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multiple mammarenaviruses circulating in angolan rodents.rodents are a speciose group of mammals with strong zoonotic potential. some parts of africa are still underexplored for the occurrence of rodent-borne pathogens, despite this high potential. angola is at the convergence of three major biogeographical regions of sub-saharan africa, each harbouring a specific rodent community. this rodent-rich area is, therefore, strategic for studying the diversity and evolution of rodent-borne viruses. in this study we examined 290 small mammals, almost all rod ...202134070551
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
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
mastomys natalensis is a possible natural rodent reservoir for encephalomyocarditis virus.encephalomyocarditis virus (emcv) infects a wide range of hosts and can cause encephalitis, myocarditis, reproductive disorders and diabetes mellitus in selected mammalian species. as for humans, emcv infection seems to occur by the contact with animals and can cause febrile illnesses in some infected patients. here we isolated emcv strain zm12/14 from a natal multimammate mouse (mastomys natalensis: m. natalensis) in zambia. pairwise sequence similarity of the zm12/14 p1 region consisting of an ...202133533710
expression of different l1 isoforms of mastomys natalensis papillomavirus as mechanism to circumvent adaptive immunity.although many high-risk mucosal and cutaneous human papillomaviruses (hpvs) theoretically have the potential to synthesize l1 isoforms differing in length, previous seroepidemiological studies only focused on the short l1 variants, co-assembling with l2 to infectious virions. using the multimammate mouse mastomys coucha as preclinical model, this is the first study demonstrating seroconversion against different l1 isoforms during the natural course of papillomavirus infection. intriguingly, posi ...202032746966
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
host competence of the african rodents arvicanthis neumanni, a. niloticus and mastomys natalensis for leishmania donovani from ethiopia and l. (mundinia) sp. from ghana.visceral leishmaniasis caused by leishmania donovani is regarded as mostly anthroponotic, but a role for animal reservoir hosts in transmission has been suggested in east africa. field studies in this region have shown the presence of this parasite in several mammalian species, including rodents of the genera arvicanthis and mastomys. further, the natural reservoirs of leishmania (mundinia) sp. causing human cutaneous disease in ghana, west africa, are unknown. this study assessed the potential ...202031879594
mastomys natalensis, cricetomys gambianus and taterillus sp. were found pcr positive for leishmania major in burkina faso, west africa.ouagadougou, the capital city of burkina faso, was recognized as a focus of zoonotic cutaneous leishmaniosis in april 2000. leishmania major was the only strain isolated in this focus. we conducted a prospective study to detect l. major in rodents, animals which are described as reservoir of the parasite. rodents were caught in five city areas from november 2005 to october 2006. giemsa stained smears were realized from the cutaneous lesions when present after macroscopic examination of external ...202032592548
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
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
life history and habitat do not mediate temporal changes in body size due to climate warming in rodents.temporal changes in body size have been documented in a number of vertebrate species, with different contested drivers being suggested to explain these changes. among these are climate warming, resource availability, competition, predation risk, human population density, island effects and others. both life history traits (intrinsic factors such as lifespan and reproductive rate) and habitat (extrinsic factors such as vegetation type, latitude and elevation) are expected to mediate the existence ...202033024624
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
detection of possible spillover of a novel hantavirus in a natal mastomys from guinea.to date, only two rodent-borne hantaviruses have been detected in sub-saharan africa. here, we report the detection of a yet unknown hantavirus in a natal mastomys (mastomys natalensis) in méliandou, guinea, in 2014. the phylogenetic placement of this virus suggests that it might represent a cross-order spillover event from an unknown bat or eulipotyphlan host.202031654295
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
species composition and community structure of small pest rodents (muridae) in cultivated and fallow fields in maize-growing areas in mayuge district, eastern uganda.pest rodents remain key biotic constraints to cereal crops production in the east african region where they occur, especially in seasons of outbreaks. despite that, uganda has scant information on rodents as crop pests to guide effective management strategies.a capture-mark-recapture (cmr) technique was employed to study the ecology of small rodents, specifically to establish the species composition and community structure in a maize-based agro ecosystem. trapping of small rodents was conducted ...201931346445
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
diagnostics for lassa fever virus: a genetically diverse pathogen found in low-resource settings.lassa fever virus (lasv) causes acute viral haemorrhagic fever with symptoms similar to those seen with ebola virus infections. lasv is endemic to west africa and is transmitted through contact with excretions of infected mastomys natalensis rodents and other rodent species. due to a high fatality rate, lack of treatment options and difficulties with prevention and control, lasv is one of the high-priority pathogens included in the who r&d blueprint. the who lasv vaccine strategy relies on avail ...201930899575
host competence of african rodents arvicanthis neumanni, a. niloticus and mastomys natalensis for leishmania major.cutaneous leishmaniasis caused by leishmania major is a typical zoonosis circulating in rodents. in sub-saharan africa the reservoirs remain to be identified, although l. major has been detected in several rodent species including members of the genera arvicanthis and mastomys. however, differentiation of true reservoir hosts from incidental hosts requires in-depth studies both in the field and in the laboratory, with the best method for testing the infectiousness of hosts to biting vectors bein ...201930740304
relationship between population density and viral infection: a role for personality?conspecific density and animal personality (consistent among-individual differences in behavior) may both play an important role in disease ecology. nevertheless, both factors have rarely been studied together but may provide insightful information in understanding pathogen transmission dynamics. in this study, we investigated how both personality and density affect viral infections both direct and indirectly, using the multimammate mice (mastomys natalensis) and morogoro arenavirus (morv) as a ...201931624546
host competency of the multimammate rat mastomys natalensis demonstrated by prolonged spirochetemias with the african relapsing fever spirochete borrelia crocidurae.african multimammate rats, mastomys natalensis, are widely distributed in sub-saharan africa and live in close association with humans. in west africa, numerous field studies have shown these animals may be naturally infected with the relapsing fever spirochete borrelia crocidurae, the primary cause of tick-borne relapsing fever in this region of the continent. however, naturally infected individual rats have never been examined over time; therefore, the true host competency of these rats for th ...201931674298
molecular detection and genetic characterization of bartonella species from rodents and their associated ectoparasites from northern tanzania.bartonellae are intracellular bacteria, which can cause persistent bacteraemia in humans and a variety of animals. several rodent-associated bartonella species are human pathogens but data on their global distribution and epidemiology are limited. the aims of the study were to: 1) determine the prevalence of bartonella infection in rodents and fleas; 2) identify risk factors for bartonella infection in rodents; and 3) characterize the bartonella genotypes present in these rodent and flea populat ...201931613914
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
seroprevalence of toxoplasma gondii in commensal rodents sampled across senegal, west africa.risks related to toxoplasma gondii infection in humans remain poorly known in senegal. although rodent surveys could help to assess the circulation of t. gondii, they have seldom been set up in sub-saharan africa. the aim of this study was to examine toxoplasma seroprevalence in rodents from villages and towns across senegal. rodents were sampled in 40 localities using a standardised trapping protocol. detection of t. gondii antibodies was performed on 1205 rodents, using a modified agglutinatio ...201830016257
neural damage in experimental trypanosoma brucei gambiense infection: the suprachiasmatic nucleus.trypanosoma brucei (t. b.) gambiense is the parasite subspecies responsible for most reported cases of human african trypanosomiasis (hat) or sleeping sickness. this severe infection leads to characteristic disruption of the sleep-wake cycle, recalling attention on the circadian timing system. most animal models of the disease have been hitherto based on infection of laboratory rodents with the t. b. brucei subspecies, which is not infectious to humans. in these animal models, functional, rather ...201829491832
effect of synthetic hormones on reproduction in mastomys natalensis.rodent pest management traditionally relies on some form of lethal control. developing effective fertility control for pest rodent species could be a major breakthrough particularly in the context of managing rodent population outbreaks. this laboratory-based study is the first to report on the effects of using fertility compounds on an outbreaking rodent pest species found throughout sub-saharan africa. mastomys natalensis were fed bait containing the synthetic steroid hormones quinestrol and l ...201829367841
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
arenavirus infection correlates with lower survival of its natural rodent host in a long-term capture-mark-recapture study.parasite evolution is hypothesized to select for levels of parasite virulence that maximise transmission success. when host population densities fluctuate, low levels of virulence with limited impact on the host are expected, as this should increase the likelihood of surviving periods of low host density. we examined the effects of morogoro arenavirus on the survival and recapture probability of multimammate mice (mastomys natalensis) using a seven-year capture-mark-recapture time series. mastom ...201829422075
endoparasites of small mammals in edo state, nigeria: public health implications.some small mammals occur as household pests and harbour a number of parasites that could be of public health importance. this study profiled the helminth and protozoan parasites in trapped small mammals within and around human dwelling places (houses) located across 4 major towns (auchi, benin, ekpoma, and uromi) and environs in edo state, nigeria. six genera (apodemus sp., crocidura sp., mastomys natalensis, mus musculus, rattus sp., and sorex sp.) were identified from 502 trapped small mammals ...201829529857
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
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
does exploratory behavior or activity in a wild mouse explain susceptibility to virus infection?exploration and activity are often described as trade-offs between the fitness benefits of gathering information and resources, and the potential costs of increasing exposure to predators and parasites. more exploratory individuals are predicted to have higher rates of parasitism, but this relationship has rarely been examined for virus infections in wild populations. here, we used the multimammate mouse mastomys natalensis to investigate the relationship between exploration, activity, and infec ...201830323837
identification and characterization of orientia chuto in trombiculid chigger mites collected from wild rodents in kenya.we present data that concurs with the reported geographical expansion of scrub typhus outside the "tsutsugamushi triangle" and addition of orientia chuto as a second species in the orientia genus. wild rodents were caught in marigat, baringo county, kenya, and ectoparasites, including chiggers, were recovered. rodent and chigger species were identified by taxonomic features. dna was extracted from the chiggers and used to amplify and/or sequence the 47-kda high temperature transmembrane protein ...201830282787
the shape of the contact-density function matters when modelling parasite transmission in fluctuating populations.models of disease transmission in a population with changing densities must assume a relation between infectious contacts and density. typically, a choice is made between a constant (frequency-dependence) and a linear (density-dependence) contact-density function, but it is becoming increasingly clear that intermediate, nonlinear functions are more realistic. it is currently not clear, however, what the exact consequences would be of different contact-density functions in fluctuating populations ...201729291115
comparative non-metric and morphometric analyses of rats at residential halls of the university of benin campus, nigeria.in mammals and across rat species, the variation in conformation is markedly observed in the head and the variation in the shape of the head is mostly determined by the shape of the skull. hence comparative topographic analysis and morphometry is a veritable tool in precise categorization of peri-domestic rats and species identification.201728967498
diagnosis and genetic analysis of the worldwide distributed rattus-borne trypanosoma (herpetosoma) lewisi and its allied species in blood and fleas of rodents.trypanosoma (herpetosoma) lewisi is a cosmopolitan parasite of rodents strongly linked to the human dispersal of rattus spp. from asia to the rest of the world. this species is highly phylogenetically related to trypanosomes from other rodents (t. lewisi-like), and sporadically infects other mammals. t. lewisi may opportunistically infect humans, and has been considered an emergent rat-borne zoonosis associated to poverty. we developed the thecatl-pcr based on cathepsin l (catl) sequences to spe ...201728882517
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
serological survey of zoonotic viruses in invasive and native commensal rodents in senegal, west africa.increasing studies on rodent-borne diseases still highlight the major role of rodents as reservoirs of numerous zoonoses of which the frequency is likely to increase worldwide as a result of accelerated anthropogenic changes, including biological invasions. such a situation makes pathogen detection in rodent populations important, especially in the context of developing countries characterized by high infectious disease burden. here, we used indirect fluorescent antibody tests to describe the ci ...201728873024
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 ( ...201728167603
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 ...201728076397
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.201728748835
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 ...201728449693
arenavirus dynamics in experimentally and naturally infected rodents.infectious diseases of wildlife are typically studied using data on antibody and pathogen levels. in order to interpret these data, it is necessary to know the course of antibodies and pathogen levels after infection. such data are typically collected using experimental infection studies in which host individuals are inoculated in the laboratory and sampled over an extended period, but because laboratory conditions are controlled and much less variable than natural conditions, the immune respons ...201728616660
the interplay of uv and cutaneous papillomavirus infection in skin cancer development.cutaneous human papillomaviruses (hpvs) are considered as cofactors for non-melanoma skin cancer (nmsc) development, especially in association with uvb. extensively studied transgenic mouse models failed to mimic all aspects of virus-host interactions starting from primary infection to the appearance of a tumor. using the natural model mastomys coucha, which reflects the human situation in many aspects, we provide the first evidence that only uvb and mastomys natalensis papillomavirus (mnpv) inf ...201729190285
polymorphism in vkorc1 gene of natal multimammate mice, mastomys natalensis, in tanzania.resistance of rodents to anticoagulant rodenticides has emerged in several areas across the world. single nucleotide mutations in the vkorc1 gene have been shown to elicit various levels of anticoagulant resistance, and these mutations are prevalent in several rattus and mus musculus populations. in sub-saharan africa, the natal multimammate mouse, mastomys natalensis, is one of the most damaging pests to crops, and anticoagulant poisons such as bromadiolone are frequently used to control these ...201626223233
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 ...201627406468
outbreak of lassa fever in nigeria: measures for prevention and control. 201627347299
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 ...201627140942
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.201626982388
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 ...201626981786
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 ...201626895631
16s rrna amplicon sequencing for epidemiological surveys of bacteria in wildlife.the human impact on natural habitats is increasing the complexity of human-wildlife interactions and leading to the emergence of infectious diseases worldwide. highly successful synanthropic wildlife species, such as rodents, will undoubtedly play an increasingly important role in transmitting zoonotic diseases. we investigated the potential for recent developments in 16s rrna amplicon sequencing to facilitate the multiplexing of the large numbers of samples needed to improve our understanding o ...201627822541
fleas and trypanosomes of peridomestic small mammals in sub-saharan mali.fleas are obligate blood-feeding ectoparasites and vectors of several bacterial zoonotic pathogens as well as trypanosomes that parasitize rodents and other small mammals. during investigations of tick- and rodent-borne diseases in mali, west africa, we included fleas and rodent-borne trypanosomes, both of which are poorly known in this country, but are attracting greater public health interest.201627724960
transcriptome analysis of mastomys natalensis papillomavirus in productive lesions after natural infection.mastomys coucha, an african rodent, is a useful animal model of papillomavirus infection, as it develops both premalignant and malignant skin tumors as a consequence of a persistent infection with mastomys natalensis papillomavirus (mnpv). in this study, we mapped the mnpv transcriptome in productive lesions by both classical molecular techniques and high-throughput rna sequencing. combination of these methods revealed a complex and comprehensive transcription map, with novel splicing events not ...201627043420
genetic distinction between contiguous urban and rural multimammate mice in tanzania despite gene flow.special conditions are required for genetic differentiation to arise at a local geographical scale in the face of gene flow. the natal multimammate mouse, mastomys natalensis, is the most widely distributed and abundant rodent in sub-saharan africa. a notorious agricultural pest and a natural host for many zoonotic diseases, it can live in close proximity to humans and appears to compete with other rodents for the synanthropic niche. we surveyed its population genetic structure across a 180-km t ...201627306876
the role of endogenous gastrin in the development of enterochromaffin-like cell carcinoid tumors in mastomys natalensis: a study with the specific gastrin receptor antagonist ag-041r.we examined the effects of a newly synthesized gastrin receptor antagonist, ag-041r, on the growth of enterochromaffin-like (ecl) carcinoid tumors in mastomys natalensis both in vitro and in vivo. ag-041r was as potent as the well known gastrin antagonist l365,260 in inhibiting not only the gastrin-induced release of histamine from but also histidine decarboxylase (hdc) gene expression in the ecl carcinoid tumor cells. ag-041r also inhibited gastrin-induced dna synthesis and c-fos gene expressio ...201610461356
host evolution in mastomys natalensis (rodentia: muridae): an integrative approach using geometric morphometrics and genetics.the commensal rodent mastomys natalensis is the natural reservoir of lassa arenavirus (lasv), which causes hemorrhagic fever in west africa. to study a possible effect of the virus on phenotypic and genotypic variation of its persistently infected host, we compared lasv-positive and non-infected wild-caught m. natalensis. the lasv effects on the phenotypic variation were explored using standard external morphometric measurements, geometric morphometric analyses of the cranial size and shape, and ...201526331855
effects of land use on plague (yersinia pestis) activity in rodents in tanzania.understanding the effects of land-use change on zoonotic disease risk is a pressing global health concern. here, we compare prevalence of yersinia pestis, the etiologic agent of plague, in rodents across two land-use types-agricultural and conserved-in northern tanzania. estimated abundance of seropositive rodents nearly doubled in agricultural sites compared with conserved sites. this relationship between land-use type and abundance of seropositive rodents is likely mediated by changes in roden ...201525711606
comparative pathogenicity of trypanosoma brucei rhodesiense strains in swiss white mice and mastomys natalensis rats.we evaluated mastomys natelensis rat as an animal model for rhodesian sleeping sickness. parasitaemia, clinical and pathological characteristics induced by t. b. rhodesiense isolates, ketri 3439, 3622 and 3637 were compared in mastomys rats and swiss white mice. each isolate was intra-peritonially injected in mice and rat groups (n=12) at 1×10(4) trypanosomes/0.2ml. pre-patent period (pp) range for ketri 3439 and ketri 3622-groups was 3-6 days for mice and 4-5 days for rats while for ketri 3637- ...201526099681
diversity and habitat association of small mammals in aridtsy forest, awi zone, ethiopia.here, we conducted a survey to examine the diversity, distribution and habitat association of small mammals from august 2011 to february 2012 incorporating both wet and dry seasons in aridtsy forest, awi zone, ethiopia. using sherman live traps and snap traps in four randomly selected trapping grids, namely, natural forest, bushland, grassland and farmland, a total of 468 individuals comprising eight species of small mammals (live traps) and 89 rodents of six species (snap traps) were trapped in ...201525855227
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 ...201526483768
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 ...201526085474
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 ...201526022445
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 ...201525811712
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 ...201525559385
prevalence and diversity of small mammal-associated bartonella species in rural and urban kenya.several rodent-associated bartonella species are human pathogens but little is known about their epidemiology. we trapped rodents and shrews around human habitations at two sites in kenya (rural asembo and urban kibera) to determine the prevalence of bartonella infection. bartonella were detected by culture in five of seven host species. in kibera, 60% of rattus rattus were positive, as compared to 13% in asembo. bartonella were also detected in c. olivieri (7%), lemniscomys striatus (50%), mast ...201525781015
evidence of cryptic speciation in mesostigmatid mites from south africa.laelaps giganteus and laelaps muricola (mesostigmata; laelapidae) are widespread and locally abundant host generalists on small mammals in southern africa. the large host range and complex life history of these ectoparasites may allude to possible intraspecific cryptic diversity in these taxa. to assess genetic and morphological diversity in l. giganteus and l. muricola, we sampled 228 rodents at eight localities in south africa. this sample included nine previously recorded host species and on ...201424923552
spatial segregation between invasive and native commensal rodents in an urban environment: a case study in niamey, niger.invasive rodents have been responsible for the diffusion worldwide of many zoonotic agents, thus representing major threats for public health. cities are important hubs for people and goods exchange and are thus expected to play a pivotal role in invasive commensal rodent dissemination. yet, data about urban rodents' ecology, especially invasive vs. native species interactions, are dramatically scarce. here, we provide results of an extensive survey of urban rodents conducted in niamey, niger, d ...201425379785
anthropogenic soils and land use patterns in relation to small mammal and flea abundance in plague endemic area of western usambara mountains, tanzania.heterogeneity in the landscapes of west usambara mountains on land use and human activities has been reported. however, the interface of land use patterns and human modified soils with small mammal and flea abundance for possible explanation of plague has not been explored. this study was carried out to determine the link between anthropogenic soils and land use patterns on small mammal and flea abundance and the occurrence of reported plague in the western usambara mountains in tanzania. standa ...201426867282
vegetation habitats and small mammals in a plague endemic area in western usambara mountains, tanzania.human plague still exists in different parts of the world, including some landscapes in north-eastern tanzania. wherever the hotspot of plague, small mammals seem to play a key role as host. the objective of this study was to investigate the relationship between vegetation habitats types and small mammals in a plague endemic area of lushoto district in tanzania. a combination of field survey and landsat images was used to identify the vegetation habitats. small mammals were trapped in the mapped ...201426867279
small mammal distribution and diversity in a plague endemic area in west usambara mountains, tanzania.small mammals play a role in plague transmission as hosts in all plague endemic areas. information on distribution and diversity of small mammals is therefore important for plague surveillance and control in such areas. the objective of this study was to investigate small mammals' diversity and their distribution in plague endemic area in the west usambara mountains in north-eastern tanzania. landsat images and field surveys were used to select trapping locations in different landscapes. three l ...201426867277
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 ...201425229705
variable effects of host characteristics on species richness of flea infracommunities in rodents from three continents.we studied the effect of host gender and body mass on species richness of flea infracommunities in nine rodent host species from three biomes (temperate zone of central europe, desert of the middle east and the tropics of east africa). using season- and species-specific generalized linear mixed models and controlling for year-to-year variation, spatial clustering of rodent sampling and over-dispersion of the data, we found inconsistent associations between host characteristics and flea species r ...201424820040
protective vaccination against papillomavirus-induced skin tumors under immunocompetent and immunosuppressive conditions: a preclinical study using a natural outbred animal model.certain cutaneous human papillomaviruses (hpvs), which are ubiquitous and acquired early during childhood, can cause a variety of skin tumors and are likely involved in the development of non-melanoma skin cancer, especially in immunosuppressed patients. hence, the burden of these clinical manifestations demands for a prophylactic approach. to evaluate whether protective efficacy of a vaccine is potentially translatable to patients, we used the rodent mastomys coucha that is naturally infected w ...201424586150
histamine metabolism of gastric carcinoids in mastomys natalensis.pharmacological inhibition of gastric acid secretion and subsequent hypergastrinemia in mastomys natalensis is an experimental model well suited for the study of gastric carcinoid formation. the genetic susceptibility of mastomys to develop such tumors is a feature reminiscent of the situation in patients with the men-1 zollinger ellison syndrome, in whom tumor-induced hypergastrinemia, promotes the development of gastric carcinoids. chronic hypergastrinemia, induced by the irreversible h2-recep ...201410461353
sex-biased parasitism is not universal: evidence from rodent-flea associations from three biomes.the distribution of parasites among individual hosts is characterised by high variability that is believed to be a result of variations in host traits. to find general patterns of host traits affecting parasite abundance, we studied flea infestation of nine rodent species from three different biomes (temperate zone of central europe, desert of middle east and tropics of east africa). we tested for independent and interactive effects of host sex and body mass on the number of fleas harboured by a ...201323636459
pterygodermatites (mesopectines) niameyensis n. sp. (nematoda: rictulariidae), a parasite of mastomys natalensis (smith, 1834) (rodentia: muridae) from niger.pterygodermatites (mesopectines) niameyensis n. sp. is described from mastomys natalensis in niamey/niger (west africa). it differs from other species of same subgenus by the morphology of the head, which presents 4 simple cephalic papillae and nearly axial oral opening, a number of caudal papillae, precloacal cuticular formations, and the spicule length/body length ratio. scanning electron microscopy shows the presence of 2 pairs of lateral sensory structures for male worms.201323902298
plague in tanzania: an overview.human plague remains a public health concern in tanzania despite its quiescence in most foci for years, considering the recurrence nature of the disease. despite the long-standing history of this problem, there have not been recent reviews of the current knowledge on plague in tanzania. this work aimed at providing a current overview of plague in tanzania in terms of its introduction, potential reservoirs, possible causes of plague persistence and repeated outbreaks in the country. plague is bel ...201326591701
factors associated with flea infestation among the different rodent species in mbulu and karatu districts, northern tanzania.flea infection with the bacterium, yersinia pestis is acquired from reservoirs which include several rodents and other small mammals. in areas that are endemic of plague, reservoirs of y. pestis and various flea vectors are responsible for perpetuating existence of the disease. the objective of this cross sectional study was to investigate the magnitude and factors associated with flea infestation among different rodent species of northern tanzania, where outbreaks of plague have been recently r ...201326591705
evidence of yersinia pestis dna in rodents in plague outbreak foci in mbulu and karatu districts, northern tanzania.human plague remains a public health concern in tanzania despite its quiescence in most foci for years, considering the recurrence nature of the disease. appreciable researches have involved serological screening of rodents, fleas and humans but none has involved molecular detection and hence proving the presence of yersinia pestis in rodents in the most recent affected foci, mbulu and karatu districts in northern tanzania. the objective of the current study was to employ a simple pcr to detect ...201326591703
toxoplasmosis seroprevalence in urban rodents: a survey in niamey, niger.a serological survey of toxoplasma gondii was conducted on 766 domestic and peridomestic rodents from 46 trapping sites throughout the city of niamey, niger. a low seroprevalence was found over the whole town with only 1.96% of the rodents found seropositive. however, differences between species were important, ranging from less than 2% in truly commensal mastomys natalensis, rattus rattus and mus musculus, while garden-associated arvicanthis niloticus displayed 9.1% of seropositive individuals. ...201323828008
trichuris spp. (nematoda: trichuridae) from two rodents, mastomys natalensis and gerbilliscus vicinus in tanzania.during a survey of the helminth community of several rodent species in the morogoro region (tanzania), trichuris whipworms (nematoda: trichuridae) were found in the ceca of the natal multimammate mouse, mastomys natalensis and a gerbil, gerbilliscus vicinus (both rodentia: muridae). the taxonomic literature regarding trichuris from african native rodents describes 10 species, but includes few metric and morphologic characters that discriminate between some of the pairs. the whipworms we sampled ...201323560615
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 ...201324340119
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.201324188212
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 ...201323282054
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 ...201323041432
the effects of unilateral truncal vagotomy on gastric carcinogenesis in hypergastrinemic japanese female cotton rats.the stomach is innervated by the vagal nerve. several studies have demonstrated that the vagal nerve has a trophic effect on the rat oxyntic mucosa and that the trophic effect of hypergastrinemia is dependent on intact vagal innervation. the effect of vagal denervation on gastric carcinogenesis has been examined in mastomys natalensis and hypergastrinemic transgenic ins-gas mice, with no effect of unilateral vagotomy in mastomys but an anti-carcinogenic effect in ins-gas mice. a proportion of fe ...201323499800
population dynamics and breeding patterns of multimammate mouse, mastomys natalensis (smith 1834), in irrigated rice fields in eastern tanzania.multimammate mice are the most important vertebrate pests in sub-saharan africa and are also reservoirs of many zoonotic diseases, including sylvan plague. this study investigated the population dynamics and breeding patterns of this mouse in irrigated rice cropping systems in eastern tanzania.201322718470
seasonal abundance and epidemiological indices of potential plague vectors dinopsyllus lypusus (siphonaptera: hystrichopsyllidae) and ctenophthalmus calceatus (siphonaptera: ctenophthalmidae) on rodents captured from three habitat types of hatcliffe and dzivarasekwa suburbs of harare, zimbabwe.the seasonal abundance of dinopsyllus lypusus jordan and rothschild and ctenophthalmus calceatus waterson (potential vectors of plague in southern africa) were studied on rodent hosts captured in selected habitat types of two periurban suburbs of harare, zimbabwe. removal trapping was used to capture the rodents, from which fleas were collected and identified. prevalence (proportion of animals infested) and specific flea index (sfi = number of fleas per animal) were calculated for each species o ...201223270175
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, ...201222615894
molecular surveillance and phylogenetic analysis of old world arenaviruses in zambia.in order to survey arenaviruses in the republic of zambia, we captured 335 rodents from three cities between 2010 and 2011. eighteen luna virus (lunv) and one lymphocytic choriomeningitis virus (lcmv)-related virus rnas were detected by one-step rt-pcr from mastomys natalensis and mus minutoides, respectively. four lunv strains and one lcmv-related virus were isolated, and the whole genome nucleotide sequence was determined by pyrosequencing. phylogenetic analyses revealed that the lunv clade co ...201222815269
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 ...201223202493
the prostate in pregnant and non-pregnant praomys (mastomys) natalensis at the subcellular level.the prostate of the pregnant praomys appears more active than that of the non-pregnant praomys. at the light microscopic level, the most obvious features are heightening of secretory cells and increased secretory product in acinar lumina. apparent at the electron microscopic level are an increase and dilation of the rough endoplasmic reticulum, numerous scattered secretion granules, and a dilated golgi apparatus. therefore, stimulation of the gland is evident upon cytological evaluation and this ...20123370610
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