary groups, and persons infected within the community who develop clinical disease may introduce the virus into hospital and begin a cycle of nosocomial infection.between 1969, when lassa fever was first described, an ... | 1975 | 782738 |
| isolation of an arenavirus closely related to lassa virus from mastomys natalensis in south-east africa. | five unidentified virus strains were recovered from the multimammate mouse ,mastomys natalensis, during the course of studies on arbovirus infections in mozambique. these agents were found to be morphologically and immunologically related to lassa virus. four of 19 sera from mastomys captured in the study area had antibodies to both lassa virus and one of the unidentified strains. although not definitive, the differences noted in results of complement fixation and indirect immunofluorescent test ... | 1977 | 304387 |
| the structure of rodent faunas associated with arenaviral infections. | the biogeographical examination of rodent faunas associated with arenaviruses reveals two distinct patterns. lymphocytic choriomeningitis (lcm) virus is associated primarily with a single murid species, mus musculus, although it is also known to cause laboratory infections in other species. on the other hand, the arenaviruses from the western hemisphere are associated exclusively with a large and diverse group of cricetid rodents. studies to date, although limited, have not demonstrated their as ... | 1975 | 182403 |
| at home with mastomys and rattus: human-rodent interactions and potential for primary transmission of lassa virus in domestic spaces. | the multimammate mouse (mastomys natalensis) 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 (n = 51), a quantitative survey ( ... | 2017 | 28167603 |
| advanced vaccine candidates for lassa fever. | lassa virus (lasv) is the most prominent human pathogen of the arenaviridae. the virus is transmitted to humans by a rodent reservoir, mastomys natalensis, and is capable of causing lethal lassa fever (lf). lasv has the highest human impact of any of the viral hemorrhagic fevers (with the exception of dengue fever) with an estimated several hundred thousand infections annually, resulting in thousands of deaths in western africa. the sizeable disease burden, numerous imported cases of lf in non-e ... | 2012 | 23202493 |
| novel arenavirus, zambia. | to investigate arenavirus in zambia, we characterized virus from the kidneys of 5 arenavirus rna-positive rodents (mastomys natalensis) among 263 captured. full-genome sequences of the viruses suggested that they were new strains similar to lassa virus-related arenaviruses. analyzing samples from additional rodents and other species can elucidate epizootiologic aspects of arenaviruses. | 2011 | 22000372 |
| novel arenavirus sequences in hylomyscus sp. and mus (nannomys) setulosus from c+¦te d'ivoire: implications for evolution of arenaviruses in africa. | this study aimed to identify new arenaviruses and gather insights in the evolution of arenaviruses in africa. during 2003 through 2005, 1,228 small mammals representing 14 different genera were trapped in 9 villages in south, east, and middle west of c+¦te d'ivoire. specimens were screened by pan-old world arenavirus rt-pcrs targeting s and l rna segments as well as immunofluorescence assay. sequences of two novel tentative species of the family arenaviridae, menekre and gbagroube virus, were de ... | 2011 | 21695269 |
| presence of mopeia virus, an african arenavirus, related to biotope and individual rodent host characteristics: implications for virus transmission. | abstract the east african mopeia virus (mopv) is an arenavirus closely related to the highly pathogenic west african lassa virus, even sharing the same reservoir rodent host mastomys natalensis. because mopv is not known to cause human disease, it offers a unique alternative for studying lassa virus transmission. we investigated how habitat, population density, and host characteristics are related to mopv occurrence in m. natalensis populations in morogoro, tanzania. in 3 contrasting habitats, 5 ... | 2010 | 21142956 |
| rodent host cell/lassa virus interactions: evolution and expression of α-dystroglycan, large-1 and large-2 genes, with special emphasis on the mastomys genus. | arenaviruses are usually rodent-borne viruses that constitute a major threat for human health. among them, lassa fever virus (lfv) occurs in western africa where it infects hundreds of thousands of people annually. according to the most recent surveys, lfv is hosted by one of the multimammate rats, mastomys natalensis, but has never been detected in its sibling and sometimes sympatric species mastomys erythroleucus. this pattern suggests that intrinsic, i.e. genetic properties underlie such a dr ... | 2010 | 20674789 |
| prevalence and risk factors of lassa seropositivity in inhabitants of the forest region of guinea: a cross-sectional study. | lassa fever is a viral hemorrhagic fever endemic in west africa. the reservoir host of the virus is a multimammate rat, mastomys natalensis. prevalence estimates of lassa virus antibodies in humans vary greatly between studies, and the main modes of transmission of the virus from rodents to humans remain unclear. we aimed to (i) estimate the prevalence of lassa virus-specific igg antibodies (lv igg) in the human population of a rural area of guinea, and (ii) identify risk factors for positive lv ... | 2009 | 19924222 |
| risk maps of lassa fever in west africa. | lassa fever is caused by a viral haemorrhagic arenavirus that affects two to three million people in west africa, causing a mortality of between 5,000 and 10,000 each year. the natural reservoir of lassa virus is the multi-mammate rat mastomys natalensis, which lives in houses and surrounding fields. with the aim of gaining more information to control this disease, we here carry out a spatial analysis of lassa fever data from human cases and infected rodent hosts covering the period 1965-2007. i ... | 2009 | 19255625 |
| host and viral traits predict zoonotic spillover from mammals. | the majority of human emerging infectious diseases are zoonotic, with viruses that originate in wild mammals of particular concern (for example, hiv, ebola and sars). understanding patterns of viral diversity in wildlife and determinants of successful cross-species transmission, or spillover, are therefore key goals for pandemic surveillance programs. however, few analytical tools exist to identify which host species are likely to harbour the next human virus, or which viruses can cross species ... | 2017 | 28636590 |
| reproductive characteristics of mastomys natalensis and lassa virus prevalence in guinea, west africa. | we recently reported increased prevalence of lassa virus (lasv) infection in mastomys natalensis during the rainy season in guinea, west africa. here, the association of lasv prevalence with fecundity, fertility, and the age structure of the rodent population was analyzed using data from the previous study. the animals reproduced throughout the year, but highest fecundity was observed during the rainy season. accordingly, the rodent population was aged at the beginning and young at the end of th ... | 2008 | 18237265 |
| fluctuation of abundance and lassa virus prevalence in mastomys natalensis in guinea, west africa. | based on empiric surveillance data, the incidence of human lassa fever (lf) cases in guinea and other west african countries has been reported to increase during the dry season compared to the rainy season. to investigate possible links with the ecology of the rodent reservoir of the virus, we conducted a 2-year longitudinal survey of mastomys natalensis in a region of high human lassa virus (lasv) seropositivity in guinea. standardized rodent trapping with similar trapping efforts between seaso ... | 2007 | 17627428 |
| lassa fever in west african sub-region: an overview. | lassa fever is an acute viral zoonotic illness caused by lassa virus, an arenavirus known to be responsible for a severe haemorrhagic fever characterised by fever, muscle aches, sore throat, nausea, vomiting and, chest and abdominal pain. the virus exhibits persistent, asymptomatic infection with profuse urinary virus excretion in the ubiquitous rodent vector, mastomys natalensis. lassa fever is endemic in west africa and has been reported from sierra leone, guinea, liberia, and nigeria. some st ... | 2007 | 17378212 |
| mastomys natalensis and lassa fever, west africa. | pcr screening of 1,482 murid rodents from 13 genera caught in 18 different localities of guinea, west africa, showed lassa virus infection only in molecularly typed mastomys natalensis. distribution of this rodent and relative abundance compared with m. erythroleucus correlates geographically with lassa virus seroprevalence in humans. | 2006 | 17326956 |
| [the mammals of guinea as reservoirs and carriers of arboviruses]. | a great body of data on the fauna and ecology of wild mammals and their participation in the circulation of arboviruses were collected when the ecology of the latter of the republic of guinea was studied in 1978 to 1989. a hundred and eighteen species belonging to 10 orders were identified. over 2,000 biological specimens were virologically and serologically examined. six arboviruses were isolated. these included dugbe virus (from the hussar monkey cercopithecus (erythrocebus patas) and 5 viruse ... | 2006 | 16562748 |
| lassa virus: seroepidemiological survey of rodents caught in ekpoma and environs. | of the 876 rodents caught in different parts of ekpoma, nigeria, and environs, 218 were mastomys natalensis, while 658 were other rodents. of the 218 m. natalensis caught, 102 (46.79%) were positive for complement fixing antibody to lassa virus. | 2005 | 15712534 |
| when viruses don't go viral: the importance of host phylogeographic structure in the spatial spread of arenaviruses. | many emerging infections are rna virus spillovers from animal reservoirs. reservoir identification is necessary for predicting the geographic extent of infection risk, but rarely are taxonomic levels below the animal species considered as reservoir, and only key circumstances in nature and methodology allow intrinsic virus-host associations to be distinguished from simple geographic (co-)isolation. we sampled and genetically characterized in detail a contact zone of two subtaxa of the rodent mas ... | 2017 | 28076397 |
| landscape determinants of fine-scale genetic structure of a small rodent in a heterogeneous landscape (hluhluwe-imfolozi park, south africa). | small mammals provide ecosystem services, acting, for example, as pollinators and seed dispersers. in addition, they are also disease reservoirs that can be detrimental to human health and they can also act as crop pests. knowledge of their dispersal preferences is therefore useful for population management and landscape planning. genetic data were used alongside landscape data to examine the influence of the landscape on the demographic connectedness of the natal multimammate mouse (mastomys na ... | 2016 | 27406468 |
| outbreak of lassa fever in nigeria: measures for prevention and control. | | 2016 | 27347299 |
| new hosts of the lassa virus. | lassa virus (lasv) causes a deadly haemorrhagic fever in humans, killing several thousand people in west africa annually. for 40 years, the natal multimammate rat, mastomys natalensis, has been assumed to be the sole host of lasv. we found evidence that lasv is also hosted by other rodent species: the african wood mouse hylomyscus pamfi in nigeria, and the guinea multimammate mouse mastomys erythroleucus in both nigeria and guinea. virus strains from these animals were isolated in the bsl-4 labo ... | 2016 | 27140942 |
| arenavirus diversity and phylogeography of mastomys natalensis rodents, nigeria. | mastomys natalensis rodents are natural hosts for lassa virus (lasv). detection of lasv in 2 mitochondrial phylogroups of the rodent near the niger and benue rivers in nigeria underlines the potential for lasv emergence in fresh phylogroups of this rodent. a mobala-like sequence was also detected in eastern nigeria. | 2016 | 26982388 |
| lassa virus seroprevalence in sibirilia commune, bougouni district, southern mali. | lassa virus (lasv) is endemic to several nations in west africa. in mali, lasv was unknown until an exported case of lassa fever was reported in 2009. since that time, rodent surveys have found evidence of lasv-infected mastomys natalensis rats in several communities in southern mali, near the border with côte d'ivoire. despite increased awareness, to date only a single case of lassa fever has been confirmed in mali. we conducted a survey to determine the prevalence of lasv exposure among person ... | 2016 | 26981786 |
| rat-atouille: a mixed method study to characterize rodent hunting and consumption in the context of lassa fever. | lassa fever is a zoonotic hemorrhagic illness predominant in areas across nigeria, sierra leone, guinea, liberia, and southern mali. the reservoir of lassa virus is the multimammate mouse (mastomys natalensis), a highly commensal species in west africa. primary transmission to humans occurs through direct or indirect contact with rodent body fluids such as urine, feces, saliva, or blood. our research draws together qualitative and quantitative methods to provide a fuller and more nuanced perspec ... | 2016 | 26895631 |
| gairo virus, a novel arenavirus of the widespread mastomys natalensis: genetically divergent, but ecologically similar to lassa and morogoro viruses. | despite its near pan-african range, the natal multimammate mouse, mastomys natalensis, carries the human pathogen lassa virus only in west africa, while the seemingly non-pathogenic arenaviruses mopeia, morogoro, and luna have been detected in this semi-commensal rodent in mozambique/zimbabwe, tanzania and zambia, respectively. here, we describe a novel arenavirus in m. natalensis from gairo district of central tanzania, for which we propose the name "gairo virus". surprisingly, the virus is not ... | 2015 | 25559385 |
| lassa serology in natural populations of rodents and horizontal transmission. | lassa virus causes hemorrhagic fever in west africa. previously, we demonstrated by pcr screening that only the multimammate mouse, mastomys natalensis, hosts lassa virus in guinea. in the present study, we used the same specimen collection from 17 villages in coastal, upper, and forest guinea to investigate the lassa virus serology in the rodent population. the aim was to determine the dynamics of antibody development in m. natalensis and to detect potential spillover infections in other rodent ... | 2014 | 25229705 |
| geographic distribution and genetic characterization of lassa virus in sub-saharan mali. | lassa fever is an acute viral illness characterized by multi-organ failure and hemorrhagic manifestations. lassa fever is most frequently diagnosed in nigeria, sierra leone, liberia, and guinea, although sporadic cases have been recorded in other west african countries, including mali. the etiological agent of lassa fever is lassa virus (lasv), an arenavirus which is maintained in nature and frequently transmitted to humans by mastomys natalensis. the purpose of this study was to better define t ... | 2013 | 24340119 |
| two novel arenaviruses detected in pygmy mice, ghana. | two arenaviruses were detected in pygmy mice (mus spp.) by screening 764 small mammals in ghana. the natal multimammate mouse (mastomys natalensis), the known lassa virus reservoir, was the dominant indoor rodent species in 4 of 10 sites, and accounted for 27% of all captured rodents. no rodent captured indoors tested positive for an arenavirus. | 2013 | 24188212 |
| housing equity for health equity: a rights-based approach to the control of lassa fever in post-war sierra leone. | poor quality housing is an infringement on the rights of all humans to a standard of living adequate for health. among the many vulnerabilities of those without adequate shelter is the risk of disease spread by rodents and other pests. one such disease is lassa fever, an acute and sometimes severe viral hemorrhagic illness endemic in west africa. lassa virus is maintained in the rodent mastomys natalensis, commonly known as the "multimammate rat," which frequently invades the domestic environmen ... | 2013 | 23282054 |
| density thresholds for mopeia virus invasion and persistence in its host mastomys natalensis. | well-established theoretical models predict host density thresholds for invasion and persistence of parasites with a density-dependent transmission. studying such thresholds in reality, however, is not obvious because it requires long-term data for several fluctuating populations of different size. we developed a spatially explicit and individual-based seir model of mopeia virus in multimammate mice mastomys natalensis. this is an interesting model system for studying abundance thresholds becaus ... | 2013 | 23041432 |
| the impact of human conflict on the genetics of mastomys natalensis and lassa virus in west africa. | environmental changes have been shown to play an important role in the emergence of new human diseases of zoonotic origin. the contribution of social factors to their spread, especially conflicts followed by mass movement of populations, has not been extensively investigated. here we reveal the effects of civil war on the phylogeography of a zoonotic emerging infectious disease by concomitantly studying the population structure, evolution and demography of lassa virus and its natural reservoir, ... | 2012 | 22615894 |
| prevalence of lassa virus among rodents trapped in three south-south states of nigeria. | lassa fever has been endemic in nigeria since 1969. the rodent mastomys natalensis has been widely claimed to be the reservoir host of the lassa virus. this study was designed to investigate the dis- tribution of species of rodents in three states (edo, delta and bayelsa) of nigeria and to determine the prevalence of lassa virus amongst trapped rodents in the selected states. | 2017 | 28748835 |
| no measurable adverse effects of lassa, morogoro and gairo arenaviruses on their rodent reservoir host in natural conditions. | in order to optimize net transmission success, parasites are hypothesized to evolve towards causing minimal damage to their reservoir host while obtaining high shedding rates. for many parasite species however this paradigm has not been tested, and conflicting results have been found regarding the effect of arenaviruses on their rodent host species. the rodent mastomys natalensis is the natural reservoir host of several arenaviruses, including lassa virus that is known to cause lassa haemorrhagi ... | 2017 | 28449693 |
| lassa virus isolates from mali and the ivory coast represent an emerging fifth lineage. | previous imported cases of lassa fever (lf) into the united kingdom from the ivory coast and mali, as well as the detection of lassa virus (lasv) among the mastomys natalensis population within mali has led to the suggestion that the endemic area for lf is expanding. initial phylogenetic analyses arrange isolates from mali and the ivory coast separately from the classical lineage iv isolates taken from sierra leone, guinea, and liberia. the availability of full genome sequences continues to incr ... | 2015 | 26483768 |
| mapping the zoonotic niche of lassa fever in africa. | lassa fever is a viral haemorrhagic illness responsible for disease outbreaks across west africa. it is a zoonosis, with the primary reservoir species identified as the natal multimammate mouse, mastomys natalensis. the host is distributed across sub-saharan africa while the virus' range appears to be restricted to west africa. the majority of infections result from interactions between the animal reservoir and human populations, although secondary transmission between humans can occur, particul ... | 2015 | 26085474 |
| shedding dynamics of morogoro virus, an african arenavirus closely related to lassa virus, in its natural reservoir host mastomys natalensis. | arenaviruses can cause mild to severe hemorrhagic fevers. humans mainly get infected through contact with infected rodents or their excretions, yet little is known about transmission dynamics within rodent populations. morogoro virus (morv) is an old world arenavirus closely related to lassa virus with which it shares the same host species mastomys natalensis. we injected morv in its host, and sampled blood and excretions at frequent intervals. infection in adults was acute; viral rna disappeare ... | 2015 | 26022445 |
| sequence variability and geographic distribution of lassa virus, sierra leone. | lassa virus (lasv) is endemic to parts of west africa and causes highly fatal hemorrhagic fever. the multimammate rat (mastomys natalensis) is the only known reservoir of lasv. most human infections result from zoonotic transmission. the very diverse lasv genome has 4 major lineages associated with different geographic locations. we used reverse transcription pcr and resequencing microarrays to detect lasv in 41 of 214 samples from rodents captured at 8 locations in sierra leone. phylogenetic an ... | 2015 | 25811712 |