scholarly journals Wastewater SARS-CoV-2 Concentration and Loading Variability from Grab and 24-Hour Composite Samples

2020 ◽  
Author(s):  
Kyle Curtis ◽  
David Keeling ◽  
Kathleen Yetka ◽  
Allison Larson ◽  
Raul Gonzalez
Keyword(s):  
Mean Deviation ◽  
Clinical Testing ◽  
Public Health Response ◽  
Composite Sampling ◽  
Catchment Population ◽  
Sampling Schemes ◽  
Grab Sample ◽  
Health Response ◽  
Spread Of Infection ◽  
Composite Samples

The ongoing COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) requires a significant, coordinated public health response. Assessing case density and spread of infection is critical and relies largely on clinical testing data. However, clinical testing suffers from known limitations, including test availability and a bias towards enumerating only symptomatic individuals. Wastewater-based epidemiology (WBE) has gained widespread support as a potential complement to clinical testing for assessing COVID-19 infections at the community scale. The efficacy of WBE hinges on the ability to accurately characterize SARS-CoV-2 concentrations in wastewater. To date, a variety of sampling schemes have been used without consensus around the appropriateness of grab or composite sampling. Here we address a key WBE knowledge gap by examining the variability of SARS-CoV-2 concentrations in wastewater grab samples collected every 2 hours for 72 hours compared with corresponding 24-hour flow-weighted composite samples. Results show relatively low variability (mean for all assays = 741 copies 100 mL-1, standard deviation = 508 copies 100 mL-1) for grab sample concentrations, and good agreement between most grab samples and their respective composite (mean deviation from composite = 159 copies 100 mL-1). When SARS-CoV-2 concentrations are used to calculate viral load, the discrepancy between grabs (log10 difference = 12.0) or a grab and its associated composite (log10 difference = 11.8) are amplified. A similar effect is seen when estimating carrier prevalence in a catchment population with median estimates based on grabs ranging 62-1853 carriers. Findings suggest that grab samples may be sufficient to characterize SARS-CoV-2 concentrations, but additional calculations using these data may be sensitive to grab sample variability and warrant the use of flow-weighted composite sampling. These data inform future WBE work by helping determine the most appropriate sampling scheme and facilitate sharing of datasets between studies via consistent methodology.

A lasting public health response to an outbreak of HIV infection in a Scottish prison?

1998 ◽  
Vol 9 (1) ◽  
pp. 25-30 ◽  
Author(s):  
David Goldberg ◽  
Avril Taylor ◽  
James McGregor ◽  
Barbara Davis ◽  
John Wrench ◽  
...  
Keyword(s):  
Public Health ◽  
Hepatitis B ◽  
Hiv Infection ◽  
Harm Minimization ◽  
Public Health Response ◽  
Health Response ◽  
Drug Injecting ◽  
Prevention Of Infections ◽  
Spread Of Infection ◽  
Bloodborne Infections

Summary: Between April and June 1993, 8 cases of acute clinical hepatitis B infection and 2 seroconversions to HIV infection were detected among drug injecting inmates of HM Prison Glenochil in Scotland. To prevent the further spread of infection, an initiative which involved counselling and voluntary attributable HIV testing was conducted over a 10-day period commencing at the end of June. A team of 18 counsellors and phlebotomists was brought together rapidly as part of a unique organizational exercise in the field of public health. Fourteen cases of HIV infection were identified of which 13 were almost certainly infected in Glenochil. Following the exercise, a range of harm reduction measures for injecting prisoners was introduced; these included the availability of hepatitis B vaccine, provision of bleach tablets which could be used to clean injecting equipment, a methadone detoxification programme, increased training for prison officers and improved access to drug and harm minimization counselling for inmates. By mid-1996 all these measures had been sustained and several could be found in many other prisons throughout Scotland. Follow-up investigations showed no evidence of epidemic spread of HIV during the 12 months after the initiative. While the frequency of injecting and needle/syringe sharing may have decreased over the last 3 years, these activities are still being reported and it is highly likely that transmissions of bloodborne infections, in paticular hepatitis C, continue to occur. The surveillance and prevention of infections associated with injecting drug use in the prison setting remain a high public health priority.

You're not alone: A public health response to immigrant/refugee distress in the current sociopolitical context.

2020 ◽  
Vol 17 (S1) ◽  
pp. 128-138 ◽  
Author(s):  
Rebecca E. Ford-Paz ◽  
Catherine DeCarlo Santiago ◽  
Claire A. Coyne ◽  
Claudio Rivera ◽  
Sisi Guo ◽  
...  
Keyword(s):  
Public Health ◽  
Public Health Response ◽  
Health Response ◽  
Sociopolitical Context

Responsibility and Blame

2018 ◽  
Author(s):  
Joshua M. Sharfstein
Keyword(s):  
Public Health ◽  
Health Agency ◽  
Public Health Response ◽  
Difficult Situation ◽  
Health Training ◽  
Health Response ◽  
Public Health Training ◽  
Health Agencies ◽  
Sincere Apology

Issues of responsibility and blame are very rarely discussed in public health training, but are seldom forgotten in practice. Blame often follows a crisis, and leaders of health agencies should be able to think strategically about how to handle such accusations before being faced with the pain of dealing with them. When the health agency is not at all at fault, officials can make the case for a strong public health response without reservation. When the agency is entirely to blame, a quick and sincere apology can allow the agency to retain credibility. The most difficult situation is when the agency is partly to blame. The goal in this situation is to accept the appropriate amount of blame while working quickly to resolve the crisis.

scholarly journals Evaluating the accuracy of Listeria monocytogenes assemblies from quasimetagenomic samples using long and short reads

BMC Genomics ◽  
2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Seth Commichaux ◽  
Kiran Javkar ◽  
Padmini Ramachandran ◽  
Niranjan Nagarajan ◽  
Denis Bertrand ◽  
...  
Keyword(s):  
Public Health ◽  
Public Health Response ◽  
High Quality ◽  
Short Read ◽  
Short Reads ◽  
The Core ◽  
Long Reads ◽  
Health Response ◽  
Long Read ◽  
Core Genes

Abstract Background Whole genome sequencing of cultured pathogens is the state of the art public health response for the bioinformatic source tracking of illness outbreaks. Quasimetagenomics can substantially reduce the amount of culturing needed before a high quality genome can be recovered. Highly accurate short read data is analyzed for single nucleotide polymorphisms and multi-locus sequence types to differentiate strains but cannot span many genomic repeats, resulting in highly fragmented assemblies. Long reads can span repeats, resulting in much more contiguous assemblies, but have lower accuracy than short reads. Results We evaluated the accuracy of Listeria monocytogenes assemblies from enrichments (quasimetagenomes) of naturally-contaminated ice cream using long read (Oxford Nanopore) and short read (Illumina) sequencing data. Accuracy of ten assembly approaches, over a range of sequencing depths, was evaluated by comparing sequence similarity of genes in assemblies to a complete reference genome. Long read assemblies reconstructed a circularized genome as well as a 71 kbp plasmid after 24 h of enrichment; however, high error rates prevented high fidelity gene assembly, even at 150X depth of coverage. Short read assemblies accurately reconstructed the core genes after 28 h of enrichment but produced highly fragmented genomes. Hybrid approaches demonstrated promising results but had biases based upon the initial assembly strategy. Short read assemblies scaffolded with long reads accurately assembled the core genes after just 24 h of enrichment, but were highly fragmented. Long read assemblies polished with short reads reconstructed a circularized genome and plasmid and assembled all the genes after 24 h enrichment but with less fidelity for the core genes than the short read assemblies. Conclusion The integration of long and short read sequencing of quasimetagenomes expedited the reconstruction of a high quality pathogen genome compared to either platform alone. A new and more complete level of information about genome structure, gene order and mobile elements can be added to the public health response by incorporating long read analyses with the standard short read WGS outbreak response.

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