Clinical Presentation and Outcomes of Alpha-Gal Syndrome.

BACKGROUND AND AIMS: Alpha-gal syndrome (AGS) is an IgE-mediated allergic reaction to galactose-α-1,3-galactose, primarily linked with Lone Star tick bites in the United States. It presents with symptoms ranging from urticaria and gastrointestinal (GI) manifestations to delayed anaphylaxis following red meat consumption. We aimed to study AGS patients' clinical manifestations, diagnosis, and outcomes. METHODS: A retrospective chart review of patients who underwent serological testing for suspected AGS between 2014 and 2023 at Mayo Clinic was performed. Patients with positive serology were age and sex matched with those who tested negative. Clinical characteristics of seropositive cohort with and without GI symptoms were compared, and outcomes assessed. RESULTS: Of 1260 patients who underwent testing, 124 tested positive for AGS. They were matched with 380 seronegative control subjects. AGS patients reported a higher frequency of tick bites (odds ratio [OR], 26.0; 95% confidence interval [CI], 9.8-68.3), reported a higher prevalence of urticaria (56% vs 37%; P = .0008), and were less likely to have asthma (OR, 0.4; 95% CI, 0.3-0.7). They had a lower prevalence of heartburn (6% vs 12%; P = .03) and bloating (6% vs 13%; P = .03). A total of 47% had GI symptoms, and a higher proportion were female than those without GI symptoms (69% vs 35%; P = .002). During a mean follow-up of 27 months, 22 of 40 patients reported symptom resolution after avoiding red meat, and 7 were able to transition to regular diet. CONCLUSIONS: A diagnosis of AGS should be strongly considered in patients with a history of tick bites and clinical presentation of allergic or GI manifestations. Dietary intervention is effective in most but not all patients.

Rickettsia africae infections in sub-Saharan Africa: A systematic literature review of epidemiological studies and summary of case reports.

Rickettsia africae is a tick-borne bacteria known to cause African tick bite fever (ATBF). While the disease was first described more than 100 years ago, knowledge of transmission risk factors and disease burden remain poorly described. To better understand the burden of R. africae, this article reviewed and summarized the published literature related to ATBF epidemiology and clinical management. Using a systematic approach, consistent with the PRISMA guidelines, we identified more than 100 eligible articles, including 65 epidemiological studies and 41 case reports. Most reports described R. africae in ticks and livestock, while human studies were less common. Human disease case reports were exclusively among returning travellers from non-endemic areas, which limits our disease knowledge among at-risk populations: people living in endemic regions. Substantial efforts to elucidate the ATBF risk factors and clinical manifestations among local populations are needed to develop effective preventative strategies and facilitate appropriate and timely diagnosis.

Alpha-Gal Syndrome and Cardiac Surgery.

Galactose-alpha-1,3-galactose (alpha-gal) is a carbohydrate expressed by all mammals except for humans and certain old-world primates. It can be found in a plethora of products derived from mammals, including milk, organs, skeletal muscle and gelatin, in addition to products prepared with mammalian cells or constituents. In the late 2000s, an association between tick bites and the development of immunoglobulin E antibodies to the alpha-gal carbohydrate was discovered. The term "alpha-gal syndrome" (AGS) was then coined to describe allergic reactions to mammalian meat or other alpha-gal-containing products derived from mammals. Symptoms are often delayed several hours from consumption and can be urticarial and/or gastrointestinal. Medications and bioprosthetic inserts derived from mammals were also noted to cause allergic reactions in affected patients. Cardiac surgery, in particular, is considered high risk, given that unfractionated heparin has a bovine or porcine origin and is administered in large doses for cardiopulmonary bypass. Bioprosthetic valves have similar origins and risks. Awareness of AGS in cardiac surgery patients can lead to decreased risk preoperatively and inform management perioperatively and postoperatively. In this narrative review, we have reviewed the published literature relevant to AGS in patients undergoing cardiac surgery and shared our treatment approach.

Repellent activity of the non-host semiochemical (E)-2-octenal against Amblyomma sculptum and Amblyomma dubitatum ticks under field conditions.

Amblyomma ticks pose a significant public health threat due to their potential to transmit pathogens associated with rickettsial diseases. (E)-2-octenal, a compound found in donkeys (Equus asinus), exhibits strong repellent properties against Amblyomma sculptum nymphs under laboratory conditions. This study assessed the effectiveness of the (E)-2-octenal in wearable slow-release devices for personal human protection against Amblyomma ticks under natural conditions. Slow-release devices treated with (E)-2-octenal and untreated controls were prepared and tested on two volunteers walking through a tick-infested area in Goiania, Brazil. The experiment was conducted twice daily for three series of 10 days, with each volunteer wearing two devices attached to each leg, one on the ankle and one just above the thigh. Volunteers with control and treated devices exchanged them between rounds. Also, the daily release rate of (E)-2-octenal from the slow-release devices was determined in the laboratory, increasing significantly from 0.77 ± 0.14 µg/day on the first day to 9.93 ± 1.92 µg/day on the 4th day and remaining constant until the 16th day. A total of 5409 ticks were collected from both volunteers. Treated devices resulted in recovering fewer ticks (n = 1,666; 31%) compared to untreated devices (control: n = 3,743; 69%). (E)-2-octenal effectively repelled Amblyomma spp. larvae, A. sculptum adults, and exhibited pronounced repellency against A. dubitatum nymphs and adults. These findings suggest the potential of (E)-2-octenal delivered by wearable slow-release devices as a green-based repellent. Further improvements, however, are necessary to provide better protection for humans against A. sculptum and A. dubitatum in field conditions.

Nonanaphylactic Variant of Alpha-Gal Syndrome as an Etiology for Chronic Gastrointestinal Symptoms in Children.

We report 3 pediatric patients who presented with only nonanaphylactic symptoms of alpha-gal syndrome. This report highlights the necessity of not discounting alpha-gal syndrome from a differential diagnosis for patients with recurrent gastrointestinal distress and emesis after consuming mammalian meat, even in the absence of an anaphylactic reaction.

Clinical and laboratory features of patients diagnosed with alpha-gal syndrome-2010-2019.

BACKGROUND: Alpha-gal syndrome (AGS) is an IgE-mediated allergy to galactose-alpha-1,3-galactose. Clinical presentation ranges from hives to anaphylaxis; episodes typically occur 2-6 h after exposure to alpha-gal-containing products. In the United States, lone star tick bites are associated with the development of AGS. To characterize features of AGS, we evaluated a cohort of patients presenting for care at the University of North Carolina, focusing on symptoms, severity, and identifying features unique to specific alpha-gal-containing product exposures. METHODS: We performed a chart review and descriptive analysis of 100 randomly selected patients with AGS during 2010-2019. RESULTS: Median age at onset was 53 years, 56% were female, 95% reported White race, 86% reported a history of tick bite, and 75% met the criteria for anaphylaxis based on the involvement of ≥2 organ systems. Those reporting dairy reactions were significantly less likely to report isolated mucocutaneous symptoms (3% vs. 24%; ratio [95% CI]: 0.1 [0.1, 0.3]) than those who tolerated dairy, and were more likely to report gastrointestinal symptoms (79% vs. 59%; ratio [95% CI]: 1.3 [0.7, 2.6]), although this difference was not statistically significant. Dairy-tolerant patients demonstrated higher alpha-gal sIgE titers (as a percentage of total IgE) than dairy-reactive patients (GM 4.1 [95% CI: 2.7, 6.1] vs. GM 2.5 [95% CI: 1.3, 4.8], respectively; ratio -1.6 [95% CI: -1.0, 3.9]). CONCLUSION: While tick exposure is common in the southern United States, nearly all AGS patients reported a tick bite. Gastrointestinal symptoms were prominent among those reporting reactions to dairy. Anaphylaxis was common, underscoring the severity and need to raise awareness of AGS among patients and providers.

Epidemiological study of ticks harbouring Aeromonas hydrophila in areas endemic and non-endemic to Japanese-spotted fever.

OBJECTIVES: Aeromonas spp. often cause life-threatening diseases, including necrotizing fasciitis, which may lead to septic shock and ultimately death. Aeromonas infections are believed to be transmitted via minor wounds or the consumption of fresh fish. However, after the detection of Aeromonas hydrophila in ticks in areas endemic to Japanese-spotted fever (JSF), a novel transmission route of A. hydrophila (i.e., via tick bites) has been proposed. We investigated the prevalence of A. hydrophila in ticks in areas endemic and not endemic to JSF in the Mie Prefecture, Japan. METHODS: We collected ticks from endemic and nonendemic areas in summer and winter and assessed them for presence of A. hydrophila using polymerase chain reaction. RESULTS: Six A. hydrophila isolates were obtained from 95 ticks in endemic areas, whereas one A. hydrophila isolate was obtained from 142 ticks in non-endemic areas, in summer. All ticks that harboured A. hydrophila were Haemaphysalis longicornis (H.L); these ticks were almost at the larval stage and also carried Rickettsia spp. in the endemic area. In contrast, 51 and 41 ticks in the endemic and non-endemic areas were captured in winter, respectively; A. hydrophila was not detected in these. CONCLUSIONS: This study revealed the prevalence of tick-borne A. hydrophila. Therefore, the risk of transmission of A. hydrophila via a tick bite should be considered in the following conditions: areas abundant in H. L. harbouring Rickettsia spp., in areas endemic for JSF, presence of ticks in the larval stage and during the summer season.

Evaluation of under-testing and under-diagnosis of tick-borne encephalitis in Germany.

BACKGROUND: Tick-borne encephalitis (TBE), a viral infectious disease affecting the central nervous system, potentially resulting in prolonged neurological symptoms and other long-term sequelae. Case identification can be challenging as TBE can be associated with non-specific symptoms, and even in cases consistent with typical TBE symptoms, the rate of laboratory testing to confirm cases is unknown. This study assessed real-world TBE laboratory testing rates across Germany. METHODS: In this retrospective cross-sectional study, physicians provided data on TBE decision-making, laboratory testing (serological), and diagnostics behavior via in-depth qualitative interviews (N = 12) or a web-based quantitative survey of their patient medical records (N = 166). Hospital-based physicians who specialized in infectious disease, intensive care unit, emergency room, neurology, or pediatrics with experience managing and ordering testing for patients with meningitis, encephalitis, or non-specific central nervous system symptoms in the past 12 months were included. Data were summarized via descriptive statistics. TBE testing and positivity rates were assessed for the aggregate sample of 1400 patient charts and reported by presenting symptoms, region, and tick bite exposure. RESULTS: TBE testing rates ranged from 54.0% (non-specific neurological symptoms only) to 65.6% (encephalitis symptoms only); the percentage of TBE positive results ranged from 5.3% (non-specific neurological symptoms only) to 36.9% (meningitis symptoms only). TBE testing rates were higher among those with a tick bite history and/or who presented with headache, high fever, or flu-like symptoms. CONCLUSIONS: The findings of this study suggest that patients with typical TBE symptoms are likely under-tested, thus likely leading to under-diagnosis in Germany. To ensure appropriate case identification, TBE testing should be consistently integrated into routine practice for all patients who present with relevant symptoms or exposure to common risk factors.

Dermatological aspects of ticks in Australia: An update.

Ticks are ectoparasites that cause dermatologic reactions directly by their bites and indirectly as vectors of bacterial, protozoal and viral diseases. Consequences vary from minor local reactions to significant systemic sequelae and are therefore of clinical relevance to dermatologists. In this article, Australian ticks of medical importance are reviewed through the lens of dermatology.

Inflammatory cytokine profile and T cell responses in African tick bite fever patients.

African tick bite fever, an acute febrile illness, is caused by the obligate intracellular bacterium Rickettsia africae. Immune responses to rickettsial infections have so far mainly been investigated in vitro with infected endothelial cells as the main target cells, and in mouse models. Patient studies are rare and little is known about the immunology of human infections. In this study, inflammatory mediators and T cell responses were examined in samples from 13 patients with polymerase chain reaction-confirmed R. africae infections at different time points of illness. The Th1-associated cytokines IFNγ and IL-12 were increased in the acute phase of illness, as were levels of the T cell chemoattractant cytokine CXCL-10. In addition, the anti-inflammatory cytokine IL-10 and also IL-22 were elevated. IL-22 but not IFNγ was increasingly produced by CD4+ and CD8+ T cells during illness. Besides IFNγ, IL-22 appears to play a protective role in rickettsial infections.

Tick bites in different professions and regions: pooled cross-sectional study in the focus area Bavaria, Germany.

BACKGROUND: As the vector-borne diseases tick-borne encephalitis (TBE) and Lyme borreliosis (LB) are common in Germany and transmitted by tick bites, the aim of this study was to assess differences in the number of tick bites in various professions and regions across southern Germany to evaluate the differences in tick-associated risk. MATERIALS AND METHODS: The analysis is based on three cross-sectional studies that were conducted in 2016 and 2017 in two real-life settings and in one medical setting in Bavaria. All participants filled in a paper-based questionnaire about their history with tick bites. Only adult participants (≥ 18 years) were included in this study. RESULTS: Overall, 3503 individuals (mean age 50.8 ± 15.2 years, median age 53.0 ± 12.2 years, 54.0% female) were included. Of these, 50% worked in an outdoor profession and 56% lived in environs. Around 70% of participants reported at least one previous tick bite. In comparison to indoor workers, forestry workers (OR = 2.50; 95% CI: 1.10-5.68) had the highest risk for a tick bite followed by farmers (OR = 1.22; 95% CI: 1.01-1.47). Furthermore, people living in rural areas (OR = 1.97, 95% CI:1.49-2.59) and environs (OR = 1.98, 95% CI: 1.54-2.55) were twice as likely to have a previous tick bite than people living in urban areas. In general, slightly more tick bites were reported by people living in eastern Bavaria. CONCLUSION: Rising numbers of TBE and LB indicate the need for further prevention strategies, which should focus on outdoor professions with a higher risk and people living in environs and rural areas.

Rickettsia africae infection rates and transovarial transmission in Amblyomma hebraeum ticks in Mnisi, Bushbuckridge, South Africa.

Rickettsia africae is a gram-negative bacterium, which causes African tick bite fever (ATBF) in humans. ATBF is a febrile disease mainly affecting travellers to southern Africa. This bacterium is known to be transmitted by Amblyomma hebraeum and Amblyomma variegatum ticks. In southern Africa, the principal vector is A. hebraeum. Febrile disease is a serious issue in the study area. There is a high prevalence of non-malaria illness caused by Rickettsia, so there is a need to have more knowledge on these species. Infection rates and transovarial transmission efficiency of R. africae in A. hebraeum ticks were investigated in a rural area of Mpumalanga province, South Africa. Adult and engorged A. hebraeum female ticks were collected from cattle. Larvae were collected by dragging a cloth at ground level using 100 steps, equivalent to an area of 100 m2. Tick identification was performed according to standard taxonomic keys using a microscope. Engorged ticks were incubated to oviposit and egg masses were collected. DNA was extracted from the ticks, larvae and egg masses, and screened for gltA and ompA genes, using quantitative real-time PCR and conventional PCR, respectively. Positive ompA amplicons were sequenced and phylogenetic analysis showed 99.8-100% identity with R. africae. Infection rates were 13.7 and 12.7% for adults and larvae, respectively. Transovarial transmission of R. africae in A. hebraeum from this study was 85.7%. The results provide a clear indication that people living in the study area and travellers that visit the area are at risk of contracting ATBF.

Emergence of Lyme Disease on Treeless Islands, Scotland, United Kingdom.

Lyme disease is usually associated with forested habitats but has recently emerged on treeless islands in the Western Isles of Scotland. The environmental and human components of Lyme disease risk in open habitats remain unknown. We quantified the environmental hazard and risk factors for human tick bite exposure among treeless islands with low and high Lyme disease incidence in the Western Isles. We found a higher prevalence of Borrelia burgdorferi sensu lato-infected ticks on high-incidence than on low-incidence islands (6.4% vs. 0.7%); we also found that residents of high-incidence islands reported increased tick bite exposure. Most tick bites (72.7%) occurred <1 km from the home, including many in home gardens. Residents of high Lyme disease incidence islands reported increasing problems with ticks; many suggested changing deer distribution as a potential driver. We highlight the benefits of an integrated approach in understanding the factors that contribute to Lyme disease emergence.

Antibiotic prophylaxis for prevention against Lyme disease following tick bite: an updated systematic review and meta-analysis.

BACKGROUND: In areas where Lyme disease is endemic, bites from ticks are common, but no vaccine is currently available against Lyme disease for humans. Therefore, the feasibility of using antibiotic prophylaxis to prevent Lyme disease after a tick bite is worth further exploration. Previous meta-analyses lack sufficient power to demonstrate the efficacy of about antibiotic prophylaxis for the prevention of Lyme disease following a tick bite. In this study, we explored more precise evidence and attempted to identify and update optimum treatment strategies. METHODS: We searched PubMed, Embase, and the Cochrane Library for studies until March 23, 2021. We included studies if the enrolled patients were randomly allocated to a treatment or control group within 72 h following a tick bite and had no clinical evidence of Lyme disease at enrolment. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guidelines were followed for data abstraction. Two authors (GZZ and XX) independently reviewed the abstracts and identified articles for detailed assessment. We used a random-effects model to calculate the pooled results and reported the 95% confidence interval (CI). Study quality was assessed using a modified Jadad scale, and publication bias was assessed using Egger's test. We calculated the risk ratio (RR) for the rates of unfavorable events in patients who received intervention versus the control group. This study is registered with PROSPERO, number CRD42021245002. RESULTS: Six studies (3,766 individuals) were included. The pooled rate of unfavorable events in persons receiving treatment and the control group were 0.4% (95%CI: 0.1-1.1%) and 2.2% (95%CI: 1.6-3.0%), respectively. The pooled RR was 0.38 (95%CI: 0.22-0.66). Subgroup analysis revealed that the pooled RR was 0.29 (95%CI: 0.14-0.60) in the single-use 200-mg doxycycline group; 0.28 (95%CI: 0.05-1.67) in a 10-day course group (Amoxicillin, Penicillin or tetracycline); and 0.73 (95%CI: 0.25-2.08) in a topical antibiotic treatment group (Azithromycin). CONCLUSIONS: The available evidence supports the use of antibiotics for the prevention of Lyme disease, and reveals advantages of using single-dose; however, further confirmation is needed.

Ticking on Pandora's box: a prospective case-control study into 'other' tick-borne diseases.

BACKGROUND: Tick-borne pathogens other than Borrelia burgdorferi sensu lato - the causative agent of Lyme borreliosis - are common in Ixodes ricinus ticks. How often these pathogens cause human disease is unknown. In addition, diagnostic tools to identify such diseases are lacking or reserved to research laboratories. To elucidate their prevalence and disease burden, the study 'Ticking on Pandora's Box' has been initiated, a collaborative effort between Amsterdam University Medical Center and the National Institute for Public Health and the Environment. METHODS: The study investigates how often the tick-borne pathogens Anaplasma phagocytophilum, Babesia species, Borrelia miyamotoi, Neoehrlichia mikurensis, spotted fever group Rickettsia species and/or tick-borne encephalitis virus cause an acute febrile illness after tick-bite. We aim to determine the impact and severity of these tick-borne diseases in the Netherlands by measuring their prevalence and describing their clinical picture and course of disease. The study is designed as a prospective case-control study. We aim to include 150 cases - individuals clinically suspected of a tick-borne disease - and 3 matched healthy control groups of 200 persons each. The controls consist respectively of a group of individuals with either a tick-bite without complaints, the general population and of healthy blood donors. During a one-year follow-up we will acquire blood, urine and skin biopsy samples and ticks at baseline, 4 and 12 weeks. Additionally, participants answer modified versions of validated questionnaires to assess self-reported symptoms, among which the SF-36, on a 3 monthly basis. DISCUSSION: This article describes the background and design of the study protocol of 'Ticking on Pandora's Box'. With our study we hope to provide insight into the prevalence, clinical presentation and disease burden of the tick-borne diseases anaplasmosis, babesiosis, B. miyamotoi disease, neoehrlichiosis, rickettsiosis and tick-borne encephalitis and to assist in test development as well as provide recommendations for national guidelines. TRIAL REGISTRATION: NL9258 (retrospectively registered at Netherlands Trial Register, trialregister.nl in in February 2021).

Three cases diagnosed not Lyme disease but "tick-associated rash illness (TARI)" in Japan.

We report three cases of tick-associated rash illness (TARI) in Japan that presented with erythema migrans (EM) after a tick bite. Although EM is considered to be a characteristic finding of Lyme disease, EM can occur even if patient is not affected by Lyme disease and if it is bitten by a tick. In Japan, the vector of Lyme disease pathogens are not distributed in most areas, and patients with EM are unlikely to have Lyme disease. We aim to raise TARI awareness among physicians.

First Recognized Human Bite in the United States by the Asian Longhorned Tick, Haemaphysalis longicornis.

We present the case summary of the first human recognized to have been bitten by the Haemaphysalis longicornis tick in the United States, which occurred in New York State. Subsequent field studies confirmed that this tick was present in multiple geographic locations near the patient's residence, including on manicured lawns.

Prevalence and Impact of Type I Sensitization to Alpha-Gal in Patients Consulting an Allergy Unit.

BACKGROUND: Alpha-gal syndrome is a complex allergy with high clinical relevance regarding mammalian-derived food and drugs and is characterized by the presence of IgE antibodies directed at the carbohydrate galactose-α-1,3-galactose. As not all alpha-gal sIgE-positive individuals pre-sent clinical symptoms upon consumption of mammalian meat, the diagnostic value of alpha-gal sIgE has yet to be clarified. OBJECTIVE: To investigate the prevalence of alpha-gal-sIgE positivity among allergy patients, examine the impact of tick bites as associated risk factors and determine the diagnostic value of alpha-gal-sIgE positivity. METHODS: A retrospective cross-sectional study evaluating patients in the Allergy Unit was performed. Alpha-gal-sIgE levels were assessed by ImmunoCAP assay. Exposure to tick bites was assessed by a questionnaire. A receiver operating characteristics (ROC) curve analysis was performed to determine the diagnostic value of alpha-gal sIgE for the diagnosis of alpha-gal syndrome. RESULTS: In the study population (n = 1369), the overall prevalence of alpha-gal-sIgE-positive (≥0.10 kUA/L) individuals was 19.9%, and the highest prevalence (30.2%) was found in patients with insect venom allergies. A reported tick bite within the 12 months prior to blood sampling significantly increased the risk of alpha-gal-sIgE positivity (OR 2.084). The ROC curve analysis indicated alpha-gal sIgE ≥0.54 kUA/L as the optimal cutoff point for assessing the diagnostic value of alpha-gal syndrome in allergy patients. CONCLUSIONS: In allergy care settings, alpha-gal-sIgE positivity is a common finding. Alpha-gal sIgE is a sensitive marker in the diagnosis of alpha-gal syndrome but has limited predictive value for the characteristics or severity of this allergy.

Serologic evidence of rickettsial diseases associated with tick bites in workers of urban veterinary clinics.

BACKGROUND & OBJECTIVES: Rickettsial and other zoonotic diseases are a latent risk for workers of veterinary clinics. The objective of this study was to evaluate the prevalence and the associated risk factors of parasitosis caused by Rhipicephalus sanguineus, and to estimate the seroprevalence of rickettsial diseases in workers of urban veterinary clinics of Juárez city, México. METHODS: The participants of the study were recruited from 63 private veterinary clinics and hospitals. The serological analysis of the blood samples collected was carried out using immunofluorescence assay (IFA). The statistical analysis for prevalences, risk factors, and correlation was performed with the SAS program. RESULTS: In total, 167 veterinary workers were included in the study. The prevalence of tick bites was 40% (67/167), and the risk factors associated with the occurrence of bites included the activities performed in the clinic and the number of labour hours spent per week. About 21% (35/167) of participants were seropositive to R. rickettsii, 28% (47/167) to Ehrlichia chaffeensis, and 24% (40/167) to Anaplasma phagocytophilum. A correlation was observed between: the number of workers in the clinics and the proportion of tick bites (r2 = 0.865); the prevalence of bites and the seropositivity of the participants to at least one pathogen (r2 = 0.924); and the number of bites per individual and infection to pathogens (r2 = 0.838). INTERPRETATION & CONCLUSION: Workers in urban veterinary clinics are highly exposed to tick bites and, therefore, to the diseases they transmit. Hence, it is important to implement prevention measures and perform constant monitoring of these diseases.

Genetic diversity of Rickettsia africae isolates from Amblyomma hebraeum and blood from cattle in the Eastern Cape province of South Africa.

Rickettsia africae is a re-emerging tick-borne pathogen causing African tick bite fever (ATBF) in humans. Amblyomma variegatum is the principal vector in most sub-Sahara African countries, whereas in South Africa it is A. hebraeum. Reports of high genetic heterogeneity among R. africae isolates in southern Africa have prompted the need for molecular investigations of isolates form South Africa. Therefore, this study aimed to determine the prevalence and genetic diversity of R. africae in A. hebraeum collected from cattle, grazing pasture, as well as from blood of cattle in the Eastern Cape Province of South Africa. Amblyomma hebraeum and blood from cattle were screened by PCR and the gltA, ompA, ompB, sca4, and 17kDa genes were sequenced for R. africae from samples collected from Caquba in Port St. Johns along the coastal region in the Eastern Cape province of South Africa. The overall proportion of adult A. hebraeum that were positive for the gltA and ompA genes was 0.63 (108/180). The overall proportion of nymphs positive for the gltA and ompA genes was 0.62 (23/37) and 0.22 (20/90) from cattle blood. A positive R. africae infection was inferred by analysis of 26 sequences of the ompA, gltA, ompB, 17kDa and sca4 genes. Neighbour-joining and Maximum Likelihood analysis revealed that the study isolates were closely related to R. africae isolates from South Africa deposited in GenBank, forming a clade that was separate from north, east and west African strains. This study provides new information on the epidemiology and phylogeny of R. africae isolated from A. hebraeum ticks in the Eastern Cape province of South Africa. The heterogeneity observed between R. africae isolates from South Africa deposited in GenBank and R. africae isolates from Africa retrieved from Genbank highlight the importance of differentiation and tracking of the genetic movement among R. africae isolates in southern Africa for the better characterisation of ATBF cases, especially in rural communities and travellers visiting the region.