RESUMEN
Egyptian rousette bats (ERBs) are implicated as reservoir hosts for Marburg virus (MARV), but natural mechanisms involved in maintenance of MARV in ERB populations remain undefined. A number of hematophagous ectoparasites, including fleas, parasitize bats. Subcutaneous (SC) inoculation of ERBs with MARV consistently results in viremia, suggesting that infectious MARV could be ingested by blood-sucking ectoparasites during feeding. In our study, MARV RNA was detected in fleas that took a blood meal during feeding on viremic bats on days 3, 7, and 11 after SC inoculation. Virus concentration in individual ectoparasites was consistent with detectable levels of viremia in the blood of infected host bats. There was neither seroconversion nor viremia in control bats kept in close contact with MARV-infected bats infested with fleas for up to 40 days post-exposure. In fleas inoculated intracoelomically, MARV was detected up to 14 days after intracoelomic (IC) inoculation, but the virus concentration was lower than that delivered in the inoculum. All bats that had been infested with inoculated, viremic fleas remained virologically and serologically negative up to 38 days after infestation. Of 493 fleas collected from a wild ERB colony in Matlapitsi Cave, South Africa, where the enzootic transmission of MARV occurs, all tested negative for MARV RNA. While our findings seem to demonstrate that bat fleas lack vectorial capacity to transmit MARV biologically, their role in mechanical transmission should not be discounted. Regular blood-feeds, intra- and interhost mobility, direct feeding on blood vessels resulting in venous damage, and roosting behaviour of ERBs provide a potential physical bridge for MARV dissemination in densely populated cave-dwelling bats by fleas. The virus transfer might take place through inoculation of skin, mucosal membranes, and wounds when contaminated fleas are squashed during auto- and allogrooming, eating, biting, or fighting.
Asunto(s)
Quirópteros , Enfermedad del Virus de Marburg , Marburgvirus , Siphonaptera , Animales , Quirópteros/virología , Marburgvirus/genética , Marburgvirus/fisiología , Siphonaptera/virología , Enfermedad del Virus de Marburg/virología , Enfermedad del Virus de Marburg/transmisión , Reservorios de Enfermedades/virología , Viremia , Infestaciones por Pulgas/veterinaria , Infestaciones por Pulgas/transmisión , Infestaciones por Pulgas/virología , ARN Viral/genética , EgiptoRESUMEN
OBJECTIVE: To cohouse cats experimentally infected with Bartonella clarridgeiae (Bc) with naive cats in a flea-free environment or with Ctenocephalides felis, Bartonella henselae (Bh), Mycoplasma haemofelis, and Candidatus Mycoplasma haemominutum to determine which flea could be a vector and to assess whether transmission of the infectious agents could be blocked by fipronil and (S)-methoprene. ANIMALS: Specific pathogen-free cats (n = 34). METHODS: In experiment 1, Bc was inoculated in 1 cat that was housed with 9 naive cats without C felis. In experiment 2, the 2 cats inoculated with Bc were housed with 6 other cats (2 inoculated with Bh, 2 inoculated with M haemofelis, and 2 inoculated with Candidatus M haemominutum) in the center (enclosure 2) of 3 housing enclosures separated by mesh walls that allow passage of fleas but precludes fighting. C felis were placed only on cats in enclosure 2 (5 times). Cats in enclosures 1 (n = 8) and 2 (8) were untreated, and cats in enclosure 3 (8) were administered fipronil and (S)-methoprene. Blood was collected from all cats for PCR assays for the pathogens. RESULTS: None of the cats housed with the cat inoculated with Bc became PCR positive in the absence of C felis. All cats in enclosure 2 became Bc DNA positive. While 2 of 8 cats in enclosure 1 became Bc PCR positive, none of the treated cats in enclosure 3 became infected. CLINICAL RELEVANCE: The study demonstrated that C felis can be a vector for Bc. The results support the recommendation that flea control products can reduce the risk of transmission of flea-borne pathogens.
Asunto(s)
Infecciones por Bartonella , Bartonella , Enfermedades de los Gatos , Ctenocephalides , Metopreno , Pirazoles , Animales , Gatos , Enfermedades de los Gatos/transmisión , Enfermedades de los Gatos/microbiología , Enfermedades de los Gatos/prevención & control , Ctenocephalides/microbiología , Ctenocephalides/efectos de los fármacos , Pirazoles/farmacología , Metopreno/farmacología , Infecciones por Bartonella/transmisión , Infecciones por Bartonella/veterinaria , Infecciones por Bartonella/prevención & control , Infestaciones por Pulgas/veterinaria , Infestaciones por Pulgas/transmisión , Infestaciones por Pulgas/prevención & control , Insecticidas/farmacología , Femenino , Masculino , Organismos Libres de Patógenos Específicos , Mycoplasma , Insectos Vectores/microbiologíaRESUMEN
BACKGROUND: The human flea, Pulex irritans, is widespread globally and has a long association with humans, one of its principal hosts. Its role in plague transmission is still under discussion, although its high prevalence in plague-endemic regions and the presence of infected fleas of this species during plague outbreaks has led to proposals that it has been a significant vector in human-to-human transmission in some historical and present-day epidemiologic situations. However, based on a limited number of studies, P. irritans is considered to be a poor vector and receives very little attention from public health policymakers. In this study we examined the vector competence of P. irritans collected from foxes and owls in the western United States, using a standard protocol and artificial infection system. METHODS: Wild-caught fleas were maintained in the laboratory and infected by allowing them to feed on human or rat blood containing 2 × 108 to 1 × 109 Y. pestis/ml. The fleas were then monitored periodically for infection rate and bacterial load, mortality, feeding rate, bacterial biofilm formation in the foregut (proventricular blockage), and ability to transmit Y. pestis after their single infectious blood meal. RESULTS: P. irritans were susceptible to infection, with more than 30% maintaining high bacterial loads for up to 20 days. Transmission during this time was infrequent and inefficient, however. Consistent with previous studies, a low level of early-phase transmission (3 days after the infectious blood meal) was detected in some trials. Transmission at later time points was also sporadic, and the incidence of proventricular blockage, required for this mode of transmission, was low in fleas infected using rat blood and never occurred in fleas infected using human blood. The highest level of blockage and transmission was seen in fleas infected using rat blood and allowed to feed intermittently rather than daily, indicating that host blood and feeding frequency influence vector competence. CONCLUSIONS: Our results affirm the reputation of P. irritans as a feeble vector compared to rodent flea species examined similarly, and its vector competence may be lower when infected by feeding on bacteremic human blood.
Asunto(s)
Insectos Vectores/microbiología , Peste/transmisión , Siphonaptera/microbiología , Yersinia pestis/fisiología , Animales , Sangre/metabolismo , Brotes de Enfermedades , Femenino , Infestaciones por Pulgas/transmisión , Zorros/parasitología , Humanos , Peste/microbiología , Estrigiformes/parasitología , Estados UnidosRESUMEN
An infestation of cat fleas in a research center led to the detection of two genotypes of Ctenocephalides felis biting humans in New Jersey, USA. The rarer flea genotype had an 83% incidence of Rickettsia asembonensis, a recently described bacterium closely related to R. felis, a known human pathogen. A metagenomics analysis developed in under a week recovered the entire R. asembonensis genome at high coverage and matched it to identical or almost identical (> 99% similarity) strains reported worldwide. Our study exposes the potential of cat fleas as vectors of human pathogens in crowded northeastern U.S, cities and suburbs where free-ranging cats are abundant. Furthermore, it demonstrates the power of metagenomics to glean large amounts of comparative data regarding both emerging vectors and their pathogens.
Asunto(s)
Infestaciones por Pulgas/transmisión , Insectos Vectores/parasitología , Metagenoma , Metagenómica , Infecciones por Rickettsia/epidemiología , Rickettsia felis/genética , Enfermedades de la Piel/epidemiología , Animales , Gatos , Infestaciones por Pulgas/epidemiología , Infestaciones por Pulgas/parasitología , Genotipo , Humanos , New England/epidemiología , Infecciones por Rickettsia/diagnóstico , Infecciones por Rickettsia/parasitología , Rickettsia felis/aislamiento & purificación , Rickettsia felis/patogenicidad , Enfermedades de la Piel/diagnóstico , Enfermedades de la Piel/parasitología , Población UrbanaRESUMEN
Rickettsia felis is an obligate intracellular bacterium that is being increasingly recognized as an etiological agent of human rickettsial disease globally. The agent is transmitted through the bite of an infected vector, the cat flea, Ctenocephalides felis, however there is to date, no consensus on the pathogen's vertebrate reservoir, required for the maintenance of this agent in nature. This study for the first time, demonstrates the role of the domestic dog (Canis familiaris) as a vertebrate reservoir of R. felis. The ability of dogs to sustain prolonged periods of rickettsemia, ability to remain asymptomatically infected with normal haematological parameters and ability to act as biological vehicles for the horizontal transmission of R. felis between infected and uninfected fleas provides indication of their status as a mammalian reservoir of this emerging zoonosis.
Asunto(s)
Infestaciones por Pulgas/etiología , Infestaciones por Pulgas/transmisión , Rickettsia felis/patogenicidad , Rickettsiosis Exantemáticas/etiología , Zoonosis/etiología , Zoonosis/transmisión , Animales , Gatos , Perros , Femenino , Infestaciones por Pulgas/parasitología , Técnica del Anticuerpo Fluorescente , Masculino , Reacción en Cadena de la Polimerasa , Zoonosis/parasitologíaRESUMEN
Zoonotic Vector-Borne Diseases (VBDs) represent a relevant health issue for pets and humans. Italy is a major epidemiological hub for feline VBDs, because of suitable conditions for vector biology and disease transmission patterns. The present study investigated the exposure to major zoonotic arthropod-borne pathogens of cats in Italy, along with the evaluation of clinic-pathological features and a risk factor analysis. Out of 167 examined cats, 52 (31.1%) were seropositive for at least one vector-borne pathogen, being positivity for Bartonella henselae the most recorded (18%). Also, various cats seroreacted for Rickettsia felis (10.8%) and Rickettisa typhi (4.2%), Leishmania infantum (3%), Anaplasma phagocytophilum (2.4%) and Ehrlichia canis (2.4%). Forty-six cats were tested also for antibodies against D. immitis and two (4.3%) scored positive. The statistical analysis showed a positive association between flea infestation and seropositivity to B. henselae, other than an association between the administration of monthly ectoparasiticide treatments and seronegativity for Rickettsia spp.; seropositive cats were older than negative animals and the lifestyle (i.e. indoor vs outdoor) was not correlated with exposure to vector-borne pathogens. The majority of seropositive cats appeared clinically healthy or showed aspecific clinical signs. Around 80% of seropositive cats had one or more biochemical and/or complete blood count abnormalities. The present data confirm the endemicity of zoonotic feline VBDs in Italy and indicate that awareness on arthropod infections and transmitted pathogens should be kept high and possible implemented, towards the protection of animal and human health with adequate surveillance plans.
Asunto(s)
Enfermedades de los Gatos/transmisión , Vectores de Enfermedades , Mascotas/parasitología , Zoonosis/transmisión , Animales , Bartonella/patogenicidad , Enfermedades de los Gatos/epidemiología , Enfermedades de los Gatos/microbiología , Gatos , Ehrlichia canis/patogenicidad , Infestaciones por Pulgas/transmisión , Italia/epidemiología , Rickettsia/patogenicidad , Factores de Riesgo , Zoonosis/epidemiología , Zoonosis/microbiologíaRESUMEN
The origin of Yersinia pestis and the early stages of its evolution are fundamental subjects of investigation given its high virulence and mortality that resulted from past pandemics. Although the earliest evidence of Y. pestis infections in humans has been identified in Late Neolithic/Bronze Age Eurasia (LNBA 5000-3500y BP), these strains lack key genetic components required for flea adaptation, thus making their mode of transmission and disease presentation in humans unclear. Here, we reconstruct ancient Y. pestis genomes from individuals associated with the Late Bronze Age period (~3800 BP) in the Samara region of modern-day Russia. We show clear distinctions between our new strains and the LNBA lineage, and suggest that the full ability for flea-mediated transmission causing bubonic plague evolved more than 1000 years earlier than previously suggested. Finally, we propose that several Y. pestis lineages were established during the Bronze Age, some of which persist to the present day.
Asunto(s)
ADN Antiguo/análisis , Genoma Bacteriano/genética , Peste/transmisión , Yersinia pestis/genética , Animales , Pulpa Dental/microbiología , Infestaciones por Pulgas/epidemiología , Infestaciones por Pulgas/microbiología , Infestaciones por Pulgas/transmisión , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Pandemias , Filogenia , Peste/epidemiología , Peste/microbiología , Polimorfismo de Nucleótido Simple , Federación de Rusia/epidemiología , Siphonaptera/microbiología , Virulencia/genética , Yersinia pestis/clasificación , Yersinia pestis/patogenicidadRESUMEN
Fleas are commonly recorded on stray as well as domestic dogs and cats in Hong Kong. Fleas can be a major cause of pruritus in dogs and cats and also vectors of potentially zoonotic bacteria in the genera Rickettsia and Bartonella. Morphological examination of 174 fleas from dogs and cats living in Hong Kong revealed only cat fleas (Ctenocephalides felis). Cytochrome c oxidase subunit 1 gene (cox1) genotyping of 20 randomly selected specimens, revealed three cox1 haplotypes (HK-h1 to HK-h3). The most common haplotype was HK-h1 with 17 specimens (17/20, 85%). HK-h1 was identical to cox1 sequences of fleas in Thailand and Fiji. HK-h1 and HK-h2 form a distinct cat flea cox1 clade previously recognized as the Clade 3. HK-h3 forms a new Clade 6. A multiplex Bartonella and Rickettsia real-time PCR of DNA from 20 C. felis found Bartonella and Rickettsia DNA in three (15%) and ten (50%) C. felis, respectively. DNA sequencing confirmed the presence of R. felis, B. clarridgeiae and Bartonella henselae. This is the first reported study of that kind in Hong Kong, and further work is required to expand the survey of companion animals in the geographical region. The sampling of fleas on domestic cats and dogs in Hong Kong revealed them to be exclusively infested by the cat flea and to be harbouring pathogens of zoonotic potential.
Asunto(s)
Bartonella/aislamiento & purificación , Ctenocephalides/microbiología , Rickettsia felis/aislamiento & purificación , Animales , Bartonella/genética , Bartonella/patogenicidad , Infecciones por Bartonella/epidemiología , Gatos/parasitología , Ctenocephalides/genética , Perros/parasitología , Complejo IV de Transporte de Electrones , Infestaciones por Pulgas/epidemiología , Infestaciones por Pulgas/parasitología , Infestaciones por Pulgas/transmisión , Haplotipos , Hong Kong/epidemiología , Reacción en Cadena de la Polimerasa Multiplex , Infecciones por Rickettsia/epidemiología , Rickettsia felis/genética , Rickettsia felis/patogenicidad , Análisis de Secuencia de ADNAsunto(s)
Acaricidas/administración & dosificación , Infestaciones por Pulgas/veterinaria , Insecticidas/administración & dosificación , Siphonaptera/efectos de los fármacos , Infestaciones por Garrapatas/veterinaria , Garrapatas/efectos de los fármacos , Absorción Fisiológica , Animales , Ctenocephalides/efectos de los fármacos , Enfermedades de los Perros/tratamiento farmacológico , Enfermedades de los Perros/parasitología , Perros , Infestaciones por Pulgas/tratamiento farmacológico , Infestaciones por Pulgas/transmisión , Insecticidas/efectos adversos , Insecticidas/uso terapéutico , Infestaciones por Garrapatas/sangre , Infestaciones por Garrapatas/tratamiento farmacológico , Infestaciones por Garrapatas/transmisiónRESUMEN
BACKGROUND: The cat flea, Ctenocephalides felis, is the most prevalent flea species detected on dogs and cats in Europe and other world regions. The status of flea infestation today is an evident public health concern because of their cosmopolitan distribution and the flea-borne diseases transmission. This study determines the spatial distribution of the cat flea C. felis infesting dogs in Spain. Using geospatial tools, models were constructed based on entomological data collected from dogs during the period 2013-2015. Bioclimatic zones, covering broad climate and vegetation ranges, were surveyed in relation to their size. RESULTS: The models builded were obtained by negative binomial regression of several environmental variables to show impacts on C. felis infestation prevalence: land cover, bioclimatic zone, mean summer and autumn temperature, mean summer rainfall, distance to urban settlement and normalized difference vegetation index. In the face of climate change, we also simulated the future distributions of C. felis for the global climate model (GCM) "GFDL-CM3" and for the representative concentration pathway RCP45, which predicts their spread in the country. CONCLUSIONS: Predictive models for current climate conditions indicated the widespread distribution of C. felis throughout Spain, mainly across the central northernmost zone of the mainland. Under predicted conditions of climate change, the risk of spread was slightly greater, especially in the north and central peninsula, than for the current situation. The data provided will be useful for local veterinarians to design effective strategies against flea infestation and the pathogens transmitted by these arthropods.
Asunto(s)
Distribución Animal , Ctenocephalides/fisiología , Enfermedades de los Perros/epidemiología , Enfermedades de los Perros/transmisión , Perros/parasitología , Infestaciones por Pulgas/veterinaria , Modelos Estadísticos , Animales , Gatos/parasitología , Cambio Climático , Enfermedades de los Perros/parasitología , Infestaciones por Pulgas/epidemiología , Infestaciones por Pulgas/transmisión , Prevalencia , Estaciones del Año , España/epidemiología , Análisis EspacialRESUMEN
Scientists and health-care professionals sometimes use a swabbing technique to collect fleas from rodent burrows, and later test the fleas for Yersinia pestis, the causative agent of plague. Detection of Y. pestis is enhanced when large pools of fleas are available. The following study investigated factors that might affect the rate at which fleas are collected from burrows in colonies of black-tailed prairie dogs (Cynomys ludovicianus). Data were collected from 13 colonies in New Mexico during 0600-1000 hours, June-August 2010-2011. Fleas were scarce on swabs inserted into burrows that were not actively used by prairie dogs; fleas are presumably suppressed in burrows that are void of hosts and might have begun to collapse due to a lack of maintenance. Fleas were scarce on swabs inserted into burrows with little sunlight entering the tunnel; many species of fleas use changes in light intensity to locate objects, but if light is limited, it might be difficult to locate a swab. Fleas were scarce on swabs inserted to shallow depths underground, especially during hot mornings, and during the hottest portions of mornings; when conditions are hot above ground, ectothermic fleas might migrate into the deep components of burrows, or become less willing to jump onto hosts, making it difficult to collect the fleas with swabs. If the swabbing technique is used to survey for Y. pestis on colonies of black-tailed prairie dogs, investigators might use the results of this study to modify their methods and increase the number of fleas collected.
Asunto(s)
Infestaciones por Pulgas/veterinaria , Parasitología/métodos , Peste/veterinaria , Enfermedades de los Roedores/transmisión , Sciuridae , Siphonaptera/microbiología , Yersinia pestis/aislamiento & purificación , Animales , Ambiente , Infestaciones por Pulgas/parasitología , Infestaciones por Pulgas/transmisión , New Mexico , Peste/microbiología , Peste/transmisión , Enfermedades de los Roedores/microbiología , Enfermedades de los Roedores/parasitología , TemperaturaRESUMEN
The communication substantiates the opinion that the theory of natural nidality of plague; which is based on the fundamental recognition that fleas play a leading role in the transmission and accumulation of the plague pathogen, cannot be disproved or substantially changed on the alternative weakly reasoned assumptions and hypotheses. All its "bottlenecks" are quite understandable when considering the long-term volumetric materials that have been gathered directly in nature and generalized in multiple publications. Plague is an obligate transmissive infection; its, agent is a highly specialized parasite that is completely associated in its vital activity with the only group of the blood-sucking insects--fleas and that is transmitted through periodic colonization of warm-blooded animals for a short time. All other types of plague microbe persistence in nature are either occasional or minor and do not play any significant role in pathogen persistence in the natural foci of this disease. There are no strong grounds for seriously considering the attempts to revise the main points of the theory of natural nidality of plague, which are widely held in current academic publications.
Asunto(s)
Infestaciones por Pulgas/transmisión , Infestaciones por Pulgas/veterinaria , Insectos Vectores/microbiología , Peste/transmisión , Peste/veterinaria , Siphonaptera/microbiología , Animales , Aves/microbiología , Infestaciones por Pulgas/epidemiología , Infestaciones por Pulgas/microbiología , Mamíferos/microbiología , Peste/epidemiología , Peste/microbiología , Roedores/microbiología , Federación de Rusia/epidemiología , Yersinia pestis/patogenicidad , Yersinia pestis/fisiologíaRESUMEN
There is evidence that in 1923-2014 the sharp aggravations of the epizootic situation of plague in the area of its Caspian sandy natural focus after long interepizootic periods are in time with the ups of the Caspian Sea in the extrema of 11-year solar cycles. There were cases of multiple manifestations of plague in the same areas in the epizootic cycles of 1946-1954, 1979-1996, 2001, and 2013-2014. The paper considers the possible role of amebae of the genus Acanthamoeba and nematodes, the representatives of the orders Rhabditida and Tylenchida in the microfocal pattern of plague manifestations.
Asunto(s)
Brotes de Enfermedades , Infestaciones por Pulgas/transmisión , Infestaciones por Pulgas/veterinaria , Insectos Vectores/microbiología , Peste/transmisión , Peste/veterinaria , Siphonaptera/microbiología , Acanthamoeba/microbiología , Animales , Reservorios de Enfermedades/microbiología , Reservorios de Enfermedades/veterinaria , Infestaciones por Pulgas/epidemiología , Infestaciones por Pulgas/microbiología , Humanos , Nematodos/microbiología , Océanos y Mares , Peste/epidemiología , Peste/microbiología , Roedores/microbiología , Roedores/parasitología , Federación de Rusia/epidemiología , Actividad Solar , Yersinia pestis/patogenicidad , Yersinia pestis/fisiología , Zoonosis/epidemiología , Zoonosis/microbiologíaRESUMEN
The paper gives the results of a comparative analysis of the prerequisites for the emergence and spread of epidemics of particularly dangerous infections, by using plague in Manchuria (1910-1911) and Ebola virus disease in West Africa (2014-2015) as examples. Analysis of literature and archival data and online information could reveal a number of common factors and conditions, which substantially contributed to the epidemics. Organization of anti-epidemic (preventive) measures in cases of the threatening epidemic spread, of particularly dangerous diseases must be based on the minimization, of the influence of the specific factors and conditions, which facilitate disease transmission in a given area in a given time.
Asunto(s)
Conflictos Armados/historia , Brotes de Enfermedades/historia , Infestaciones por Pulgas/veterinaria , Fiebre Hemorrágica Ebola/epidemiología , Peste/epidemiología , Siphonaptera/microbiología , África/epidemiología , Animales , China/epidemiología , Ebolavirus/patogenicidad , Ebolavirus/fisiología , Infestaciones por Pulgas/epidemiología , Infestaciones por Pulgas/historia , Infestaciones por Pulgas/transmisión , Fiebre Hemorrágica Ebola/historia , Fiebre Hemorrágica Ebola/transmisión , Fiebre Hemorrágica Ebola/virología , Historia del Siglo XX , Migración Humana/historia , Humanos , Peste/historia , Peste/microbiología , Peste/transmisión , Roedores/microbiología , Yersinia pestis/patogenicidad , Yersinia pestis/fisiologíaRESUMEN
The paper gives the results of analyzing the data of long-term studies of the natural focal pattern of plague in the Gornyi Altai natural focus. It describes a wide range of biological processes occurring in the focus and shows the most important patterns of its functioning as a complex multilevel ecological system. The key features of the formation of the focus have been revealed. The plague focus in South-Western Altai has formed relatively, recently, about half a century ago, then it has intensively developed and its enzootic area and the activity of epizootic manifestations have considerably increased. This process is due to the space-time transformations of the basic ecological and population characteristics of Pallas' pika (Ochotoma pallasi), the principal vector of the pathogen of plague and fleas parasitizing the mammal, which is in turn related to the aridization of mountain steppes in South-Western Altai.
Asunto(s)
Brotes de Enfermedades , Infestaciones por Pulgas/transmisión , Infestaciones por Pulgas/veterinaria , Insectos Vectores/microbiología , Peste/transmisión , Peste/veterinaria , Siphonaptera/microbiología , Animales , Ecosistema , Infestaciones por Pulgas/epidemiología , Infestaciones por Pulgas/microbiología , Humanos , Lagomorpha/microbiología , Peste/epidemiología , Peste/microbiología , Siberia/epidemiología , Yersinia pestis/patogenicidad , Yersinia pestis/fisiología , Zoonosis/epidemiología , Zoonosis/microbiologíaRESUMEN
Populations of large wildlife are declining on local and global scales. The impacts of this pulse of size-selective defaunation include cascading changes to smaller animals, particularly rodents, and alteration of many ecosystem processes and services, potentially involving changes to prevalence and transmission of zoonotic disease. Understanding linkages between biodiversity loss and zoonotic disease is important for both public health and nature conservation programs, and has been a source of much recent scientific debate. In the case of rodent-borne zoonoses, there is strong conceptual support, but limited empirical evidence, for the hypothesis that defaunation, the loss of large wildlife, increases zoonotic disease risk by directly or indirectly releasing controls on rodent density. We tested this hypothesis by experimentally excluding large wildlife from a savanna ecosystem in East Africa, and examining changes in prevalence and abundance of Bartonella spp. infection in rodents and their flea vectors. We found no effect of wildlife removal on per capita prevalence of Bartonella infection in either rodents or fleas. However, because rodent and, consequently, flea abundance doubled following experimental defaunation, the density of infected hosts and infected fleas was roughly twofold higher in sites where large wildlife was absent. Thus, defaunation represents an elevated risk in Bartonella transmission to humans (bartonellosis). Our results (i) provide experimental evidence of large wildlife defaunation increasing landscape-level disease prevalence, (ii) highlight the importance of susceptible host regulation pathways and host/vector density responses in biodiversity-disease relationships, and (iii) suggest that rodent-borne disease responses to large wildlife loss may represent an important context where this relationship is largely negative.
Asunto(s)
Animales Salvajes/parasitología , Infecciones por Bartonella/epidemiología , Infestaciones por Pulgas/epidemiología , Infestaciones por Piojos/epidemiología , Enfermedades de los Roedores/epidemiología , Roedores/parasitología , Xenopsylla , África Oriental/epidemiología , Animales , Animales Salvajes/microbiología , Infecciones por Bartonella/transmisión , Biodiversidad , Ecosistema , Infestaciones por Pulgas/transmisión , Humanos , Kenia/epidemiología , Infestaciones por Piojos/transmisión , Prevalencia , Factores de Riesgo , Roedores/microbiología , Zoonosis/epidemiologíaRESUMEN
The relative number of plague pathogen strains isolated from some flea species in different Gorno-Altai natural plague foci substantially varies; this indicator also varies with time. These patterns are due to the difference in the structure of multispecies communities of ectoparasites in these areas and their long-term transformation. As of now, the three species Paradoxopsyllus scorodumovi, Ctenophyllus hirticrus, and Amphalius runatus are widely involved in pathogen transmission in all three foci. These ectoparasites should be referred to as main plague vectors. In each focus, they are joined by other flea species, such as Rhadinopsylla dahurica and Amphipsylla primaris in the Ulandryk focus, Frontopsylla hetera, R. dahurica, Paradoxopsyllus kalabukhovi, and Paramonopsyllus scalodae in the Tarkhatin focus, and P. scalonae and P. kalabukhovi in the Kurai focus, which should be classified as an additional vector.
Asunto(s)
Infestaciones por Pulgas/veterinaria , Insectos Vectores/microbiología , Peste/veterinaria , Siphonaptera/microbiología , Análisis Espacio-Temporal , Yersinia pestis/aislamiento & purificación , Animales , Monitoreo Epidemiológico , Infestaciones por Pulgas/epidemiología , Infestaciones por Pulgas/microbiología , Infestaciones por Pulgas/transmisión , Insectos Vectores/clasificación , Mamíferos/microbiología , Mamíferos/parasitología , Peste/epidemiología , Peste/parasitología , Peste/transmisión , Roedores/microbiología , Roedores/parasitología , Federación de Rusia/epidemiología , Siphonaptera/clasificación , ZoonosisRESUMEN
A study design was created to assess the potential for fleas to infest cats directly from other cats. In the first experiment, six cats were infested with 100 fleas each and then immediately put in contact with six flea-free cats for 24 h. After removal of all fleas the study was repeated and the contact between cats lasted 48 h. The total numbers of fleas recovered out of the 600 fleas deposited on the 6 donor cats after each infestation were 499 and 486 at 24 h and 48 h respectively. At 1 h post-contact, five fleas were found on the receiver cats, with three cats having one flea and one cat, two fleas. The number of fleas recovered on receiver cats increased towards the end of the study. At 24 h, 20% of the fleas were found on the receiver cats, and at 48 h, 23%. In a second experiment, the six flea-free cats were put in contact with the six donor cats which were each infested by 100 fleas 48 h before. Fewer fleas were found on the receiver cats (n = 15), representing 3.8% of all fleas recovered (n = 403). All the observed fleas had fed. The fleas collected on receiving cats comprised 10 males and 5 females, and 4 of the 5 females were engorged and contained eggs. The fleas collected on donor cats comprised 153 males and 235 females, they were all fed and all females contained eggs. This experiment demonstrated that gravid female fleas have a tendency to become permanently but not exclusively parasitic. Nevertheless, a few can change their cat host in as little as 1 h, which may play a role in the rapid introduction of a new flea population into a cat environment.
Asunto(s)
Enfermedades de los Gatos/transmisión , Ctenocephalides/fisiología , Infestaciones por Pulgas/veterinaria , Conducta Social , Animales , Enfermedades de los Gatos/parasitología , Gatos , Femenino , Infestaciones por Pulgas/transmisión , Masculino , Factores SexualesRESUMEN
Fleas and ticks may transmit zoonotic diseases. This is an overview of tick- and flea-borne zoonoses where dogs and cats are involved in the epidemiology.
Asunto(s)
Vectores Arácnidos/microbiología , Enfermedades de los Gatos/transmisión , Reservorios de Enfermedades/veterinaria , Enfermedades de los Perros/transmisión , Insectos Vectores/microbiología , Zoonosis , Animales , Enfermedades de los Gatos/epidemiología , Gatos , Enfermedades de los Perros/epidemiología , Perros , Infestaciones por Pulgas/epidemiología , Infestaciones por Pulgas/transmisión , Infestaciones por Pulgas/veterinaria , Humanos , Salud Pública , Infestaciones por Garrapatas/epidemiología , Infestaciones por Garrapatas/transmisión , Infestaciones por Garrapatas/veterinariaRESUMEN
Fleas and ticks may cause skin problems in dogs and cats and transmit (zoonotic) diseases. This is an overview about the present situation of the ectoparasites control.