1
|
Yip SWY, Griffith JF, Tong CSL, Cheung KK, Tsoi C, Hung EHY. Ultrasound accuracy for brachial plexus pathology. Clin Radiol 2024; 79:e916-e923. [PMID: 38644074 DOI: 10.1016/j.crad.2024.03.010] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 03/13/2024] [Accepted: 03/16/2024] [Indexed: 04/23/2024]
Abstract
AIM To determine (a) the accuracy of ultrasound in detecting brachial plexus pathology and (b) outline the advantages and limitations of ultrasound compared to MRI for imaging the brachial plexus. MATERIAL AND METHODS cases with clinically suspected brachial plexus pathology were evaluated first by ultrasound, followed by MRI. Patients with prior brachial plexus imaging were excluded. The final diagnosis was based on a combination of ultrasound, MRI, clinical follow-up, and surgical findings. The accuracy of the ultrasound was assessed by comparing the ultrasound and the final diagnoses. The mean clinical follow-up time following ultrasound was 1.8 ± 1.4 years. RESULTS Ninety-two (64%) of the 143 cases had normal brachial plexus ultrasound and MRI examinations. Fifty-one (36%) of 143 cases had brachial plexus pathology on MRI, comprising post-radiation fibrosis (n=25, 49%), nerve sheath tumor (n=11, 21%), traumatic injury (n=7, 14%), inflammatory polyneuropathy (n=4, 8%), malignant infiltration (n=2, 4%), desmoid fibromatosis (n=1,2%), and neuralgic amyotrophy (n=1, 2%). Overall diagnostic accuracy of ultrasound for brachial plexus pathology was 98% (140/143), with three discordant cases (neuralgic amyotrophy n=1, inflammatory neuropathy n=1, postradiation fibrosis n=1) regarded as normal on ultrasound assessment. Sensitivity, specificity, and positive and negative predictive value of ultrasound for identifying brachial plexus pathology were 94%, 100%, 100%, and 97%, respectively. CONCLUSION Ultrasound identifies brachial plexus pathology with high accuracy and specificity, showing comparable diagnostic efficacy to MRI. Ultrasound can serve as an effective first-line imaging investigation for suspected brachial plexus pathology.
Collapse
|
2
|
Zimmer-Faust AG, Griffith JF, Steele JA, Santos B, Cao Y, Asato L, Chiem T, Choi S, Diaz A, Guzman J, Laak D, Padilla M, Quach-Cu J, Ruiz V, Woo M, Weisberg SB. Relationship between coliphage and Enterococcus at southern California beaches and implications for beach water quality management. WATER RESEARCH 2023; 230:119383. [PMID: 36630853 DOI: 10.1016/j.watres.2022.119383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Revised: 11/08/2022] [Accepted: 11/17/2022] [Indexed: 06/17/2023]
Abstract
Coliphage have been suggested as an alternative to fecal indicator bacteria for assessing recreational beach water quality, but it is unclear how frequently and at what types of beaches coliphage produces a different management outcome. Here we conducted side-by-side sampling of male-specific and somatic coliphage by the new EPA dead-end hollow fiber ultrafiltration (D-HFUF-SAL) method and Enterococcus at southern California beaches over two years. When samples were combined for all beach sites, somatic and male-specific coliphage both correlated with Enterococcus. When examined categorically, Enterococcus would have resulted in approximately two times the number of health advisories as somatic coliphage and four times that of male-specific coliphage,using recently proposed thresholds of 60 PFU/100 mL for somatic and 30 PFU/100 mL for male-specific coliphage. Overall, only 12% of total exceedances would have been for coliphage alone. Somatic coliphage exceedances that occurred in the absence of an Enterococcus exceedance were limited to a single site during south swell events, when this beach is known to be affected by nearby minimally treated sewage. Thus, somatic coliphage provided additional valuable health protection information, but may be more appropriate as a supplement to FIB measurements rather than as replacement because: (a) EPA-approved PCR methods for Enterococcus allow a more rapid response, (b) coliphage is more challenging owing to its greater sampling volume and laboratory time requirements, and (c) Enterococcus' long data history has yielded predictive management models that would need to be recreated for coliphage.
Collapse
|
3
|
Rothman JA, Saghir A, Chung SA, Boyajian N, Dinh T, Kim J, Oval J, Sharavanan V, York C, Zimmer-Faust AG, Langlois K, Steele JA, Griffith JF, Whiteson KL. Longitudinal metatranscriptomic sequencing of Southern California wastewater representing 16 million people from August 2020-21 reveals widespread transcription of antibiotic resistance genes. WATER RESEARCH 2023; 229:119421. [PMID: 36455460 DOI: 10.1016/j.watres.2022.119421] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 11/22/2022] [Accepted: 11/23/2022] [Indexed: 06/17/2023]
Abstract
Municipal wastewater provides a representative sample of human fecal waste across a catchment area and contains a wide diversity of microbes. Sequencing wastewater samples provides information about human-associated and medically important microbial populations, and may be useful to assay disease prevalence and antimicrobial resistance (AMR). Here, we present a study in which we used untargeted metatranscriptomic sequencing on RNA extracted from 275 sewage influent samples obtained from eight wastewater treatment plants (WTPs) representing approximately 16 million people in Southern California between August 2020 - August 2021. We characterized bacterial and viral transcripts, assessed metabolic pathway activity, and identified over 2,000 AMR genes/variants across all samples. Because we did not deplete ribosomal RNA, we have a unique window into AMR carried as ribosomal mutants. We show that AMR diversity varied between WTPs (as measured through PERMANOVA, P < 0.001) and that the relative abundance of many individual AMR genes/variants increased over time (as measured with MaAsLin2, Padj < 0.05). Similarly, we detected transcripts mapping to human pathogenic bacteria and viruses suggesting RNA sequencing is a powerful tool for wastewater-based epidemiology and that there are geographical signatures to microbial transcription. We captured the transcription of gene pathways common to bacterial cell processes, including central carbon metabolism, nucleotide synthesis/salvage, and amino acid biosynthesis. We also posit that due to the ubiquity of many viruses and bacteria in wastewater, new biological targets for microbial water quality assessment can be developed. To the best of our knowledge, our study provides the most complete longitudinal metatranscriptomic analysis of a large population's wastewater to date and demonstrates our ability to monitor the presence and activity of microbes in complex samples. By sequencing RNA, we can track the relative abundance of expressed AMR genes/variants and metabolic pathways, increasing our understanding of AMR activity across large human populations and sewer sheds.
Collapse
|
4
|
Rothman JA, Saghir A, Chung SA, Boyajian N, Dinh T, Kim J, Oval J, Sharavanan V, York C, Zimmer-Faust AG, Langlois K, Steele JA, Griffith JF, Whiteson KL. Longitudinal metatranscriptomic sequencing of Southern California wastewater representing 16 million people from August 2020-21 reveals widespread transcription of antibiotic resistance genes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2022:2022.08.02.502560. [PMID: 35982656 PMCID: PMC9387120 DOI: 10.1101/2022.08.02.502560] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Municipal wastewater provides a representative sample of human fecal waste across a catchment area and contains a wide diversity of microbes. Sequencing wastewater samples provides information about human-associated and medically-important microbial populations, and may be useful to assay disease prevalence and antimicrobial resistance (AMR). Here, we present a study in which we used untargeted metatranscriptomic sequencing on RNA extracted from 275 sewage influent samples obtained from eight wastewater treatment plants (WTPs) representing approximately 16 million people in Southern California between August 2020 - August 2021. We characterized bacterial and viral transcripts, assessed metabolic pathway activity, and identified over 2,000 AMR genes/variants across all samples. Because we did not deplete ribosomal RNA, we have a unique window into AMR carried as ribosomal mutants. We show that AMR diversity varied between WTPs and that the relative abundance of many individual AMR genes/variants increased over time and may be connected to antibiotic use during the COVID-19 pandemic. Similarly, we detected transcripts mapping to human pathogenic bacteria and viruses suggesting RNA sequencing is a powerful tool for wastewater-based epidemiology and that there are geographical signatures to microbial transcription. We captured the transcription of gene pathways common to bacterial cell processes, including central carbon metabolism, nucleotide synthesis/salvage, and amino acid biosynthesis. We also posit that due to the ubiquity of many viruses and bacteria in wastewater, new biological targets for microbial water quality assessment can be developed. To the best of our knowledge, our study provides the most complete longitudinal metatranscriptomic analysis of a large population's wastewater to date and demonstrates our ability to monitor the presence and activity of microbes in complex samples. By sequencing RNA, we can track the relative abundance of expressed AMR genes/variants and metabolic pathways, increasing our understanding of AMR activity across large human populations and sewer sheds.
Collapse
|
5
|
Tsai CSC, Lee RKL, Tam KKW, Yung PSH, Griffith JF. Focal Bone Lesions Following Ultrasound Diathermy: Case Series. HONG KONG JOURNAL OF RADIOLOGY 2022. [DOI: 10.12809/hkjr2217230] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
|
6
|
Kim S, Kennedy LC, Wolfe MK, Criddle CS, Duong DH, Topol A, White BJ, Kantor RS, Nelson KL, Steele JA, Langlois K, Griffith JF, Zimmer-Faust AG, McLellan SL, Schussman MK, Ammerman M, Wigginton KR, Bakker KM, Boehm AB. SARS-CoV-2 RNA is enriched by orders of magnitude in primary settled solids relative to liquid wastewater at publicly owned treatment works. ENVIRONMENTAL SCIENCE : WATER RESEARCH & TECHNOLOGY 2022. [PMID: 35433013 DOI: 10.1101/2021.11.10.21266138] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Wastewater-based epidemiology has gained attention throughout the world for detection of SARS-CoV-2 RNA in wastewater to supplement clinical testing. Raw wastewater consists of small particles, or solids, suspended in liquid. Methods have been developed to measure SARS-CoV-2 RNA in the liquid and the solid fraction of wastewater, with some studies reporting higher concentrations in the solid fraction. To investigate this relationship further, six laboratories collaborated to conduct a study across five publicly owned treatment works (POTWs) where both primary settled solids obtained from primary clarifiers and raw wastewater influent samples were collected and quantified for SARS-CoV-2 RNA. Settled solids and influent samples were processed by participating laboratories using their respective methods and retrospectively paired based on date of collection. SARS-CoV-2 RNA concentrations, on a mass equivalent basis, were higher in settled solids than in influent by approximately three orders of magnitude. Concentrations in matched settled solids and influent were positively and significantly correlated at all five POTWs. RNA concentrations in both settled solids and influent were correlated to COVID-19 incidence rates in the sewersheds and thus representative of disease occurrence; the settled solids methods appeared to produce a comparable relationship between SARS-CoV-2 RNA concentration measurements and incidence rates across all POTWs. Settled solids and influent methods showed comparable sensitivity, N gene detection frequency, and calculated empirical incidence rate lower limits. Analysis of settled solids for SARS-CoV-2 RNA has the advantage of using less sample volume to achieve similar sensitivity to influent methods.
Collapse
|
7
|
Kim S, Kennedy LC, Wolfe MK, Criddle CS, Duong DH, Topol A, White BJ, Kantor RS, Nelson KL, Steele JA, Langlois K, Griffith JF, Zimmer-Faust AG, McLellan SL, Schussman MK, Ammerman M, Wigginton KR, Bakker KM, Boehm AB. SARS-CoV-2 RNA is enriched by orders of magnitude in primary settled solids relative to liquid wastewater at publicly owned treatment works. ENVIRONMENTAL SCIENCE : WATER RESEARCH & TECHNOLOGY 2022; 8:757-770. [PMID: 35433013 PMCID: PMC8969789 DOI: 10.1039/d1ew00826a] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 02/04/2022] [Indexed: 05/21/2023]
Abstract
Wastewater-based epidemiology has gained attention throughout the world for detection of SARS-CoV-2 RNA in wastewater to supplement clinical testing. Raw wastewater consists of small particles, or solids, suspended in liquid. Methods have been developed to measure SARS-CoV-2 RNA in the liquid and the solid fraction of wastewater, with some studies reporting higher concentrations in the solid fraction. To investigate this relationship further, six laboratories collaborated to conduct a study across five publicly owned treatment works (POTWs) where both primary settled solids obtained from primary clarifiers and raw wastewater influent samples were collected and quantified for SARS-CoV-2 RNA. Settled solids and influent samples were processed by participating laboratories using their respective methods and retrospectively paired based on date of collection. SARS-CoV-2 RNA concentrations, on a mass equivalent basis, were higher in settled solids than in influent by approximately three orders of magnitude. Concentrations in matched settled solids and influent were positively and significantly correlated at all five POTWs. RNA concentrations in both settled solids and influent were correlated to COVID-19 incidence rates in the sewersheds and thus representative of disease occurrence; the settled solids methods appeared to produce a comparable relationship between SARS-CoV-2 RNA concentration measurements and incidence rates across all POTWs. Settled solids and influent methods showed comparable sensitivity, N gene detection frequency, and calculated empirical incidence rate lower limits. Analysis of settled solids for SARS-CoV-2 RNA has the advantage of using less sample volume to achieve similar sensitivity to influent methods.
Collapse
|
8
|
Ahmed W, Simpson SL, Bertsch PM, Bibby K, Bivins A, Blackall LL, Bofill-Mas S, Bosch A, Brandão J, Choi PM, Ciesielski M, Donner E, D'Souza N, Farnleitner AH, Gerrity D, Gonzalez R, Griffith JF, Gyawali P, Haas CN, Hamilton KA, Hapuarachchi HC, Harwood VJ, Haque R, Jackson G, Khan SJ, Khan W, Kitajima M, Korajkic A, La Rosa G, Layton BA, Lipp E, McLellan SL, McMinn B, Medema G, Metcalfe S, Meijer WG, Mueller JF, Murphy H, Naughton CC, Noble RT, Payyappat S, Petterson S, Pitkänen T, Rajal VB, Reyneke B, Roman FA, Rose JB, Rusiñol M, Sadowsky MJ, Sala-Comorera L, Setoh YX, Sherchan SP, Sirikanchana K, Smith W, Steele JA, Sabburg R, Symonds EM, Thai P, Thomas KV, Tynan J, Toze S, Thompson J, Whiteley AS, Wong JCC, Sano D, Wuertz S, Xagoraraki I, Zhang Q, Zimmer-Faust AG, Shanks OC. Minimizing errors in RT-PCR detection and quantification of SARS-CoV-2 RNA for wastewater surveillance. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022. [PMID: 34818780 DOI: 10.20944/preprints202104.0481.v1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Wastewater surveillance for pathogens using reverse transcription-polymerase chain reaction (RT-PCR) is an effective and resource-efficient tool for gathering community-level public health information, including the incidence of coronavirus disease-19 (COVID-19). Surveillance of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) in wastewater can potentially provide an early warning signal of COVID-19 infections in a community. The capacity of the world's environmental microbiology and virology laboratories for SARS-CoV-2 RNA characterization in wastewater is increasing rapidly. However, there are no standardized protocols or harmonized quality assurance and quality control (QA/QC) procedures for SARS-CoV-2 wastewater surveillance. This paper is a technical review of factors that can cause false-positive and false-negative errors in the surveillance of SARS-CoV-2 RNA in wastewater, culminating in recommended strategies that can be implemented to identify and mitigate some of these errors. Recommendations include stringent QA/QC measures, representative sampling approaches, effective virus concentration and efficient RNA extraction, PCR inhibition assessment, inclusion of sample processing controls, and considerations for RT-PCR assay selection and data interpretation. Clear data interpretation guidelines (e.g., determination of positive and negative samples) are critical, particularly when the incidence of SARS-CoV-2 in wastewater is low. Corrective and confirmatory actions must be in place for inconclusive results or results diverging from current trends (e.g., initial onset or reemergence of COVID-19 in a community). It is also prudent to perform interlaboratory comparisons to ensure results' reliability and interpretability for prospective and retrospective analyses. The strategies that are recommended in this review aim to improve SARS-CoV-2 characterization and detection for wastewater surveillance applications. A silver lining of the COVID-19 pandemic is that the efficacy of wastewater surveillance continues to be demonstrated during this global crisis. In the future, wastewater should also play an important role in the surveillance of a range of other communicable diseases.
Collapse
|
9
|
Ahmed W, Simpson SL, Bertsch PM, Bibby K, Bivins A, Blackall LL, Bofill-Mas S, Bosch A, Brandão J, Choi PM, Ciesielski M, Donner E, D'Souza N, Farnleitner AH, Gerrity D, Gonzalez R, Griffith JF, Gyawali P, Haas CN, Hamilton KA, Hapuarachchi HC, Harwood VJ, Haque R, Jackson G, Khan SJ, Khan W, Kitajima M, Korajkic A, La Rosa G, Layton BA, Lipp E, McLellan SL, McMinn B, Medema G, Metcalfe S, Meijer WG, Mueller JF, Murphy H, Naughton CC, Noble RT, Payyappat S, Petterson S, Pitkänen T, Rajal VB, Reyneke B, Roman FA, Rose JB, Rusiñol M, Sadowsky MJ, Sala-Comorera L, Setoh YX, Sherchan SP, Sirikanchana K, Smith W, Steele JA, Sabburg R, Symonds EM, Thai P, Thomas KV, Tynan J, Toze S, Thompson J, Whiteley AS, Wong JCC, Sano D, Wuertz S, Xagoraraki I, Zhang Q, Zimmer-Faust AG, Shanks OC. Minimizing errors in RT-PCR detection and quantification of SARS-CoV-2 RNA for wastewater surveillance. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 805:149877. [PMID: 34818780 PMCID: PMC8386095 DOI: 10.1016/j.scitotenv.2021.149877] [Citation(s) in RCA: 123] [Impact Index Per Article: 61.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Revised: 08/20/2021] [Accepted: 08/20/2021] [Indexed: 05/18/2023]
Abstract
Wastewater surveillance for pathogens using reverse transcription-polymerase chain reaction (RT-PCR) is an effective and resource-efficient tool for gathering community-level public health information, including the incidence of coronavirus disease-19 (COVID-19). Surveillance of Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) in wastewater can potentially provide an early warning signal of COVID-19 infections in a community. The capacity of the world's environmental microbiology and virology laboratories for SARS-CoV-2 RNA characterization in wastewater is increasing rapidly. However, there are no standardized protocols or harmonized quality assurance and quality control (QA/QC) procedures for SARS-CoV-2 wastewater surveillance. This paper is a technical review of factors that can cause false-positive and false-negative errors in the surveillance of SARS-CoV-2 RNA in wastewater, culminating in recommended strategies that can be implemented to identify and mitigate some of these errors. Recommendations include stringent QA/QC measures, representative sampling approaches, effective virus concentration and efficient RNA extraction, PCR inhibition assessment, inclusion of sample processing controls, and considerations for RT-PCR assay selection and data interpretation. Clear data interpretation guidelines (e.g., determination of positive and negative samples) are critical, particularly when the incidence of SARS-CoV-2 in wastewater is low. Corrective and confirmatory actions must be in place for inconclusive results or results diverging from current trends (e.g., initial onset or reemergence of COVID-19 in a community). It is also prudent to perform interlaboratory comparisons to ensure results' reliability and interpretability for prospective and retrospective analyses. The strategies that are recommended in this review aim to improve SARS-CoV-2 characterization and detection for wastewater surveillance applications. A silver lining of the COVID-19 pandemic is that the efficacy of wastewater surveillance continues to be demonstrated during this global crisis. In the future, wastewater should also play an important role in the surveillance of a range of other communicable diseases.
Collapse
|
10
|
Rothman JA, Loveless TB, Kapcia J, Adams ED, Steele JA, Zimmer-Faust AG, Langlois K, Wanless D, Griffith M, Mao L, Chokry J, Griffith JF, Whiteson KL. RNA Viromics of Southern California Wastewater and Detection of SARS-CoV-2 Single-Nucleotide Variants. Appl Environ Microbiol 2021; 87:e0144821. [PMID: 34550753 PMCID: PMC8579973 DOI: 10.1128/aem.01448-21] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Accepted: 09/14/2021] [Indexed: 11/20/2022] Open
Abstract
Municipal wastewater provides an integrated sample of a diversity of human-associated microbes across a sewershed, including viruses. Wastewater-based epidemiology (WBE) is a promising strategy to detect pathogens and may serve as an early warning system for disease outbreaks. Notably, WBE has garnered substantial interest during the coronavirus disease 2019 (COVID-19) pandemic to track disease burden through analyses of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA. Throughout the COVID-19 outbreak, tracking SARS-CoV-2 in wastewater has been an important tool for understanding the spread of the virus. Unlike traditional sequencing of SARS-CoV-2 isolated from clinical samples, which adds testing burden to the health care system, in this study, metatranscriptomics was used to sequence virus directly from wastewater. Here, we present a study in which we explored RNA viral diversity through sequencing 94 wastewater influent samples across seven wastewater treatment plants (WTPs), collected from August 2020 to January 2021, representing approximately 16 million people in Southern California. Enriched viral libraries identified a wide diversity of RNA viruses that differed between WTPs and over time, with detected viruses including coronaviruses, influenza A, and noroviruses. Furthermore, single-nucleotide variants (SNVs) of SARS-CoV-2 were identified in wastewater, and we measured proportions of overall virus and SNVs across several months. We detected several SNVs that are markers for clinically important SARS-CoV-2 variants along with SNVs of unknown function, prevalence, or epidemiological consequence. Our study shows the potential of WBE to detect viruses in wastewater and to track the diversity and spread of viral variants in urban and suburban locations, which may aid public health efforts to monitor disease outbreaks. IMPORTANCE Wastewater-based epidemiology (WBE) can detect pathogens across sewersheds, which represents the collective waste of human populations. As there is a wide diversity of RNA viruses in wastewater, monitoring the presence of these viruses is useful for public health, industry, and ecological studies. Specific to public health, WBE has proven valuable during the coronavirus disease 2019 (COVID-19) pandemic to track the spread of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) without adding burden to health care systems. In this study, we used metatranscriptomics and reverse transcription-droplet digital PCR (RT-ddPCR) to assay RNA viruses across Southern California wastewater from August 2020 to January 2021, representing approximately 16 million people from Los Angeles, Orange, and San Diego counties. We found that SARS-CoV-2 quantification in wastewater correlates well with county-wide COVID-19 case data, and that we can detect SARS-CoV-2 single-nucleotide variants through sequencing. Likewise, wastewater treatment plants (WTPs) harbored different viromes, and we detected other human pathogens, such as noroviruses and adenoviruses, furthering our understanding of wastewater viral ecology.
Collapse
|
11
|
Ng AWH, Griffith JF, Ng ISH. MRI of carpal tunnel syndrome: before and after carpal tunnel release. Clin Radiol 2021; 76:940.e29-940.e35. [PMID: 34474748 DOI: 10.1016/j.crad.2021.07.015] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2021] [Accepted: 07/26/2021] [Indexed: 10/20/2022]
Abstract
Carpal tunnel syndrome (CTS) is the most common peripheral nerve entrapment syndrome. Magnetic resonance imaging (MRI) is increasingly used to diagnose CTS, exclude secondary causes of CTS, and investigate patients with persistent symptoms after carpal tunnel release. Median nerve compression may also be either subclinical in the early stages or present with atypical symptoms. Radiologists are therefore not infrequently the first to alert clinicians as to the possibly of subclinical or atypical CTS. This review shows the normal and abnormal appearances of the carpal tunnel before and after CTR.
Collapse
|
12
|
McClary-Gutierrez JS, Mattioli MC, Marcenac P, Silverman AI, Boehm AB, Bibby K, Balliet M, de Los Reyes FL, Gerrity D, Griffith JF, Holden PA, Katehis D, Kester G, LaCross N, Lipp EK, Meiman J, Noble RT, Brossard D, McLellan SL. SARS-CoV-2 Wastewater Surveillance for Public Health Action. Emerg Infect Dis 2021. [PMID: 34424162 DOI: 10.20944/preprints202104.0167.v1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/04/2023] Open
Abstract
Wastewater surveillance for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has garnered extensive public attention during the coronavirus disease pandemic as a proposed complement to existing disease surveillance systems. Over the past year, methods for detection and quantification of SARS-CoV-2 viral RNA in untreated sewage have advanced, and concentrations in wastewater have been shown to correlate with trends in reported cases. Despite the promise of wastewater surveillance, for these measurements to translate into useful public health tools, bridging the communication and knowledge gaps between researchers and public health responders is needed. We describe the key uses, barriers, and applicability of SARS-CoV-2 wastewater surveillance for supporting public health decisions and actions, including establishing ethics consideration for monitoring. Although wastewater surveillance to assess community infections is not a new idea, the coronavirus disease pandemic might be the initiating event to make this emerging public health tool a sustainable nationwide surveillance system, provided that these barriers are addressed.
Collapse
|
13
|
McClary-Gutierrez JS, Mattioli MC, Marcenac P, Silverman AI, Boehm AB, Bibby K, Balliet M, de Los Reyes FL, Gerrity D, Griffith JF, Holden PA, Katehis D, Kester G, LaCross N, Lipp EK, Meiman J, Noble RT, Brossard D, McLellan SL. SARS-CoV-2 Wastewater Surveillance for Public Health Action. Emerg Infect Dis 2021; 27:1-8. [PMID: 34424162 PMCID: PMC8386792 DOI: 10.3201/eid2709.210753] [Citation(s) in RCA: 59] [Impact Index Per Article: 19.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Wastewater surveillance for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has garnered extensive public attention during the coronavirus disease pandemic as a proposed complement to existing disease surveillance systems. Over the past year, methods for detection and quantification of SARS-CoV-2 viral RNA in untreated sewage have advanced, and concentrations in wastewater have been shown to correlate with trends in reported cases. Despite the promise of wastewater surveillance, for these measurements to translate into useful public health tools, bridging the communication and knowledge gaps between researchers and public health responders is needed. We describe the key uses, barriers, and applicability of SARS-CoV-2 wastewater surveillance for supporting public health decisions and actions, including establishing ethics consideration for monitoring. Although wastewater surveillance to assess community infections is not a new idea, the coronavirus disease pandemic might be the initiating event to make this emerging public health tool a sustainable nationwide surveillance system, provided that these barriers are addressed.
Collapse
|
14
|
Zimmer-Faust AG, Steele JA, Xiong X, Staley C, Griffith M, Sadowsky MJ, Diaz M, Griffith JF. A Combined Digital PCR and Next Generation DNA-Sequencing Based Approach for Tracking Nearshore Pollutant Dynamics Along the Southwest United States/Mexico Border. Front Microbiol 2021; 12:674214. [PMID: 34421839 PMCID: PMC8377738 DOI: 10.3389/fmicb.2021.674214] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Accepted: 05/25/2021] [Indexed: 12/27/2022] Open
Abstract
Ocean currents, multiple fecal bacteria input sources, and jurisdictional boundaries can complicate pollution source tracking and associated mitigation and management efforts within the nearshore coastal environment. In this study, multiple microbial source tracking tools were employed to characterize the impact and reach of an ocean wastewater treatment facility discharge in Mexico northward along the coast and across the Southwest United States- Mexico Border. Water samples were evaluated for fecal indicator bacteria (FIB), Enterococcus by culture-based methods, and human-associated genetic marker (HF183) and Enterococcus by droplet digital polymerase chain reaction (ddPCR). In addition, 16S rRNA gene sequence analysis was performed and the SourceTracker algorithm was used to characterize the bacterial community of the wastewater treatment plume and its contribution to beach waters. Sampling dates were chosen based on ocean conditions associated with northern currents. Evidence of a gradient in human fecal pollution that extended north from the wastewater discharge across the United States/Mexico border from the point source was observed using human-associated genetic markers and microbial community analysis. The spatial extent of fecal contamination observed was largely dependent on swell and ocean conditions. These findings demonstrate the utility of a combination of molecular tools for understanding and tracking specific pollutant sources in dynamic coastal water environments.
Collapse
|
15
|
Zimmer-Faust AG, Steele JA, Griffith JF, Schiff K. The challenges of microbial source tracking at urban beaches for Quantitative Microbial Risk Assessment (QMRA). MARINE POLLUTION BULLETIN 2020; 160:111546. [PMID: 32898736 DOI: 10.1016/j.marpolbul.2020.111546] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 07/27/2020] [Accepted: 07/31/2020] [Indexed: 06/11/2023]
Abstract
Urban beaches are frequently impacted from multiple sources of fecal contamination. This along with high beach usage underscores the importance of appropriate management that protects swimmer health. The USEPA has enabled the use of QMRA as a tool for quantifying swimmer health risk and setting site-specific water quality objectives. This study illustrates the challenges associated with human and non-human source identification and how these challenges influence the decision of whether QMRA at typical urban beaches for water quality management is appropriate. In this study, a similar and correlated spatial relationship with elevated Enterococcus and avian-specific markers was observed, suggesting shorebirds as a primary source of FIB. However, human-associated markers were also detected frequently but at low concentrations. Ultimately, a QMRA was not conducted because pathogen loading from potential human sources could not be confidently quantified, having consequences for health risk in receiving waters where recreational contact occurs.
Collapse
|
16
|
Rothman JA, Loveless TB, Griffith ML, Steele JA, Griffith JF, Whiteson KL. Metagenomics of Wastewater Influent from Southern California Wastewater Treatment Facilities in the Era of COVID-19. Microbiol Resour Announc 2020; 9:e00907-20. [PMID: 33033132 PMCID: PMC7545286 DOI: 10.1128/mra.00907-20] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Accepted: 09/18/2020] [Indexed: 12/02/2022] Open
Abstract
Sequencing wastewater may be useful for detecting pathogens and assaying microbial water quality. We concentrated, extracted, and sequenced nucleic acids from 17 composite influent wastewater samples spanning seven southern California wastewater treatment facilities in May 2020. Bacteria were the most proportionally abundant taxonomic group present, followed by viruses and archaea.
Collapse
|
17
|
Wu D, Griffith JF, Lam SHM, Wong P, Yue J, Shi L, Li EK, Cheng IT, Li TK, Hung VW, Qin L, Tam LS. Comparison of bone structure and microstructure in the metacarpal heads between patients with psoriatic arthritis and healthy controls: an HR-pQCT study. Osteoporos Int 2020; 31:941-950. [PMID: 31938819 DOI: 10.1007/s00198-020-05298-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Accepted: 01/10/2020] [Indexed: 01/01/2023]
Abstract
UNLABELLED Human cadaveric study has indicated that the metacarpal head (MCH) is intracapsular in location. We hypothesized that exposure to the intra-articular inflammatory milieu in psoriatic arthritis (PsA) will lead to bone loss in the MCH. INTRODUCTION To compare the bone structure and microstructure in the MCH between patients with PsA and healthy controls by high-resolution peripheral quantitative CT (HR-pQCT), and to ascertain factors associated with bone loss in PsA patients. METHODS Sixty-two PsA patients without joint destruction and 62 age-, gender-, and body mass index-matched healthy subjects underwent HR-pQCT imaging of the second and third MCH (MCH 2&3). The number and volume of bone erosion and enthesiophytes, as well as volumetric bone mineral density (vBMD) and microstructure at the MCH 2&3, were recorded. Correlation analysis and multivariable linear regression models were used to determine the association of demographic and disease-specific variables with compromised bone structure and microstructure in PsA. RESULTS At the MCH 2&3, bone erosion (p = 0.003) and enthesiophyte (p = 0.000) volumes in PsA patients were significantly larger than healthy controls. In PsA patients, older age was associated with a larger erosion and enthesiophyte volume. Concerning the mean vBMD and microstructure at the MCH 2&3, PsA patients had significantly lower mean vBMD (average vBMD - 6.9%, trabecular vBMD - 8.8%, peri-trabecular vBMD - 7.7%, meta-trabecular vBMD - 9.8%), trabecular bone volume fraction (- 8.8%), and trabecular thickness (- 8.1%) compared with control subjects. Multivariable regression analysis revealed that older age and a higher C-reactive protein level were associated with trabecular bone loss. CONCLUSIONS PsA patients had a higher burden of bone damages (erosions and enthesiophytes) and trabecular bone loss compared with healthy control at the MCH. Inflammation contributed to the deterioration in trabecular microstructure in these patients.
Collapse
|
18
|
Catalan L, Xiao F, Griffith JF. Reporting of Osteoporotic Vertebral Fracture Detected Opportunistically on Thoraco-abdominal Computed Tomography. HONG KONG JOURNAL OF RADIOLOGY 2019. [DOI: 10.12809/hkjr1916919] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
|
19
|
Wáng YXJ, Che-Nordin N, Deng M, Griffith JF, Leung JCS, Kwok AWL, Leung PC, Kwok TCY. Elderly males with or without existing osteoporotic vertebral fracture have much lower future vertebral fracture risk than elderly females: the MrOS (Hong Kong) year-4 follow-up spine radiograph study. Osteoporos Int 2019; 30:2505-2514. [PMID: 31478068 DOI: 10.1007/s00198-019-05136-x] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Accepted: 08/16/2019] [Indexed: 12/18/2022]
Abstract
UNLABELLED MrOS (Hong Kong)'s year-4 follow-up shows, for subjects at baseline without vertebral deformity (VD) and endplate or/and cortex fracture (ECF), the VD progression/new VD rate during follow-up in males was half of our paired MsOS (Hong Kong) study's results. For those with VD or ECF, the VD progression/new VD was less than one sixth of females' rate. INTRODUCTION This study documents MrOS (Hong Kong)'s year-4 follow-up, and the results are compared with the MsOS (Hong Kong) study. Of elderly females with Genant's grade-0, -1, -2, and -3 VD, at year-4 follow-up, 4.6%, 8%, 10.6%, and 28.9% had at least one VD progression or incident VD, respectively. METHODS Spine radiographs of 1500 Chinese males with baseline (mean age 71.7 years, range 65-91 years) and year-4 follow-up were evaluated according to Genant's VD criteria and ECF (non-existent, ECF0; or existent, ECF1). Grade-2 VDs were divided into mild (VD2m, 25-34% height loss) and severe (VD2s, 34-40% height loss) subgroups. Study subjects were graded into eight categories: VD0/ECF0, VD1/ECF0, VD2m/ECF0, VD0/ECF1, VD1/ECF1, VD2m/ECF1, VD2s/ECF1, and VD3/ECF1. With an existing VD, a further height loss of ≥ 15% was a VD progression. A new VD incident was a change from grade-0 to grade-2/3, or to grade-1 with ≥ 10% height loss. RESULTS Of subjects with Genant's grade-0, 2.05% (25/1219) developed at least one VD progression or/and new VD, while of subjects with Genant's grade-1, -2, and -3 VD, only 2% (3/149), 3.1% (3/96), and 2.8% (1/36) developed at least one VD progression/new VD, respectively. Among the three ECF0 groups, there was a significant difference in new ECF incidence, with VD0/ECF0 being the lowest and VD2m/ECF0 being the highest. CONCLUSION VD progression/new VD is much less common in elderly men than in elderly women. Vertebrae with VD had a higher risk of developing ECF.
Collapse
|
20
|
Gomez-Alvarez V, Ashbolt NJ, Griffith JF, Santo Domingo J, Lu J. Whole-Genome Sequencing of Four Campylobacter Strains Isolated from Gull Excreta Collected from Hobie Beach (Oxnard, CA, USA). Microbiol Resour Announc 2019; 8:e00560-19. [PMID: 31395635 PMCID: PMC6687922 DOI: 10.1128/mra.00560-19] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2019] [Accepted: 07/17/2019] [Indexed: 12/16/2022] Open
Abstract
Campylobacter spp. are commensal organisms in avian species and are one of the leading causes of bacterial foodborne human diarrheal disease worldwide. We report the draft genome sequences of Campylobacter volucris, C. lari, and C. jejuni strains isolated from California gull (Larus californicus) excreta collected from a California beach.
Collapse
|
21
|
Wáng YXJ, Che-Nordin N, Deng M, Leung JCS, Kwok AWL, He LC, Griffith JF, Kwok TCY, Leung PC. Osteoporotic vertebral deformity with endplate/cortex fracture is associated with higher further vertebral fracture risk: the Ms. OS (Hong Kong) study results. Osteoporos Int 2019; 30:897-905. [PMID: 30666373 DOI: 10.1007/s00198-019-04856-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2018] [Accepted: 01/13/2019] [Indexed: 12/12/2022]
Abstract
UNLABELLED Compared with vertebrae without deformity, vertebrae with mild/moderate deformity have a higher risk of endplate or/and cortex fracture (ecf). Compared with subjects without ecf, subjects with ecf are at a higher risk of short-term (4-year period) deformity progression and new incident deformity. INTRODUCTION The progression and incidence of osteoporotic vertebral deformity/fracture (VD/VF) in elderly Chinese females remain not well documented. METHODS Spine radiographs of 1533 Chinese females with baseline and year-4 follow-up (mean age 75.7 years) were evaluated according to Genant's VD criteria and endplate/cortex fracture (non-existent: ecf0 or existent: ecf1). Grade-2 VDs were divided into mild (vd2m, 25-34% height loss) and severe (vd2s, 34-40% height loss) subgroups. According to their VD/VF, subjects were graded into seven categories: vd0/ecf0, vd1/ecf0, vd2m/ecf0, vd1/ecf1, vd2m/ecf1, vd2s/ecf1, and vd3/ecf1. With an existing VD, a further height loss of ≥ 15% was a VD progression. A new incident VD was a change from grade-0 to grade-2/3 or to grade-1 with ≥ 10% height loss. RESULTS Of subjects with Genant's grades 0, - 1, - 2, and - 3 VD, at follow-up, 4.6%, 8%, 10.6%, and 28.9% had at least one VD progression or new incident VD respectively. Among the three ecf0 groups, there was no difference in VD progression or new VD; while there was a significant difference in new ecf incidence, with vd0/ecf0 being lowest and vd2m/ecf0 being highest. Vd1/ecf0 and vd2m/ecf0 vertebrae had a higher risk of turning to ecf1 than vd0/ecf0 vertebrae. If vd1/ecf0 and vd2m/ecf0 subjects were combined together (range 20-34% height loss) to compare with vd1/ecf1 and vd2m/ecf1 subjects, the latter had significantly higher VD progression and new VD rates. CONCLUSION Vertebrae with grade-1/2 VDs had a higher risk of developing ECF. Subjects with pre-existing ECFs had a higher risk of worsening or new vertebral deformities.
Collapse
|
22
|
Steele JA, Blackwood AD, Griffith JF, Noble RT, Schiff KC. Quantification of pathogens and markers of fecal contamination during storm events along popular surfing beaches in San Diego, California. WATER RESEARCH 2018; 136:137-149. [PMID: 29501758 DOI: 10.1016/j.watres.2018.01.056] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Revised: 01/19/2018] [Accepted: 01/24/2018] [Indexed: 05/08/2023]
Abstract
Along southern California beaches, the concentrations of fecal indicator bacteria (FIB) used to quantify the potential presence of fecal contamination in coastal recreational waters have been previously documented to be higher during wet weather conditions (typically winter or spring) than those observed during summer dry weather conditions. FIB are used for management of recreational waters because measurement of the bacterial and viral pathogens that are the potential causes of illness in beachgoers exposed to stormwater can be expensive, time-consuming, and technically difficult. Here, we use droplet digital Polymerase Chain Reaction (digital PCR) and digital reverse transcriptase PCR (digital RT-PCR) assays for direct quantification of pathogenic viruses, pathogenic bacteria, and source-specific markers of fecal contamination in the stormwater discharges. We applied these assays across multiple storm events from two different watersheds that discharge to popular surfing beaches in San Diego, CA. Stormwater discharges had higher FIB concentrations as compared to proximal beaches, often by ten-fold or more during wet weather. Multiple lines of evidence indicated that the stormwater discharges contained human fecal contamination, despite the presence of separate storm sewer and sanitary sewer systems in both watersheds. Human fecal source markers (up to 100% of samples, 20-12440 HF183 copies per 100 ml) and human norovirus (up to 96% of samples, 25-495 NoV copies per 100 ml) were routinely detected in stormwater discharge samples. Potential bacterial pathogens were also detected and quantified: Campylobacter spp. (up to 100% of samples, 16-504 gene copies per 100 ml) and Salmonella (up to 25% of samples, 6-86 gene copies per 100 ml). Other viral human pathogens were also measured, but occurred at generally lower concentrations: adenovirus (detected in up to 22% of samples, 14-41 AdV copies per 100 ml); no enterovirus was detected in any stormwater discharge sample. Higher concentrations of avian source markers were noted in the stormwater discharge located immediately downstream of a large bird sanctuary along with increased Campylobacter concentrations and notably different Campylobacter species composition than the watershed that had no bird sanctuary. This study is one of the few to directly measure an array of important bacterial and viral pathogens in stormwater discharges to recreational beaches, and provides context for stormwater-based management of beaches during high risk wet-weather periods. Furthermore, the combination of culture-based and digital PCR-derived data is demonstrated to be valuable for assessing hydrographic relationships, considering delivery mechanisms, and providing foundational exposure information for risk assessment.
Collapse
|
23
|
Cao Y, Sivaganesan M, Kelty CA, Wang D, Boehm AB, Griffith JF, Weisberg SB, Shanks OC. A human fecal contamination score for ranking recreational sites using the HF183/BacR287 quantitative real-time PCR method. WATER RESEARCH 2018; 128:148-156. [PMID: 29101858 PMCID: PMC7228037 DOI: 10.1016/j.watres.2017.10.071] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2017] [Revised: 10/25/2017] [Accepted: 10/31/2017] [Indexed: 05/05/2023]
Abstract
Human fecal pollution of recreational waters remains a public health concern worldwide. As a result, there is a growing interest in the application of human-associated fecal source identification quantitative real-time PCR (qPCR) technologies for water quality research and management. However, there are currently no standardized approaches for field implementation and interpretation of qPCR data. In this study, a standardized HF183/BacR287 qPCR method was combined with a water sampling strategy and a novel Bayesian weighted average approach to establish a human fecal contamination score (HFS) that can be used to prioritize sampling sites for remediation based on measured human waste levels. The HFS was then used to investigate 975 study design scenarios utilizing different combinations of sites with varying sampling intensities (daily to once per week) and number of qPCR replicates per sample (2-14 replicates). Findings demonstrate that site prioritization with HFS is feasible and that both sampling intensity and number of qPCR replicates influence reliability of HFS estimates. The novel data analysis strategy presented here provides a prescribed approach for the implementation and interpretation of human-associated HF183/BacR287 qPCR data with the goal of site prioritization based on human fecal pollution levels. In addition, information is provided for future users to customize study designs for optimal HFS performance.
Collapse
|
24
|
Cao Y, Raith MR, Griffith JF. Testing of General and Human-Associated Fecal Contamination in Waters. Methods Mol Biol 2018; 1768:127-140. [PMID: 29717441 DOI: 10.1007/978-1-4939-7778-9_8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
qPCR has become increasingly popular for microbial water quality testing because it is faster, more specific, and more flexible than culture-based methods. However, qPCR method limitations such as quantification bias introduced by reliance on standards and susceptibility to PCR inhibitors are major obstacles for implementation in water testing. This is because water testing requires accurate quantification of rare targets and because environmental waters often contain PCR inhibitors. Digital PCR offers the opportunity to maintain qPCR's advantages over culture-based methods while ameliorating two of qPCR's major limitations: the necessity to run standard curves and high susceptibility to inhibition. Here we describe a complete method for simultaneous testing for a general microbial water quality indicator (Enterococcus spp.) and a human-associated fecal marker in environmental waters. The complete method includes water sampling and filtration to capture bacteria, DNA extraction from bacteria captured on the filter, and droplet digital PCR to quantify the genetic markers from bacteria indicative of general and human-associated fecal contamination.
Collapse
|
25
|
Arnold BF, Schiff KC, Ercumen A, Benjamin-Chung J, Steele JA, Griffith JF, Steinberg SJ, Smith P, McGee CD, Wilson R, Nelsen C, Weisberg SB, Colford JM. Acute Illness Among Surfers After Exposure to Seawater in Dry- and Wet-Weather Conditions. Am J Epidemiol 2017; 186:866-875. [PMID: 28498895 PMCID: PMC5860265 DOI: 10.1093/aje/kwx019] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2016] [Accepted: 01/23/2017] [Indexed: 11/17/2022] Open
Abstract
Rainstorms increase levels of fecal indicator bacteria in urban coastal waters, but it is unknown whether exposure to seawater after rainstorms increases rates of acute illness. Our objective was to provide the first estimates of rates of acute illness after seawater exposure during both dry- and wet-weather periods and to determine the relationship between levels of indicator bacteria and illness among surfers, a population with a high potential for exposure after rain. We enrolled 654 surfers in San Diego, California, and followed them longitudinally during the 2013–2014 and 2014–2015 winters (33,377 days of observation, 10,081 surf sessions). We measured daily surf activities and illness symptoms (gastrointestinal illness, sinus infections, ear infections, infected wounds). Compared with no exposure, exposure to seawater during dry weather increased incidence rates of all outcomes (e.g., for earache or infection, adjusted incidence rate ratio (IRR) = 1.86, 95% confidence interval (CI): 1.27, 2.71; for infected wounds, IRR = 3.04, 95% CI: 1.54, 5.98); exposure during wet weather further increased rates (e.g., for earache or infection, IRR = 3.28, 95% CI: 1.95, 5.51; for infected wounds, IRR = 4.96, 95% CI: 2.18, 11.29). Fecal indicator bacteria measured in seawater (Enterococcus species, fecal coliforms, total coliforms) were strongly associated with incident illness only during wet weather. Urban coastal seawater exposure increases the incidence rates of many acute illnesses among surfers, with higher incidence rates after rainstorms.
Collapse
|