Case report indicates tick presence linked to Borrelia turicatae and relapsing fever symptoms — Evidence Review
Published in Open Forum Infectious Diseases, by researchers from Baylor College of Medicine, Texas Department of State Health Services
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Table of Contents
A recent case report describes the first likely urban exposure to soft tick-borne relapsing fever (STRF) in Austin, Texas, highlighting the presence of infected Ornithodoros turicata ticks in city homes. Related studies generally support the emergence and endemicity of Borrelia turicatae in urban environments and underscore the complexity of diagnosing tick-borne relapsing fever in both humans and animals, as detailed in Open Forum Infectious Diseases.
- Urban cases of STRF, though rare, align with prior research indicating the circulation of Borrelia turicatae and its tick vector in both urban and rural Texas, as well as the potential for city-based transmission events 2 5.
- The clinical features and diagnostic challenges detailed in this case are consistent with broader literature showing intermittent fever, neurological symptoms, and diagnostic uncertainty, especially when STRF is not initially considered 3 7.
- Previous studies emphasize the underdiagnosis of tick-borne relapsing fever in both human and veterinary medicine, supporting calls for increased surveillance and improved diagnostic tools in endemic regions 3 4 5.
Study Overview and Key Findings
This case report is notable not only for documenting a probable urban exposure to soft tick-borne relapsing fever, but also for the combination of clinical, entomological, and molecular evidence directly linking a city-dwelling tick to human disease. The incident occurred in a residential apartment in Austin, Texas, where the patient experienced recurrent fever and neurological symptoms. The tick, collected indoors, was confirmed to be Ornithodoros turicata harboring Borrelia turicatae, the causative agent of STRF. This urban case highlights the need for increased awareness among clinicians and public health officials regarding the risk of tick-borne relapsing fever not only in rural but also in metropolitan settings—a shift from traditional epidemiological assumptions.
| Property | Value |
|---|---|
| Study Year | 2026 |
| Organization | Baylor College of Medicine, Texas Department of State Health Services |
| Journal Name | Open Forum Infectious Diseases |
| Authors | Serhii Filatov, Bonny Mayes, Sarah M Gunter, Alexander R Kneubehl, Job E Lopez |
| Population | Resident with suspected soft tick-borne relapsing fever |
| Methods | Case Report |
| Outcome | Presence of Borrelia turicatae in ticks, symptoms of STRF |
| Results | Tick identified as carrying Borrelia turicatae, linked to STRF symptoms. |
Literature Review: Related Studies
To contextualize this new case report, we searched the Consensus database, which aggregates over 200 million research papers. The following search queries were used to identify relevant literature:
- Borrelia turicatae tick relapsing fever
- tick-borne diseases symptoms Austin
- relapsing fever epidemiology and prevention
Below, related studies are grouped by thematic questions, with key findings and relevant citation numbers.
| Topic | Key Findings |
|---|---|
| What is the epidemiology and geographic spread of tick-borne relapsing fever (TBRF) in the US and globally? | - Borrelia turicatae and its tick vector, Ornithodoros turicata, are established in the southern US, including urban centers like Austin, Texas, suggesting urban emergence is plausible 2 5. - TBRF shows a complex, evolving epidemiogeography, with cases reported worldwide except for Antarctica and Australia 3 8 10. |
| How do clinical presentations and diagnostic challenges of STRF/TBRF manifest in humans and animals? | - The hallmark is relapsing fever with neurological complications being relatively frequent; diagnosis can be difficult due to symptom overlap with other diseases and limited access to molecular diagnostics 3 7. - TBRF is underdiagnosed in both human and veterinary medicine, with clinical features including fever, rash, and thrombocytopenia 4 7. |
| What is the diversity and transmission potential of Borrelia species in ticks? | - Limited local diversity of Borrelia relapsing fever group strains is observed in tick populations, with several genotypes for B. turicatae and related species 1. - Phylogenetic analyses show B. turicatae is closely related to other relapsing fever Borrelia species, with evidence of zoonotic and possibly urban transmission 2. |
| What are the prevention, treatment, and outcomes for TBRF? | - Standard treatments include beta-lactams, tetracyclines, or macrolides, with Jarisch-Herxheimer reactions less common in TBRF than louse-borne relapsing fever 3 11. - Surveillance and control remain critical, especially in endemic and emerging areas, to reduce missed diagnoses and improve outcomes 3 10. |
What is the epidemiology and geographic spread of tick-borne relapsing fever (TBRF) in the US and globally?
The new Austin case fits with evidence that Borrelia turicatae and its tick vectors are present not only in rural but also in urban environments in Texas. This supports a growing recognition that TBRF is not confined to wilderness or remote settings. The emergence of urban cases is consistent with findings from Austin and elsewhere, and with the complex, globally evolving epidemiology of TBRF.
- Borrelia turicatae has been detected in Ornithodoros ticks within and near Austin, Texas, indicating local endemicity and the potential for both rural and urban transmission 2 5.
- TBRF has a wide but patchy geographic distribution, with cases reported in the US, Africa, and the Middle East, and with different Borrelia species and tick vectors dominating in various regions 3 8 10.
- The presence of Borrelia-infected ticks in city parks and residential areas suggests that urban residents may be at risk, challenging assumptions that TBRF is a disease of rural exposure only 5.
- Surveillance and mapping efforts reveal that TBRF's epidemiology is dynamic, with new urban foci being identified 3 5 10.
How do clinical presentations and diagnostic challenges of STRF/TBRF manifest in humans and animals?
Clinical features of STRF, such as relapsing fever, rash, and neurological symptoms, are well-documented in the literature, but often lead to misdiagnosis, particularly in non-endemic or urban settings. The Austin case illustrates these challenges, mirroring the broader experience reported in both human and veterinary contexts.
- Relapsing fever is universal among TBRF cases, but additional symptoms can include rash, headache, fatigue, and neurological complications such as facial paralysis 3 4 7.
- Diagnosis often relies on clinical suspicion and microscopy; however, molecular methods provide species-level identification but are not always available 3 4.
- Veterinary reports show similar diagnostic challenges, with TBRF underrecognized in dogs and possibly in humans, especially in areas where Lyme disease or other fevers are more commonly considered 4.
- Early recognition and improved diagnostic tools are needed to reduce missed diagnoses and improve patient outcomes 3 7.
What is the diversity and transmission potential of Borrelia species in ticks?
Genetic and phylogenetic studies indicate that Borrelia turicatae has limited local diversity but is closely related to other relapsing fever Borrelia species. These findings suggest a potential for both zoonotic and human transmission, with Ornithodoros ticks acting as primary vectors in the US.
- Multiple genotypes of B. turicatae circulate within tick populations, but local diversity is limited, which may influence patterns of transmission and outbreak potential 1.
- Phylogenetic studies confirm B. turicatae as a distinct but closely related species within the relapsing fever group, with documented ability to infect both animals and humans in the southern US 2.
- Ornithodoros ticks, including O. turicata, are confirmed vectors, and their urban presence increases risk for human exposure 2 5.
- Understanding the diversity and transmission potential of Borrelia species is critical for predicting and managing disease emergence 1 2.
What are the prevention, treatment, and outcomes for TBRF?
Treatment protocols for TBRF are established, but outcomes depend on timely diagnosis and awareness among healthcare providers. The risk of treatment-related Jarisch-Herxheimer reactions is significant but lower in TBRF compared to louse-borne forms, and surveillance remains a cornerstone of prevention.
- Beta-lactams, tetracyclines, and macrolides are effective, but delayed treatment can lead to complications, especially neurological ones 3 11.
- Jarisch-Herxheimer reactions occur less frequently in TBRF than in louse-borne relapsing fever but remain an important consideration in clinical management 3 11.
- Ongoing surveillance and public health education are essential, particularly as TBRF emerges in new geographic and urban settings 3 10.
- Preventive measures include control of tick vectors in both rural and urban environments and increasing diagnostic capacity 3 10.
Future Research Questions
Further research is needed to clarify the epidemiology, clinical management, and prevention strategies for tick-borne relapsing fever, especially as cases are increasingly recognized in urban settings. Key questions arise from gaps in current knowledge, including the true prevalence of urban cases, effective diagnostic approaches, and optimal strategies for surveillance and vector control.
| Research Question | Relevance |
|---|---|
| What is the true prevalence of urban tick-borne relapsing fever cases in the United States? | Understanding the scale of urban TBRF is critical for public health planning, as most surveillance has focused on rural exposures 3 5. |
| How can diagnostic tools for Borrelia turicatae infection be improved for timely detection in urban settings? | Early and accurate diagnosis is essential for effective treatment, but current methods may lack sensitivity or accessibility, particularly in non-endemic areas 3 4 7. |
| What environmental factors promote the establishment of Ornithodoros turicata ticks in urban environments? | Understanding tick ecology and adaptation to urban niches is key for vector control and risk reduction 5 8. |
| Are there differences in clinical manifestations or outcomes between urban and rural STRF cases? | Comparative studies could reveal important differences in disease severity, risk factors, and response to treatment between urban and rural cases 3 10. |
| What are the most effective public health strategies for monitoring and controlling urban tick-borne relapsing fever? | As urban cases increase, targeted surveillance and control programs are needed to reduce transmission risk and improve health outcomes 3 5 10. |