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1.
Ticks Tick Borne Dis ; 12(6): 101820, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34555711

RESUMO

Ticks are vectors of a wide range of zoonotic viruses of medical and veterinary importance. Recently, metagenomics studies demonstrated that they are also the source of potentially pathogenic novel viruses. During the period from 2015 to 2017, questing ticks were collected by dragging the vegetation from geographically distant locations in the Republic of Korea (ROK) and a target-independent high-throughput sequencing method was utilized to study their virome. A total of seven viruses, including six putative novel viral entities, were identified. Genomic analysis showed that the novel viruses were most closely related to members in the orders Jingchuvirales and Bunyavirales. Phylogenetic reconstruction showed that the Bunyavirales-like viruses grouped in the same clade with other viruses within the Nairovirus and Phlebovirus genera, while the novel Jingchuvirales-like virus grouped together with other viruses within the family Chuviridae. Real-time RT-PCR was used to determine the geographic distribution and prevalence of these viruses in adult ticks. These novel viruses have a wide geographic distribution in the ROK with prevalences ranging from 2% to 18%. Our study expands the knowledge about the composition of the tick virome and highlights the wide diversity of viruses they harbor in the ROK. The discovery of novel viruses associated with ticks in the ROK highlights the need for an active tick-borne disease surveillance program to identify possible reservoirs of putative novel human pathogens.


Assuntos
Ixodidae/virologia , Vírus/isolamento & purificação , Animais , Ixodidae/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Larva/virologia , Ninfa/crescimento & desenvolvimento , Ninfa/virologia , República da Coreia , Doenças Transmitidas por Carrapatos/microbiologia , Doenças Transmitidas por Carrapatos/parasitologia , Doenças Transmitidas por Carrapatos/transmissão , Doenças Transmitidas por Carrapatos/virologia
2.
Acta Trop ; 221: 106012, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34126090

RESUMO

The seasonal distribution of hard ticks was investigated in 2018 in Gyeongbuk Province, Republic of Korea. Ticks were assayed for severe fever with thrombocytopenia syndrome virus (SFTSV). Ticks were collected monthly using CO2-baited traps from April to November in four habitats (grasslands, grave sites, hiking trails, and mixed forests). Based on morphological and molecular identification, Haemaphysalis longicornis was the most commonly collected species, followed by H. flava and Ixodes nipponensis. Ticks were more commonly collected in grassland habitats, followed by the grave sites, hiking trails, and mixed forests. Peak numbers of nymphs and adults of H. longicornis occurred in May and June, respectively, and Haemaphysalis larvae were collected from August to October. A total of 9/187 (4.8%) pools were positive for SFTSV between June and October in 2018. Phylogenetic analysis of partial fragments of the SFTSV obtained in this study showed that all positive virus samples clustered into genotype B.


Assuntos
Ixodidae/virologia , Phlebovirus/isolamento & purificação , Estações do Ano , Animais , Ecossistema , Ixodes/virologia , Filogenia , República da Coreia
3.
PLoS Negl Trop Dis ; 15(6): e0009480, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-34106924

RESUMO

The microbial flora associated with Hyalomma anatolicum ticks was investigated using culture-dependent (CD) and independent (next generation sequencing, NGS) methods. The bacterial profiles of different organs, development stages, sexes, and of host cattle skins were analyzed using the CD method. The egg and female gut microbiota were investigated using NGS. Fourteen distinct bacterial strains were identified using the CD method, of which Bacillus subtilis predominated in eggs, larval guts and in adult female and male guts, suggesting probable transovarial transmission. Bacillus velezensis and B. subtilis were identified in cattle skin and tick samples, suggesting that skin is the origin of tick bacteria. H.anatolicum males harbour lower bacterial diversity and composition than females. The NGS analysis revealed five different bacterial phyla across all samples, Proteobacteria contributing to >95% of the bacteria. In all, 56611sequences were generated representing 6,023 OTUs per female gut and 421 OTUs per egg. Francisellaceae family and Francisella make up the vast majority of the OTUs. Our findings are consistent with interference between Francisella and Rickettsia. The CD method identified bacteria, such B. subtilis that are candidates for vector control intervention approaches such paratransgenesis whereas NGS revealed high Francisella spp. prevalence, indicating that integrated methods are more accurate to characterize microbial community and diversity.


Assuntos
Vetores Aracnídeos/microbiologia , Doenças dos Bovinos/transmissão , Febre Hemorrágica da Crimeia/veterinária , Ixodidae/microbiologia , Microbiota , Animais , Vetores Aracnídeos/fisiologia , Vetores Aracnídeos/virologia , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bovinos , Doenças dos Bovinos/virologia , Feminino , Vírus da Febre Hemorrágica da Crimeia-Congo/genética , Vírus da Febre Hemorrágica da Crimeia-Congo/efeitos da radiação , Febre Hemorrágica da Crimeia/transmissão , Febre Hemorrágica da Crimeia/virologia , Ixodidae/fisiologia , Ixodidae/virologia , Masculino , Filogenia
4.
Ticks Tick Borne Dis ; 12(4): 101730, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33957484

RESUMO

Hunters are at a higher risk for exposure to zoonotic pathogens due to their close interactions with wildlife and arthropod vectors. In this study, high throughput sequencing was used to explore the viromes of two tick species, Amblyomma dissimile and Haemaphysalis juxtakochi, removed from hunted wildlife in Trinidad and Tobago. We identified sequences from 3 new viral species, from the viral families Orthomyxoviridae, Chuviridae and Tetraviridae in A. dissimile.


Assuntos
Cervos , Iguanas , Ixodidae/virologia , Infecções por Orthomyxoviridae/veterinária , Orthomyxoviridae/isolamento & purificação , Animais , Orthomyxoviridae/classificação , Orthomyxoviridae/genética , Infecções por Orthomyxoviridae/virologia , Filogenia , Infestações por Carrapato/parasitologia , Infestações por Carrapato/veterinária , Trinidad e Tobago , Proteínas Virais/análise
5.
PLoS Negl Trop Dis ; 15(5): e0009384, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-34048430

RESUMO

Crimean-Congo haemorrhagic fever (CCHF) is a severe tick-borne viral zoonosis endemic to parts of Africa, Europe, the Middle East and Central Asia. Human cases are reported annually in South Africa, with a 25% case fatality rate since the first case was recognized in 1981. We investigated CCHF virus (CCHFV) seroprevalence and risk factors associated with infection in cattle and humans, and the presence of CCHFV in Hyalomma spp. ticks in central South Africa in 2017-18. CCHFV IgG seroprevalence was 74.2% (95%CI: 64.2-82.1%) in 700 cattle and 3.9% (95%CI: 2.6-5.8%) in 541 farm and wildlife workers. No veterinary personnel (117) or abattoir workers (382) were seropositive. The prevalence of CCHFV RNA was significantly higher in Hyalomma truncatum (1.6%) than in H. rufipes (0.2%) (P = 0.002). Seroprevalence in cattle increased with age and was greater in animals on which ticks were found. Seroprevalence in cattle also showed significant geographic variation. Seroprevalence in humans increased with age and was greater in workers who handled livestock for injection and collection of samples. Our findings support previous evidence of widespread high CCHFV seroprevalence in cattle and show significant occupational exposure amongst farm and wildlife workers. Our seroprevalence estimate suggests that CCHFV infections are five times more frequent than the 215 confirmed CCHF cases diagnosed in South Africa in the last four decades (1981-2019). With many cases undiagnosed, the potential seriousness of CCHF in people, and the lack of an effective vaccine or treatment, there is a need to improve public health awareness, prevention and disease control.


Assuntos
Doenças dos Bovinos/epidemiologia , Vírus da Febre Hemorrágica da Crimeia-Congo/isolamento & purificação , Febre Hemorrágica da Crimeia/epidemiologia , Ixodidae/virologia , Estudos Soroepidemiológicos , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Bovinos , Doenças dos Bovinos/parasitologia , Doenças dos Bovinos/virologia , Feminino , Vírus da Febre Hemorrágica da Crimeia-Congo/imunologia , Febre Hemorrágica da Crimeia/etiologia , Humanos , Imunoglobulina G/sangue , Masculino , Pessoa de Meia-Idade , Exposição Ocupacional , Prevalência , Fatores de Risco , África do Sul/epidemiologia , Infestações por Carrapato/veterinária
6.
J Med Entomol ; 58(2): 873-879, 2021 03 12.
Artigo em Inglês | MEDLINE | ID: mdl-33710315

RESUMO

Following the recent discovery of Bourbon virus (BRBV) as a human pathogen, and the isolation of the virus from Amblyomma americanum (L.) collected near the location of a fatal human case, we undertook a series of experiments to assess the laboratory vector competence of this tick species for BRBV. Larval ticks were infected using an immersion technique, and transstadial transmission of virus to the nymphal and then to the adult stages was demonstrated. Transstadially infected nymphs transmitted virus to adult ticks at very high rates during cofeeding, indicating the presence of infectious virus in the saliva of engorging ticks. Vertical transmission by transstadially infected females to their progeny occurred, but at a low rate. Rabbits fed on by infected ticks of all active life stages developed high titers of antibody to the virus, demonstrating host exposure to BRBV antigens/live virus during tick blood feeding. These results demonstrate that A. americanum is a competent vector of BRBV and indicate that cofeeding could be critical for enzootic maintenance.


Assuntos
Amblyomma/virologia , Infecções por Orthomyxoviridae/transmissão , Thogotovirus , Experimentação Animal , Animais , Vetores Aracnídeos/virologia , Vetores de Doenças , Ixodidae/virologia , Coelhos , Saliva/virologia
7.
Ticks Tick Borne Dis ; 12(2): 101622, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33388553

RESUMO

Crimean-Congo hemorrhagic fever (CCHF) is a tick-borne viral disease in the old continents, in many countries south of the 50 °North Parallel. The agent is known to be the most prevalent and major cause of severe and fatal human hemorrhagic diseases among the tick-borne viruses, and is the second most widespread of all medically critical arboviruses following dengue. Members of the Hyalomma genus are mainly involved in the natural transmission of the CCHF virus (CCHFV); of those, H. marginatum is known to be the primary vector of the disease in the Western Palaearctic. In general, epidemiological studies have been based on serological detections in the hosts and/or virus screening of ticks collected from the hosts. To the best of our knowledge, only a few studies have been carried out to screen the virus in unfed, questing field ticks. Nevertheless, detection of the virus in questing ticks is known to be a crucial parameter to determine the possible vector roles of the ticks and to understand the ecological dynamics of related diseases. In this study, 200 (75 males,125 females) questing H. marginatum adults collected from the field in nine villages in Thrace, located in the European part of Turkey, were screened individually for CCHFV using nested PCR. As a result, 103 (51.5 %) ticks were determined as positive with various strains of CCHFV. High positivity in questing vectors in a region where a significantly lower number of human cases have been encountered suggests that there should be some region-specific drivers that are effective in the natural dynamics of the disease. Detailed etiological and epidemiological studies are needed to reveal the possible reason for this unexpected discrepancy.


Assuntos
Genoma Viral , Genótipo , Vírus da Febre Hemorrágica da Crimeia-Congo/genética , Ixodidae/virologia , Animais , Feminino , Vírus da Febre Hemorrágica da Crimeia-Congo/classificação , Masculino , Filogenia , Turquia
8.
Transbound Emerg Dis ; 68(3): 993-1000, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-32738065

RESUMO

Crimean-Congo haemorrhagic fever virus (CCHFV) is the causative agent of the severe tick-borne, often fatal, zoonotic Crimean-Congo haemorrhagic fever (CCHF), which is widely distributed worldwide. The CCHFV transmission to humans occurs through tick bite, crushing of engorged ticks or contact with infected host blood. Previously, CCHFV genotype Africa III was reported in Spain. Given the emergence of CCHF and the role of ticks in pathogen maintenance and transmission, we investigated the presence and genotype identity of the virus in tick species parasitizing abundant wild host species in south-western Spain. A total of 613 adult ticks were collected from hunter-harvested wild ungulates in twenty locations throughout south-western Spain. Ticks were identified, nucleic acids were extracted, RNA was analysed by a nested RT-PCR targeting CCHFV S segment, and the amplicons were sequenced. According to the 212-bp sequence amplified, the presence of CCHFV human genotype Europe V was detected in Hyalomma lusitanicum and Dermacentor marginatus ticks collected from red deer, fallow deer and Eurasian wild boar in different locations from south-western Spain. Genotype Africa IV was also detected in a H. lusitanicum tick collected from a red deer. The detection of CCHFV in different tick species collected from various wild hosts and localities provided strong evidence of widespread CCHFV presence in the region, suggesting that the circulation of the virus in Spain requires more attention. Additionally, the identification of the CCHFV genotype Europe V in ticks suggested that its introduction in Spain was probably from Eastern Europe.


Assuntos
Genótipo , Vírus da Febre Hemorrágica da Crimeia-Congo/isolamento & purificação , Febre Hemorrágica da Crimeia/veterinária , Doenças dos Suínos/diagnóstico , Animais , Vírus da Febre Hemorrágica da Crimeia-Congo/genética , Febre Hemorrágica da Crimeia/diagnóstico , Febre Hemorrágica da Crimeia/virologia , Ixodidae/virologia , Reação em Cadeia da Polimerase/veterinária , Espanha , Sus scrofa , Suínos , Doenças dos Suínos/virologia
9.
Acta Trop ; 214: 105790, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33309594

RESUMO

Ngari virus is a mosquito-borne virus belonging to the genus Orthobunyavirus (Peribunyaviridae family). This virus is pathogenic to humans and causes severe illness. Ngari virus is present in several African countries, including Madagascar. Here, we report the detection of Ngari virus in ixodid ticks collected from cows in Guinea. A tick survey was conducted in March-November of 2018 in six regions of Guinea. The sample comprised 710 pools, with a total of 2067 ticks belonging to five species collected from 197 cows. At the initial stage, we screened a subsample of tick pools of vector-borne viruses with a multiplex genus-specific primer panel. In the second stage of the study, we narrowed the search and screened all the samples by qPCR for the detection of Ngari virus. All positive samples were sequenced with primers flanking Ngari virus-specific fragments on the S and M segments. We found Ngari virus in 12 pools that were formed from engorged ticks collected from livestock in three villages of the Kindia and Kankan regions. Sequencing of the S and M segments confirmed that the detected viruses belong to Ngari virus, and the viruses were most similar to the strain Adrar, which was isolated in Mauritania. We detected viral RNA in ticks of the following species: Amblyomma variegatum, Rhipicephalus geigyi, and Rh. (Boophilus) spp. There is no evidence that ixodid ticks are competent vectors of the Ngari virus. Most likely, the ticks obtained the virus through blood from an infected host. The study of engorged ticks can be recommended as a simpler approach for the wide screening of the Ngari virus and subsequent testing of cattle and mosquitos in those locations where the PCR-positive ticks were collected.


Assuntos
Infecções por Bunyaviridae/veterinária , Doenças dos Bovinos/epidemiologia , Ixodidae/virologia , Orthobunyavirus/isolamento & purificação , Infestações por Carrapato/veterinária , Animais , Infecções por Bunyaviridae/epidemiologia , Infecções por Bunyaviridae/transmissão , Bovinos , Doenças dos Bovinos/parasitologia , Doenças dos Bovinos/transmissão , Doenças dos Bovinos/virologia , Feminino , Guiné/epidemiologia , Humanos , Orthobunyavirus/genética , Infestações por Carrapato/epidemiologia , Infestações por Carrapato/parasitologia
10.
Ticks Tick Borne Dis ; 12(1): 101585, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33113476

RESUMO

Trombidiformes and Mesostigmata mites, as well as Ixodida ticks, infest ectothermic tetrapods worldwide, potentially acting as vectors of bacteria, viruses and protozoa. The relationship among ectoparasites, transmitted pathogenic agents (e.g., Borrelia spp., Coxiella spp., Hepatozoon spp., and Rickettsia spp.) and ectothermic hosts has been scarcely investigated. This research focuses on a large collection of Brazilian herpetofauna screened for the presence of arthropod ectoparasites and vector-borne microbial agents. Reptiles (n = 121) and amphibians (n = 49) from various locations were infested by ectoparasites. Following genomic extraction, microbial agents were detected in 81 % of the Acari (i.e. n = 113 mites and n = 26 ticks). None of the mites, ticks and tissues from amphibians yielded positive results for any of the screened agents. Blood was collected from reptiles and processed through blood cytology and molecular analyses (n = 48). Of those, six snakes (12.5 %) showed intraerythrocytic alterations compatible with Hepatozoon spp. gamonts and Iridovirus inclusions. Hepatozoon spp. similar to Hepatozoon ayorgbor and Hepatozoon musa were molecularly identified from seven hosts, two mite and two tick species. Rickettsia spp. (e.g., Rickettsia amblyommatis, Rickettsia bellii-like, Rickettsia sp.) were detected molecularly from four mite species and Amblyomma rotundatum ticks. Phylogenetic analyses confirmed the molecular identification of the above-mentioned microbial agents of mites and ticks related to snakes and lizards. Overall, our findings highlighted that the Brazilian herpetofauna and its ectoparasites harbour potentially pathogenic agents, particularly from the northern and south-eastern regions. The detection of several species of spotted fever group Rickettsia pointed out the potential role of ectothermic hosts and related arthropod ectoparasites in the epidemiological cycle of these bacteria in Brazil.


Assuntos
Eucoccidiida/isolamento & purificação , Iridoviridae/isolamento & purificação , Ixodidae , Ácaros , Répteis , Rickettsia/isolamento & purificação , Animais , Brasil , Reservatórios de Doenças , Eucoccidiida/classificação , Feminino , Iridoviridae/classificação , Ixodidae/crescimento & desenvolvimento , Ixodidae/microbiologia , Ixodidae/parasitologia , Ixodidae/virologia , Larva/crescimento & desenvolvimento , Larva/microbiologia , Larva/parasitologia , Larva/virologia , Masculino , Ácaros/crescimento & desenvolvimento , Ácaros/microbiologia , Ácaros/parasitologia , Ácaros/virologia , Ninfa/crescimento & desenvolvimento , Ninfa/microbiologia , Ninfa/parasitologia , Ninfa/virologia , Filogenia , Répteis/microbiologia , Répteis/parasitologia , Répteis/virologia , Rickettsia/classificação
11.
Ticks Tick Borne Dis ; 12(1): 101601, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33176235

RESUMO

Crimean-Congo haemorrhagic fever is a viral tick-borne zoonotic disease caused by a Nairovirus, Crimean-Congo haemorrhagic fever virus (CCHFV). The present survey aimed to determine the exposure of one-humped camels (Camelus dromedarius) from southern Tunisia to CCHFV. A total of 273 sera from extensively reared camels were collected from Tataouine district, Tunisia, and tested by CCHFV-specific enzyme linked immunosorbent assays. By combining the results of three serological tests, the overall seroprevalence of CCHFV was estimated as 89.7% (245/273). No viral RNA was detected from camel sera using quantitative real-time PCR (RT-qPCR). A total of 165 ticks were collected from camels and tested with RT-qPCR, and only one Hyalomma impeltatum tick was positive for virus RNA.


Assuntos
Vírus da Febre Hemorrágica da Crimeia-Congo/isolamento & purificação , Febre Hemorrágica da Crimeia/epidemiologia , Ixodidae/virologia , Animais , Camelus , Ensaio de Imunoadsorção Enzimática/veterinária , Feminino , Febre Hemorrágica da Crimeia/virologia , Masculino , Prevalência , RNA Viral/análise , Reação em Cadeia da Polimerase em Tempo Real/veterinária , Estudos Soroepidemiológicos , Tunísia/epidemiologia
12.
Parasit Vectors ; 13(1): 504, 2020 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-33023633

RESUMO

BACKGROUND: In the South of Kazakhstan, Almaty Oblast' (region) is endemic for tick-borne encephalitis, with 0.16-0.32 cases/100,000 population between 2016-2018. The purpose of this study was to determine the prevalence and circulating subtypes of tick-borne encephalitis virus (TBEV) in Almaty Oblast' and Kyzylorda Oblast'. METHODS: In 2015 we investigated 2341 ticks from 7 sampling sites for the presence of TBEV. Ticks were pooled in 501 pools and isolated RNA was tested for the presence of TBEV by RT-qPCR. For the positive samples, the E gene was amplified, sequenced and a phylogenetic analysis was carried out. RESULTS: A total of 48 pools were TBEV-positive by the RT-qPCR. TBEV-positive ticks were only detected in three districts of Almaty Oblast' and not in Kyzylorda Oblast'. The positive TBEV pools were found within Ixodes persulcatus, Haemaphysalis punctata and Dermacentor marginatus. These tick species prevailed only in Almaty Oblast' whereas in Kyzylorda Oblast' Hyalomma asiaticum and D. marginatus are endemic. The minimum infection rates (MIR) in the sampling sites were 4.4% in Talgar, 2.8% in Tekeli and 1.1% in Yenbekshikazakh, respectively. The phylogenetic analysis of the generated sequences indicates that TBEV strains found in Almaty Oblast' clusters in the Siberian subtype within two different clades. CONCLUSIONS: We provided new data about the TBEV MIR in ticks in Almaty Oblast' and showed that TBEV clusters in the Siberian Subtype in two different clusters at the nucleotide level. These results indicate that there are different influences on the circulating TBEV strains in south-eastern Kazakhstan. These influences might be caused by different routes of the virus spread in ticks which might bring different genetic TBEV lineages to Kazakhstan. The new data about the virus distribution and vectors provided here will contribute to an improvement of monitoring of tick-borne infections and timely anti-epidemic measures in Kazakhstan.


Assuntos
Vírus da Encefalite Transmitidos por Carrapatos , Encefalite Transmitida por Carrapatos/epidemiologia , Ixodidae/virologia , Animais , Vetores Aracnídeos/virologia , Vírus da Encefalite Transmitidos por Carrapatos/genética , Vírus da Encefalite Transmitidos por Carrapatos/isolamento & purificação , Encefalite Transmitida por Carrapatos/transmissão , Genes Virais , Humanos , Ixodes/virologia , Cazaquistão/epidemiologia , Epidemiologia Molecular , Ninfa/virologia , Patologia Molecular/métodos , Filogenia , Reação em Cadeia da Polimerase em Tempo Real
13.
Ticks Tick Borne Dis ; 11(6): 101516, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32993936

RESUMO

Haemaphysalis longicornis, the Asian longhorned tick, is an invasive tick species that has spread rapidly across the northeastern and southeastern regions of the United States in recent years. This invasive pest species, known to transmit several tick-borne pathogens in its native range, is a potential threat to wildlife, livestock, domestic animals, and humans. Questing larval (n = 25), nymph (n = 10), and adult (n = 123), along with host-derived adult (n = 25) H. longicornis ticks were collected from various locations on Staten Island, NY. The pathobiome of each specimen was examined using two different high throughput sequencing approaches, virus enrichment and shotgun metagenomics. An average of 45,828,061 total reads per sample were recovered from the virus enriched samples and an average of 11,381,144 total reads per sample were obtained using shotgun metagenomics. Aside from endogenous viral sequences, no viruses were identified through either approach. Through shotgun metagenomics, Coxiella-like bacteria, Legionella, Sphingomonas, and other bacterial species were recovered. The Coxiella-like agent was ubiquitous and present at high abundances in all samples, suggesting it may be an endosymbiont. The other bacterial agents are not known to be transmitted by ticks. From these analyses, H. longicornis do not appear to host any endemic human tick-borne pathogens in the New York City region.


Assuntos
Ixodidae/microbiologia , Metagenoma , Microbiota , Viroma , Animais , Ixodidae/crescimento & desenvolvimento , Ixodidae/virologia , Larva/crescimento & desenvolvimento , Larva/microbiologia , Larva/virologia , Metagenômica , Cidade de Nova Iorque , Ninfa/crescimento & desenvolvimento , Ninfa/microbiologia , Ninfa/virologia
14.
Lancet Planet Health ; 4(8): e320-e329, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32800150

RESUMO

BACKGROUND: Haemaphysalis longicornis, a vector of various pathogens with medical and veterinary importance, is native to eastern Asia, and recently reached the USA as an emerging disease threat. In this study, we aimed to identify the geographical distribution, hosts, and associated pathogens of H longicornis. METHODS: Data were collected from multiple sources, including a field survey, reference book, literature review, and related websites. The thematic maps showing geographical distribution of H longicornis and associated pathogens were produced by ArcGIS. Hosts of H longicornis and positive rates for H longicornis-associated pathogens were estimated by meta-analysis. Ecological niche modelling was used to predict potential global distribution of H longicornis. FINDINGS: H longicornis was found to be present in ten countries, predominantly in eastern Asia, the USA, Australia, and New Zealand. The tick was known to feed on a variety of domestic and wild animals, and humans. At least 30 human pathogens were associated with H longicornis, including seven species of spotted fever group rickettsiae, seven species in the family of Anaplasmataceae, four genospecies in the complex Borrelia burgdorferi sensu lato, two Babesia species, six species of virus, and Francisella, Bartonella, Coxiella, and Toxoplasma, which were mainly reported in eastern Asia. The predictive modelling revealed that H longicornis might affect more extensive regions, including Europe, South America, and Africa, where the tick has never been recorded before. INTERPRETATION: H longicornis is relatively common in the world, and is associated with various human and animal pathogens. Authorities and health-care workers should be aware of the threat of the tick species to public health and veterinary medicine. Surveillance and further investigations should be enhanced globally. FUNDING: National Natural Science Foundation of China and National Key Research and Development Program of China.


Assuntos
Distribuição Animal , Interações Hospedeiro-Patógeno , Ixodidae/fisiologia , Animais , China , Ixodidae/microbiologia , Ixodidae/parasitologia , Ixodidae/virologia , Modelos Biológicos
15.
Ticks Tick Borne Dis ; 11(5): 101498, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32723625

RESUMO

Tick-borne diseases (TBDs), in particular Crimean-Congo hemorrhagic fever (CCHF) and tick-borne encephalitis (TBE), have been found to be expanding beyond their traditional geographic locations in Kazakhstan, which led to increased awareness and concern against TBDs in recent years. The tick fauna of Kazakhstan includes more than 30 species of human-biting ixodid ticks, recognized as carriers of a number of dangerous infectious pathogens that cause CCHF, TBE, tularemia, tick-borne rickettsioses and Lyme borreliosis. This paper presents the current knowledge of the main vectors of tick-borne pathogens (TBP) occurring in Kazakhstan, as well as a review of recent studies of ticks performed with the use of molecular methods being currently developed and widely utilized by Kazakh epidemiologists.


Assuntos
Vetores Aracnídeos/microbiologia , Vetores Aracnídeos/parasitologia , Ixodidae/microbiologia , Ixodidae/parasitologia , Doenças Transmitidas por Carrapatos/epidemiologia , Animais , Vetores Aracnídeos/virologia , Biodiversidade , Incidência , Ixodidae/virologia , Cazaquistão/epidemiologia , Prevalência , Doenças Transmitidas por Carrapatos/microbiologia , Doenças Transmitidas por Carrapatos/parasitologia , Doenças Transmitidas por Carrapatos/virologia
16.
Ticks Tick Borne Dis ; 11(5): 101490, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32723628

RESUMO

Haemaphysalis longicornis (Acari: Ixodidae) is an important vector of pathogens causing tick-borne diseases such as severe fever with thrombocytopenia syndrome (SFTS) in eastern Asia. Although an understanding of the overwintering ecology of ticks is fundamental to management of this vector, its winter biology remains unclear. Therefore, we conducted a field survey from eight provinces in South Korea to characterize overwintering sites of H. longicornis and investigate their SFTS virus infection rates. First, we conducted flagging which consists of horizontal sweeping of a 1 m2 cloth back-and-forth to collect ticks that may exhibit questing behaviors in four different landscapes: grassland, shrub, coniferous forest, and deciduous forest. From 640 sweeps of flagging (where each sweep covered 3.8 m2), we collected five unfed ixodid ticks. However, H. longicornis was not found. After the flagging, to locate overwintering ticks, we inspected a total of 679 samples consisting of three different structures: ground (leaf litter, soil surface, and topsoil layer), rocks, and dead trees. From the samples inspected, 85 unfed overwintering ixodid ticks were found. Haemaphysalis longicornis was the dominant species (88 %), and mostly nymphs were collected (94 %). This species was collected from ground samples, especially from the topsoil layer. Most H. longicornis were found in herbaceous landscapes such as grassland (46 %) and shrub (52 %). SFTS virus was found in 3 out of 38 pools of unfed nymphs (minimal infection rate: 4 %). Our results can serve as baseline information for the development of vector management programs.


Assuntos
Distribuição Animal , Ixodidae/fisiologia , Ixodidae/virologia , Phlebovirus/isolamento & purificação , Animais , Ixodidae/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Larva/fisiologia , Larva/virologia , Ninfa/crescimento & desenvolvimento , Ninfa/fisiologia , Ninfa/virologia , República da Coreia , Estações do Ano
17.
Ticks Tick Borne Dis ; 11(5): 101448, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32723637

RESUMO

We conducted orthonairovirus RNA screening of 7043 tick specimens-representing 16 species-collected from various regions of Anatolia. In 602 pools, Crimean-Congo hemorrhagic fever virus (CCHFV) Europe 1 and 2 lineages were detected in seven pools (1.1 %) comprising Hyalomma marginatum, Hyalomma scupense, Rhipicephalus bursa, Rhipicephalus sanguineus sensu lato and Rhipicephalus turanicus ticks. In pools of Hyalomma aegyptium, we detected Tamdy virus (TAMV) and an unclassified nairovirus sequence. Next-generation sequencing revealed complete coding regions of three CCHFV Europe 2 (AP92-like) viruses, TAMV and the novel orthonairovirus, tentatively named herein as Meram virus. We further performed in silico functional analysis of all available CCHFV Europe 2, TAMV, Meram and related virus genomes. The CCHFV Europe 2 viruses possessed several conserved motifs, including those with OTU-like cysteine protease activity. Probable recombinations were identified in L genome segments of CCHFV and TAMV. Through phylogeny reconstruction using individual genome segments, Meram virus emerged as a distinct virus among species within the Orthonairovirus genus. It further exhibited conserved motifs associated with RNA binding, encapsidation, signal peptidase cleavage, post-translational modification, RNA-dependent RNA polymerase and OTU-like activities. Bole tick virus 3 was also detected in two pools with CCHFV reactivity. Hereby, we describe a novel tick-associated orthonairovirus, in a CCHFV-endemic region with confirmed TAMV activity. Human and animal health impact of these viruses need to be addressed.


Assuntos
Genoma Viral , Ixodidae/virologia , Nairovirus/isolamento & purificação , Animais , Simulação por Computador , Feminino , Vírus da Febre Hemorrágica da Crimeia-Congo/genética , Vírus da Febre Hemorrágica da Crimeia-Congo/isolamento & purificação , Sequenciamento de Nucleotídeos em Larga Escala , Ixodidae/crescimento & desenvolvimento , Larva/crescimento & desenvolvimento , Larva/virologia , Masculino , Nairovirus/classificação , Nairovirus/genética , Ninfa/crescimento & desenvolvimento , Ninfa/virologia , Filogenia , Rhipicephalus/crescimento & desenvolvimento , Rhipicephalus/virologia , Turquia
18.
Zoonoses Public Health ; 67(6): 684-696, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32697888

RESUMO

Schoolyards and suburban parks are two environments where active tick surveillance may inform local management approaches. Even in a state such as New York with a robust active tick surveillance programme operated by the state Department of Health, these settings are not routinely covered. The goal of this study was to highlight the importance of active surveillance for tick-borne pathogens by describing their prevalence in ticks collected from schoolyards and suburban parks and to guide the use of integrated pest management in these settings. Tick dragging was performed in three regions of New York State: Long Island, the Lower Hudson Valley and the Capital Region. A total of 19 schoolyards and 32 parks were sampled. The location, habitat and weather at the time of tick collection were recorded. Ticks were speciated and tested for the presence of 17 pathogens with a novel application of nanoscale real-time PCR. The causative agents of Lyme disease, anaplasmosis, babesiosis and Powassan virus disease were all detected from Ixodes scapularis in various sites throughout the capital region and south-eastern counties of New York state. The most common agent detected was Borrelia burgdorferi, and coinfection rates were as high as 36%. This surveillance study also captured the first of the invasive Asian longhorned tick species, Haemaphysalis longicornis, in New York state (collected 2 June 2017). Results from this study highlight the importance of collaborative efforts and data sharing for improvement of surveillance for tick-borne disease agents.


Assuntos
Bactérias/isolamento & purificação , Vírus da Encefalite Transmitidos por Carrapatos/isolamento & purificação , Ixodidae/microbiologia , Doenças Transmitidas por Carrapatos/microbiologia , Animais , Bactérias/classificação , Bactérias/genética , DNA Bacteriano/genética , Vírus da Encefalite Transmitidos por Carrapatos/classificação , Feminino , Humanos , Ixodidae/virologia , Masculino , New York/epidemiologia , Ninfa , Filogenia , Doenças Transmitidas por Carrapatos/epidemiologia , Zoonoses
19.
J Vet Med Sci ; 82(8): 1226-1230, 2020 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-32522895

RESUMO

Dabieshan tick virus (DBV) belongs to Phlebovirus and its pathogenicity to human and animals is unknown. To investigate the presence of Dabieshan tick virus in Zhoushan, 353 ticks were collected from May 2018 to October 2019. The detection result showed that the average prevalence rate among these samples was 30.3% (107 positives out of 353 samples), which means DBVs are widely distributed in tick populations in Zhoushan of China. In a phylogenetic analysis based on the nucleotide sequences of the L and S segments of the virus (ZS-DBS-2018 tick virus) in the study, it clustered with Dabieshan tick virus (KM817666.1, KM817733.1) with a 97.1% and 99.6% nucleotide identity, respectively. Further studies involving virus isolation are required to characterize Dabieshan tick virus and to expand the geographical distribution of the sampled ticks.


Assuntos
Ixodidae/virologia , Phlebovirus/classificação , Phlebovirus/isolamento & purificação , Animais , China , Ixodidae/classificação , Ixodidae/genética , Phlebovirus/genética , Filogenia , Prevalência , RNA Ribossômico 16S , Análise de Sequência de RNA
20.
PLoS Negl Trop Dis ; 14(6): e0008368, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32520966

RESUMO

Severe fever with thrombocytopenia syndrome virus (SFTSV) is a novel phlebovirus in the Bunyaviridae family, causing SFTS with high mortality rate. Haemaphysalis longicornis ticks has been demonstrated as a competent vector of SFTSV by experimental transmission study and field study. However, there has been query whether other tick species that infest human beings in the SFTS endemic regions are capable of transmitting the pathogen. Here by performing experimental transmission study, we compared the capable of transmitting SFTSV among Ixodes sinensis, Ixodes persulcatus and Dermacentor silvarum ticks. The transovarial transmission was seen in the I. sinensis ticks with a rate of 40%, but neither in I. persulcatus nor in D. silvarum ticks. I. sinensis ticks also have the ability to transmit SFTSV horizontally to uninfected mice at 7 days after feeding, but not for I. persalcatus or D. silvarum ticks. In the transstadial transmission of I. persulcatus and D. silvarum ticks, I. persulcatus ticks were tested negative from larvae to adults. But the D. silvarum ticks were tested positive from larvae to nymphs, with the positive rate of 100% (10/10) for engorged larval ticks and 81.25% (13/16) for molted nymphs. However, the mice bitten by SFTSV-infected D. silvarum nymphs were negative for SFTSV detection. Therefore, there is not enough evidence to prove the transstadial transmission of SFTSV in I. persalcatus and D. silvarum ticks.


Assuntos
Vetores Aracnídeos/virologia , Infecções por Bunyaviridae/transmissão , Infecções por Bunyaviridae/virologia , Transmissão de Doença Infecciosa/veterinária , Ixodidae/virologia , Phlebovirus/fisiologia , Animais , Feminino , Humanos , Ixodes/virologia , Ixodidae/classificação , Larva/virologia , Camundongos , Ninfa , Coelhos
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