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Highly pathogenic avian influenza (HPAI) viruses cause high mortality rates in wild birds and farmed poultry, and their potential for adaptation to humans remains a major pandemic threat (2). In [...]

BackgroundMolecular diagnostics such as pathogen-directed PCRs have transformed testing for ocular infections since the late 1990s. Although these assays remain important diagnostic tools for samples with low biomass, the lack of diagnostic range motivates alternative molecular approaches for ocular infections. The aim of this study was to determine the performance of a high-throughput RNA sequencing approach, RNA-seq, to detect infectious agents in ocular samples from patients with presumed ocular infections.MethodsWe compared the performance of RNA-seq to pathogen-directed PCRs using remnant nucleic acids from 41 aqueous or vitreous samples of patients with presumed ocular infections. Pathogen-directed PCRs were performed at the CLIA-certified Stanford Clinical Virology Laboratory. RNA-seq was performed in a masked manner at the Proctor Foundation at the University of California San Francisco. Percent positive and negative agreement between the two testing approaches were calculated. Discordant results were subjected to orthogonal testing.ResultsThe positive percent agreement between RNA-seq and pathogen-directed PCRs was 100% (95% confidence interval (CI): 78.5%-100%). The negative percent agreement was 92.6% (95% CI: 76.6%-97.9%). RNA-seq identified pathogens not on the differential diagnosis for 9.7% (4/41) of the samples. Two pathogens solely identified with RNA-seq were confirmed with orthogonal testing.ConclusionsRNA-seq can accurately identify common and rare pathogens in aqueous and vitreous samples of patients with presumed ocular infections. Such an unbiased approach to testing has the potential to improve diagnostics although practical clinical utility warrants additional studies.

Pathogen cell-free DNA (pcfDNA) in blood and urine is an attractive biomarker; however, the impact of preanalytical factors is not well understood. Blood and urine samples from healthy donors spiked with cfDNA from Mycobacterium tuberculosis, Salmonella enterica, Aspergillus fumigatus, and Epstein-Barr virus (EBV) and samples from tuberculosis patients were used to evaluate the impact of blood collection tube, urine preservative, processing delay, processing method, freezing and thawing, and sample volume on pcfDNA. The PCR cycle threshold (CT ) was used to measure amplifiable cfDNA. In spiked samples, the median CT values for M. tuberculosis, S. enterica, and EBV cfDNA were significantly lower in blood collected in K2EDTA tubes than those in Streck and PAXgene blood collection tubes, and they were was significantly lower in urine preserved with EDTA (EDTA-urine) than in urine preserved with Streck reagent (Streck-urine). Blood and urine samples from TB patients preserved with K2EDTA and Tris-EDTA, respectively, showed significantly lower median M. tuberculosis CT values than with the Streck blood collection tube and Streck urine preservative. Processing delay increased the median pathogen CT values for Streck and PAXgene but not K2EDTA blood samples and for urine preserved with Streck reagent but not EDTA. Double-spin compared with single-spin plasma separation increased the median pathogen CT regardless of blood collection tube. No differences were observed between whole urine and supernatant and between fresh and thawed plasma and urine after 24 weeks at -80°C. Larger plasma and urine volumes in contrived and patient samples showed a significantly lower median M. tuberculosis CT These findings suggest that large-volume single-spin K2EDTA-plasma and EDTA-whole urine with up to a 24-h processing delay may optimize pcfDNA detection.

Monkeypox virus (MPXV) is an enveloped, double-stranded DNA virus in the family Poxvirus, genus Orthopoxvirus, and is related to variola, the causative agent of smallpox. In 2022, MPXV transmission caused [...]

PurposeThe etiology of conjunctivitis is often misdiagnosed. An ideal diagnostic test would identify all possible infectious causes. In this study, we apply unbiased metagenomic RNA deep sequencing (MDS) to identify pathogens causing conjunctivitis.DesignMolecular study of prospectively collected conjunctival swabs from patients with presumed infectious conjunctivitis.ParticipantsPatients with presumed acute infectious conjunctivitis.MethodsConjunctival swabs were collected from patients presenting with acute conjunctivitis. Swabs were processed for MDS. Pathogens were identified using a rapid computational pipeline to analyze the nonhost sequences obtained from MDS. Differential gene expression analysis was performed to evaluate for host transcriptome signatures for infectious types. Clinical samples were deidentified, and laboratory personnel handling the samples and interpreting the data were masked.Main outcome measuresPathogens and differential transcripts identified by MDS.ResultsMetagenomic RNA deep sequencing detected pathogens in 86% (12/14) of the patients tested. Swabs from 10 of 14 patients were positive for human adenovirus (HAdV) while swabs from 2 of 14 patients were positive for Vittaforma corneae (a parasitic fungal species of the microsporidia group). Samples positive for HAdV by RNA-seq were independently verified in a CLIA-certified laboratory. Pathogen-directed polymerase chain reaction confirmed the presence of V. corneae genome in the samples positive by RNA-seq. Local host transcriptome analysis identified 12 differentially expressed genes that provided distinct expression signatures for patients infected with HAdV compared with V. corneae.ConclusionsMetagenomic RNA deep sequencing can reliably detect and quantify common and rare pathogens causing conjunctivitis, and identify strains. The unbiased nature of metagenomic RNA deep sequencing allowed an expanded scope of pathogen detection, including fungal species not commonly associated with acute conjunctivitis. In addition, the identification of infection type-specific local host transcriptome signatures may allow for pathogen detection even when the pathogen load is too low for direct identification.

ObjectivesHigh-risk human papilloma viruses (hrHPV) are the causative agents of cervical cancer, the leading cause of cancer deaths among Zimbabwean women. The objective of this study was to describe the hrHPV types found in Zimbabwe for consideration in cervical cancer screening and vaccination efforts.Design and methodsTo determine hrHPV prevalence and type distribution in Zimbabwe we implemented a community-based cross-sectional study of self-collected cervicovaginal samples with hrHPV screening using near-point-of-care Cepheid GeneXpert HPV.ResultsThe hrHPV prevalence was 17% (112/643); 33% (41/123) vs. 14% (71/520) among HIV-1-positive and -negative participants, respectively (p=2.3E-07). Typing via Xpert HPV showed very good overall agreement (77.2%, kappa=0.698) with the Seegene Anyplex II HPV HR Detection kit. The most common types were HPV16, HPV18, HPV35, HPV52, HPV58, HPV68, HPV18, and HPV51, each of which appeared in 14-20% of infections. 37% (28/76) of women with positive cytology results (ASCUS+) had a type not included in the basic vaccine and 25% (19/76) had a type not currently in the nine-valent vaccine.ConclusionshrHPV type distribution includes less common high-risk types in rural Zimbabwe. The distribution and carcinogenicity of hrHPV type distribution should be considered during screening assay design, program development, as well as vaccine distribution and design.

The 2022 multicountry monkeypox outbreak has been linked primarily to intimate contact among men who have sex with men (1,2). We describe a case of monkeypox in a traveler who [...]

In December 2020, a 61-year-old woman living with HIV/AIDS was tested for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection at a community testing center in California, USA; she produced [...]

Real-time reverse transcription PCR (rRT-PCR) is the standard diagnostic method for coronavirus disease 2019, but it cannot differentiate between actively replicating and inactive virus. Active replication is a critical factor [...]

Measles is a highly contagious, vaccine-preventable, systemic viral disease caused by measles virus (MV), an enveloped, single-stranded, negativesense RNA virus in the genus Morbillivirus, family Paramyxoviridae. MV may cause persistent [...]

The ability of clinical laboratories to meet the demand for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) testing is critical for reducing coronavirus disease (COVID-19)-related illness, death, and economic impact. [...]

Dengue virus (DENV) is a reemerging arbovirus with an expansive worldwide range (1). Recent modeling studies suggest wider dengue circulation in Africa than previously recognized (2). In addition, both major [...]

Detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) typically relies on molecular testing of respiratory tract specimens, although viral RNA can be detected in other specimens (1). Real-time reverse [...]