Probability of Spirochete Borrelia miyamotoi Transmission from Ticks to Humans

Case report: First case of Borrelia miyamotoi meningitis in an immunocompromised patient in Norway

Background

Tick-borne disease caused by B. miyamotoi (BMD) usually manifest as a febrile illness in humans. Complications include relapsing fever and in rare occasions involvement of the central nervous system. Only a few cases of meningoencephalitis have been described, mostly in immunosuppressed patients.

Case presentation

A 70-year-old female receiving immunosuppressive rituximab therapy presented with frontal headache, dizziness, nausea, vomiting and chills. Clinical laboratory blood analyses were normal. Cerebrospinal fluid (CSF) was translucent and analysis showed increased leucocyte count (187 106/L) and elevated level of protein (1056 mg/L). Empiric antibiotic treatment was initiated. The patient showed an early symptomatic relief and 24 h after admission she was discharged from the hospital and antibiotic treatment was discontinued. Two weeks after hospitalisation the B. miyamotoi specific PCR turned out positive in both CSF and serum. At the time, the patient was recovered with mild residual headache. She was treated with high dose doxycycline and her subtle symptoms disappeared.

Conclusions

To our knowledge, we present the first patient with BMD-associated meningitis in Norway, one of eight cases reported worldwide. The patient had mild symptoms and received an early diagnosis. A more severe progression or relapse of disease may have been prevented by antibiotic treatment. BMD should be considered as causes of aseptic meningitis, especially in immunosuppressed patients living in endemic areas.

Prevalence and clinical manifestation of Borrelia miyamotoi in Ixodes ticks and humans in the northern hemisphere: a systematic review and meta-analysis

BACKGROUND

Various studies have evaluated the infection of Ixodes ticks and humans with the relapsing fever spirochaete Borrelia miyamotoi. However, to our knowledge, the prevalence of infection and disease has not been assessed systematically. We aimed to examine the prevalence of B miyamotoi in Ixodes ticks and humans, and the disease it can cause, in the northern hemisphere.

METHODS

For this systematic review and meta-analysis, we searched PubMed and Web of Science up to March 1, 2021. Studies assessing Ixodes tick infection published since Jan 1, 2011 were eligible, whereas no time limitation was placed on reports of human infection and disease. We extracted B miyamotoi test positivity ratios and used a random-effects model to calculate estimated proportions of infected ticks, infected humans, and human disease with 95% CI. This study was registered with PROSPERO, CRD42021268996.

FINDINGS

We identified 730 studies through database searches and 316 additional studies that referenced two seminal articles on B miyamotoi. Of these 1046 studies, 157 were included in the review, reporting on 165 637 questing ticks, 45 608 unique individuals, and 504 well described cases of B miyamotoi disease in humans. In ticks, the highest prevalence of B miyamotoi was observed in Ixodes persulcatus (2·8%, 95% CI 2·4-3·1) and the lowest in Ixodes pacificus (0·7%, 0·6-0·8). The overall seroprevalence in humans was 4·4% (2·8-6·3), with significantly (p<0·0001) higher seroprevalences in the high-risk group (4·6%, 2·6-7·1), participants with confirmed or suspected Lyme borreliosis (4·8%, 1·8-8·8), and individuals suspected of having a different tick-borne disease (11·9%, 5·6-19·9) than in healthy controls (1·3%, 0·4-2·8). Participants suspected of having a different tick-borne disease tested positive for B miyamotoi by PCR significantly more often than did the high-risk group (p=0·025), with individuals in Asia more likely to test positive than those in the USA (odds ratio 14·63 [95% CI 2·80-76·41]).

INTERPRETATION

B miyamotoi disease should be considered an emerging infectious disease, especially in North America and Asia. Prospective studies and increased awareness are required to obtain further insights into the burden of disease.

FUNDING

ZonMW and the European Regional Development Fund (Interreg).

Tick borne relapsing fever - a systematic review and analysis of the literature

Tick borne relapsing fever (TBRF) is a zoonosis caused by various Borrelia species transmitted to humans by both soft-bodied and (more recently recognized) hard-bodied ticks. In recent years, molecular diagnostic techniques have allowed to extend our knowledge on the global epidemiological picture of this neglected disease. Nevertheless, due to the patchy occurrence of the disease and the lack of large clinical studies, the knowledge on several clinical aspects of the disease remains limited. In order to shed light on some of these aspects, we have systematically reviewed the literature on TBRF and summarized the existing data on epidemiology and clinical aspects of the disease. Publications were identified by using a predefined search strategy on electronic databases and a subsequent review of the reference lists of the obtained publications. All publications reporting patients with a confirmed diagnosis of TBRF published in English, French, Italian, German, and Hungarian were included. Maps showing the epidemiogeographic mosaic of the different TBRF Borrelia species were compiled and data on clinical aspects of TBRF were analysed. The epidemiogeographic mosaic of TBRF is complex and still continues to evolve. Ticks harbouring TBRF Borrelia have been reported worldwide, with the exception of Antarctica and Australia. Although only molecular diagnostic methods allow for species identification, microscopy remains the diagnostic gold standard in most clinical settings. The most suggestive symptom in TBRF is the eponymous relapsing fever (present in 100% of the cases). Thrombocytopenia is the most suggestive laboratory finding in TBRF. Neurological complications are frequent in TBRF. Treatment is with beta-lactams, tetracyclines or macrolids. The risk of Jarisch-Herxheimer reaction (JHR) appears to be lower in TBRF (19.3%) compared to louse-borne relapsing fever (LBRF) (55.8%). The overall case fatality rate of TBRF (6.5%) and LBRF (4-10.2%) appears to not differ. Unlike LBRF, where perinatal fatalities are primarily attributable to abortion, TBRF-related perinatal fatalities appear to primarily affect newborns.

First detection of Borrelia miyamotoi infections in ticks and humans from the northeast of Inner Mongolia, China

Borrelia miyamotoi is a relapsing fever spirochete that can cause chills, fatigue, headache, myalgia, arthralgia, and even meningitis, damaging human health. B. miyamotoi has a wide distribution since its discovery in Ixodes persulcatus in 1994. The human B. miyamotoi disease was first described in Russia in 2011. However, the epidemiological information in China is limited. Here, we report the molecular detection of B. miyamotoi in the northeast of Inner Mongolia, China. A total of 774 adult ticks and 771 blood samples of patients were collected, from April 2017 to August 2019 in the northeast of Inner Mongolia, and tested for B. miyamotoi using real time-PCR. Gene sequences of 16S rRNA, fla, and glpQ were obtained to reconstruct the phylogenetic relationship of B. miyamotoi from humans and ticks. The results showed the total prevalence of B. miyamotoi in ticks was 1.3% of 774 ticks, with rates of 2.6% in I. persulcatus, 0.78% in Dermacentor nuttalli, 1.3% in D. silvarum, and 0.4% in Haemaphysalis longicornis. Thirteen (1.7%) patients were confirmed as positive for B. miyamotoi. Patients were mainly 50-60-years old and had a history of tick contact. They presented flu-like symptoms, including fever, headache, poor spirit, dizziness, nausea, vomiting, hypodynamic, chest distress, and myalgia. Phylogenetic analysis showed that the B. miyamotoi in the present study belonged to the Siberian type, distinct from European and American types and the I. ovatus isolate from Japan. This is the first report of B. miyamotoi detection in both ticks and humans in the northeast of Inner Mongolia, China, indicating B. miyamotoi is present in the area. These findings suggest that people have a risk of infection with B. miyamotoi in this region, where it should be included the differential diagnosis of tick-borne diseases.

Pathogenesis of Relapsing Fever

Relapsing fever (RF) is caused by several species of Borrelia; all, except two species, are transmitted to humans by soft (argasid) ticks. The species B. recurrentis is transmitted from one human to another by the body louse, while B. miyamotoi is vectored by hard-bodied ixodid tick species. RF Borrelia have several pathogenic features that facilitate invasion and dissemination in the infected host. In this article we discuss the dynamics of vector acquisition and subsequent transmission of RF Borrelia to their vertebrate hosts. We also review taxonomic challenges for RF Borrelia as new species have been isolated throughout the globe. Moreover, aspects of pathogenesis including symptomology, neurotropism, erythrocyte and platelet adhesion are discussed. We expound on RF Borrelia evasion strategies for innate and adaptive immunity, focusing on the most fundamental pathogenetic attributes, multiphasic antigenic variation. Lastly, we review new and emerging species of RF Borrelia and discuss future directions for this global disease.

The Unexpected Holiday Souvenir: The Public Health Risk to UK Travellers from Ticks Acquired Overseas

Overseas travel to regions where ticks are found can increase travellers' exposure to ticks and pathogens that may be unfamiliar to medical professionals in their home countries. Previous studies have detailed non-native tick species removed from recently returned travellers, occasionally leading to travel-associated human cases of exotic tick-borne disease. There are 20 species of tick endemic to the UK, yet UK travellers can be exposed to many other non-native species whilst overseas. Here, we report ticks received by Public Health England's Tick Surveillance Scheme from humans with recent travel history between January 2006 and December 2018. Altogether, 16 tick species were received from people who had recently travelled overseas. Confirmed imports (acquired outside of the UK) were received from people who recently travelled to 22 countries. Possible imports (acquired abroad or within the UK) were received from people who had recently travelled to eight European countries. Species-specific literature reviews highlighted nine of the sixteen tick species are known to vector at least one tick-borne pathogen to humans in the country of acquisition, suggesting travellers exposed to ticks may be at risk of being bitten by a species that is a known vector, with implications for novel tick-borne disease transmission to travellers.

A new Borrelia on the block: Borrelia miyamotoi - a human health risk?

Background

Borrelia miyamotoi clusters phylogenetically among relapsing fever borreliae, but is transmitted by hard ticks. Recent recognition as a human pathogen has intensified research into its ecology and pathogenic potential.

Aims

We aimed to provide a timely critical integrative evaluation of our knowledge on B. miyamotoi, to assess its public health relevance and guide future research.

Methods

This narrative review used peer-reviewed literature in English from January 1994 to December 2018.

Results

Borrelia miyamotoi occurs in the world’s northern hemisphere where it co-circulates with B. burgdorferi sensu lato, which causes Lyme disease. The two borreliae have overlapping vertebrate and tick hosts. While ticks serve as vectors for both species, they are also reservoirs for B. miyamotoi. Three B. miyamotoi genotypes are described, but further diversity is being recognised. The lack of sufficient cultivable isolates and vertebrate models compromise investigation of human infection and its consequences. Our understanding mainly originates from limited case series. In these, human infections mostly present as influenza-like illness, with relapsing fever in sporadic cases and neurological disease reported in immunocompromised patients. Unspecific clinical presentation, also occasionally resulting from Lyme- or other co-infections, complicates diagnosis, likely contributing to under-reporting. Diagnostics mainly employ PCR and serology. Borrelia miyamotoi infections are treated with antimicrobials according to regimes used for Lyme disease.

Conclusions

With co-infection of tick-borne pathogens being commonplace, diagnostic improvements remain important. Developing in vivo models might allow more insight into human pathogenesis. Continued ecological and human case studies are key to better epidemiological understanding, guiding intervention strategies.

Borrelia miyamotoi Infections in Humans and Ticks, Northeastern China

We conducted an investigation of Borrelia miyamotoi infections in humans and ticks in northeastern China. Of 984 patients reporting recent tick bites, 14 (1.4%) were found to be infected with B. miyamotoi by PCR and genomic sequencing. The 14 patients had nonspecific febrile manifestations, including fever, headache, anorexia, asthenia, and arthralgia. Rash, eschar, and regional lymphadenopathy were each observed in 1 patient. Four (28.6%) patients were hospitalized because of severe disease. B. miyamotoi was detected in 3.0% (19/627) of Ixodes persulcatus, 1 (2.8%) of 36 Haemaphysalis concinna, and none of 29 Dermacentor silvarum ticks. Phylogenetic analyses based on sequences of a nearly entire 16s rRNA gene, a partial flagellin gene, and the glycerophosphodiester phosphodiesterase gene revealed that B. miyamotoi identified in patients and ticks were clustered in the group of the Siberian type. These findings indicate that B. miyamotoi is endemic in northeastern China and its public health significance deserves further investigation.

[Follow-up of patients with Ixodes tick-borne borrelioses caused by Borrelia miyamotoi or Borrelia burgdorferi sensu lato]

Ixodes tick-borne borrelioses (ITBB) are caused by two different spirochetes: Borrelia from the group of Borrelia burgdorferi sensu lato, the agents of the classic Lyme borreliosis (LB), and Borrelia miyamotoi that belongs to the group of Borrelia causing tick-borne relapsing fevers. ITBB caused by B. miyamotoi (BM-ITBB) is a previously unknown infectious disease discovered in Russia. It is known that the LB sequelae may reduce the long-term life guality of convalescents.

AIM

To study the follow-up of those who have recovered from new BM-ITBB infection in comparison with persons who have had LB.

SUBJECTS AND METHODS

The investigation enrolled 41 patients with BM-ITBB and 41 patients with LB who were treated at the Republican Infectious Diseases Hospital of Udmurtia. Within a year after the disease, they were followed up through clinical and instrumental examination of cardiac performance, expanded biochemical analysis of blood and urine, which could; estimate kidney and liver functions, and psychological questioning.

RESULTS

Asthenic syndrome and complaints about and objective signs of cardiac dysfunctions persisted supraventricular extrasystoles, left ventricular diastolic dysfunction, and elevated and/or unstable systolic blood pressure were detected in 20-30% of the convalescents for a long time. Kidney dysfunctions were manifested in albuminuria and the decrease of glomerular filtration rate. A year following the disease, 10-20% patients had persistently elevated concentrations of alanine aminotransferase, aspartate aminotransferase, and C-reactive protein and had higher levels of total cholesterol and low-density lipoproteins. The pathological consequences of ITBB were polymorphic and varied in different patients; in general, only 68% of them showed health improvement.

CONCLUSION

We assume that a significant role in the pathogenesis of BM-ITBB and LB is played by vascular endothelial damage possibly associated with the inflammatory and autoimmune aspects of an immune response in Borrelia infection. The consequences of this damage may persist and even intensify during a year, which provokes chronic dysfunction of the heart, kidney, or liver in a number of convalescents.

Serodiagnosis of Borrelia miyamotoi disease by measuring antibodies against GlpQ and variable major proteins

OBJECTIVES

Borrelia miyamotoi disease (BMD) is an emerging tick-borne disease in the Northern hemisphere. Serodiagnosis by measuring antibodies against glycerophosphodiester-phosphodiesterase (GlpQ) has been performed experimentally but has not been extensively clinically validated. Because we had previously shown the differential expression of antigenic variable major proteins (Vmps) in B. miyamotoi, our aim was to study antibody responses against GlpQ and Vmps in PCR-proven BMD patients and controls.

METHODS

We assessed seroreactivity against GlpQ and four Vmps in a well-described, longitudinal cohort of sera from BMD patients (n=182), healthy blood donors (n=136) and controls (n=68). All samples were tested by ELISA and positive sera were tested by western blot, and antibody dynamics and diagnostic value were assessed.

RESULTS

IgM antibodies against GlpQ and Vmps peaked between 11 and 20 days, and IgG between 21 and 50 days, after disease onset. Various combinations of GlpQ and Vmps increased sensitivity and/or specificity compared to single antigens. Notably, the GlpQ or variable large protein (Vlp)-15/16 combination yielded a sensitivity of 94.7% (95% CI: 75.4-99.7) 11-20 days after disease onset and a specificity of 96.6% (92.7-98.4) for IgM. A specificity of 100% (97.8-100) for IgM, and 98.3% for IgG (95.2-100), was found when positivity was defined as reactivity to GlpQ and any Vmp, with maximum sensitivities of 79% (56.7-91.5) for IgM and 86.7% (62.1-97.6) for IgG.

CONCLUSIONS

We clearly demonstrate here the diagnostic potential of these seromarkers. Our findings will facilitate future epidemiological and clinical studies on BMD and lead to the development of a serologic test to be used in clinical practice.

Evaluation of a serological test for the diagnosis of Borrelia miyamotoi disease in Europe

BACKGROUND

Borrelia miyamotoi causes systemic febrile illness and is transmitted by the same tick species that transmits Borrelia burgdorferi sensu lato and tick-borne encephalitis virus. We describe a serological test using a fragment of glycerophosphodiester phosphodiesterase (GlpQ) as an antigen, and determined its performance in well-defined patient categories.

METHODS

Serum of patients with PCR-confirmed Borrelia miyamotoi disease (BMD), Lyme borreliosis (LB), tick-borne encephalitis (TBE), and healthy blood donors (HBD) were collected in Udmurt Republic, Russia. Sera of BMD and LB patients were collected at hospital admission, one week, one month and one year after admission.

RESULTS

The levels of IgM and IgG anti-GlpQ antibodies, determined as optical density values in Luminex bead-based assays, were significantly higher in the BMD patient group than in LB patients, TBE patients or HBD group (all p<0.05).

CONCLUSIONS

By using a strict cut-off value, it was possible to exclude B. miyamotoi infection in LB and TBE patients and to serologically confirm B. miyamotoi infection in 44% to 94% of the PCR-positive BMD patients (95% confidence interval). Thus, sensitive serological assays should not solely rely on rGlpQ, to support the diagnosis of acute BMD.

Host Immune Evasion by Lyme and Relapsing Fever Borreliae: Findings to Lead Future Studies for Borrelia miyamotoi

The emerging pathogen, Borrelia miyamotoi, is a relapsing fever spirochete vectored by the same species of Ixodes ticks that carry the causative agents of Lyme disease in the US, Europe, and Asia. Symptoms caused by infection with B. miyamotoi are similar to a relapsing fever infection. However, B. miyamotoi has adapted to different vectors and reservoirs, which could result in unique physiology, including immune evasion mechanisms. Lyme Borrelia utilize a combination of Ixodes-produced inhibitors and native proteins [i.e., factor H-binding proteins (FHBPs)/complement regulator-acquiring surface proteins, p43, BBK32, BGA66, BGA71, CD59-like protein] to inhibit complement, while some relapsing fever spirochetes use C4b-binding protein and likely Ornithodoros-produced inhibitors. To evade the humoral response, Borrelia utilize antigenic variation of either outer surface proteins (Osps) and the Vmp-like sequences (Vls) system (Lyme borreliae) or variable membrane proteins (Vmps, relapsing fever borreliae). B. miyamotoi possesses putative FHBPs and antigenic variation of Vmps has been demonstrated. This review summarizes and compares the common mechanisms utilized by Lyme and relapsing fever spirochetes, as well as the current state of understanding immune evasion by B. miyamotoi.

Borrelia miyamotoi in vectors and hosts in The Netherlands

Ixodes ticks transmit Borrelia burgdorferi sensu lato (s.l.), the causative agent of Lyme borreliosis (LB). These tick species also transmit Borrelia miyamotoi, which was recently found to cause infections in humans. We were interested in the prevalence of B. miyamotoi infection in ticks and natural hosts in The Netherlands, and to what extent ticks are co-infected with B. burgdorferi. In addition, erythema migrans has been sporadically described in B. miyamotoi-infected patients, but these skin lesions might as well represent co-infections with B. burgdorferi s.l. We therefore investigated whether B. miyamotoi was present in LB-suspected skin lesions of patients referred to our tertiary Lyme disease clinic. 3360 questing Ixodes ricinus nymphs as well as spleen tissue of 74 rodents, 26 birds and 10 deer were tested by PCR for the presence of B. miyamotoi. Tick lysates were also tested for the presence of B. burgdorferi s.l. Next, we performed a PCR for B. miyamotoi in 31 biopsies from LB-suspected skin lesions in patients visiting our tertiary Lyme center. These biopsies had been initially tested for B. burgdorferi s.l. by PCR, and the skin lesions had been investigated by specialized dermatologists. Out of 3360 unfed (or questing) nymphs, 313 (9.3%) were infected with B. burgdorferi s.l., 70 (2.1%) were infected with B. miyamotoi, and 14 (0.4%) were co-infected with B. burgdorferi s.l. and B. miyamotoi. Co-infection of B. burgdorferi s.l. with B. miyamotoi occurred more often than expected from single infection prevalences (p=0.03). Both rodents (9%) and birds (8%) were found positive for B. miyamotoi by PCR, whereas the roe deer samples were negative. Out of 31 LB-suspected skin biopsies, 10 (32%) were positive for B. burgdorferi s.l. while none were positive for B. miyamotoi. The significant association of B. burgdorferi s.l. with B. miyamotoi in nymphs implies the existence of mutual reservoir hosts. Indeed, the presence of B. miyamotoi DNA indicates systemic infections in birds as well as rodents. However, their relative contributions to the enzootic cycle of B. miyamotoi requires further investigation. We could not retrospectively diagnose B. miyamotoi infection using biopsies of LB-suspected skin lesions, supporting the hypothesis that B. miyamotoi is not associated with LB-associated skin manifestations. However, this warrants further studies in larger sets of skin biopsies. A prospective study focused on acute febrile illness after a tick bite could provide insight into the incidence and clinical manifestations of B. miyamotoi infection in The Netherlands.

Insights into Borrelia miyamotoi infection from an untreated case demonstrating relapsing fever, monocytosis and a positive C6 Lyme serology

We describe a patient from the United States with PCR- and serology-confirmed Borrelia miyamotoi infection who recovered without antibiotics. Our findings suggest that B. miyamotoi infection may cause relapsing fever, blood monocytosis and antibody reactivity to the C6 peptide. Further studies are required to better define the spectrum of clinical and laboratory findings for this emerging tick-transmitted infection.