BACKGROUND: Modified 2-tiered testing (MTTT) for Lyme disease utilizes automatable, high throughput immunoassays (AHTIs) in both tiers without involving western immunoblots, offering performance and practical advantages over standard 2-tiered testing (STTT; first-tier AHTI followed by immunoglobulin M (IgM) and immunoglobulin G (IgG) western immunoblots). For MTTT, Centers for Disease Control and Prevention recommends using AHTI test kits that have been cleared by Food and Drug Administration (FDA) specifically for this intended use. We evaluated performance of FDA-cleared MTTT commercial test kits from 3 manufacturers by comparing with STTT results.
METHODS: We performed MTTT (total antibody AHTI with reflex to separate IgM and IgG AHTIs) using test kits from Diasorin, Gold Standard Diagnostics (GSD), and Zeus Scientific on 382 excess serum samples submitted to the clinical laboratory for routine Lyme disease serologic testing in July 2018, measuring agreement between MTTT and STTT using the κ statistic.
RESULTS: Overall agreement with STTT was 0.87 (95% confidence interval [CI], .77-.97) using Diasorin assays (almost perfect agreement), 0.80 (95% CI, .68-.93) using GSD assays (substantial agreement) and 0.79 (95% CI, .68-.90) using Zeus assays (substantial agreement). For detection of IgM reactivity, agreement between MTTT and STTT was 0.70 (.51-.90; substantial), 0.63 (95% CI, .44-.82; substantial) and 0.56 (95% CI, .38-.73; moderate), respectively. For detection of IgG reactivity, MTTT/STTT agreement was 0.73 (95% CI,.58-.88), 0.78 (95% CI, .62-.94), and 0.75 (95% CI, .60-.90), respectively (substantial agreement in all cases).
CONCLUSIONS: MTTT results obtained using commercial test kits from 3 different manufacturers had substantial to almost perfect agreement with STTT results overall and moderate to substantial agreement for IgM and IgG detection independently. Commercial MTTT tests can be used broadly for the diagnosis of Lyme disease.

Background: Borrelia burgdorferi sensu stricto is the causative agent of Lyme disease (LD). Possible early symptoms include flu-like symptoms and erythema migrans and later, the risk of disruption of the nervous system, joints, and heart. A two-tiered testing method is employed for serological diagnostics. The Public Health Agency of Canada guidelines recommend that samples tested negative on first-tiered test need not be confirmed by second-tiered test. Due to the challenging nature of diagnosis leading to misconceptions among physicians about false negatives, confirmatory testing is requested despite the initial negative result. Methods: Hundred screen-negative Lyme patient samples from 2007 to 2016 were tested by Western blot (WB) second-tiered confirmatory test upon physician\'s request in British Columbia to study the first-tiered screening test sufficiency. Results: Those negative for first-tiered enzyme-linked immunosorbent assay were also negative by WB. Conclusion: Results demonstrate that confirmatory testing is not necessary on screen-negative samples. Hence, first-tiered test is sufficient to rule out LD.

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.

Lyme disease progresses through three distinct clinical phases: early localized, early disseminated, and late disseminated. Lyme arthritis is characterized by attacks of joint swelling lasting for weeks to months, potentially causing permanent joint damage in late disseminated disease. Our case focuses on a 63-year-old, obese, type 2 diabetic, wheelchair-bound, Caucasian male with severe bilateral knee pain. Our patient had previously undergone bilateral knee arthroscopies for meniscal tears and also had knee injections performed previously without the desired level of pain alleviation. He indicated a recent cough that was treated with erythromycin and noted his knees felt better during the course of the antibiotic. The patient recreationally enjoyed hunting and mentioned that his dog had Lyme Disease. Laboratory confirmation of Lyme disease prompted our patient to be treated with doxycycline. Upon completion of doxycycline therapy, our patient noted significant improvement in his knee pain. The improvement was significant enough that the patient canceled a planned bilateral knee replacement with his orthopedic surgeon, and no longer required the use of a wheelchair as he was able to return to ambulating independently. The patient\'s quality of life improved significantly, and he could also return to work. Lyme disease should be a consideration in the differential diagnosis of patients in areas endemic to the disease, and patients who tend to have outdoor lifestyles.

Borrelia burgdorferi sensu lato (Bb) are a complex of bacteria genospecies that can cause Lyme disease (LD) in humans after the bite of an infected Ixodes spp. vector tick. In Canada, incidence of LD is increasing in part due to the rapid geographic expansion of Ixodes scapularis across the southcentral and eastern provinces. To better understand temporal and spatial (provincial) prevalence of Bb infection of I. scapularis and how tick surveillance is utilized in Canada to assess LD risk, a literature review was conducted. Tick surveillance studies published between January 1975 to November 2023, that measured the prevalence of Bb in I. scapularis via \"passive surveillance\" from the public citizenry or \"active surveillance\" by drag or flag sampling of host-seeking ticks in Canada were included for review. Meta-analyses were conducted via random effects modeling. Forty-seven articles, yielding 26 passive and 28 active surveillance studies, met inclusion criteria. Mean durations of collection for I. scapularis were 2.1 years in active surveillance studies (1999-2020) and 5.5 years by passive surveillance studies (1990-2020). Collectively, data were extracted on 99,528 I. scapularis nymphs and adults collected between 1990-2020 across nine provinces, including Newfoundland & Labrador (33 ticks) and Alberta (208 ticks). More studies were conducted in Ontario (36) than any other province. Across nine provinces, the prevalence of Bb infection in I. scapularis collected by passive surveillance was 14.6% with the highest prevalence in Nova Scotia at 20.5% (minimum studies >1). Among host-seeking I. scapularis collected via active surveillance, Bb infection prevalence was 10.5% in nymphs, 31.9% in adults, and 23.8% across both life stages. Host-seeking I. scapularis nymphs and adults from Ontario had the highest Bb prevalence at 13.6% and 34.8%, respectively. Between 2007-2019, Bb infection prevalence in host-seeking I. scapularis was positively associated over time (p<0.001) which is concurrent with a ∼25-fold increase in the number of annually reported LD cases in Canada over the same period. The prevalence of Bb-infection in I. scapularis has rapidly increased over three decades as reported by tick surveillance studies in Canada which coincides with increasing human incidence for LD. The wide-ranging distribution and variable prevalence of Bb-infected I. scapularis ticks across provinces demonstrates the growing need for long-term standardized tick surveillance to monitor the changing trends in I. scapularis populations and best define LD risk areas in Canada.

Lyme disease is a progressive infectious disease caused by the Borrelia species that affects multiple organ systems, including the brain, heart, skin, and musculoskeletal systems. The cardiac manifestations of Lyme disease typically present with atrioventricular nodal conduction abnormalities and, more rarely, myocarditis. We report a case of an immunocompromised 57-year-old woman who presented with acute onset shortness of breath, hypervolemia, injective conjunctiva, and global vision loss of the left eye in the setting of a recent tick bite. Serologic testing confirmed borreliosis, and cardiac testing demonstrated acute isolated systolic heart failure without any cardiac conduction system abnormalities on the electrocardiogram. The diagnosis of Lyme carditis was made, and the patient was started on doxycycline with complete recovery of cardiac systolic function. This case demonstrates atypical cardiac manifestations of Lyme disease and highlights the difficulty in workup and understanding of Lyme carditis particularly in immunocompromised patients.

Tracing the profile of pediatric Lyme borreliosis (LB) in Europe is difficult due to the interregional variation in its incidence and lack in notifications. Moreover, the identification of LB can be challenging. This study is an 18-year case series of 130 children and adolescents aged under 18 years referred to the Pediatric Infectious Diseases Unit at L. Sacco Hospital, Milan, with suspicion of LB, between January 2005 and July 2023. The routine serological workup consisted of a two-step process: an initial screening test followed by Western blot (WB). Forty-four (34%) patients were diagnosed with LB. The median age was six years, and 45% were females. Of the children with erythema migrans (EM), 33 (57%) were confirmed as having true EM, and, of these, 4 (12%) were atypical. Ten (23%) patients had early disseminated/late diseases, including facial nerve palsy (n = 3), early neuroborreliosis (n = 1), arthritis (n = 3), relapsing fever (n = 2), and borrelial lymphocytoma (n = 1). No asymptomatic infections were documented. Over seventy percent of confirmed LB cases (n = 31/44) recalled a history of tick bites; in this latter group, 19 (61%) were from the area of the Po River valley in Lombardy. Almost half of the children evaluated for LB complained of non-specific symptoms (fatigue, musculoskeletal pain, skin lesions/rash, and persistent headache), but these symptoms were observed in only two patients with confirmed LB. Most LB cases in our study were associated with EM; two-tier testing specificity was high, but we found frequent non-adherence to international recommendations with regard to the timing of serology, application of the two-step algorithm, and antibiotic over-prescription. Most children were initially assessed for a tick bite or a skin lesion suggestive of EM by a family pediatrician, highlighting the importance of improving awareness and knowledge around LB management at the primary healthcare level. Finally, the strengthening of LB surveillance at the national and European levels is necessary.

Vector-borne infections may underlie some rheumatic diseases, particularly in people with joint effusions. This study aimed to compare serum and synovial fluid antibodies to B. burgdorferi and Bartonella spp. in patients with rheumatic diseases. This observational, cross-sectional study examined paired synovial fluid and serum specimens collected from 110 patients with joint effusion between October 2017 and January 2022. Testing for antibodies to B. burgdorferi (using CDC criteria) and Bartonella spp. via two indirect fluorescent antibody (IFA) assays was performed as part of routine patient care at the Institute for Specialized Medicine (San Diego, CA, USA). There were 30 participants (27%) with positive two-tier B. burgdorferi serology and 26 participants (24%) with IFA seroreactivity (≥1:256) to B. henselae and/or B. quintana. Both B. burgdorferi IgM and IgG were detected more frequently in synovial fluid than serum: 27% of patients were either IgM or IgG positive in synovial fluid, compared to 15.5% in serum (P = 0.048). Conversely, B. henselae and B. quintana antibodies were detected more frequently in serum than synovial fluid; overall only 2% of patients had positive IFA titers in synovial fluid, compared to 24% who had positive IFA titers in serum (P < 0.001). There were no significant associations between B. burgdorferi or Bartonella spp. seroreactivity with any of the clinical rheumatological diagnoses. This study provides preliminary support for the importance of synovial fluid antibody testing for documenting exposure to B. burgdorferi but not for documenting exposure to Bartonella spp.
OBJECTIVE: This study focuses on diagnostic testing for two common vector-borne diseases in an affected patient population. In it, we provide data showing that antibodies to B. burgdorferi, but not Bartonella spp., are more commonly found in synovial fluid than serum of patients with joint effusion. Since Lyme arthritis is a common-and sometimes difficult to diagnose-rheumatic disease, improving diagnostic capabilities is of utmost importance. While our findings are certainly not definitive for changes to practice, they do suggest that synovial fluid could be a useful sample for the clinical diagnosis of Lyme disease, and future prospective studies evaluating this claim are warranted.

Cardiac involvement, such as myocarditis and pericarditis, can be a severe complication of monkeypox virus (mpox) infection and could be related to other co-infections with cardiac involvement. Tecovirimat is an antiviral specifically designed to inhibit smallpox infection diffusion and approved by the FDA for other Orthopoxvirus infections; its efficacy in mpox-infected patients is not well established. We present the case of a cardiac complication during mpox infection in a previously undiagnosed Lyme disease in a 42-year-old man living with HIV. Two days after the typical maculopapular rash, the patient reported a rise in body temperature up to 39 °C, chest pain without irradiation, and shortness of breath. We found an increase in troponin level, a slight reduction in ejection fraction, and grade 2 AV block (Mobitz 1 and 2) with frequent sinus pauses (the longest of 10.1 s). Given the suspicion of myopericarditis with cardiac conduction system involvement, the patient was admitted to the Intermediate Care Unit for continuous monitoring and further evaluation. Treatment included Ibuprofen 600 mg every 12 hours (bid) and colchicine 1 mg once daily for anti-inflammatory purposes. Concomitantly, treatment with tecovirimat was started at 600 mg bid for a total of 14 days. Cardiac MRI with gadolinium showed mild interstitial edema and pericardial enhancement. However, despite the clinical and laboratory resolution of the acute phase, bradycardia with episodes of AV block persisted at follow-up, suggesting the possibility of an additional etiology. Thus, the patient was investigated for Lyme disease because high-degree AV block is the most common presentation of Lyme carditis. Serological results evidenced a previous Borrelia burgdorferi senso latu. We decided to start treatment with doxycycline 100 mg every 12h, even pending the uncertainty of the role of a previous Lyme disease in determining the cardiac rhythm disturbances. At the evaluation on day 44, the patient was systemically well, and after cardiologist consultation, pace-maker implantation was not deemed indicated. This case underscores the importance of considering alternative causes of carditis when the clinical picture remains unclear or persists after the acute phase.

暂无摘要。