Preliminary clinical performance of a Cas13a-based lateral flow assay for detecting in urine specimens.

Nucleic acid amplification testing (NAAT) for is unavailable in resource-limited settings. We previously developed a CRISPR-based lateral flow assay for detecting . We aimed to pair that assay with point-of-care DNA extraction, assess performance in clinical urine specimens, and optimize assay kinetics.

Analysis of Powassan Virus Genome Sequences from Human Cases Reveals Substantial Genetic Diversity with Implications for Molecular Assay Development.

Powassan virus (POWV) is an emerging tick-borne virus that causes severe meningoencephalitis in the United States, Canada, and Russia. Serology is generally the preferred diagnostic modality, but PCR on cerebrospinal fluid, blood, or urine has an important role, particularly in immunocompromised patients who are unable to mount a serologic response. Although the perceived poor sensitivity of PCR in the general population may be due to the biology of infection and health-seeking behavior (with short viremic periods that end before hospital presentation), limitations in assay design may also contribute.

Evaluation of Lyme serologic quantitative test indexes: High first-tier test index values predict positive second-tier result in standard and modified 2-tier Lyme testing algorithms.

Objectives: In this study, we evaluated the potential utility of reporting a quantitative Lyme serologic test index to improve the utility of results from first-tier Lyme assays.

Methods: Serum from consecutive samples sent to our laboratory for Lyme testing were tested on 2 commercial first-tier Lyme assays and evaluated to determine the probability of second-tier confirmation based on the serologic index value.

Results: For both assays, we identified an index value above which 100% of samples confirmed on second-tier testing using both standard and modified 2-tier testing algorithms.

Laboratory Testing for Powassan Virus: Past, Present, and Future.

Powassan virus is a tick-borne flavivirus that can cause severe neuroinvasive disease, with areas of endemicity in the Northeast and Midwest United States, Canada, and Russia. Diagnosis is challenging and relies on a high index of suspicion and choosing the right test based on duration of infection and the patient's immune status. This review covers laboratory testing for Powassan virus, including historical considerations, modern options, and methods being developed in the research space.

Comparative Evaluation of Commercial Test Kits Cleared for Use in Modified Two-Tiered Testing Algorithms for Serodiagnosis of Lyme Disease.

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.

Second Time's the Charm? Assessing the Sensitivity and Yield of Inpatient Diagnostic Algorithms for Pulmonary Tuberculosis in a Low-Prevalence Setting.

Background: For persons with suspected pulmonary tuberculosis, the guidelines of the Centers for Disease Control and Prevention recommend collecting 3 respiratory specimens 8 to 24 hours apart for acid-fast bacilli (AFB) smear and culture, in addition to 1 nucleic acid amplification test (NAAT). However, data supporting this approach are limited. Our objective was to estimate the performance of 1, 2, or 3 AFB smears with or without NAATs to detect pulmonary tuberculosis in a low-prevalence setting.

Clinical Performance of Cas13a-based Point-of-Care Lateral Flow Assay for Detecting .

Background: Diagnosis of is dependent on nucleic acid amplification testing (NAAT), which is not available in resource-limited settings where the prevalence of infection is highest. Recent advances in molecular diagnostics leveraging the high specificity of CRISPR enzymes can permit field-deployable, point-of-care lateral flow assays. We previously reported on the development and performance of a lateral flow assay for detecting .

Borrelia-specific antibody profiles and complement deposition in joint fluid distinguish antibiotic-refractory from -responsive Lyme arthritis.

Lyme arthritis, caused by the spirochete is the most common feature of late disseminated Lyme disease in the United States. While most Lyme arthritis resolves with antibiotics, termed "antibiotic-responsive", some individuals develop progressive synovitis despite antibiotic therapy, called "antibiotic-refractory" Lyme arthritis (LA). The primary drivers behind antibiotic-refractory arthritis remain incompletely understood.

Cerebrospinal fluid metagenomics has greatest added value as a test for Powassan virus among patients in New England with suspected central nervous system infection.

Cerebrospinal fluid (CSF) metagenomic next generation sequencing (mNGS) can detect diverse pathogens in patients with central nervous system infection. Due to its high cost and unclear clinical utility, it is typically reserved for patients with unrevealing routine workups. A multi-center retrospective analysis of real-world CSF mNGS was performed involving orders between 2017 and 2022 at a large New England healthcare system.

Dematiaceous fungal infections: clinical and pathologic conundrums.

Dematiaceous fungi are defined by pigment within their cell walls. They are increasingly recognised human pathogens, causing a wide range of clinical presentations, from localised subcutaneous infections to disseminated disease in rare cases. We report our institutional experience with diagnosis of dematiaceous fungal infections from 2005 to 2022 and highlight four instructive cases that clinically and pathologically mimicked other diseases for which the diagnosis was confirmed by fungal culture (one case) or supported by PCR with 28S rRNA and internal transcribed spacer primers (three cases).

Sensitivity of Two-Tiered Lyme Disease Serology in Children With an Erythema Migrans Lesion.

In our prospective cohort of 192 children with a physician-diagnosed erythema migrans (EM) lesion, two-tier Lyme disease serology had higher sensitivity in children with multiple EM lesions (76.8% multiple lesions vs. 38.

Development of Cas13a-based assays for detection and gyrase A determination.

is one of the most common bacterial sexually transmitted infections. The emergence of antimicrobial-resistant is an urgent public health threat. Currently, the diagnosis of infection requires expensive laboratory infrastructure, while antimicrobial susceptibility determination requires bacterial culture, both of which are infeasible in low-resource areas where the prevalence of infection is highest.

Whole genome sequencing of human Borrelia burgdorferi isolates reveals linked blocks of accessory genome elements located on plasmids and associated with human dissemination.

Lyme disease is the most common vector-borne disease in North America and Europe. The clinical manifestations of Lyme disease vary based on the genospecies of the infecting Borrelia burgdorferi spirochete, but the microbial genetic elements underlying these associations are not known. Here, we report the whole genome sequence (WGS) and analysis of 299 B.

Evaluation of the rapid Quidel Sofia Lyme fluorescent immunoassay as a first-tier test in a modified 2-tier testing algorithm for Lyme disease: A comparison with the Zeus ELISA Borrelia VlsE1/pepC10 lgG/IgM assay followed by the Zeus monovalent IgM/IgG confirmatory assay.

Objectives: Recently modified 2-tier testing (MTTT) algorithms using 2 enzyme immunoassays (EIAs) as opposed to an EIA followed by immunoblot have been approved by the US Food and Drug Administration (FDA) for the screening and confirmation of Lyme disease. The Quidel Sofia Lyme fluorescent immunoassay is a rapid lateral-flow method that can be performed in real time, permitting on-demand testing. We evaluated the performance of the Sofia assay as a first-tier test in an MTTT algorithm.

Biomarkers for Pediatric Bacterial Musculoskeletal Infections in Lyme Disease-Endemic Regions.

Objectives: Bacterial musculoskeletal infections (MSKIs) are challenging to diagnose because of the clinical overlap with other conditions, including Lyme arthritis. We evaluated the performance of blood biomarkers for the diagnosis of MSKIs in Lyme disease-endemic regions.

Methods: We conducted a secondary analysis of a prospective cohort study of children 1 to 21 years old with monoarthritis presenting to 1 of 8 Pedi Lyme Net emergency departments for evaluation of potential Lyme disease.

Development of Cas13a-based Assays for Detection and Gyrase A Determination.

Background: is one of the most common bacterial sexually transmitted infections. The emergence of antimicrobial-resistant is an urgent public health threat. Currently, diagnosis of infection requires expensive laboratory infrastructure, while antimicrobial susceptibility determination requires bacterial culture, both of which are infeasible in low-resource areas where prevalence is highest.

Multiplex High-Definition Polymerase Chain Reaction Assay for the Diagnosis of Tick-borne Infections in Children.

Background: ticks can carry species as well as other pathogens that cause human disease. The frequency of tick-borne infections and coinfections in children with suspected Lyme disease is unknown, creating clinical uncertainty about the optimal approach to diagnosis.

Methods: We enrolled children aged 1-21 years presenting to 1 of 8 Pedi Lyme Net emergency departments for evaluation of Lyme disease.

Variant With Multiple Resistance Mutations Detected in an Immunocompromised Patient Receiving Atovaquone Prophylaxis.

We report genomic sequences with multiple mutations in the atovaquone-target region of cytochrome b, including a newly identified Y272S mutation, plus 1 mutation of undetermined significance in the azithromycin-associated ribosomal protein L4. The parasite was sequenced from an immunocompromised patient on prophylactic atovaquone for pneumonia before diagnosis of babesiosis.

Whole genome sequencing of isolates reveals linked clusters of plasmid-borne accessory genome elements associated with virulence.

Lyme disease is the most common vector-borne disease in North America and Europe. The clinical manifestations of Lyme disease vary based on the genospecies of the infecting spirochete, but the microbial genetic elements underlying these associations are not known. Here, we report the whole genome sequence (WGS) and analysis of 299 patient-derived sensu stricto ( ) isolates from patients in the Eastern and Midwestern US and Central Europe.

Evaluation of the Rapid Quidel Sofia 2 Lyme Immunoassay as a First-Tier Test in a Two-Tier Testing Algorithm for Lyme Disease: Comparison to the Zeus ELISA Borrelia VlsE1/pepC10 IgG/IgM Assay Followed by Immunoblot.

Objectives: Two-tiered serologic testing for Lyme disease is usually performed using an enzyme-linked immunosorbent assay (ELISA) as the first-tier test. The Quidel Sofia 2 Lyme test is a relatively new lateral flow method to provide more rapid turnaround time. We evaluated its performance in comparison to an established ELISA method.

Fun with fungi: a comprehensive review of common fungal organisms encountered in cytology.

The ability to detect and diagnose infection is essential in the practice of cytopathology. The identification of suppurative or granulomatous inflammation should prompt careful evaluation for infection. Many of the most commonly encountered fungal organisms demonstrate characteristic microscopic appearances that allow accurate identification even with routine cytology stains, particularly when considered in the context of clinical factors such as geographic location, social history, patient immune status, and symptoms.