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  • OPEN ACCESS
    A comparison of infectious agents between hatchery-enhanced and wild out-migrating juvenile chinook salmon (Oncorhynchus tshawytscha) from Cowichan River, British Columbia
    FACETS • Vol. 3 • No. 1 • pp. 695 - 721
    Infectious diseases are likely contributing to large-scale declines in chinook salmon stocks in the Pacific Northwest, but the specific agents and diseases involved, and the prevalences in migratory salmon, are mostly unknown. We applied a high-throughput microfluidics platform to screen for 45 infectious agents in 556 out-migrating juvenile chinook salmon, collected from freshwater (FW) and saltwater (SW) locations in the Cowichan River system on Vancouver Island, Canada, during 2014. Nineteen agents (5 bacterial, 2 viral, and 12 parasitic) were detected, with prevalences ranging from 0.2% to 57.6%. Co-infections between Candidatus Branchiomonas cysticola Toenshoff, Kvellestad, Mitchell, Steinum, Falk, Colquhoun & Horn, 2012, Paranucleospora theridion Nylund, Nylund, Watanabe, Arnesen & Kalrsbakk, 2010, and gill chlamydia, all associated with gill disease, were observed in SW samples. We detected agents known to cause large-scale mortalities in Pacific salmon (Ceratonova shasta (Noble, 1950), Parvicapsula minibicornis Kent, Whitaker & Dawe, 1977), and agents only recently reported in Pacific salmon in BC (Ca. B. cysticola, P. theridion, Facilispora margolisi Jones, Prosperi-Porta & Kim, 2012 and Parvicapsula pseudobranchicola Karlsbakk, Saether, Hostlund, Fjellsoy & Nylund, 2002). Wild and hatchery fish were most divergent in agent profiles in FW, with higher agent diversity in wild fish. Differences in prevalence largely dissipated once they converged in the marine environment, although hatchery fish may be infected by a greater diversity of agents sooner after ocean entry by virtue of their more rapid migration from nearshore to offshore environments.
  • OPEN ACCESS
    Why colour is complex: Evidence that bees perceive neither brightness nor green contrast in colour signal processing
    FACETS • Vol. 3 • No. 1 • pp. 800 - 817
    Honey bees (Apis mellifera Linnaeus, 1758) potentially rely on a variety of visual cues when searching for flowers in the environment. Both chromatic and achromatic (brightness) components of flower signals have typically been considered simultaneously to understand how flower colours have evolved. However, it is unclear whether honey bees actually use brightness information in their colour perception. We investigated whether free-flying honey bees can process brightness cues in achromatic stimuli when presented at a large visual angle of 28° to ensure colour processing. We found that green contrast (modulation of the green receptor against the background) and brightness contrast (modulation of all three receptors against the background) did not have a significant effect on the proportion of correct choices made by bees, indicating that they did not appear to use brightness cues in a colour processing context. Our findings also reveal that, even at a small visual angle, honeybees do not reliably process single targets solely based on achromatic information, at least considering values up to 60% modulation of brightness. We discuss these findings in relation to proposed models of bee colour processing. Therefore, caution should be taken when interpreting elemental components of complex flower colours as perceived by different animals.
  • OPEN ACCESS
    Initial indications of polycyclic aromatic hydrocarbon exposure in Saskatchewan common loons
    FACETS • Vol. 3 • No. 1 • pp. 849 - 857
    Mercury (Hg) and polycyclic aromatic hydrocarbons (PAHs) are global pollutants known for their toxicity to wildlife. Because of their trophic position, common loons (Gavia immer (Brünnich 1764)) are excellent indicators of environmental quality. In 2014 and 2015, tissue samples of ten adult common loons (plus one recapture) were obtained in Meadow Lake Provincial Park, Saskatchewan, and assessed for Hg and PAH exposure. Blood and feather levels of these contaminants are indicative of exposure during breeding and in wintering areas, respectively. Compared with an international Hg database, blood Hg levels were low (<1 μg/g). In most loons (90.5%, 10 out of 11), blood PAH concentrations were also low (<10 ng/g), but high (120 ng/g) for one individual (9.5% 1 out of 11). Feather PAH concentrations were high (95.9 ng/g and 250.6 ng/g) in two of the four loons (50%) caught in 2015. These data indicate that loons breeding in Meadow Lake Provincial Park were exposed to low levels of Hg; however, some individuals are being exposed to PAHs in both their breeding and wintering locations. The effect of these environmental pollutants on individual loon fitness is unclear, but because of their extreme toxicity in biological systems we suggest that future monitoring in the surrounding region is warranted.
  • OPEN ACCESS
    Neuroprotective effect of Panax ginseng extract against cerebral ischemia–reperfusion-injury-induced oxidative stress in middle cerebral artery occlusion models
    FACETS • Vol. 4 • No. 1 • pp. 52 - 68
    The present study investigated the in vivo neuroprotective role of Panax ginseng extract (PGE) pretreatment against transient cerebral ischemia in a middle cerebral artery occlusion (MCAO) model. Rats were randomly divided as follows: group I, control; group II, sham-operated; group III, where animals were subjected to MCAO surgery; and group IV, where animals were orally administered 10 mL PGE per day (200 mg/kg of body weight per day) for 30 d followed by MCAO induction at day 31. Following 24 h of reperfusion, blood and tissue (brain, liver, and kidney) samples were collected for biochemical and histopathological examination. Biochemical testing included lipid profile, liver enzymes, kidney function tests, C-reactive protein (CRP), lactate dehydrogenase (LDH), glucose, and total protein estimation. Tissue antioxidants (catalase, superoxide dismutase, and glutathione) were assessed in brain, liver, and kidney tissues. MCAO-induced histopathological changes were also examined in the tissues. Pretreatment with PGE showed significant improvement in tissue antioxidant status in brain, liver and kidney tissues. PGE treatment maintains plasma lipid profile, liver enzymes, kidney function, and CRP, LDH, and glucose levels. Histologically, monocytes and macrophage infiltration were observed in the tissues of MCAO animals, whereas PGE treatment preserved tissue architecture and minimal monocyte infiltration. PGE supplementation showed a neuroprotective effect against ischemia–reperfusion injury by effectively increasing endogenous antioxidant enzyme activity.
  • OPEN ACCESS
    Pyrogenic and neuroinflammatory properties of zymosan and its potential as an alternative to live yeast in antipyretic drug testing
    FACETS • Vol. 4 • No. 1 • pp. 162 - 182
    Zymosan, an immunogenic cell wall extract of Saccharomyces cerevisiae has potential for use as an experimental pyrogen. However, the short-lived sickness responses noted with intraperitoneal and intra-articular administration of zymosan limits investigations on the long-term effectiveness of antipyretic drugs. Thus, there remains a need to establish an alternative route of zymosan administration that could induce long-lived fevers and inflammation. We injected male Sprague Dawley rats (250–300 g) subcutaneously with zymosan (30 or 300 mg/kg) or saline; n = 7–8. We measured core body temperature, cage activity, food intake and body mass for 24 h after injection. Blood and brain samples were collected at 2, 8, and 18 h after injection. Zymosan (300 mg/kg) induced fever, lethargy, and anorexia, which lasted for 24 h. Zymosan-induced sickness responses were accompanied by increased blood plasma levels of interleukin (IL)-6 and tumor necrosis factor (TNF)-α; activation of inflammatory transcription factors (nuclear factor (NF) for IL-6, signal transducer and activator of transcription (STAT)-3, and NF-κB) in the hypothalamus and circumventricular organs; and increased hypothalamic mRNA expression of TNF-α, IL-1β, and IL-6 and rate-limiting enzymes for prostaglandin synthesis. Our results confirm the suitability of subcutaneous administration of zymosan for screening antipyretic and anti-inflammatory drugs in rats.
  • OPEN ACCESS
    Defining modifiable barriers to uptake of dietary recommendations in Chinese immigrants with type 2 diabetes: a qualitative study
    FACETS • Vol. 4 • No. 1 • pp. 551 - 565
    The objective is to support development of a nutritional intervention for Chinese immigrants with diabetes by defining current deficiencies and identifying modifiable factors and mechanisms of change. Semi-structured interviews conducted with 13 ethnic Chinese with type 2 diabetes identified modifiable problems related to culturally relevant diabetes resources and low cultural acceptability of recommended diets. These factors could be addressed through creation of resources developed in partnership with Chinese-speaking health care professionals and persons with diabetes.
  • OPEN ACCESS
    Strength and competitiveness are more strongly predictive of retrospective sport participation than 2D:4D in university-aged women
    FACETS • Vol. 4 • No. 1 • pp. 459 - 471
    Objective: Females continue to participate in sport at lower rates than males. Girls who participate in sport gain many advantages. Even with programs designed to emphasize participation, some females continue with sport participation while others do not. Given the advantages and controversies surrounding testosterone and female sport, it is possible that testosterone may predispose females toward sport participation. Our objective was to determine if the second to fourth digit (2D:4D) ratio, a proxy for prenatal androgen exposure, correlates with sport participation throughout female adolescence and young adulthood. Methods: A cross-sectional analysis of indirect prenatal androgen exposure (i.e., 2D:4D) was completed on 18–30-year-old women (n = 92) using demographics, anthropometrics, sport-specific behaviour tendencies, and retrospective sport participation. Results: 2D:4D was not significantly correlated with total sport participation (TSP) (r = −0.065, p = 0.538). Secondary analyses revealed significant correlations between TSP and maximum hand grip (r = 0.406, p = 0.000) and the Sport Orientation Questionnaire (SOQcomp (r = 0.513475, p = 0.000), SOQgoal (r = 0.253, p = 0.015), SOQwin (r = 0.366, p = 0.000)). Conclusion: Although strength and competitiveness are strongly correlated with female sport participation, the impact of prenatal androgen exposure (i.e., 2D:4D) remains to be determined given its weak and negative association with female sport participation. Given that females participate in sport at lower rates than males, continuing to determine what factors influence sport participation is an important goal.
  • OPEN ACCESS
    Global estrogen receptor-α knockout has differential effects on cortical and cancellous bone in aged male mice
    FACETS • Vol. 5 • No. 1 • pp. 328 - 348
    Estrogen receptor-α knockout (ERKO) in female rodents results in bone loss associated with increased osteocyte sclerostin expression; whether this also occurs in males is unknown. Here, we examined the effects of ERKO on femoral cortical geometry, trabecular microarchitecture, and osteocyte sclerostin expression of the femur and lumbar vertebrae. At 14 months of age, male ERKO and wild-type (WT) littermates (n = 6 per group) were sacrificed, and femora and vertebra were collected. Cortical geometry and trabecular microarchitecture were assessed via micro-computed tomography; osteocyte sclerostin expression was assessed via immunohistochemistry. ANCOVA with body weight was used to compare ERKO and WT for cortical geometry; t-tests were used for all other outcomes. Regardless of skeletal site, ERKO mice had greater trabecular bone volume and trabecular number and decreased trabecular separation compared with WT. In the femoral diaphysis, ERKO had lower total area, cortical area, and cortical thickness compared with WT. The percentage of sclerostin+ osteocytes was increased in ERKO animals in cortical bone but not in cancellous bone of the femur or the lumbar vertebrae. In conclusion, ERKO improved trabecular microarchitecture in aged male mice, but negatively altered femoral cortical geometry associated with a trend towards increased cortical sclerostin expression.
  • OPEN ACCESS
    Age-dependent stress response DNA demethylation and gene upregulation accompany nuclear and skeletal muscle remodeling following acute resistance-type exercise in rats
    FACETS • Vol. 5 • No. 1 • pp. 455 - 473
    Efficacy of high-intensity resistance exercise becomes progressively compromised with aging. Previously, to investigate this, we developed a rodent model of high-intensity training consisting of stretch-shortening contractions (SSCs) and determined that following one month of training, young rats exhibit a robust stress response and 20% performance increase, whereas old rats display a muted stress response and 30% performance decrease. Whether these age-specific responses occur early in training and constitute primary factors in adaptation/maladaptation was not addressed. The aim of the present study was to characterize performance, remodeling, and stress response transcriptional profile 6–120 h following acute SSC exposure. For young rats, the stress response pathway was highly regulated (≥20 differentially expressed genes at each time point) and was accompanied by robust DNA demethylation, tissue remodeling, and isometric torque recovery. For old rats, a muted transcriptional profile (13 and 2 differentially expressed genes at 6 and 120 h, respectively) coincided with deficiencies in demethylation, muscle remodeling, and torque recovery. These findings occurred in the context of heightened chronic levels of stress response gene expression with aging. This demonstrates that age-related constitutive elevations in stress response gene expression was accompanied by diminished SSC-induced responsiveness in epigenomic regulation and tissue remodeling.
  • OPEN ACCESS
    Global patterns of ranavirus detections
    FACETS • Vol. 6 • pp. 912 - 924
    Ranaviruses are emerging pathogens of poikilothermic vertebrates. In 2015 the Global Ranavirus Reporting System (GRRS) was established as a centralized, open access, online database for reports of the presence (and absence) of ranavirus around the globe. The GRRS has multiple data layers (e.g., location, date, host(s) species, and methods of detection) of use to those studying the epidemiology, ecology, and evolution of this group of viruses. Here we summarize the temporal, spatial, diagnostic, and host-taxonomic patterns of ranavirus reports in the GRRS. The number, distribution, and host diversity of ranavirus reports have increased dramatically since the mid 1990s, presumably in response to increased interest in ranaviruses and the conservation of their hosts, and also the availability of molecular diagnostics. Yet there are clear geographic and taxonomic biases among the reports. We encourage ranavirus researchers to add their studies to the portal because such collation can provide collaborative opportunities and unique insights to our developing knowledge of this pathogen and the emerging infectious disease that it causes.
  • OPEN ACCESS
    Lack of molecular detection of frog virus 3-like ranavirus (FV3) in mosquitoes during natural outbreak and nonoutbreak conditions
    FACETS • Vol. 5 • No. 1 • pp. 812 - 820
    Ranaviruses are worldwide pathogens of ectothermic vertebrates that can threaten herptile conservation efforts. Identifying transmission routes is critical for understanding disease ecology and promoting species conservation. Frog virus 3 (FV3) DNA was detected in mosquitoes during a ranavirus outbreak in semicaptive box turtles, but the role that insect vectors play under natural conditions is unknown. To address this knowledge gap, we collected mosquito species known to take blood meals from reptiles and amphibians (Aedes canadensis, Culex erraticus, Culex territans, and Uranotaenia sapphirina) from mid-May to early August, 2014, at four study sites in Vermilion County, Illinois, two of which had historic or ongoing FV3 outbreaks in box turtles and amphibians. Mosquitoes were batched by date and species, DNA was extracted, and quantitative polymerase chain reaction was performed for detection of FV3. FV3 was not detected despite one of the sites having an active FV3 outbreak during the study period. Our findings indicate that FV3 detection is uncommon in mosquitoes during outbreak and nonoutbreak conditions at these sites in Illinois. Thus, we cannot establish that mosquitoes contribute to transmission during natural mortality events without performing further studies.
  • OPEN ACCESS
    Relaxin peptides reduce cellular damage in cultured brain slices exposed to transient oxygen–glucose deprivation: an effect mediated by nitric oxide
    FACETS • Vol. 6 • pp. 118 - 130
    The effect of treatment with human relaxins on cell death was studied in oxygen- and glucose-deprived brain slices. In addition, involvement of nitric oxide and the relaxin receptor, RXFP3, was studied. Brain slices (n = 12–18/group) were cultured under standard conditions for two weeks and then exposed to: (i) an oxygenated balanced salt solution, (ii) a deoxygenated, glucose-free balanced salt solution (OGD media), or (iii) OGD media containing 10−7 mol/L H2 relaxin, 10−7 mol/L H2 relaxin with 50 μmol/L L-NIL, 10−7 mol/L H3 relaxin, or 10−7 mol/L H3 relaxin with 50 μmol/L L-NIL. Cell death was assessed using propidium iodide fluorescence. In a separate experiment, 10−5 mol/L R3 B1-22R (an antagonist of RXFP3) was added to both H2 and H3 relaxin treatments. H2 and H3 relaxin treatment reduced cell damage or death in OGD slices and L-NIL partially attenuated the effect of H3 relaxin. Antagonism of RXFP3 blocked the effect of H3 but not H2 relaxin. These data increase our understanding of the role of relaxin ligands and their receptors in protecting tissues throughout the body from ischemia and reperfusion injury.
  • OPEN ACCESS
    Non-HDL cholesterol level and depression among Canadian elderly—a cross-sectional analysis of the baseline data from the CLSA
    FACETS • Vol. 5 • No. 1 • pp. 1006 - 1018
    To explore whether non-high-density-lipoprotein cholesterol (non-HDL-c) is associated with depression, a total of 26 819 Canadians aged 45–85 from the Canadian Longitudinal Study on Aging (CLSA) were included in analysis. Non-HDL-c, the difference between total-c and HDL-c, was categorized into five levels, i.e., <2.6, 2.6 to <3.7, 3.7 to <4.8, 4.8 to 5.7, and ≥5.7 mmol/L. History of clinical depression was collected by questionnaire at an in-home interview, and current potential depression status was determined by CES-D10 (Center for Epidemiological Studies Depression Scale 10 questions version) score, i.e., ≥10 vs. <10. Logistic continuation ratio model for ordinal data was used to estimate the odds of being at or above a higher non-HDL-c category for depression status. Compared with those without clinical depression history and currently undepressed, the adjusted odds ratios (95% CI) were 1.09 (1.02, 1.17) for those without clinical depression history but currently depressed, 1.05 (0.98, 1.12) for those had clinical depression history but currently undepressed, and 1.21 (1.10, 1.32) for those had clinical depression history and currently depressed. The average of non-HDL-c for four depression groups were 3.64, 3.71, 3.69, and 3.82 mmol/L, respectively, and group 4 was statistically higher than others (p < 0.001). In conclusion, people with both current depression and a history clinical depression are at an increased risk of having high level of non-HDL-c.
  • OPEN ACCESS
    Establishment, contagiousness, and initial spread of SARS-CoV-2 in Canada
    FACETS • Vol. 6 • pp. 180 - 194
    This study empirically quantifies dynamics of SARS-CoV-2 establishment and early spread in Canada. We developed a transmission model that was simulation tested and fitted in a Bayesian framework to timeseries of new cases per day prior to physical distancing interventions. A hierarchical version was fitted to all provinces simultaneously to obtain average estimates for Canada. Across scenarios of a latent period of 2–4 d and an infectious period of 5–9 d, the R0 estimate for Canada ranges from a minimum of 3.0 (95% CI: 2.3–3.9) to a maximum of 5.3 (95% CI: 3.9–7.1). Among provinces, the estimated commencement of community transmission ranged from 3 d before to 50 d after the first reported case and from 2 to 25 d before the first reports of community transmission. Among parameter scenarios and provinces, the median reduction in transmission needed to obtain R0 < 1 ranged from 46% (95% CI: 43%–48%) to 89% (95% CI: 88%–90%). Our results indicate that local epidemics of SARS-CoV-2 in Canada entail high levels of stochasticity, contagiousness, and observation delay, which facilitates rapid undetected spread and requires comprehensive testing and contact tracing for its containment.
  • OPEN ACCESS
    α1-adrenergic stimulation increases ventricular action potential duration in the intact mouse heart
    FACETS • Vol. 6 • pp. 823 - 836
    The role of α1-adrenergic receptors (α-ARs) in the regulation of myocardial function is less well-understood than that of β-ARs. Previous reports in the mouse heart have described that α1-adrenergic stimulation shortens action potential duration in isolated cells or tissues, in contrast to prolongation of the action potential reported in most other mammalian hearts. It has since become appreciated, however, that the mouse heart exhibits marked variation in inotropic response to α1-adrenergic stimulation between ventricles and even individual cardiomyocytes. We investigated the effects of α1-adrenergic stimulation on action potential duration at 80% of repolarization in the right and left ventricles of Langendorff-perfused mouse hearts using optical mapping. In hearts under β-adrenergic blockade (propranolol), phenylephrine or noradrenaline perfusion both increased action potential duration in both ventricles. The increased action potential duration was partially reversed by subsequent perfusion with the α-adrenergic antagonist phentolamine (1 μmol L−1). These data show that α1-receptor stimulation may lead to a prolonging of action potential in the mouse heart and thereby refine our understanding of how action potential duration adjusts during sympathetic stimulation.
  • OPEN ACCESS
    Easing the disruption of COVID-19: supporting the mental health of the people of Canada—October 2020—an RSC Policy Briefing
    FACETS • Vol. 5 • No. 1 • pp. 1071 - 1098
    The COVID-19 pandemic has had a significant impact on the mental health of the people of Canada. Most have found it challenging to cope with social distancing, isolation, anxiety about infection, financial security and the future, and balancing demands of work and home life. For some, especially those who have had to face pre-existing challenges such as structural racism, poverty, and discrimination and those with prior mental health problems, the pandemic has been a major impact.The Policy Briefing Report focuses on the current situation, how the COVID-19 pandemic has exacerbated significant long-standing weaknesses in the mental health system and makes specific recommendations to meet these challenges to improve the well-being of the people of Canada.The COVID-19 pandemic has had a detrimental effect on mental health of people in Canada but the impact has been variable, impacting those facing pre-existing structural inequities hardest. Those living in poverty, and in some socially stratified groups facing greater economic and social disadvantage, such as some racialized and some Indigenous groups and those with preexisting mental health problems, have suffered the most. Some occupational groups have been more exposed to the virus and to psychological stress with the pandemic. The mental health care system was already overextended and under resourced. The pandemic has exacerbated the problems. The care system responded by a massive move to virtual care. The future challenge is for Canada to strengthen our knowledge base in mental health, to learn from the pandemic, and to provide all in Canada the support they need to fully participate in and contribute to Canada’s recovery from the pandemic.
  • OPEN ACCESS
    Socioeconomic settings and food consumption patterns of 2–5-year-old children in developed countries: a scoping review
    FACETS • Vol. 6 • pp. 1495 - 1509
    Introduction: Early childhood overweight and obesity, as a result of unhealthy dietary habits and sedentary life, is a growing global public health concern, particularly in Canada. There are limited data on how socioeconomic factors influence dietary habits of young children living in developed countries. Methods: We conducted a scoping review to examine the existing literature on how socioeconomic settings influence food consumption patterns of children 2–5 years old in developed countries. The inclusion criteria were relevant articles in the English language between 2007 and 2019. Results: From the initial 1854 articles, only 12 articles from Europe, Canada, and the United States met the inclusion criteria. There are differences in eating patterns of preschool-aged children based on parental education, whereas income level did not have a clear influence on dietary patterns. The existing studies suffer from a variety of limitations that limit a cohesive conclusion. Conclusion: Studies with children 2–5 years old are scarce. Parental education seems to influence the dietary habits of young children, whereas the role of income is not clear. There is a need for further high-quality research, preferably longitudinal studies, to inform health promotion initiatives and preventive strategies to facilitate healthy growth and development in young children.
  • OPEN ACCESS
    Seeking shelter: homelessness and COVID-19
    FACETS • Vol. 6 • pp. 925 - 958
    Those experiencing homelessness in Canada are impacted inequitably by COVID-19 due to their increased exposure, vulnerability of environment and medical comorbidities, and their lack of access to preventive care and treatment in the context of the pandemic. In shelter environments one is unable to effectively physically distance, maintain hygiene, obtain a test, or isolate. As a result, unique strategies are required for this population to protect them and those who serve them. Recommendations are provided to reduce or prevent further negative consequences from the COVID-19 pandemic for people experiencing homelessness. These recommendations were informed by a systematic review of the literature, as well as a jurisdictional scan. Where evidence did not exist, expert consensus from key providers and those experiencing homelessness throughout Canada was included. These recommendations recognize the need for short-term interventions to mitigate the immediate risk to this community, including coordination of response, appropriate precautions and protective equipment, reducing congestion, cohorting, testing, case and contact management strategies, dealing with outbreaks, isolation centres, and immunization. Longer-term recommendations are also provided with a view to ending homelessness by addressing the root causes of homelessness and by the provision of adequate subsidized and supportive housing through a Housing First strategy. It is imperative that meaningful changes take place now in how we serve those experiencing homelessness and how we mitigate specific vulnerabilities. These recommendations call for intersectoral, collaborative engagement to work for solutions targeted towards protecting the most vulnerable within our community through both immediate actions and long-term planning to eliminate homelessness.
  • OPEN ACCESS
    Fundamental limitations of contact tracing for COVID-19
    FACETS • Vol. 6 • pp. 1993 - 2001
    Contact tracing has played a central role in COVID-19 control in many jurisdictions and is often used in conjunction with other measures such as travel restrictions and social distancing mandates. Contact tracing is made ineffective, however, by delays in testing, calling, and isolating. Even if delays are minimized, contact tracing triggered by testing of symptomatic individuals can only prevent a fraction of onward transmissions from contacts. Without other measures in place, contact tracing alone is insufficient to prevent exponential growth in the number of cases in a population with little immunity. Even when used effectively with other measures, occasional bursts in call loads can overwhelm contact tracing systems and lead to a loss of control. We propose embracing approaches to COVID-19 contact tracing that broadly test individuals without symptoms, in whatever way is economically feasible—either with fast and cheap tests that can be deployed widely, with pooled testing, or with screening of judiciously chosen groups of high-risk individuals. These considerations are important both in regions where widespread vaccination has been deployed and in those where few residents have been immunized.
  • OPEN ACCESS
    Detection of SARS-CoV-2 in wastewater in Halifax, Nova Scotia, Canada, using four RT-qPCR assays
    FACETS • Vol. 6 • pp. 959 - 965
    Wastewater-based surveillance methods have been implemented in several countries as a tool for monitoring SARS-CoV-2 at a community scale. A variety of methods have been used for concentrating, extracting, and detecting the virus, with no clear consensus on the most effective approach. In this note, we report preliminary findings from a study that is tracking SARS-CoV-2 in wastewater in Halifax, Nova Scotia, with a specific focus on the use of four reverse transcriptase quantitative PCR (RT-qPCR) assays for detecting the virus in wastewater. We were able to detect the virus in wastewater samples during the initial rise of cases in the Halifax region in early November 2020. Levels of the targeted SARS-CoV-2 gene fragments increased and fell in response to reported cases of COVID-19. The CDC N1 and E RT-qPCR assays demonstrated greater relative sensitivity than the CDC N2 and N3 assays for detection of SARS-CoV-2 in raw sewage samples.