Charles Chiu

Charles Chiu
University of California, San Francisco | UCSF · Department of Laboratory Medicine

MD, PhD

About

443
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Publications

Publications (443)
Article
Conflicts: M.D.T., P.B., N.B., V.S., M.O., J.S., M.H., D.I., M.W. declare no conflict of interests. A.P.W., B.O., T.B., B.M. and S.M. are employed by and own equity in Delve Bio. C.Y.C. is a founder of Delve Bio and on the scientific advisory board for Delve Bio, Flightpath Biosciences, Biomeme, Mammoth Biosciences, BiomeSense and Poppy Health. He...
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Background. Lymphocytic choriomeningitis virus (LCMV) infection in immunocompromised hosts can result in disseminated disease, meningoencephalitis, and death. Published cases in transplant recipients have been traced to transmission from infected donors. We report 2 cases of serious, non–donor-derived LCMV infection in solid organ transplant recipi...
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Background/aim: Plasma Epstein-Barr virus (EBV) viral load measurement is prognostic in nasopharyngeal carcinoma (NPC) disease monitoring; however, a consensus measurement approach does not exist. This study characterized the clinical performance of metagenomic next-generation sequencing (mNGS), an unbiased sequencing-based assay distinct from pol...
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Metagenomic next-generation sequencing (mNGS) of cerebrospinal fluid (CSF) is an agnostic method for broad-based diagnosis of central nervous system (CNS) infections. Here we analyzed the 7-year performance of clinical CSF mNGS testing of 4,828 samples from June 2016 to April 2023 performed by the University of California, San Francisco (UCSF) clin...
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Tools for rapid identification of novel and/or emerging viruses are urgently needed for clinical diagnosis of unexplained infections and pandemic preparedness. Here we developed and clinically validated a largely automated metagenomic next-generation sequencing (mNGS) assay for agnostic detection of respiratory viral pathogens from upper respirator...
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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...
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Inflammatory syndromes, including those caused by infection, are a major cause of hospital admissions among children and are often misdiagnosed because of a lack of advanced molecular diagnostic tools. In this study, we explored the utility of circulating cell-free RNA (cfRNA) in plasma as an analyte for the differential diagnosis and characterizat...
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Background COVID-19 continues to cause hospitalizations and severe disease in children and adults. Methods This study compared the risk factors, symptoms, and outcomes of children and adults hospitalized for COVID-19 from March 2020 to May 2023 across age strata at five US sites participating in the PreVAIL consortium. Eligible patients had an upp...
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Background Five organs (heart, right lung, liver, right, and left kidneys) from a deceased patient were transplanted into five recipients in four US states; the deceased patient was identified as part of a healthcare‐associated fungal meningitis outbreak among patients who underwent epidural anesthesia in Matamoros, Mexico. Methods After transplan...
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Central nervous system (CNS) infections carry a substantial burden of morbidity and mortality worldwide, and accurate and timely diagnosis is required to optimize management. Metagenomic next-generation sequencing (mNGS) has proven to be a valuable tool in detecting pathogens in patients with suspected CNS infection. By sequencing microbial nucleic...
Preprint
Full-text available
Tools for rapid identification of novel and/or emerging viruses are urgently needed for clinical diagnosis of unexplained infections and pandemic preparedness. Here we developed and clinically validated a largely automated metagenomic next-generation sequencing (mNGS) assay for agnostic detection of respiratory viral pathogens from upper respirator...
Preprint
Full-text available
Tools for rapid identification of novel and/or emerging viruses are urgently needed for clinical diagnosis of unexplained infections and pandemic preparedness. Here we developed and clinically validated a largely automated metagenomic next-generation sequencing (mNGS) assay for agnostic detection of respiratory viral pathogens from nasopharyngeal s...
Preprint
Full-text available
Studies have shown that metagenomic next-generation sequencing (mNGS) testing of cerebrospinal fluid (CSF) in central nervous system (CNS) infections can improve diagnostic yields and provide actionable information. We analyzed the results of all CSF mNGS tests (n=4,828) performed at the University of California, San Francisco (UCSF) clinical micro...
Preprint
Inflammatory syndromes, including those caused by infection, are a major cause of hospital admissions among children and are often misdiagnosed because of a lack of advanced molecular diagnostic tools. In this study, we explored the utility of circulating cell-free RNA (cfRNA) in plasma as an analyte for the differential diagnosis and characterizat...
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Full-text available
The emergence of SARS-CoV-2 recombinants is of particular concern as they can result in a sudden increase in immune evasion due to antigenic shift. Recent recombinants XBB and XBB.1.5 have higher transmissibility than previous recombinants such as “Deltacron.” We hypothesized that immunity to a SARS-CoV-2 recombinant depends on prior exposure to it...
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Introduction The SARS-CoV-2 pandemic represented a formidable scientific and technological challenge to public health due to its rapid spread and evolution. To meet these challenges and to characterize the virus over time, the State of California established the California SARS-CoV-2 Whole Genome Sequencing (WGS) Initiative, or “California COVIDNet...
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Background: In 2021, four patients who had received solid organ transplants in the USA developed encephalitis beginning 2-6 weeks after transplantation from a common organ donor. We describe an investigation into the cause of encephalitis in these patients. Methods: From Nov 7, 2021, to Feb 24, 2022, we conducted a public health investigation in...
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Viral load quantitation is useful in clinical point-of-care settings to assess the status of patients with infectious disease, track response to treatment, and estimate infectiousness. However, existing methods for quantitating viral loads are complex and difficult to integrate into these settings. Here, we describe a simple, instrument-free approa...
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Mutations in the complement factor I ( CFI ) gene have previously been identified as causes of recurrent CNS inflammation. We present a case of a 26-year-old man with 18 episodes of recurrent meningitis, who had a variant in CFI (c.859G>A,p.Gly287Arg) not previously associated with neurologic manifestations. He achieved remission with canakinumab,...
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Bacteriophages, viruses that infect bacteria, have great specificity for their bacterial hosts at the strain and species level. However, the relationship between the phageome and associated bacterial population dynamics is unclear. Here we generated a computational pipeline to identify sequences associated with bacteriophages and their bacterial ho...
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Metagenomic next-generation sequencing (mNGS) has enabled the high-throughput multiplexed identification of sequences from microbes of potential medical relevance. This approach has become indispensable for viral pathogen discovery and broad-based surveillance of emerging or re-emerging pathogens. From 2015 to 2019, plasma was collected from 9586 i...
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We describe a 4-year-old male patient in Ohio, USA, who had encephalitis caused by Powassan virus lineage 2. Virus was detected by using metagenomic next-generation sequencing and confirmed with IgM and plaque reduction neutralization assays. Clinicians should recognize changing epidemiology of tickborne viruses to enhance encephalitis diagnosis an...
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Differential host responses in coronavirus disease 2019 (COVID-19) and multisystem inflammatory syndrome in children (MIS-C) remain poorly characterized. Here, we use next-generation sequencing to longitudinally analyze blood samples from pediatric patients with COVID-19 or MIS-C across three hospitals. Profiling of plasma cell-free nucleic acids u...
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As of August 2022, clusters of acute severe hepatitis of unknown etiology in children have been reported from 35 countries, including the United States1,2. Previous studies have found human adenoviruses (HAdVs) in the blood from cases in Europe and the United States3-7, although it is unclear whether this virus is causative. Here we used PCR testin...
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Background Pathogens carried by insects, such as Bunyaviruses, are frequently transmitted into human populations and cause disease. Knowing which spillover events represent a public health threat remains a challenge. Metagenomic next-generation sequencing (mNGS) can support infectious disease diagnostics by enabling detection of any pathogen from c...
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The human gut virome and its early life development are poorly understood. Prior studies have captured single-point assessments with the evolution of the infant virome remaining largely unexplored. We performed viral metagenomic sequencing on stool samples collected longitudinally from a cohort of 53 infants from age 2 weeks to 3 years (80.7 billio...
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From two SARS-CoV-2 household transmission studies (enrolling April 2020 - January 2022) with rapid enrollment and specimen collection for 14 days, 61% (43/70) of primary cases had culturable-virus detected ≥6 days post-onset. Risk of secondary infection among household contacts tended to be greater when primary cases had culturable-virus detected...
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A patient in California, USA, with rare and usually fatal Balamuthia mandrillaris granulomatous amebic encephalitis survived after receiving treatment with a regimen that included the repurposed drug nitroxoline. Nitroxoline, which is a quinolone typically used to treat urinary tract infections, was identified in a screen for drugs with amebicidal...
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Severe COVID-19 is associated with epithelial and endothelial barrier dysfunction within the lung as well as in distal organs. While it is appreciated that an exaggerated inflammatory response is associated with barrier dysfunction, the triggers of vascular leak are unclear. Here, we report that cell-intrinsic interactions between the Spike (S) gly...
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Full-text available
Zika virus (ZIKV) is a mosquito-borne arbovirus that can cause severe congenital birth defects. The utmost goal of ZIKV vaccines is to prevent both maternal-fetal infection and congenital Zika syndrome. A Zika purified inactivated virus (ZPIV) was previously shown to be protective in non-pregnant mice and rhesus macaques. In this study, we further...
Preprint
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Withdrawal Statement The authors have withdrawn their manuscript owing to data from patients who had not been consented being inadvertently used in the preprint. This has been corrected in the version of the study published in Cell Reports Medicine. Therefore, the authors do not wish this work to be cited as reference for the project. If you have a...
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Background: As of early 2022, the Omicron variants are the predominant circulating lineages globally. Understanding neutralizing antibody responses against Omicron BA.1 and BA.2 following vaccine breakthrough infections will provide insights into BA.2 infectivity and susceptibility to subsequent re-infection. Methods: Live virus neutralization a...
Preprint
Full-text available
As of August 2022, cases of acute severe hepatitis of unknown etiology in children have been reported from 35 countries, including the United States. Here we used PCR testing, viral enrichment based sequencing, and agnostic metagenomic sequencing to analyze 27 samples, including nasopharyngeal swab, stool, plasma, and/or whole blood, from 16 such c...
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The impact of vaccination on SARS-CoV-2 infectiousness is not well understood. We compared longitudinal viral shedding dynamics in unvaccinated and fully vaccinated adults. SARS-CoV-2-infected adults were enrolled within 5 days of symptom onset and nasal specimens were self-collected daily for two weeks and intermittently for an additional two week...
Preprint
Full-text available
Bacteriophage, viruses that infect bacteria, are abundant in the human body but the relationship between the phageome and bacterial population dynamics is unclear. Because bacteriophage are often highly specific to bacterial host strains and species, we asked whether bacteriophage present in cell-free DNA (cfDNA) reflect bacterial infections in sep...
Preprint
Full-text available
Bacteriophage, viruses that infect bacteria, are abundant in the human body but the relationship between the phageome and bacterial population dynamics is unclear. Because bacteriophage are often highly specific to bacterial host strains and species, we asked whether bacteriophage present in cell-free DNA (cfDNA) reflect bacterial infections in sep...
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Full-text available
The COVID-19 pandemic is exacting an increasing toll worldwide, with new SARS-CoV-2 variants emerging that exhibit higher infectivity rates and that may partially evade vaccine and antibody immunity. Rapid deployment of non-invasive therapeutic avenues capable of preventing infection by all SARS-CoV-2 variants could complement current vaccination e...
Preprint
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This case report describes a survivor of Balamuthia mandrillaris granulomatous amoebic encephalitis (GAE) after treatment with the novel agent nitroxoline, a drug typically used to treat urinary tract infections. Nitroxoline was previously identified in a screen of US and European approved drugs for amoebicidal activity against this pathogen. We de...
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Background Cache Valley virus (CVV) is a mosquito-borne virus that is a rare cause of disease in humans. In the Fall of 2020, a patient developed encephalitis six weeks following kidney transplantation and receipt of multiple blood transfusions. Methods After ruling out more common etiologies, metagenomic next-generation sequencing (mNGS) of cereb...
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Full-text available
Background Lyme disease is a tick-borne illness that causes an estimated 476,000 infections annually in the United States. New diagnostic tests are urgently needed, as existing antibody-based assays lack sufficient sensitivity and specificity. Methods Here we perform transcriptome profiling by RNA sequencing (RNA-Seq), targeted RNA-Seq, and/or mac...
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SARS-CoV-2 Delta and Omicron are globally relevant variants of concern (VOCs). While individuals infected with Delta are at risk to develop severe lung disease, infection with Omicron often causes milder symptoms, especially in vaccinated individuals1,2. The question arises whether widespread Omicron infections could lead to future cross-variant pr...
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Background Antimicrobial resistance (AMR) is rising at an alarming rate and complicating the management of infectious diseases including lower respiratory tract infections (LRTI). Metagenomic next-generation sequencing (mNGS) is a recently established method for culture-independent LRTI diagnosis, but its utility for predicting AMR has remained unc...
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Background Households have emerged as important venues for SARS-CoV-2 transmission. Little is known, however, regarding the magnitude and determinants of household transmission in increasingly vaccinated populations. Methods From September 2020 to January 2022, symptomatic non-hospitalized individuals with SARS-CoV-2 infection by RNA detection wer...
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Full-text available
Laboratory tests for the accurate and rapid identification of SARS-CoV-2 variants can potentially guide the treatment of COVID-19 patients and inform infection control and public health surveillance efforts. Here, we present the development and validation of a rapid COVID-19 variant DETECTR assay incorporating loop-mediated isothermal amplification...
Preprint
Withdrawal Statement The authors have withdrawn their manuscript owing to data from patients who had not been consented being inadvertently used in the preprint. This has been corrected in the version of the study published in Cell Reports Medicine. Therefore, the authors do not wish this work to be cited as reference for the project. If you have a...
Preprint
Full-text available
The impact of vaccination on SARS-CoV-2 infectiousness is not well understood. We compared longitudinal viral shedding dynamics in unvaccinated and fully vaccinated adults. SARS-CoV-2-infected adults were enrolled within 5 days of symptom onset and nasal specimens were self-collected daily for two weeks and intermittently for an additional two week...
Preprint
Full-text available
The virome of the human gut and its development in early life are poorly understood. Here we performed viral metagenomic sequencing on stool samples from a multiethnic, socioeconomically diverse cohort of 53 infants collected longitudinally over their first 3 years of life and their mothers to investigate and compare their viromes. The asymptomatic...
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Full-text available
During the COVID-19 pandemic, genomics and bioinformatics have emerged as essential public health tools. The genomic data acquired using these methods have supported the global health response, facilitated the development of testing methods and allowed the timely tracking of novel SARS-CoV-2 variants. Yet the virtually unlimited potential for rapid...
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The effect of vaccination on severity of subsequent COVID‐19 in patients with hematologic malignancies (HM) is unknown. In this single‐center retrospective cohort study, we found no difference in severity of COVID‐19 disease in vaccinated (n = 16) versus unvaccinated (n = 54) HM patients using an adjusted multiple logistic regression model. Recent...
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Virus-like particle (VLP) and live virus assays were used to investigate neutralizing immunity against Delta and Omicron SARS-CoV-2 variants in 259 samples from 128 vaccinated individuals. Following Delta breakthrough infection, titers against WT rose 57-fold and 3.1-fold compared to uninfected boosted and unboosted individuals, respectively, versu...
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Background: The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) infection causes coronavirus disease-2019 (COVID-19) in some individuals, while the majority remain asymptomatic. Natural killer (NK) cells play an essential role in antiviral defense. NK cell maturation and function are regulated mainly by highly polymorphic killer cell i...
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As novel SARS-CoV-2 variants continue to emerge, it is critical that their potential to cause severe disease and evade vaccine-induced immunity is rapidly assessed in humans and studied in animal models. In early January 2021, a novel SARS-CoV-2 variant designated B.1.429 comprising 2 lineages, B.1.427 and B.1.429, was originally detected in Califo...
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Full-text available
Associations between vaccine breakthrough cases and infection by different SARS coronavirus 2 (SARS-CoV-2) variants have remained largely unexplored. Here we analysed SARS-CoV-2 whole-genome sequences and viral loads from 1,373 persons with COVID-19 from the San Francisco Bay Area from 1 February to 30 June 2021, of which 125 (9.1%) were vaccine br...
Preprint
Full-text available
Virus-like particle (VLP) and live virus assays were used to investigate neutralizing immunity to Delta and Omicron SARS-CoV-2 variants in 239 samples from 125 fully vaccinated individuals. In uninfected, non-boosted individuals, VLP neutralization titers to Delta and Omicron were reduced 2.7-fold and 15.4-fold, respectively, compared to wild-type...
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Full-text available
Background : Viral diversity presents an ongoing challenge for diagnostic tests, which need to accurately detect all circulating variants. The Abbott Global Surveillance program monitors severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) variants and their impact on diagnostic test performance. Objectives : To evaluate the capacity of Ab...
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SARS-CoV-2 Delta and Omicron strains are the most globally relevant variants of concern (VOCs). While individuals infected with Delta are at risk to develop severe lung disease 1 , Omicron infection causes less severe disease, mostly upper respiratory symptoms 2,3 . The question arises whether rampant spread of Omicron could lead to mass immunizati...
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Background: Metagenomic next-generation sequencing (mNGS) for pathogen detection is becoming increasingly available as a method to identify pathogens in cases of suspected infection. mNGS analyzes the nucleic acid content of patient samples with high-throughput sequencing technologies to detect and characterize microorganism DNA and/or RNA. This u...
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Full-text available
Background The extent to which vaccinated persons diagnosed with COVID-19 can transmit to other vaccinated and unvaccinated persons is unclear. Methods Using data from the San Francisco Department of Public Health (SFDPH), this report describes outcomes of household contact tracing during January 29–July 2, 2021, where fully vaccinated COVID-19 pa...
Preprint
Full-text available
Severe COVID-19 is associated with epithelial and endothelial barrier dysfunction within the lung as well as in distal organs. While it is appreciated that an exaggerated inflammatory response is associated with barrier dysfunction, the triggers of this pathology are unclear. Here, we report that cell-intrinsic interactions between the Spike (S) gl...
Article
Full-text available
Psittacosis is a zoonotic infectious disease caused by the transmission of Chlamydia psittaci; it often presents as a pulmonary infection but rarely as disseminated disease. Because diagnoses of psittacosis are often underreported due to infrequent pathogen-specific testing, clinical metagenomic next-generation sequencing may be helpful to diagnose...
Preprint
Full-text available
Laboratory tests for the accurate and rapid identification of SARS-CoV-2 variants have the potential to guide the treatment of COVID-19 patients and inform infection control and public health surveillance efforts. Here we present the development and validation of a COVID-19 variant DETECTR assay incorporating loop-mediated isothermal amplification...
Article
Importance Cerebrospinal fluid (CSF) cytologic testing and flow cytometry are insensitive for diagnosing neoplasms of the central nervous system (CNS). Such clinical phenotypes can mimic infectious and autoimmune causes of meningoencephalitis. Objective To ascertain whether CSF metagenomic next-generation sequencing (mNGS) can identify aneuploidy,...
Preprint
Full-text available
Associations between vaccine breakthrough cases and infection by SARS coronavirus 2 (SARS-CoV-2) variants have remained largely unexplored. Here we analyzed SARS-CoV-2 whole-genome sequences and viral loads from 1,373 persons with COVID-19 from the San Francisco Bay Area from February 1 to June 30, 2021, of which 125 (9.1%) were vaccine breakthroug...
Preprint
Full-text available
As novel SARS-CoV-2 variants continue to emerge, it is critical that their potential to cause severe disease and evade vaccine-induced immunity is rapidly assessed in humans and studied in animal models. In early January 2021, a novel variant of concern (VOC) designated B.1.429 comprising 2 lineages, B.1.427 and B.1.429, was originally detected in...
Article
Full-text available
Rapidly-emerging variants jeopardize antibody-based countermeasures against SARS-CoV-2. While cell culture experiments have demonstrated loss of potency of several anti-spike neutralizing antibodies against SARS-CoV-2 variant strains1–3, the in vivo significance of these results remains uncertain. Using a panel of monoclonal antibodies (mAbs) corre...