RESUMO
Emerging tick-borne illnesses, such as anaplasmosis, babesiosis, or ehrlichiosis, are caused by obligate intracellular pathogens that have clinically comparable presentations. Diagnostics used in laboratories today are serologic assays and blood smear analyses, which have known diagnostic limits. This study evaluated the performance of a sample-to-answer direct real-time PCR laboratory-developed test for the multiplex qualitative detection of Anaplasma, Babesia, and Ehrlichia DNA in whole-blood specimens. Compared to two standard-of-care (SOC) methods, the DiaSorin tick-borne laboratory-developed test for Anaplasma detection demonstrated a positive percent agreement (PPA) and negative percent agreement (NPA) of 100% (95% CI, 0.80 to 1.0) and 89% (95% CI, 0.74 to 0.97), respectively with a discordant rate of 9.3% against microscopy. After discordant resolution, the NPA increased to 100%. For Babesia, the test demonstrated a PPA of 100% (95% CI, 0.90 to 1.0) and NPA of 100% (95% CI, 0.90 to 1.0). Compared to a SOC PCR method Anaplasma samples showed a PPA of 100% (95% CI, 0.66 to 1.0) and NPA of 100% (95% CI, 0.90 to 1.0). Ehrlichia results showed a PPA of 100% (95% CI, 0.69 to 1.0) and NPA of 100% (95% CI, 0.90 to 1.0). The total percent agreement was 98% (95% CI, 0.95 to 0.99) with a κ statistic of 0.95 (95% CI, 0.90 to 0.99) or almost perfect agreement compared to SOC methods. This laboratory-developed test for detecting Anaplasma, Babesia, and Ehrlichia DNA provides rapid and reliable detection of tick-borne infections without nucleic acid extraction. IMPORTANCE: This work demonstrates that detection of tick-borne illnesses, such as anaplasmosis, babesiosis, or ehrlichiosis, can be performed directly from whole blood with no extraction. The assay described here has a high positive and negative percent agreement with existing methods and is used as the standard of care. An increasing incidence of tick-borne illness combined with shortage of well-trained technologists to perform traditional manual testing, testing options that can be adapted to various lab settings, are of the utmost importance.
Assuntos
Anaplasma phagocytophilum , Anaplasmose , Babesia , Babesiose , Ehrlichia , Ehrlichiose , Reação em Cadeia da Polimerase em Tempo Real , Humanos , Ehrlichia/isolamento & purificação , Ehrlichia/genética , Anaplasma phagocytophilum/isolamento & purificação , Anaplasma phagocytophilum/genética , Reação em Cadeia da Polimerase em Tempo Real/métodos , Ehrlichiose/diagnóstico , Ehrlichiose/microbiologia , Babesiose/diagnóstico , Babesiose/parasitologia , Babesiose/sangue , Babesia/isolamento & purificação , Babesia/genética , Anaplasmose/diagnóstico , Anaplasmose/microbiologia , Sensibilidade e Especificidade , Doenças Transmitidas por Carrapatos/diagnóstico , Doenças Transmitidas por Carrapatos/microbiologia , Doenças Transmitidas por Carrapatos/parasitologia , DNA Bacteriano/genética , DNA Bacteriano/sangueRESUMO
This review highlights the causative organisms, clinical features, diagnosis, and treatment of the most common tick-borne illnesses in the United States, including Lyme disease, Rocky Mountain spotted fever, anaplasmosis, ehrlichiosis, tularemia, Powassan virus, and alpha-gal syndrome. Tick bite prevention strategies and some basic tick removal recommendations are also provided.
Assuntos
Doenças Transmitidas por Carrapatos , Humanos , Doenças Transmitidas por Carrapatos/diagnóstico , Doenças Transmitidas por Carrapatos/terapia , Doenças Transmitidas por Carrapatos/epidemiologia , Animais , Medicina Selvagem , Doença de Lyme/diagnóstico , Doença de Lyme/terapia , Doença de Lyme/epidemiologia , Febre Maculosa das Montanhas Rochosas/diagnóstico , Febre Maculosa das Montanhas Rochosas/terapia , Febre Maculosa das Montanhas Rochosas/epidemiologia , Estados Unidos/epidemiologia , Carrapatos/virologia , Picadas de Carrapatos/terapia , Ehrlichiose/diagnóstico , Ehrlichiose/epidemiologia , Ehrlichiose/terapia , Ehrlichiose/tratamento farmacológico , Anaplasmose/diagnóstico , Anaplasmose/epidemiologia , Anaplasmose/terapiaRESUMO
BACKGROUND: Severe Fever with Thrombocytopenia Syndrome (SFTS) is a tick-borne disease caused by the SFTS virus (SFTSV) which has the potential to become a pandemic and is currently a major public health concern. CASE PRESENTATION: We present the case of a 74-year-old female from an urban area of Chongqing, with leukocytopenia, thrombocytopenia, organ function, inflammatory, blood coagulation, and immune abnormalities. SFTSV infection was confirmed through molecular detection and metagenomic next-generation sequencing (mNGS) analysis, indicating a diagnosis of SFTS due to the patient's history of tick bites. The patient received symptomatic and supportive therapy, including antibiotics, antiviral treatment, and antifungal therapy, and finally discharged from the hospital on day 18. CONCLUSIONS: This study highlights the need for increased awareness, early diagnosis, and prompt treatment for tick-borne SFTS. It also provides a comprehensive understanding of the disease's characteristics, pathogenesis, detection methods, and available treatments.
Assuntos
Phlebovirus , Febre Grave com Síndrome de Trombocitopenia , Humanos , Feminino , Phlebovirus/genética , Phlebovirus/isolamento & purificação , Febre Grave com Síndrome de Trombocitopenia/diagnóstico , Febre Grave com Síndrome de Trombocitopenia/tratamento farmacológico , Idoso , China , Sequenciamento de Nucleotídeos em Larga Escala , Picadas de Carrapatos/complicações , Doenças Transmitidas por Carrapatos/diagnóstico , Doenças Transmitidas por Carrapatos/virologia , Doenças Transmitidas por Carrapatos/tratamento farmacológico , Antivirais/uso terapêuticoRESUMO
A 76-year-old woman infected with Yezo virus (YEZV) developed liver dysfunction and thrombocytopenia following a tick bite. Despite the severity of her elevated liver enzymes and reduced platelet counts, the patient's condition improved spontaneously without any specific treatment. To our knowledge, this represents the first documented case where the YEZV genome was detected simultaneously in a patient's serum and the tick (Ixodes persulcatus) that bit the patient. This dual detection not only supports the hypothesis that YEZV is a tick-borne pathogen but also underscores the importance of awareness and diagnostic readiness for emerging tick-borne diseases, particularly in regions where these ticks are prevalent.
Assuntos
Ixodes , Picadas de Carrapatos , Humanos , Feminino , Idoso , Animais , Picadas de Carrapatos/complicações , Ixodes/virologia , Doenças Transmitidas por Carrapatos/diagnóstico , Doenças Transmitidas por Carrapatos/virologia , Vírus da Encefalite Transmitidos por Carrapatos/isolamento & purificação , Trombocitopenia/virologia , Trombocitopenia/diagnósticoRESUMO
Ticks are responsible for the vast majority of vector-borne illnesses in the United States. The number of reported tick-borne disease (TBD) cases has more than doubled in the past 20 years. The majority of TBD cases occur in warm weather months in individuals with recent outdoor activities in wooded areas. The risk of contracting a TBD is also highly dependent on geographic location. Between 24 and 48 hours of tick attachment is required for most disease transmission to occur. Only 50% to 70% of patients with a TBD will recall being bitten by a tick, and TBDs are often initially misdiagnosed as a viral illness. Most TBDs are easily treated when diagnosed early in their course.
Assuntos
Ehrlichiose , Doenças Transmitidas por Carrapatos , Carrapatos , Animais , Humanos , Estados Unidos/epidemiologia , Ehrlichiose/diagnóstico , Ehrlichiose/terapia , Doenças Transmitidas por Carrapatos/diagnóstico , Doenças Transmitidas por Carrapatos/epidemiologia , Doenças Transmitidas por Carrapatos/terapiaRESUMO
BACKGROUND: Anaplasma phagocytophilum is a tick-borne bacterium and the cause of human granulocytic anaplasmosis (HGA). Here, we report a case of transfusion-transmitted (TT)-HGA involving a leukoreduced (LR) red blood cell (RBC) unit. CASE REPORT: A 64-year-old woman with gastric adenocarcinoma and multiple myeloma who received weekly blood transfusions developed persistent fevers, hypotension, and shortness of breath 1 week after receiving an RBC transfusion. Persistent fevers, new thrombocytopenia, and transaminitis suggested a tick-borne infection. RESULTS: The absence of blood parasites on thick and thin blood smears suggested that malaria and Babesia infection were not present, and the recipient tested negative for antibodies to Borrelia burgdorferi. Blood testing by polymerase chain reaction (PCR) for Ehrlichia and Anaplasma species identified A. phagocytophilum. Treatment with doxycycline resolved the infection; however, the recipient expired due to complications of her known malignancies. The recipient lived in a nursing home and did not have pets or spend time outdoors. The donor was a female in her 70s from Maine who was diagnosed with HGA 3 weeks after donating blood and whose LR-RBCs from the donation were transfused to the recipient 9 days following collection. CONCLUSION: This is a confirmed case of TT-HGA. Although rare, TT-HGA has been reported with LR-RBCs and platelets. In endemic areas, testing for tick-borne associated infections should be considered when investigating post-transfusion complications.
Assuntos
Anaplasma phagocytophilum , Anaplasmose , Doenças Transmitidas por Carrapatos , Humanos , Animais , Feminino , Pessoa de Meia-Idade , Doenças Transmitidas por Carrapatos/diagnóstico , Doenças Transmitidas por Carrapatos/epidemiologia , Anticorpos Antibacterianos , EritrócitosRESUMO
A 51-year-old male with a history of Cacchi-Ricci disease and long-standing infection with various species of Borrelia, Babesia, and Bartonella presented with recurrent symptoms of right-sided flank pain. Numerous renal calculi were identified on imaging. The etiology of the calculi had not been previously elucidated. Symptoms intermittently date back to 2002 when uric acid stones were identified. Subsequent calculi analysis revealed calcium oxalate stones. Despite the commonality of nephrolithiasis in patients with Cacchi-Ricci disease, the extreme number of calculi and recurrent presentation of symptoms persisted despite a plethora of medical evaluations, dietary changes, and hereditary testing. This case raises questions of etiology including possible immune deficiency and whether his uncommon microbial history contributes to recurrent stone formation.
Assuntos
Cálculos Renais , Rim em Esponja Medular , Doenças Transmitidas por Carrapatos , Masculino , Humanos , Pessoa de Meia-Idade , Cálculos Renais/complicações , Cálculos Renais/diagnóstico , Rim , Rim em Esponja Medular/complicações , Doenças Transmitidas por Carrapatos/complicações , Doenças Transmitidas por Carrapatos/diagnósticoRESUMO
Delayed treatment of Rocky Mountain spotted fever is associated with increased morbidity and mortality. Because the diagnosis cannot be established from a single serological test, guidelines recommend empirical antibiotic initiation in suspect patients. We evaluated a policy used by UNC Health of paging clinicians when acute testing for Rickettsia returned with a titer ≥1:256. Our objective was to assess the potential effect of paging on routine treatment practices. Notably, we found that a high proportion of cases (N = 28, 40%) were not prescribed antibiotics until the results were available. The vast majority of these cases did not have evidence of compatible symptoms or disease progression. These findings suggest that paging may have prompted unnecessary treatment. Overall, the policy, which has now been discontinued, appears to have had limited benefit. Efforts are urgently needed to improve adherence to testing and treatment guidelines.
Assuntos
Rickettsia , Febre Maculosa das Montanhas Rochosas , Doenças Transmitidas por Carrapatos , Humanos , North Carolina/epidemiologia , Estudos Retrospectivos , Febre Maculosa das Montanhas Rochosas/tratamento farmacológico , Doenças Transmitidas por Carrapatos/diagnóstico , Doenças Transmitidas por Carrapatos/tratamento farmacológico , Doenças Transmitidas por Carrapatos/epidemiologia , Antibacterianos/uso terapêuticoRESUMO
Tick-borne pathogens (TBPs) are often detected through classical molecular tools (PCR, nested PCR, real-time PCR), but these are limited in terms of the number of targeted pathogens due to the volume of DNA available for analysis. To solve this problem, in 2014 we developed a new high-throughput method based on real-time microfluidic PCRs that can detect 48 or 96 pathogens in 48 or 96 samples in a single run, such as ten species from the Borrelia burgdorferi sensu lato group. We then used this technique for large-scale epidemiological studies of TBPs in tick and animal samples on an international scale through numerous collaborative projects.
Assuntos
Grupo Borrelia Burgdorferi , Rickettsia , Doenças Transmitidas por Carrapatos , Carrapatos , Animais , Reação em Cadeia da Polimerase em Tempo Real , Doenças Transmitidas por Carrapatos/diagnóstico , Microfluídica , Rickettsia/genética , Grupo Borrelia Burgdorferi/genéticaRESUMO
PURPOSE OF REVIEW: Because both incidence and awareness of tick-borne infections is increasing, review of major infections and recent advances related to their diagnosis and management is important. RECENT FINDINGS: A new algorithm, termed modified two-tier testing, for testing for antibodies to Borrelia burgdorferi , the cause of Lyme disease, has been approved and may replace traditional two-tier testing. In addition, doxycycline is now acceptable to use for treatment of and/or prophylaxis for Lyme disease for up to 21âdays in children of any age. Borrelia miyamotoi , a bacterium in the relapsing fever type of Borrelia, is the first of this type of Borrelia that is transmitted by hard-bodied ticks such as Ixodes scapularis. SUMMARY: Awareness of these infections and advances in their diagnosis and treatment is important to assure the best outcomes for affected patients. Table 1 contains a summary of infections discussed.
Assuntos
Borrelia burgdorferi , Doença de Lyme , Febre Recorrente , Doenças Transmitidas por Carrapatos , Criança , Humanos , Doenças Transmitidas por Carrapatos/diagnóstico , Doenças Transmitidas por Carrapatos/tratamento farmacológico , Doenças Transmitidas por Carrapatos/epidemiologia , Doença de Lyme/diagnóstico , Doença de Lyme/tratamento farmacológico , Doença de Lyme/epidemiologia , Febre Recorrente/diagnóstico , Febre Recorrente/tratamento farmacológico , Febre Recorrente/epidemiologia , América do NorteRESUMO
As part of the NorthTick project, co-funded by the European Union through the European Regional Development Fund and the North Sea Region Programme, specialists in the field of tick-borne diseases from seven North Sea countries co-operated with patient organisations and governmental health care institutions to provide this comprehensive overview of diagnostics and treatment recommendations in the region for Lyme borreliosis, Borrelia miyamotoi infection, tick-borne encephalitis, human granulocytic anaplasmosis, rickettsiosis, neoehrlichiosis and babesiosis. The main conclusion is that the recommendations in these northern countries are essentially the same, with very few differences. This overview presents the current diagnostics and provides useful clinical guidance.
Assuntos
Babesiose , Infecções por Borrelia , Encefalite Transmitida por Carrapatos , Doença de Lyme , Doenças Transmitidas por Carrapatos , Animais , Humanos , Mar do Norte , Doenças Transmitidas por Carrapatos/diagnóstico , Doenças Transmitidas por Carrapatos/epidemiologia , Doenças Transmitidas por Carrapatos/terapia , Doença de Lyme/diagnóstico , Doença de Lyme/epidemiologia , Doença de Lyme/terapia , Babesiose/diagnóstico , Babesiose/epidemiologia , Babesiose/terapiaAssuntos
Rickettsiose do Grupo da Febre Maculosa , Doenças Transmitidas por Carrapatos , Carrapatos , Animais , Humanos , Rickettsiose do Grupo da Febre Maculosa/diagnóstico , Rickettsiose do Grupo da Febre Maculosa/epidemiologia , Doenças Transmitidas por Carrapatos/diagnóstico , Doenças Transmitidas por Carrapatos/epidemiologiaRESUMO
This JAMA Patient Page describes alpha-gal syndrome, a type of food allergy to red meat products, and its symptoms, diagnosis, and treatment.
Assuntos
Alérgenos , Hipersensibilidade Alimentar , Carne Vermelha , Doenças Transmitidas por Carrapatos , Humanos , Alérgenos/imunologia , Hipersensibilidade Alimentar/diagnóstico , Hipersensibilidade Alimentar/etiologia , Hipersensibilidade Alimentar/imunologia , Hipersensibilidade Alimentar/terapia , Carne Vermelha/efeitos adversos , Doenças Transmitidas por Carrapatos/complicações , Doenças Transmitidas por Carrapatos/diagnóstico , Doenças Transmitidas por Carrapatos/imunologia , Doenças Transmitidas por Carrapatos/terapiaRESUMO
Background and Objectives: The Wakayama prefecture is endemic for two types of tick-borne rickettsioses: Japanese spotted fever (JFS) and scrub typhus (ST). Severe fever with thrombocytopenia syndrome (SFTS) is a tick-borne hemorrhagic viral disease with a high mortality rate and is often difficult to differentiate from such rickettsioses. SFTS cases have recently increased in Wakayama prefecture. For early diagnosis, this study aimed to evaluate the clinical characterization of such tick-borne infections in the co-endemic area. Materials and Methods: The study included 64 febrile patients diagnosed with tick-borne infection in Wakayama prefecture between January 2013 and May 2022. Medical records of 19 patients with SFTS and 45 with rickettsiosis (JSF, n = 26; ST, n = 19) were retrospectively examined. The receiver operating curve (ROC) and area under the curve (AUC) were calculated to evaluate potential factors for differentiating SFTS from rickettsiosis. Results: Adults aged ≥70 years were most vulnerable to tick-borne infections (median, 75.5 years; interquartile range, 68.5-84 years). SFTS and rickettsiosis occurred mostly between summer and autumn. However, no significant between-group differences were found in age, sex, and comorbidities; 17 (89%) patients with SFTS, but none of those with rickettsiosis, experienced gastrointestinal symptoms such as vomiting, abdominal pain, and diarrhea. Meanwhile, 43 (96%) patients with rickettsiosis, but none of those with SFTS, developed a skin rash. The AUCs of white blood cells (0.97) and C-reactive protein (CRP) levels (0.98) were very high. Furthermore, the differential diagnosis of SFTS was significantly associated with the presence of gastrointestinal symptoms (AUC 0.95), the absence of a skin rash (AUC 0.98), leukopenia <3.7 × 109/L (AUC 0.95), and low CRP levels < 1.66 mg/dL (AUC 0.98) (p < 0.001 for each factor). Conclusions: Clinical characteristics and standard laboratory parameters can verify the early diagnosis of SFTS in areas where tick-borne infections are endemic.
Assuntos
Exantema , Phlebovirus , Infecções por Rickettsia , Tifo por Ácaros , Febre Grave com Síndrome de Trombocitopenia , Doenças Transmitidas por Carrapatos , Adulto , Humanos , Febre Grave com Síndrome de Trombocitopenia/diagnóstico , Febre Grave com Síndrome de Trombocitopenia/epidemiologia , Estudos Retrospectivos , Japão/epidemiologia , Infecções por Rickettsia/diagnóstico , Infecções por Rickettsia/epidemiologia , Tifo por Ácaros/complicações , Tifo por Ácaros/diagnóstico , Tifo por Ácaros/epidemiologia , Doenças Transmitidas por Carrapatos/diagnósticoRESUMO
Tick-borne diseases occur throughout the United States, with a disease burden that ranges from mild to severe. As temperatures rise with climate change, the active season for ticks increases, and more tick-borne illness is seen (Centers for Disease Control and Prevention, 2022a). Many patients present to the ED for suspected tick bites, rashes, and generalized medical complaints that may be related to a tick-borne disease, so it is important for the emergency nurse practitioner (ENP) to accurately diagnose these conditions. Because of this increasing disease burden, it has become vital for these illnesses to be recognized early, as early diagnosis can reduce possible complications of chronic illness. Familiarity with the cutaneous rashes present in several tick-borne diseases can aid the ENP to effectively diagnose and treat these conditions.
Assuntos
Exantema , Dermatopatias , Doenças Transmitidas por Carrapatos , Carrapatos , Animais , Humanos , Estados Unidos , Doenças Transmitidas por Carrapatos/diagnóstico , Doenças Transmitidas por Carrapatos/terapia , Exantema/diagnóstico , Serviço Hospitalar de EmergênciaRESUMO
PURPOSE: This study aims to develop and evaluate a cost-effective, user-friendly multiplex quantitative real-time polymerase chain reaction (qPCR) method for detecting multiple tick-borne pathogens associated with human and veterinary diseases. METHODS: In silico PCR was performed to design and evaluate primer sequences reported for amplifying Rickettsia spp., Borrelia spp., and Ehrlichia spp. Single and multiplex qPCR assays were then standardized to detect individual pathogens and multiple pathogens in a single reaction. Positive controls were generated to determine the dynamic range of the methods. In the validation phase, a total of 800 samples were screened for the presence of tick-borne pathogens. RESULTS: Identification in a single qPCR reaction (multiplex) of Ehrlichia spp., and Borrelia spp. with a limit of detection of 10 copies and Rickettsia spp. with 100 copies, a PCR efficiency (E) of 90-100% and a coefficient of correlation (R2) of 0.998-0.996 for all pathogens. CONCLUSION: The ability to detect three significant pathogens (Ehrlichia spp., Rickettsia spp., and Borrelia spp.) in a single qPCR reaction offers a significant advantage in the field of molecular diagnostics for tick-borne diseases. This advancement has a profound impact on public health as it facilitates the selection of appropriate treatment protocols, thereby reducing complications associated with disease progression. The streamlined approach provided by this method simplifies the diagnostic process and enables timely intervention, ultimately improving patient outcomes and mitigating the potential risks associated with untreated or misdiagnosed tick-borne infections.
Assuntos
Borrelia , Rickettsia , Doenças Transmitidas por Carrapatos , Carrapatos , Animais , Humanos , Carrapatos/microbiologia , Reação em Cadeia da Polimerase em Tempo Real , Rickettsia/genética , Ehrlichia/genética , Doenças Transmitidas por Carrapatos/diagnóstico , Doenças Transmitidas por Carrapatos/veterinária , Borrelia/genéticaRESUMO
BACKGROUND: The Coronavirus disease 2019 (COVID-19) pandemic was marked by an increase in diagnosis and treatment delays for a range of medical conditions. Yet the impact of the pandemic on the management of tick-borne diseases, which frequently manifest as an acute febrile illness similar to COVID-19, has not been well described. METHODS: In this retrospective cohort study of patients with suspected tick-borne disease attending the University of North Carolina Health facilities, we compared the timeliness of diagnosis and treatment in a "pre-COVID" period (March 2019 to February 2020) and a "post-COVID" period (March 2020 to February 2021). Participants included patients with an ICD-10 diagnosis code of spotted fever group rickettsiosis or ehrlichiosis and a positive Rickettsia rickettsii or Ehrlichia indirect immunofluorescence assay immunoglobulin G antibody test result. Of the 897 patients who had an eligible diagnosis, 240 (26.8%) met the inclusion criteria. The main outcome was time from initial presentation to definitive diagnosis and treatment. RESULTS: During the 2-year study period, 126 (52.5%) patients were grouped in the pre-COVID period and 114 (47.5%) were grouped in the post-COVID period; 120 (50.0%) were female; and 139 (57.9%) were aged > 50 years. Comparing the post-COVID to the pre-COVID period, the adjusted odds ratio (aOR) for delay in treatment > 0 days was 1.81 (95% confidence interval [CI] 1.07-3.07, P = 0.03), and for a treatment delay > 7 days, 1.65 (95% CI 0.94-2.90, P = 0.08). The odds of a delay in diagnosis were similar for patients in the post- and pre-COVID periods, with an aOR of 1.61 (95% CI 0.96-2.72, P = 0.07) for delays > 0 days, and aOR of 1.72 (95% CI 0.99-3.00, P = 0.05) for delays > 7 days. CONCLUSIONS: The odds of a delay in treatment > 0 days were significantly higher in the post-COVID period than in the pre-COVID period. However, the odds of a delay in treatment > 7 days, or a delay in diagnosis, were similar between these two periods. Shifts in care-seeking, alternative care delivery models and prioritization of COVID-19 may contribute to diminished timeliness of treatment for patients with tick-borne diseases.
Assuntos
COVID-19 , Ehrlichiose , Doenças Transmitidas por Carrapatos , Humanos , Feminino , Masculino , Pandemias , Estudos Retrospectivos , COVID-19/diagnóstico , COVID-19/epidemiologia , Doenças Transmitidas por Carrapatos/diagnóstico , Doenças Transmitidas por Carrapatos/tratamento farmacológico , Doenças Transmitidas por Carrapatos/epidemiologia , Teste para COVID-19RESUMO
Due to environmental and ecological changes and suitable habitats, the occurrence of vector-borne diseases is increasing. We investigated the seroprevalence of four major vector-borne pathogens in human patients with febrile illness who were clinically suspected of having Scrub Typhus (ST) caused by Orientia tsutsugamushi. A total of 187 samples (182 patient whole blood and sera samples, including 5 follow-up) were collected. Antibodies to Anaplasma phagocytophilum, Ehrlichia chaffeensis, Borrelia burgdorferi, and Bartonella henselae were tested by using indirect immunofluorescence assays. Molecular diagnoses were performed using real-time PCR. Of the 182 cases, 37 (20.3%) cases were designated as confirmed cases of ST, and the remaining 145 (79.7%) cases as other febrile diseases (OFDs). The seroprevalence of A. phagocytophilum, E. chaffeensis, B. burgdorferi, and B. henselae was 51.4% (19/37), 10.8% (4/37), 86.5% (32/37), and 10.8% (4/37) among the ST group, and 42.8% (62/145), 10.4% (19/145), 57.7% (105/145), and 15.9% (29/145) among the OFD group, respectively. There were no significant differences in the seroprevalence between the ST and the OFD groups. Considering the co-occurrence, 89.0% (162/182) had at least one antibody to tick-borne pathogens, 37.0% (60/162) were positive for two pathogens, 17.3% (28/162) for three pathogens, and 6.2% (10/162) for four pathogens. In real-time PCR, O. tsutsugamushi was positive in 16 cases [15 (40.5%) in ST group and 1 (2.2%) in OFD group], and the four other pathogens were negative in all cases except one confirmed as anaplasmosis. In evaluating the five follow-up samples, the appearance of new antibodies or an increase in the pre-existing antibody titers was detected. Our data highlighted that acute febrile illness and manifestations suggestive of a vector-borne infection must be recognized and further considered for coinfections in clinical practice and the laboratory.
Assuntos
Anaplasma phagocytophilum , Anaplasmose , Ehrlichiose , Rickettsia , Tifo por Ácaros , Doenças Transmitidas por Carrapatos , Animais , Humanos , Tifo por Ácaros/diagnóstico , Tifo por Ácaros/epidemiologia , Estudos Soroepidemiológicos , Anaplasmose/diagnóstico , Anaplasmose/epidemiologia , Anaplasma phagocytophilum/genética , Ehrlichiose/diagnóstico , Ehrlichiose/epidemiologia , Doenças Transmitidas por Carrapatos/diagnóstico , Doenças Transmitidas por Carrapatos/epidemiologiaRESUMO
Infectious disease diagnostics often depend on costly serological testing with poor sensitivity, low specificity, and long turnaround time. Here, we demonstrate proof of the principle for simultaneous detection of two tick-borne pathogens from a single test sample using barcoded magnetic bead technology on the BioCode 2500 system. Specific primer sets complementary to the conserved genes of Anaplasma phagocytophilum and Borrelia burgdorferi were used in PCR amplification of the target, followed by the hybridization of the resulting biotinylated PCR products with specific probes tethered to the barcoded magnetic beads for simultaneous detection, using a fluorophore with high quantum yield. The assay has an extremely high signal to background ratio, with a limit of detection (LOD) of 2.81 50% tissue culture infection dose (TCID50)/mL and 1 CFU/mL for A. phagocytophilum and B. burgdorferi, respectively. The observed LOD for gene blocks was 1.8 copies/reaction for both the pathogens. The assay demonstrated 100% positive and negative agreement on performance evaluation using patient specimens and blood samples spiked with 1 × LOD of pathogen stock. No cross-reactivity was observed with other related tick-borne pathogens and genomic DNA of human, cattle, and canine origin. The assay can be upgraded to a sensitive and cost-effective multiplex diagnostic approach that can simultaneously detect multiple clinically important tick-borne pathogens in a single sample with a short turnaround time. IMPORTANCE The low pathogen load in the tick-borne disease test samples and the lack of highly sensitive multiplex diagnostic approaches have impacted diagnosis during clinical testing and limited surveillance studies to gauge prior insight about the prevalence of tick-borne infections in a geographical area. This article demonstrates proof of the principle for simultaneous detection of two important tick-borne pathogens from a single test sample using digital barcoded magnetic bead technology. Using a fluorophore of high quantum yield, the diagnostic approach showed high sensitivity and specificity. The LOD was 1.8 genome copies per reaction for both A. phagocytophilum and B. burgdorferi. The assay can be upgraded for the detection of all clinically important tick-borne pathogens from a single patient sample with high sensitivity and specificity. The assay can provide a diagnostic answer to the clinician in a short turnaround time to facilitate speedy therapeutic intervention to infected patients and implement public health measures to prevent community spread.