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One Health (Amsterdam, Netherlands) Jun 2024is a spirochete species transmitted via hard ticks. Following its discovery in Japan, this pathogen has been detected around the world, and is increasingly confirmed as...
BACKGROUND
is a spirochete species transmitted via hard ticks. Following its discovery in Japan, this pathogen has been detected around the world, and is increasingly confirmed as a human pathogen causing febrile disease, namely relapsing fever. Its presence has been confirmed in the Northeast China. However, there is little information regarding the presence of and other hard-tick-borne relapsing fever spirochetes in southern China including Yunnan province, where tick and animal species are abundant and many people both inhabit and visit for recreation.
METHODS
For the present study, we collected samples of ticks, wildlife, and domestic animal hosts from different counties in Yunnan province. Nucleic acids from samples were extracted, and the presence of and other relapsing fever spirochetes was confirmed using polymerase chain reaction (PCR) for the 16S rRNA specific target gene fragment. The positive samples were then amplified for partial genome of the and genes. Statistical differences in its distribution were analyzed by SPSS 20 software. Sequence of partial 16S rRNA, and genome were analyzed and phylogenetic trees were constructed.
RESULTS
A total of 8260 samples including 2304 ticks, 4120 small mammals and 1836 blood of domestic animal hosts were collected for screening for infection of and other relapsing fever spirochetes. Cattle and sheep act as the main hosts and , were identified as the important vector host with high prevalence or wide distribution. Only one (mouse) and one (shrew) were confirmed positive for relapsing fever spirochetes. Evidence of vertical transmission in ticks was also confirmed. Two known strains of and one novel relapsing fever spirochetes, -like agent, were confirmed and described with their host adaptation, mutation, and potential risk of spreading and spillover for human beings.
CONCLUSIONS
Our results provide new evidence of relapsing fever spirochetes in vector and animal hosts in Yunnan province based on large sample sizes, and offer guidance on further investigation, surveillance and monitoring of this pathogen.
PubMed: 38711479
DOI: 10.1016/j.onehlt.2024.100735 -
Parasites & Vectors Apr 2024Ixodes inopinatus was described from Spain on the basis of morphology and partial sequencing of 16S ribosomal DNA. However, several studies suggested that morphological...
BACKGROUND
Ixodes inopinatus was described from Spain on the basis of morphology and partial sequencing of 16S ribosomal DNA. However, several studies suggested that morphological differences between I. inopinatus and Ixodes ricinus are minimal and that 16S rDNA lacks the power to distinguish the two species. Furthermore, nuclear and mitochondrial markers indicated evidence of hybridization between I. inopinatus and I. ricinus. In this study, we tested our hypothesis on tick dispersal from North Africa to Southern Europe and determined the prevalence of selected tick-borne pathogens (TBPs) in I. inopinatus, I. ricinus, and their hybrids.
METHODS
Ticks were collected in Italy and Algeria by flagging, identified by sequencing of partial TROSPA and COI genes, and screened for Borrelia burgdorferi s.l., B. miyamotoi, Rickettsia spp., and Anaplasma phagocytophilum by polymerase chain reaction and sequencing of specific markers.
RESULTS
Out of the 380 ticks, in Italy, 92 were I. ricinus, 3 were I. inopinatus, and 136 were hybrids of the two species. All 149 ticks from Algeria were I. inopinatus. Overall, 60% of ticks were positive for at least one TBP. Borrelia burgdorferi s.l. was detected in 19.5% of ticks, and it was significantly more prevalent in Ixodes ticks from Algeria than in ticks from Italy. Prevalence of Rickettsia spotted fever group (SFG) was 51.1%, with significantly greater prevalence in ticks from Algeria than in ticks from Italy. Borrelia miyamotoi and A. phagocytophilum were detected in low prevalence (0.9% and 5.2%, respectively) and only in ticks from Italy.
CONCLUSIONS
This study indicates that I. inopinatus is a dominant species in Algeria, while I. ricinus and hybrids were common in Italy. The higher prevalence of B. burgdorferi s.l. and Rickettsia SFG in I. inopinatus compared with that in I. ricinus might be due to geographical and ecological differences between these two tick species. The role of I. inopinatus in the epidemiology of TBPs needs further investigation in the Mediterranean Basin.
Topics: Animals; Ixodes; Italy; Algeria; Rickettsia; Tick-Borne Diseases; Prevalence; Borrelia; Anaplasma phagocytophilum; Female; Hybridization, Genetic; Male; RNA, Ribosomal, 16S; Borrelia burgdorferi
PubMed: 38685096
DOI: 10.1186/s13071-024-06271-z -
Pathogens (Basel, Switzerland) Apr 2024Here, we described the prevalence of s.l. and species found in mono- and double infections among ticks occurring in urban areas of the city of Poznań, Poland. We...
Here, we described the prevalence of s.l. and species found in mono- and double infections among ticks occurring in urban areas of the city of Poznań, Poland. We tested 1029 host-seeking ticks and 1268 engorged ticks removed from pet animals. and prevailed both in ticks from vegetation (3.7% and 3.7%, respectively) and from pets (3.7% and 0.6%, respectively). and were the most prevalent in host-seeking (2.6% and 1.4%, respectively) and feeding ticks (2.8% and 2.2%, respectively). sequences proved to be identical to the human pathogenic genotype "Jena/Germany". Sequences of the rarest piroplasm (0.7%) were identical with those isolated from European patients. About 1.0% of tested ticks yielded dual infections; in host-seeking ticks, prevailed in co-infections with and , whereas and dominated in double-infected feeding ticks. Dual infections, even with a low prevalence, pose a challenge for differential diagnosis in patients with acute febrile disease after a tick bite. The finding of in both tick groups suggests that could be involved in the circulation of this piroplasm.
PubMed: 38668262
DOI: 10.3390/pathogens13040307 -
Open Forum Infectious Diseases Apr 2024Emerging tick-transmitted illnesses are increasingly recognized in the United States (US). To identify multiple potential tick-borne pathogens in patients from the Upper...
BACKGROUND
Emerging tick-transmitted illnesses are increasingly recognized in the United States (US). To identify multiple potential tick-borne pathogens in patients from the Upper Midwest and Northeast US with suspected anaplasmosis, we used state-of-the-art methods (polymerase chain reaction [PCR] and paired serology) to test samples from patients in whom anaplasmosis had been excluded.
METHODS
Five hundred sixty-eight patients without anaplasmosis had optimal samples available for confirmation of alternative tick-borne pathogens, including PCR and/or paired serology (acute-convalescent interval ≤42 days).
RESULTS
Among 266 paired serology evaluations, for which the median acute-convalescent sampling interval was 28 (interquartile range, 21-33) days, we identified 35 acute/recent infections (24 [9%] ; 6 [2%] subsp []; 3 [1%] spotted fever group rickettsioses [SFGR], and 2 [<1%] ) in 33 (12%) patients. Two had concurrent or closely sequential infections (1 and , and 1 and SFGR). Using multiplex PCR and reverse-transcription PCR, we identified 7 acute infections (5/334 [1%] and 2/334 [1%] ) in 5 (1%) patients, including 2 with - coinfection, but no , SFGR, Anaplasma capra, Heartland virus, or Powassan virus infections. Thus, among 568 patients with ruled-out anaplasmosis, 38 (6.7%) had ≥1 agent of tick-borne illness identified, with 33 patients (35 infections) diagnosed by paired serology and 5 additional patients (7 infections) by PCR.
CONCLUSIONS
By identifying other tick-borne agents in patients in whom anaplasmosis had been excluded, we demonstrate that emerging tick-borne infections will be identified if specifically sought.
PubMed: 38651141
DOI: 10.1093/ofid/ofae149 -
Frontiers in Public Health 2024Ticks are one of the most important vectors that can transmit pathogens to animals and human beings. This study investigated the dominant tick-borne bacteria carried by...
Ticks are one of the most important vectors that can transmit pathogens to animals and human beings. This study investigated the dominant tick-borne bacteria carried by ticks and tick-borne infections in forestry populations in Arxan, Inner Mongolia, China. Ticks were collected by flagging from May 2020 to May 2021, and blood samples were collected from individuals at high risk of acquiring tick-borne diseases from March 2022 to August 2023. The pooled DNA samples of ticks were analyzed to reveal the presence of tick-borne bacteria using high-throughput sequencing of the 16S rDNA V3-V4 region, and species-specific polymerase chain reaction (PCR) related to sequencing was performed to confirm the presence of pathogenic bacteria in individual ticks and human blood samples. All sera samples were examined for anti-SFGR using ELISA and anti- using IFA and WB. A total of 295 ticks (282 and 13 ) and 245 human blood samples were collected. , , , and were identified in by high-throughput sequencing, while (89.00%, 89/100), (17.00%, 17/100), (7.00%, 7/100), and (7.00%, 7/100) were detected in , as well the dual co-infection with and were detected in 13.00% (13/100) of . Of the 245 individuals, (4.90%, 12/245), (0.82%, 2/245), and (0.41%, 1/245) were detected by PCR, and the sequences of the target genes of detected in humans were identical to those detected in . The seroprevalence of anti-SFGR and anti- was 5.71% and 13.47%, respectively. This study demonstrated that and were the dominant tick-borne bacteria in from Arxan, and that dual co-infection with and was frequent. This is the first time that has been identified in ticks from Arxan and has been detected in humans from Inner Mongolia. More importantly, this study demonstrated the transmission of from ticks to humans in Arxan, suggesting that long-term monitoring of tick-borne pathogens in ticks and humans is important for the prevention and control of tick-borne diseases.
Topics: Animals; Humans; Coinfection; Forestry; Seroepidemiologic Studies; Ixodes; Tick-Borne Diseases
PubMed: 38487180
DOI: 10.3389/fpubh.2024.1302133 -
The Lancet. Microbe May 2024The recent discovery of emerging relapsing fever group Borrelia (RFGB) species, such as Borrelia miyamotoi, poses a growing threat to public health. However, the global... (Review)
Review
BACKGROUND
The recent discovery of emerging relapsing fever group Borrelia (RFGB) species, such as Borrelia miyamotoi, poses a growing threat to public health. However, the global distribution and associated risk burden of these species remain uncertain. We aimed to map the diversity, distribution, and potential infection risk of RFGB.
METHODS
We searched PubMed, Web of Science, GenBank, CNKI, and eLibrary from Jan 1, 1874, to Dec 31, 2022, for published articles without language restriction to extract distribution data for RFGB detection in vectors, animals, and humans, and clinical information about human patients. Only articles documenting RFGB infection events were included in this study, and data for RFGB detection in vectors, animals, or humans were composed into a dataset. We used three machine learning algorithms (boosted regression trees, random forest, and least absolute shrinkage and selection operator logistic regression) to assess the environmental, ecoclimatic, biological, and socioeconomic factors associated with the occurrence of four major RFGB species: Borrelia miyamotoi, Borrelia lonestari, Borrelia crocidurae, and Borrelia hermsii; and mapped their worldwide risk level.
FINDINGS
We retrieved 13 959 unique studies, among which 697 met the selection criteria and were used for data extraction. 29 RFGB species have been recorded worldwide, of which 27 have been identified from 63 tick species, 12 from 61 wild animals, and ten from domestic animals. 16 RFGB species caused human infection, with a cumulative count of 26 583 cases reported from Jan 1, 1874, to Dec 31, 2022. Borrelia recurrentis (17 084 cases) and Borrelia persica (2045 cases) accounted for the highest proportion of human infection. B miyamotoi showed the widest distribution among all RFGB, with a predicted environmentally suitable area of 6·92 million km, followed by B lonestari (1·69 million km), B crocidurae (1·67 million km), and B hermsii (1·48 million km). The habitat suitability index of vector ticks and climatic factors, such as the annual mean temperature, have the most significant effect among all predictive models for the geographical distribution of the four major RFGB species.
INTERPRETATION
The predicted high-risk regions are considerably larger than in previous reports. Identification, surveillance, and diagnosis of RFGB infections should be prioritised in high-risk areas, especially within low-income regions.
FUNDING
National Key Research and Development Program of China.
Topics: Borrelia; Humans; Relapsing Fever; Animals
PubMed: 38467129
DOI: 10.1016/S2666-5247(23)00396-8 -
Internal Medicine (Tokyo, Japan) Mar 2024Yezo virus is a novel virus transmitted by tick bites that causes fever with thrombocytopenia. To date, two reports have been published on patients with Yezo virus...
Yezo virus is a novel virus transmitted by tick bites that causes fever with thrombocytopenia. To date, two reports have been published on patients with Yezo virus infection. However, the clinical characteristics of Yezo virus infection remain unclear. A patient who presented with fever, fatigue, headaches, and muscle pain and was admitted to our hospital. The patient had thrombocytopenia, leukopenia, and elevated liver enzyme and serum ferritin levels. The patient was diagnosed with Yezo virus and Borrelia miyamotoi coinfection based on the detection of Yezo virus in a blood sample by PCR and the detection of elevated serum antibody titers to Yezo virus and Borrelia miyamotoi.
PubMed: 38462519
DOI: 10.2169/internalmedicine.3225-23 -
Canada Communicable Disease Report =... Jun 2023and ticks are the principal vectors of the agent of Lyme disease and several other tick-borne diseases in Canada. Tick surveillance data can be used to identify local...
BACKGROUND
and ticks are the principal vectors of the agent of Lyme disease and several other tick-borne diseases in Canada. Tick surveillance data can be used to identify local tick-borne disease risk areas and direct public health interventions. The objective of this article is to describe the seasonal and spatial characteristics of the main Lyme disease vectors in Canada, and the tick-borne pathogens they carry, using passive and active surveillance data from 2020.
METHODS
Passive and active surveillance data were compiled from the National Microbiology Laboratory Branch (Public Health Agency of Canada), provincial and local public health authorities, and eTick (an online, image-based platform). Seasonal and spatial analyses of ticks and their associated pathogens are presented, including infection prevalence estimates.
RESULTS
In passive surveillance, (n=7,534) were submitted from all provinces except Manitoba and British Columbia, while (n=718) were submitted only from British Columbia. No ticks were submitted from the Territories. The seasonal distribution of submissions was bimodal, but unimodal for . Four tick-borne pathogens were identified in (, , and ) and one in (). In active surveillance, (n=688) were collected in Ontario, Québec and New Brunswick. Five tick-borne pathogens were identified: , , and Powassan virus.
CONCLUSION
This article provides a snapshot of the distribution of and and their associated human pathogens in Canada in 2020, which can help assess the risk of exposure to tick-borne pathogens in different provinces.
PubMed: 38444700
DOI: 10.14745/ccdr.v49i06a06 -
Ticks and Tick-borne Diseases May 2024A Borrelia miyamotoi gene with partial homology to bipA of relapsing fever spirochetes Borrelia hermsii and Borrelia turicatae was identified by a GenBank basic...
A Borrelia miyamotoi gene with partial homology to bipA of relapsing fever spirochetes Borrelia hermsii and Borrelia turicatae was identified by a GenBank basic alignment search analysis. We hypothesized that this gene product may be an immunogenic antigen as described for other relapsing fever Borrelia (RFB) and could serve as a serological marker for B. miyamotoi infections. The B. miyamotoi gene was a truncated version about half the size of the B. hermsii and B. turicatae bipA with a coding sequence of 894 base pairs. The gene product had a calculated molecular size of 32.7 kDa (including the signal peptide). Amino acid alignments with B. hermsii and B. turicatae BipA proteins and with other B. miyamotoi isolates showed conservation at the carboxyl end. We cloned the B. miyamotoi bipA-like gene (herein named bipM) and generated recombinant protein for serological characterization and for antiserum production. Protease protection analysis demonstrated that BipM was surface exposed. Serologic analyses using anti-B. miyamotoi serum samples from tick bite-infected and needle inoculated mice showed 94 % positivity against BipM. The 4 BipM negative serum samples were blotted against another B. miyamotoi antigen, BmaA, and two of them were seropositive resulting in 97 % positivity with both antigens. Serum samples from B. burgdorferi sensu stricto (s.s.)-infected mice were non-reactive against rBipM by immunoblot. Serum samples from Lyme disease patients were also serologically negative against BipM except for 1 sample which may have indicated a possible co-infection. A recently published study demonstrated that B. miyamotoi BipM was non-reactive against serum samples from B. hermsii, Borrelia parkeri, and B. turicatae infected animals. These results show that BipM has potential for a B. miyamotoi-infection specific and sensitive serodiagnostic to differentiate between Lyme disease and various RFB infections.
Topics: Humans; Animals; Mice; Relapsing Fever; Borrelia; Lyme Disease; Borrelia Infections; Antigens
PubMed: 38367587
DOI: 10.1016/j.ttbdis.2024.102324 -
The Science of the Total Environment Apr 2024Studies on density and pathogen prevalence of Ixodes ricinus indicate that vegetation and local host community drive much of their variation between green spaces....
Studies on density and pathogen prevalence of Ixodes ricinus indicate that vegetation and local host community drive much of their variation between green spaces. Contrarily, micro-geographic variation is understudied, although its understanding could reduce disease risk. We studied the density of infectious nymphal Ixodes sp. ("DIN", proxy for disease hazard), density of questing nymphs ("DON") and nymphal infection prevalence ("NIP") near recreational forest infrastructure. Drag sampling within forest stands and at adjacent benches and trails was combined with vegetation surveys, camera trapping hosts and pathogen screening of ticks. We analysed Borrelia burgdorferi s.l. and its genospecies, with complementary analyses on Rickettsia sp., Anaplasma phagocytophilum, Neoehrlichia mikurensis and Borrelia miyamotoi. DIN was highest in forest interior and at trails enclosed by forest. Lower disease hazard was observed at benches and trails at forest edges. This infrastructure effect can be attributed to variation in vegetation characteristics and the habitat use of tick hosts, specifically roe deer, rodents and songbirds. DON is the main driver of DIN at micro-geographic scale and negatively affected by infrastructure and forest edges. A positive association with vegetation cover in understorey and canopy was observed, as were positive trends for local rodent and songbird abundance. NIP of different pathogens was affected by different drivers. Lower B. burgdorferi s.l. prevalence in the interior of forest stands, driven by its most prevalent genospecies B. afzelii, points towards higher density of uninfected hosts there. B. afzelii was positively associated with understorey containing tall species and with high canopy cover, whereas local bird community composition predicts B. garinii prevalence. A positive effect of songbird abundance and a negative effect of pigeons were observed. Our findings support amplification and inhibition mechanisms within forest stands and highlight that the effect of established drivers of DIN may differ based on the considered spatial scale.
Topics: Animals; Deer; Forests; Ecosystem; Tick-Borne Diseases; Borrelia burgdorferi; Ixodes; Rodentia
PubMed: 38340833
DOI: 10.1016/j.scitotenv.2024.170749