https://orcid.org/0000-0003-4825-9794
Figures
Abstract
Background
New tick-borne pathogens are being discovered worldwide, and recognized tick-borne diseases are becoming increasingly diverse. Candidatus R. jingxinensis is endemic in Asia, but its potential to cause clinical infection in humans remains unclear. This study was designed to elucidate the prevalence and delineate the clinical profile of Candidatus Rickettsia jingxinensis infection in Liaoning Province, China.
Methods
The subjects of this study were suspected cases of tick-borne infectious diseases admitted to the First Affiliated Hospital of China Medical University or reported to the Liaoning Provincial Center for Disease Control and Prevention in 2018–2022. Epidemiological and clinical data were collected. Tick-borne pathogens were detected with a microfluidic chip detection system, and specific gene fragments of the screened pathogens were amplified, sequenced, and compared. Evolutionary and phylogenetic trees were constructed and analyzed.
Results
In total, 398 infected subjects from 14 cities were included in the study, and 255 tick-borne pathogens were detected. Among these, 11 subjects were found to be infected with Candidatus Rickettsia jingxinensis. This is the first time this strain has been shown to cause infection and illness in humans. The main clinical features of subjects infected with Candidatus R. jingxinensis included fever, fatigue, dizziness, headache, nausea, diarrhea, general pain or muscle and joint pain, reduced leukocytes and platelets, abnormal coagulation function and liver function.
Author summary
No clinical cases of Candidatus R. jingxinensis infection had been reported prior to this study. During our screening of patients for common tick-borne pathogens known to be present in ticks from Liaoning Province, we identified eleven individuals infected with Candidatus Rickettsia jingxinensis—a species first discovered in 2016 in two pools of Haemaphysalis longicornis nymphs collected in Jingxin City, Jilin Province, China. This represents the first evidence that this strain can cause infection and disease in humans. The primary clinical manifestations observed in these patients included fever, fatigue, dizziness, headache, leukopenia, thrombocytopenia, abnormal coagulation function, and hypoalbuminemia. We believe our findings will assist clinicians in recognizing and managing infections caused by Candidatus R. jingxinensis.
Citation: Gao Y, Wang Y, Du L, Liu X, Sun Y, Zhang Y, et al. (2025) Human infection with Candidatus Rickettsia jingxinensis: First identification and clinical characteristics. PLoS Negl Trop Dis 19(11): e0013685. https://doi.org/10.1371/journal.pntd.0013685
Editor: Brian Stevenson, University of Kentucky College of Medicine, UNITED STATES OF AMERICA
Received: July 16, 2025; Accepted: October 24, 2025; Published: November 5, 2025
Copyright: © 2025 Gao et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Data Availability: The data that support the findings of this study are openly available in Genbank Data Center at https://www.ncbi.nlm.nih.gov/Genbank under reference number PP922920- PP922941. And other raw data of this study are presented descriptively in Tables 4 and 5. Owing to the small sample size (n=11), statistical comparisons were not conducted to avoid overinterpretation.
Funding: This study was funded by grants from National Natural Science Foundation of China (Grant/Award Number: 12171074 to BD). The funder had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
Competing interests: The authors have declared that no competing interests exist.
Introduction
Tick-borne infectious diseases (TBDs) are natural epidemic diseases predominantly caused by the bites of ticks carrying pathogens to human and animal hosts. Ticks carry more zoonotic pathogens than any other vector arthropods [1–4]. With the continuous expansion of human activities, the adaptation of ticks and tick-borne pathogens to climate and environmental changes, and the geographic expansion of ticks, TBDs pose an increasing threat to the health of their human and non-human hosts. New pathogenic tick-borne pathogens are being discovered worldwide, and recognized TBDs are becoming increasingly diverse. Since the 1950s, as many as 44 tick-borne pathogens have been detected in China, including viruses, rickettsias, spirochaetes, protozoa, etc. [5,6]. To 2018, 11,995 cases of severe fever with thrombocytopenia syndrome (SFTS) were reported, 2,786 individuals infected with Spirochaeta, 415 infected with Anaplasma, 215 infected with Babesia, 129 infected with spotted fever group Rickettsia (SFGR), 120 infected with Francisella tularensis, and 95 suffering Q fever in China [6,7]. SFGR infection, in particular, has been drawing increasing attention both in China and worldwide [8,9].
SFGR is highly endemic, and emerging species such as Candidatus Rickettsia xinyangensis have been identified as causative agents of clinical infection [10]. Candidatus R. jingxinensis was first detected in 2016 in two pools of Haemaphysalis longicornis nymphs in Jingxin City, Jilin Province, China, from which the pathogen derives its name [11]. In recent years, Candidatus R. jingxinensis has been reported in H. longicornis and other host animals, including cattle and sheep, across multiple Chinese provinces such as Shaanxi, Guizhou, Yunnan, Guangxi, Jiangsu, and Sichuan—in many of these regions as the dominant species [12–14]. It is noteworthy that the pathogen has also been detected in South Korea, near China’s Liaoning Province [15]. However, no previous studies had documented clinical human infection with Candidatus R. jingxinensis.
In this study, we provide the first confirmation of clinical Candidatus R. jingxinensis infection in Liaoning Province and summarize the clinical characteristics of its infection. These findings are expected to aid clinicians in the diagnosis and management of infections caused by this emerging pathogen.
Methods
Ethics statement
We adhering to ethical standards established by the 1964 Helsinki Declaration and its subsequent updates. To safeguard patient privacy, all data were anonymized and personal information was appropriately de-identified. The study received approval from the Ethics Committee of China Medical University in Shenyang China (Approval number: AF-SOP-07-1.1-01). Ensuring no adverse impact on subjects’ rights or welfare, informed consent was signed.
Study design
The subjects of the study were patients with suspected tick-borne infectious diseases treated at the First Affiliated Hospital of China Medical University in Shenyang China or reported to Liaoning Provincial Center for Disease Control during the five years from 2018 to 2022. After the consent of the patients was given, serum samples, epidemiological information, clinical manifestations, and test indicators of the patients were collected (Fig 1A).
(A) Flow chart of the study design. (B) Distribution of tick-borne pathogens. The top panel illustrates the overall composition of detected tick-borne pathogens, with case numbers and colors representing different species. The bottom panel details the species-level diversity within the SFGR, with case numbers and colors corresponding to different SFGR species. SFTSV: Severe fever with thrombocytopenia syndrome virus; SFGR: Spotted fever group rickettsia.
Inclusion criteria: (1) Epidemiological history: a clear history of tick bite prior to symptom onset; a history of living or working in a tick-endemic area; or a history of contact with animals or diseased animals. (2) Fever (body temperature ≥ 37.5°C) in patients for whom the pathogen could not be identified with routine testing. (3) Other clinical manifestations: headache, fatigue, muscle or joint pain, nausea and vomiting, abdominal pain and diarrhea, body hemorrhage, petechiae, or other symptoms of nonspecific TBD.
Exclusion criteria: Lack of epidemiological information; short admission period; or no detailed clinical information or laboratory tests.
Research methods
In this study, an epidemiological questionnaire was completed by patients with suspected TBD, which mainly collected general information (name, age, sex, occupation, current address) and epidemiological information (tick-bite history, field work history, tick activity in the residence, animal rearing conditions, etc.) on the patients. Clinical information (time of onset, signs and symptoms, laboratory test indicators, medication and course records, and prognosis) were also recorded.
Serum samples (3 ml) were collected from all subjects included in the study during their first medical visit, and the supernatant was extracted by centrifugation (Sorvall ST4 Plus; Thermo Fisher Scientific, Massachusetts, USA) at 3000 rpm for 10 min. The EZ1 Virus Mini Kit v2.0 (QIAGEN, Dusseldorf, Germany) was used to extract the nucleic acid. The nucleic acid concentrations of the samples were determined with a spectrophotometer (NanoDrop; Thermo Fisher Scientific).
Microfluidic chip technology
A customized microfluidic chip pre-embedded with 10 conserved genome regions for eight tick-borne pathogens known to be carried by ticks in Liaoning Province was used, as described in previous research [16,17] (Table 1). We simultaneously screened for eight tick-borne pathogens with the Gene Expression Micro Fluidic Card (Thermo Fisher Scientific) and Real-time fluorescence quantitative PCR instrument (ABI7500, Thermo Fisher Scientific).
Gene amplification and capillary electrophoresis
Nested PCR amplifier (EASTWIN, Beijing, China) was used to amplify fragments of the 17-kDa (Table 2) and ompB (Table 3) antigen genes from the SFGR-positive specimens, and the amplicons were analyzed with capillary electrophoresis (QIAxcel Advanced, QIAGEN). The primers used for gene amplification were from Sangon Biotech (Shanghai, China).
Gene sequencing and analysis
The positive PCR products were subjected to first-generation sequencing by Tianyi Huiyuan Co., Ltd (Beijing, China). Phylogenetic analysis was conducted using PhyloSuite v1.2.3 [18]. Initially, homologous sequences for the 17-kDa and ompB genes were retrieved from the NCBI database via BLASTn. The obtained sequences were subsequently aligned using MAFFT v7.313 [19], implemented within PhyloSuite, and the alignments were concatenated into a single matrix using the built-in sequence concatenation function. The best-fit partitioning scheme and nucleotide substitution models were then determined under the corrected Akaike Information Criterion (AICc) using Model Finder, which employs a greedy search algorithm coupled with branch length linkage. Maximum likelihood (ML) phylogenetic trees were constructed with IQ-TREE, also integrated in PhyloSuite, applying the edge-linked partition model. Branch support was assessed with an ultrafast bootstrap approximation (10,000 replicates). Finally, the resulting phylogenetic tree was visualized and annotated using the online ITOL tool (https://itol.embl.de/).
Results
Screening for tick-borne pathogens
Three hundred ninety-eight patients with suspected tick-borne pathogen infections examined in 2018–2022 were included in this study. Ultimately, 255 patients infected with tick-borne pathogens were identified, including 236 patients infected with SFTSV, 13 patients infected with SFGR, five patients infected with Coxiella burnetii, and one patient infected with Anaplasma phagocytophilum. There was a co-infection of SFTSV with SFGR (Fig 1B).
Among the 13 cases of SFGR infection, two were infected with R. parkeri and R. felis, respectively. while the remaining 11 patients were infected with Candidatus R. jingxinensis.
Gene sequencing and phylogenetic analysis of SFGR-positive samples
Nested PCR and capillary electrophoresis were performed on the 11 SFGR-positive samples. The 434-bp PCR product amplified from the 17-kDa antigen gene (Fig 2A) and the 384-bp PCR product from the ompB gene (Fig 2B) were analyzed with DNA sequencing. Phylogenetic trees were constructed with the 99.11%–100% consistent sequences determined by BLAST comparison at NCBI, and other SFGR which were confirmed pathogenic around the world. On the phylogenetic trees based on the 17-kDa antigen and ompB genes (Fig 3), the 11 rickettsial strains were distributed in the SFGR clade, and were closely related to Candidatus R. jingxinensis (gene sequence number: MN463687.1 and MN463688.1). Candidatus R. jingxinensis detected in this study and the other pathogenic Rickettsia species reported in China (R. heilongjiangiensis and R. japonica) localized to the same large branch of SFGR.
Electropherogram shows the amplification of (A) the 17-kDa antigen gene and (B) the outer membrane protein B (ompB) gene fragments. Lanes 1-11 represent PCR products from different clinical samples. The rightmost lane contains a 1000-bp DNA ladder used as a molecular weight standard, with key band sizes (bp) annotated alongside. The green lines highlight the size range of the molecular weight marker, with the corresponding minimum and maximum values (in bp) indicated.
The tree was constructed from the concatenated alignment of the 17-kDa and ompB gene fragments. Bootstrap support values (10,000 replicates) are shown at the nodes. The horizontal branch lengths are drawn to scale, with the bar at the bottom representing 0.1 nucleotide substitutions per site.
Clinical characteristics of Candidatus R. jingxinensis infection
One of the 11 patients with Candidatus R. jingxinensis infection had a history of tick bites, and two patients died (Tables 4 and 5). All patients had fever, with a peak temperature range from 37.7-40.0 °C. Other symptoms included fatigue (8/11 cases), dizziness and headache (6/11 cases), nausea (5/11 cases), diarrhea (5/11 cases), general pain or muscle and joint pain (5/11 cases), skin rash (4/11 cases), vomiting (4/11 cases), petechiae or nasal mucosal hemorrhage (3/11 cases), cough (2/11 cases), and abdominal pain (one case) (Table 4). On laboratory tests, eight patients showed reduced white blood cell (WBC) counts; nine patients showed reduced platelet counts; nine patients had abnormal coagulation function; alanine amino transferase (ALT) and apartate aminotransferase (AST) were elevated in five patients (> 2 × Upper Limit of Normal); total bilirubin (TBIL) was elevated in three patients; and creatinine was elevated in three patients (Table 5).
Table 5 presents the laboratory indicators of these patients infected with Candidatus R. jingxinensis. The WBC and platelet counts were lower in the patients who died (S1 Fig), suggesting that low counts might be associated with poorer outcomes. TBIL, DBIL, alkaline phosphatase (ALP), and gamma-glutamyl transferase (GGT) levels were elevated in those who died (S1 Fig), suggesting that the impairment of hepatobiliary function might be linked to an increased risk of mortality and that these indicators are strong predictors of a poor prognosis. Albumin levels correlated positively with survival (S1 Fig), highlighting the positive impact of the nutritional status and liver function on patient survival. Coagulation times were generally prolonged in the patients who died, particularly the activated partial thromboplastin time (APTT) (S1 Fig), suggesting that coagulation disorders might be related to an increased risk of mortality.
Discussion
The ticks analyzed in this study were collected from patients visiting the hospital, suggesting the possibility of human infection with Candidatus R. jingxinensis. Previously, R. montanensis was considered non-pathogenic, but it was later found to cause illness in humans [20]. Moreover, another Candidatus Rickettsia species was detected in humans in Xinyang City, Henan Province, in 2016, which was subsequently confirmed and named Candidatus R. xinyangensis [10]. The present study is the first to confirm Candidatus R. jingxinensis in human infections.
The combination of quantitative real-time PCR (qPCR) and serological testing is likely the optimal diagnostic approach. Although serum PCR has limited sensitivity for obligate intracellular bacteria, qPCR can detect early infection before antibodies appear [21,22]. In this study, all samples were collected during the early stage of illness, whereas serological confirmation generally requires at least two weeks after symptom onset; therefore, antibody testing was not performed. Rickettsial infection was primarily diagnosed using a customized microfluidic chip—a higher-throughput method compared to conventional PCR in this study. This molecular diagnostic approach has been reported in previous studies [23,24]. Further confirmation of Candidatus R. jingxinensis was achieved by PCR amplification and sequencing, followed by phylogenetic analysis; however, this approach has limitations compared to full genomic studies. Definitive species identification usually requires rickettsial isolation, which demands specialized laboratory equipment and appropriate safety measures, posing challenges in clinical practice [22,25,26]. We plan to perform genomic sequencing in future work to further characterize Candidatus R. jingxinensis [27].
Clinical manifestations of different SFGR are similar, including fever, headache, and prominent myalgia, often accompanied by rash or an eschar [27]. In this study, all 11 patients with Candidatus R. jingxinensis infections showed fever, six patients had headache, and rash was reported in only four patients. Fatigue, nausea, diarrhea, and general pain or muscle and joint pain were also common. Most patients had reduced WBC and platelet counts, and coagulation and liver function abnormalities. Although several key laboratory indicators (e.g., WBC, platelets, ALT, and AST,) differed significantly between the patients who survived and those who died, these finding cannot be confidently explained because the sample size was small. This suggests that although these indicators provide prognostic insights into the trend in survival, a diagnostic model and further validation with larger-scale studies are required for statistical rigor. Some studies suggest that rickettsiae are highly conserved and that excessive speciation may be unnecessary [25]; however, different strains exhibit considerable variation in virulence and prognosis, which influences clinical decision-making [28]. Such variation warrants differentiation among SFGR species [8]. Monitoring these clinically significant indicators and prevalence patterns may therefore help clinicians identify high-risk patients earlier and implement appropriate interventions.
The clinical manifestations of SFGR-infected patients are diverse and nonspecific, but we should be vigilant in the screening for and the diagnosis of Rickettsia infections. Unlike the symptomatic treatment of SFTS, doxycycline, a tetracycline antibiotic, has obvious efficacy in the treatment of rickettsial diseases. Although several studies have shown that a high bacteria load in the blood of rickettsial patients is uncommon [29,30], and the cycle threshold values of all the samples in this study were consistent with this view, there were still two deaths among our study subjects. Further investigation into the virulence mechanisms and drug susceptibility of Candidatus R. jingxinensis is warranted. Therefore, early diagnosis and timely treatment remain critical in SFGR infections.
This study has several limitations. First, the identification method requires further validation through pathogen isolation and sequencing. Second, the virulence characteristics of Candidatus R. jingxinensis relative to other rickettsiae need further comparative assessment. Third, the small sample size limits the generalizability of the clinical features and treatment experience described.
In conclusion, this study provides the first evidence of human infection with Candidatus R. jingxinensis in Liaoning Province, China. Our findings highlight the importance of clinical and epidemiological vigilance regarding this emerging pathogen.
Supporting information
S1 Fig. Comparison of clinical indicators between survival and death groups.
Box plots show the distributions for each indicator.
https://doi.org/10.1371/journal.pntd.0013685.s001
(TIF)
S2 Fig. Detection of tick-borne pathogens with the microfluidic chip technology in SFGR-infected patients.
https://doi.org/10.1371/journal.pntd.0013685.s002
(TIF)
References
- 1.
Durden LA. Taxonomy, host associations, life cycles and vectorial importance of ticks parasitizing small mammals. Micromammals and Macroparasites. Springer Japan:91–102. doi: https://doi.org/10.1007/978-4-431-36025-4_6
- 2. Colwell DD, Dantas-Torres F, Otranto D. Vector-borne parasitic zoonoses: emerging scenarios and new perspectives. Vet Parasitol. 2011;182(1):14–21. pmid:21852040
- 3. Jongejan F, Uilenberg G. The global importance of ticks. Parasitology. 2004;129 Suppl:S3–14. pmid:15938502
- 4. Pfäffle M, Littwin N, Muders SV, Petney TN. The ecology of tick-borne diseases. Int J Parasitol. 2013;43(12–13):1059–77. pmid:23911308
- 5. Jia W, Chen S, Chi S, He Y, Ren L, Wang X. Recent Progress on Tick-Borne Animal Diseases of Veterinary and Public Health Significance in China. Viruses. 2022;14(2):355. pmid:35215952
- 6. Zhao G-P, Wang Y-X, Fan Z-W, Ji Y, Liu M-J, Zhang W-H, et al. Mapping ticks and tick-borne pathogens in China. Nat Commun. 2021;12(1):1075. pmid:33597544
- 7. Miao D, Liu M-J, Wang Y-X, Ren X, Lu Q-B, Zhao G-P, et al. Epidemiology and Ecology of Severe Fever With Thrombocytopenia Syndrome in China, 2010‒2018. Clin Infect Dis. 2021;73(11):e3851–8. pmid:33068430
- 8. Bishop A, Borski J, Wang H-H, Donaldson TG, Michalk A, Montgomery A, et al. Increasing Incidence of Spotted Fever Group Rickettsioses in the United States, 2010-2018. Vector Borne Zoonotic Dis. 2022;22(9):491–7. pmid:36037000
- 9. McClain MT, Sexton DJ. Surveillance for Spotted Fever Group Rickettsial Infections: Problems, Pitfalls, and Potential Solutions. J Infect Dis. 2020;221(8):1238–40. pmid:31267127
- 10. Li H, Li X-M, Du J, Zhang X-A, Cui N, Yang Z-D, et al. Candidatus Rickettsia xinyangensis as Cause of Spotted Fever Group Rickettsiosis, Xinyang, China, 2015. Emerg Infect Dis. 2020;26(5):985–8. pmid:32310072
- 11. Liu H, Li Q, Zhang X, Li Z, Wang Z, Song M, et al. Characterization of rickettsiae in ticks in northeastern China. Parasit Vectors. 2016;9(1):498. pmid:27623998
- 12. Wang Q, Guo W-B, Pan Y-S, Jiang B-G, Du C-H, Que T-C, et al. Detection of Novel Spotted Fever Group Rickettsiae (Rickettsiales: Rickettsiaceae) in Ticks (Acari: Ixodidae) in Southwestern China. J Med Entomol. 2021;58(3):1363–9. pmid:33399212
- 13. Lu M, Meng C, Gao X, Sun Y, Zhang J, Tang G, et al. Diversity of Rickettsiales in Rhipicephalus microplus Ticks Collected in Domestic Ruminants in Guizhou Province, China. Pathogens. 2022;11(10):1108. pmid:36297165
- 14. Lu M, Meng C, Li Y, Zhou G, Wang L, Xu X, et al. Rickettsia sp. and Anaplasma spp. in Haemaphysalis longicornis from Shandong province of China, with evidence of a novel species “Candidatus Anaplasma Shandongensis”. Ticks Tick Borne Dis. 2023;14(1):102082. pmid:36403321
- 15. Bang MS, Kim C-M, Pyun S-H, Kim D-M, Yun NR. Molecular investigation of tick-borne pathogens in ticks removed from tick-bitten humans in the southwestern region of the Republic of Korea. PLoS One. 2021;16(6):e0252992. pmid:34129613
- 16. Wang Q, Pan Y-S, Jiang B-G, Ye R-Z, Chang Q-C, Shao H-Z, et al. Prevalence of Multiple Tick-Borne Pathogens in Various Tick Vectors in Northeastern China. Vector Borne Zoonotic Dis. 2021;21(3):162–71. pmid:33347789
- 17. Yu P-F, Niu Q-L, Liu Z-J, Yang J-F, Chen Z, Guan G-Q, et al. Molecular epidemiological surveillance to assess emergence and re-emergence of tick-borne infections in tick samples from China evaluated by nested PCRs. Acta Trop. 2016;158:181–8. pmid:26943995
- 18. Zhang D, Gao F, Jakovlić I, Zou H, Zhang J, Li WX, et al. PhyloSuite: An integrated and scalable desktop platform for streamlined molecular sequence data management and evolutionary phylogenetics studies. Mol Ecol Resour. 2020;20(1):348–55. pmid:31599058
- 19. Katoh K, Standley DM. MAFFT multiple sequence alignment software version 7: improvements in performance and usability. Mol Biol Evol. 2013;30(4):772–80. pmid:23329690
- 20. McQuiston JH, Zemtsova G, Perniciaro J, Hutson M, Singleton J, Nicholson WL, et al. Afebrile spotted fever group Rickettsia infection after a bite from a Dermacentor variabilis tick infected with Rickettsia montanensis. Vector Borne Zoonotic Dis. 2012;12(12):1059–61. pmid:23153005
- 21. Robinson MT, Satjanadumrong J, Hughes T, Stenos J, Blacksell SD. Diagnosis of spotted fever group Rickettsia infections: the Asian perspective. Epidemiol Infect. 2019;147:e286. pmid:31587667
- 22. Raoult D, Roux V. Rickettsioses as paradigms of new or emerging infectious diseases. Clin Microbiol Rev. 1997;10(4):694–719. pmid:9336669
- 23. Liu J, Kabir F, Manneh J, Lertsethtakarn P, Begum S, Gratz J, et al. Development and assessment of molecular diagnostic tests for 15 enteropathogens causing childhood diarrhoea: a multicentre study. Lancet Infect Dis. 2014;14(8):716–24. pmid:25022434
- 24. Lappan R, Henry R, Chown SL, Luby SP, Higginson EE, Bata L, et al. Monitoring of diverse enteric pathogens across environmental and host reservoirs with TaqMan array cards and standard qPCR: a methodological comparison study. Lancet Planet Health. 2021;5(5):e297–308. pmid:33964239
- 25. Dumler JS, Walker DH. Genomics Should Inform Appropriate Analysis of Taxonomy and Pathogenesis of Rickettsia. J Infect Dis. 2025;231(4):827–9. pmid:39432829
- 26. Paddock CD, Karpathy SE, Henry A, Ryle L, Hecht JA, Hacker JK, et al. Rickettsia rickettsii subsp californica subsp nov, the Etiologic Agent of Pacific Coast Tick Fever. J Infect Dis. 2025;231(4):849–58. pmid:39432903
- 27. Bumburidi YV, Berezovskiy DV, Zhakipbayeva BT, Horth RZ, Millman AJ, Nicholson WL, et al. Spotted Fever Group Rickettsioses among Hospitalized Patients and Circulation of Rickettsia in Ticks, Kazakhstan, 2019. Emerg Infect Dis. 2025;31(10):1961–8. pmid:41017038
- 28. Galletti MFBM, Fujita A, Rosa RD, Martins LA, Soares HS, Labruna MB, et al. Virulence genes of Rickettsia rickettsii are differentially modulated by either temperature upshift or blood-feeding in tick midgut and salivary glands. Parasit Vectors. 2016;9(1):331. pmid:27287539
- 29. Ocias LF, Wilhelmsson P, Sjöwall J, Henningsson AJ, Nordberg M, Jørgensen CS, et al. Emerging tick-borne pathogens in the Nordic countries: A clinical and laboratory follow-up study of high-risk tick-bitten individuals. Ticks Tick Borne Dis. 2020;11(1):101303. pmid:31631052
- 30. Paris DH, Dumler JS. State of the art of diagnosis of rickettsial diseases: the use of blood specimens for diagnosis of scrub typhus, spotted fever group rickettsiosis, and murine typhus. Curr Opin Infect Dis. 2016;29(5):433–9. pmid:27429138