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162 result(s) for "Flea Infestations - epidemiology"
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First assessment of plague in terrestrial small mammals and fleas from Makira Natural Park and surroundings, North-eastern Madagascar
Plague, a zoonosis caused by Yersinia pestis, is endemic in Madagascar but knowledge on the epidemiological situation in the northern focus remains unclear. The aim of this study was to investigate the circulation of Y. pestis in terrestrial small mammals in north eastern Madagascar, where suspected plague outbreaks have been reported. Sampling of terrestrial small mammals and their fleas was carried out in 22 trapping sites within 9 localities of the two sectors (1 and 3) of Makira Natural Park (MNP) and surroundings, from 2020 to 2022. Yersinia pestis was investigated in terrestrial small mammal spleen samples and their fleas using bacteriological, serological and molecular methods. A total of 614 terrestrial small mammals composed of eight species and 1,754 individual fleas were collected following 4,880 trap-nights. The black rat (Rattus rattus) represented the majority (87.8%) of the small mammal species caught. Flea infestation rate was higher in sector 3 compared to sector 1. In sector 3, Xenopsylla brasiliensis, a plague vector, represented 66.4% of fleas identified. Further, one plague seropositive R. rattus individual, captured inside a house, and one Ctenocephalides felis specimen, collected on another R. rattus, was positive on PCR in this sector. Despite low detection rates, we confirmed the circulation of Y. pestis in our study area (one rat seropositive and one flea PCR positive) and highlight the risk of potential human transmission. Our results also suggest that R. rattus contributes to the maintenance and transmission of plague in MNP, as described for other areas in Madagascar. Further, these findings contribute to documentation of the known geographic distribution of the endemic plague vector S. fonquerniei and X. brasiliensis. The confirmation of the circulation of the Y. pestis through serological and molecular diagnostics in small mammals and fleas underscores the urgent need to assess awareness levels of risk factors and symptoms to monitor among local communities and health workers and ensure that trained rapid response teams are prepared to intervene promptly upon suspect case detection. The risk and epidemiology of plague circulation in remote rural areas of Madagascar remains insufficiently studied. Addressing this gap is crucial, as a more comprehensive understanding of the distribution and dynamics of the wild animal hosts, their vectors and host-vector interactions will enhance risk assessment and prevention for plague emergence and improve mitigation and early control of potential outbreaks.
Analysis of 3800-year-old Yersinia pestis genomes suggests Bronze Age origin for bubonic plague
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. Yersinia pestis has caused infections (plague) in humans since the Early Bronze Age (5000 years ago). Here, Spyrou et al. reconstruct Y. pestis genomes from Late Bronze Age individuals, and find genomic evidence compatible with flea-mediated transmission causing bubonic plague.
Variation of functional diversity structure measured as combined species dominance, functional diversity, and functional redundancy in two taxa of ectoparasitic arthropods at two spatial scales: host-associated, ecological, and geographic effects
The functional diversity structure of a community can be represented as a combination of three additive components (species dominance D, functional redundancy R, and functional diversity Q) (DRQ approach in which different facets of functional differences between species are considered simultaneously). We applied this concept to assemblages of fleas and gamasid mites parasitic on small mammals at continental (across regions of the Palearctic) and regional (across sampling sites in Slovakia) scales and asked: What are the relative effects of host species, biome/habitat type, and geographic locality on the DRQ composition of a parasite assemblage? At the continental scale, regions were partitioned according to predominant biome or geographic position in a continental section. At the regional scale, sampling sites were partitioned according to habitat type or geographic locality. We tested for differences in the functional diversity structure (measured as the DRQ composition) of an ectoparasite assemblage (a) within a host species between biomes/habitat types or continental sections/localities and (b) between host species within a biome/habitat type or a continental section/locality. At both scales, the functional diversity structure of both flea and mite assemblages differed mainly between host species within a biome/habitat or geographic regions/locations, whereas differences in the DRQ composition between biomes/habitats or geographic regions/locations were only detected in a few host species. We compare our results with the results of earlier studies and conclude that the DRQ approach has an advantage over a single diversity metric and allows a better understanding of spatial variation in different facets of ectoparasite diversity.
Identification and pathogen screening of ectoparasites from companion animals in urban Vientiane, Lao PDR
Ticks and fleas are vectors of medically important infectious diseases globally, such as Rickettsiae. These pathogens are frequently reported in Southeast Asia, including Laos; however, there are very few comprehensive reports on their prevalence and vector diversity in urban areas. This study collected ectoparasites from companion animals to assess pathogen prevalence and exposure risk. In five veterinary clinics across Vientiane capital, ectoparasites were collected from dogs and cats and identified to the species level using both morphological and molecular methods. Ectoparasite DNA samples were screened for bacteria ( 17-kDa and 16S rRNA gene). Ticks were submitted to evaluate the potential of MALDI-TOF mass spectrometry for species identification. A total of 3,771 arthropod vectors (3,658 ticks, 105 fleas, 8 lice) were removed from dogs and cats. Ticks were morphologically identified as Rhipicephalus sanguineus sensu lato (s.l.) tropical lineage (currently recognised as Rhipicephalus linnaei ), whilst fleas were classified as either Ctenocephalides felis felis (57.1%) or C. f. orientis (42.9%) and lice were Heterodoxus spiniger . The MALDI-TOF spectra in this study revealed similar mass-to-charge (m/z) peak profiles to those reported in previous studies for Rhipicephalus sanguineus . Rickettsia spp. ( Rickettsia asembonensis and Rickettsia felis ) were detected in 44.4% of pooled flea samples collected from 12 dogs and 4 cats, as well as 3.5% of tick pools collected from 142 dogs and 50% of lice pools collected from 2 dogs. In addition, Anaplasmataceae ( Ehrlichia canis and Anaplasma platys ) were detected in 22.5% of ticks collected from dogs. This study highlights the diversity of ectoparasite species collected from dogs and cats and provide preliminary insights into the use of MALDI-TOF MS for tick species identification. While promising, further research is needed to enhance the reliability and efficacy of this approach. The findings also reveal a high prevalence of pathogens in ectoparasites, emphasizing the need for increased awareness among pet owners, veterinarians, and addressing public health concerns.
Oral Flea Preventive to Control Rickettsia typhi –Infected Fleas on Reservoir Opossums, Galveston, Texas, USA, 2023–2024
Murine typhus, a fleaborne bacterial disease caused by Rickettsia typhi, has reemerged and spread in the United States. We tested spinosad, an oral flea preventive, in opossum flea reservoirs. Spinosad killed 98% of fleas infesting opossums. Oral preventives could control fleas in host species and curb murine typhus spread to humans.
Parasite species co-occurrence patterns on North American red squirrels ( Tamiasciurus hudsonicus )
Parasite species interactions, host biology traits, and external environmental factors can drive co-occurrence patterns between parasite species. We investigated co-occurrence patterns between three ectoparasite species (mite ( Neotrombicula harperi ), and fleas ( Orchopeas caedens and Ceratophyllus vison )) of North American red squirrels ( Tamiasciurus hudsonicus ). We evaluated (1) whether ectoparasites of red squirrels exhibit non-random co-occurrence patterns, and (2) the contribution of host and external environmental factors to parasite co-occurrence. Bayesian ordination and regression analysis (boral) revealed random associations between parasite species pairs when accounting for host and external environmental factors. However, the mite N. harperi exhibited a negative association with the flea O. caedens and positive association with the flea C. vison linked to temporal patterns of occurrence. Our data suggests that parasites of the investigated population of red squirrels tend to form associations based on temporal trends in infestation rather than species interactions. Further experimentation should investigate the role of additional factors on parasite co-occurrence patterns, such as temperature, precipitation, and humidity.
Declines in large wildlife increase landscape-level prevalence of rodent-borne disease in Africa
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.
Ectoparasites of European hedgehogs (Erinaceus europaeus) in Germany and their health impact
Background The European hedgehog ( Erinaceus europaeus ) is known for high levels of ectoparasitism that not only represents a health risk for the animals themselves, but also for pet animals and humans as hedgehogs are frequently taken into human care. In the present study, patterns of ectoparasite infestation were assessed in hedgehogs taken into care at northern German animal rehabilitation centres. Methods Ectoparasites (ticks, fleas and mites) of 498 hedgehogs were collected over a period of 3 years from July 2018 to May 2021. Species were identified based on morphological characteristics and also via amplification and sequencing of the partial cytochrome c oxidase subunit 2 (COX-2) gene for fleas of the family Ceratophyllidae. Seasonal changes in infestation patterns as well as correlations with animal age, body weight and health status were assessed using generalised linear models. Results Infestation with ticks, fleas and mites occurred throughout the year. Overall, 86.5% (431/498) of the examined hedgehogs were infested with ticks, 91.4% (455/498) with fleas and 17.7% (88/498) with mites . Ixodes ricinus and Ixodes hexagonus / Ixodes canisuga were the most common tick species detected, with the additional occurrence of one Ixodes frontalis. Significant seasonal changes were observed for I. ricinus , but not for I. hexagonus / I. canisuga . Additionally, I. ricinus nymph prevalence declined significantly as of 2020, probably as a consequence of the climate change-related drought as of 2018. In hedgehogs with flea infestations, Archaeopsylla erinacei , Ceratophyllus sciurorum , Nosopsyllus fasciatus and Ctenocephalides felis were identified. In all cases of mite infestation, Caparinia tripilis was detected, in addition to specimens of the family Macronyssidae and free-living mites of the family Acaridae. Statistical analyses showed correlations regarding the factors month, year, body weight and age, but no correlation was evident regarding the health status of the animals. Conclusions With a detected infestation rate of 98.6%, almost all of the examined hedgehogs were infested with at least one ectoparasite species. The seasonal activity patterns of the different ectoparasite species together with the complex annual cycle of hedgehogs lead to different seasonal patterns in ectoparasite prevalence and infestation intensities. Due to the risk of transmission of zoonotic pathogens as well as the possible negative impact on the host itself, hedgehogs should be treated against ectoparasites when taken into care facilities. Graphical Abstract
Epidemiological and molecular characterisation of flea infestations in dogs and cats in mainland Portugal
Background Fleas are major ectoparasites of dogs and cats, with significant veterinary and public health implications. This study aimed to estimate the prevalence of flea infestation in dogs and cats in mainland Portugal, identify associated risk factors and perform morphological and molecular characterisation of flea specimens. Methods A cross-sectional study was conducted from March 2022 to February 2023 in mainland Portugal. Dogs and cats were screened for flea infestations at veterinary clinics and shelters following World Association for the Advancement of Veterinary Parasitology guidelines. Fleas were morphologically identified to species level, and a subset was characterised molecularly via phylogenetic analysis of the cytochrome c oxidase subunit II gene ( cox2 ) sequences. Epidemiological data were analysed through multivariate logistic regression models to identify possible risk factors associated with flea infestation. Results A total of 1052 dogs and 1039 cats were examined, and flea infestation prevalence was determined to be 33.6% and 36.5%, respectively. Ctenocephalides felis was the predominant flea species in both hosts, accounting for 85.7% of fleas in dogs and 98.8% in cats, with molecular data confirming the subspecies C. felis felis . Other species identified included Ctenocephalides canis (9.6% in dogs; 1.8% in cats), Pulex irritans (4.2% in dogs) and Archaeopsylla erinacei maura (0.8% in dogs). The absence of insecticide use was the strongest predictor of flea infestation in both hosts (dogs: adjusted odds ratio [aOR] 4.87; cats: aOR 4.02). In dogs, the risk of infestation was higher in spring, summer and autumn compared to winter (aOR 2.08–3.72), and lower in the Lisbon Metropolitan Area, Alentejo and Algarve compared to the North region (aOR 0.14–0.45). In cats, risk was reduced in non-northern regions (Lisbon, Alentejo, Centro; aOR 0.10–0.45) and in those cats with non-domestic outdoor lifestyles (aOR 0.19). Conclusions Flea infestations are highly prevalent in dogs and cats across mainland Portugal, with C. felis felis as the dominant species. These findings provide valuable insights for the development of integrated, evidence-based strategies for flea control.
New Data on Ectoparasites of the Caucasian Squirrel Sciurus anomalus (Rodentia: Sciuridae) in Türkiye: A Case Report
Güldenstädt, 1785, known as the Caucasian squirrel, is a rodent distributed in all geographical regions of Türkiye. The material of this study consists of ectoparasites collected from male found dead on the highway (Karasu, Sakarya, Türkiye). As a result of microscopic examination, the specimens were identified: ticks as Linnaeus, 1758 (larvae and nymph), sucking louses as Ferris, 1923 (female), and fleas as (Schrank, 1803) (female and male). In this study, the presence of infestation on is reported for the first time in Türkiye.