The Clinical Severity of COVID-19 Variants of Concern: Retrospective Population-Based Analysis.

BACKGROUND: SARS-CoV-2 variants of concern (VOCs) emerged and rapidly replaced the original strain worldwide. The increased transmissibility of these new variants led to increases in infections, hospitalizations, and mortality. However, there is a scarcity of retrospective investigations examining the severity of all the main VOCs in presence of key public health measures and within various social determinants of health (SDOHs). OBJECTIVE: This study aims to provide a retrospective assessment of the clinical severity of COVID-19 VOCs in the context of heterogenous SDOHs and vaccination rollout. METHODS: We used a population-based retrospective cohort design with data from the British Columbia COVID-19 Cohort, a linked provincial surveillance platform. To assess the relative severity (hospitalizations, intensive care unit [ICU] admissions, and deaths) of Gamma, Delta, and Omicron infections during 2021 relative to Alpha, we used inverse probability treatment weighted Cox proportional hazard modeling. We also conducted a subanalysis among unvaccinated individuals, as assessed severity differed across VOCs and SDOHs. RESULTS: We included 91,964 individuals infected with a SARS-CoV-2 VOC (Alpha: n=20,487, 22.28%; Gamma: n=15,223, 16.55%; Delta: n=49,161, 53.46%; and Omicron: n=7093, 7.71%). Delta was associated with the most severe disease in terms of hospitalization, ICU admissions, and deaths (hospitalization: adjusted hazard ratio [aHR] 2.00, 95% CI 1.92-2.08; ICU: aHR 2.05, 95% CI 1.91-2.20; death: aHR 3.70, 95% CI 3.23-4.25 relative to Alpha), followed generally by Gamma and then Omicron and Alpha. The relative severity by VOC remained similar in the unvaccinated individual subanalysis, although the proportion of individuals infected with Delta and Omicron who were hospitalized was 2 times higher in those unvaccinated than in those fully vaccinated. Regarding SDOHs, the proportion of hospitalized individuals was higher in areas with lower income across all VOCs, whereas among Alpha and Gamma infections, 2 VOCs that cocirculated, differential distributions of hospitalizations were found among racially minoritized groups. CONCLUSIONS: Our study provides robust severity estimates for all VOCs during the COVID-19 pandemic in British Columbia, Canada. Relative to Alpha, we found Delta to be the most severe, followed by Gamma and Omicron. This study highlights the importance of targeted testing and sequencing to ensure timely detection and accurate estimation of severity in emerging variants. It further sheds light on the importance of vaccination coverage and SDOHs in the context of pandemic preparedness to support the prioritization of allocation for resource-constrained or minoritized groups.

De novo synthetic antimicrobial peptide design with a recurrent neural network.

Antibiotic resistance is recognized as an imminent and growing global health threat. New antimicrobial drugs are urgently needed due to the decreasing effectiveness of conventional small-molecule antibiotics. Antimicrobial peptides (AMPs), a class of host defense peptides, are emerging as promising candidates to address this need. The potential sequence space of amino acids is combinatorially vast, making it possible to extend the current arsenal of antimicrobial agents with a practically infinite number of new peptide-based candidates. However, mining naturally occurring AMPs, whether directly by wet lab screening methods or aided by bioinformatics prediction tools, has its theoretical limit regarding the number of samples or genomic/transcriptomic resources researchers have access to. Further, manually designing novel synthetic AMPs requires prior field knowledge, restricting its throughput. In silico sequence generation methods are gaining interest as a high-throughput solution to the problem. Here, we introduce AMPd-Up, a recurrent neural network based tool for de novo AMP design, and demonstrate its utility over existing methods. Validation of candidates designed by AMPd-Up through antimicrobial susceptibility testing revealed that 40 of the 58 generated sequences possessed antimicrobial activity against Escherichia coli and/or Staphylococcus aureus. These results illustrate that AMPd-Up can be used to design novel synthetic AMPs with potent activities.

Invasive pneumococcal disease surveillance in Canada, 2021-2022.

Background: Invasive pneumococcal disease (IPD, Streptococcus pneumoniae) has been a nationally notifiable disease in Canada since 2000. The use of conjugate vaccines has caused a shift in the distribution of serotypes over time. This report is a summary of the demographics, serotypes and antimicrobial resistance of IPD isolates collected in Canada in 2021 and 2022. Methods: The National Microbiology Laboratory (NML) of the Public Health Agency of Canada in Winnipeg, Manitoba collaborates with provincial and territorial public health laboratories to conduct national surveillance of IPD. There were 1,999 isolates reported in 2021 and 3,775 isolates in 2022. Serotype was determined by the Quellung reaction or whole-genome sequencing (WGS). Antimicrobial susceptibilities were determined by WGS methods, broth microdilution, or data shared by collaborators in the Canadian Antimicrobial Resistance Alliance program at the University of Manitoba. Population-based IPD incidence rates were obtained through the Canadian Notifiable Disease Surveillance System. Results: The incidence of IPD in Canada was 5.62 cases per 100,000 population in 2021, decreasing from the peak of 10.86 cases per 100,000 population in 2018. Serotypes with increasing trends (p<0.05) between 2018 and 2022 included: 4 (6.1%-12.4%), 9V (1.0%-5.1%) and 12F (4.8%-5.4%). The overall prevalence of PCV13 serotypes increased over the same period (31.2%-41.5%, p<0.05) while the prevalence of non-vaccine types decreased significantly (27.3%-21.5%, p<0.0001). The highest rates of antimicrobial resistance in 2021 and 2022 were seen with clarithromycin (21%, 2021; 24%, 2022) and erythromycin (22%, 2021; 24%, 2022). Multidrug-resistant IPD continued to increase from 2018 to 2022 (6.7%-12.6%, p<0.05). Conclusion: The number of cases of IPD continued to decrease in 2021 in comparison to previous years, however, 2022 saw a return to pre-COVID-19 levels. Disease due to PCV13 serotypes 3, 4, 9V and 19F, as well as non-PCV13 serotypes 12F and 20, is increasing in prevalence. Surveillance of IPD to monitor changing serotype distribution and antimicrobial resistance is essential.

Invasive group A streptococcal disease surveillance in Canada, 2021-2022.

Background: Invasive group A streptococcal (iGAS, Streptococcus pyogenes) disease has been a nationally notifiable disease in Canada since 2000. This report summarizes the demographics, emm types, and antimicrobial resistance of iGAS isolates collected in Canada in 2021 and 2022. Methods: The Public Health Agency of Canada's National Microbiology Laboratory collaborates with provincial and territorial public health laboratories to conduct national surveillance of invasive S. pyogenes. Emm typing was performed using the Centers for Disease Control and Prevention emm sequencing protocol or extracted from whole-genome sequencing data. Antimicrobial susceptibilities were determined using Kirby-Bauer disk diffusion according to Clinical and Laboratory Standards Institute guidelines or predicted from whole-genome sequencing data based on the presence of resistance determinants. Results: Overall, the incidence of iGAS disease in Canada was 5.56 cases per 100,000 population in 2021, decreasing from the peak of 8.6 cases per 100,000 population in 2018. A total of 2,630 iGAS isolates were collected during 2022, representing an increase from 2021 (n=2,179). In particular, there was a large increase in isolates collected from October to December 2022. The most predominant emm type overall in 2021 and 2022 was emm49, at 21.5% (n=468) and 16.9% (n=444), respectively, representing a significant increase in prevalence since 2018 (p<0.0001). The former most prevalent type, emm1, increased from 0.5% (n=10) in 2021 to 4.8% (n=125) in 2022; similarly, emm12 increased from 1.0% (n=22) in 2021 to 5.8% (n=151) in 2022. These two types together accounted for almost 25% of isolates collected in late 2022 (October to December). Antimicrobial resistance rates in 2021 and 2022 included: 14.9%/14.1% erythromycin resistance, 4.8%/3.0% clindamycin resistance, and <1% chloramphenicol resistance. Conclusion: The increase of iGAS isolates collected in Canada is an important public health concern. Continued surveillance of iGAS is critical to monitor expanding emm types and antimicrobial resistance patterns.

Rapid, high-throughput, cost-effective whole-genome sequencing of SARS-CoV-2 using a condensed library preparation of the Illumina DNA Prep kit.

The ongoing COVID-19 pandemic necessitates cost-effective, high-throughput, and timely whole-genome sequencing (WGS) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) viruses for outbreak investigations, identifying variants of concern (VoC), characterizing vaccine breakthrough infections, and public health surveillance. In addition, the enormous demand for WGS on supply chains and the resulting shortages of laboratory supplies necessitated the use of low-reagent and low-consumable methods. Here, we report an optimized library preparation method (the BCCDC cutdown method) that can be used in a high-throughput scenario, where one technologist can perform 576 library preparations (6 plates of 96 samples) over the course of one 8-hour shift. The same protocol can also be used in a rapid turnaround time scenario, from primary samples (up to 96 samples) to loading on a sequencer in an 8-hour shift. This new method uses Freed et al.'s 1,200 bp primer sets (Biol Methods Protoc 5:bpaa014, 2020, https://doi.org/10.1093/biomethods/bpaa014) and a modified and condensed Illumina DNA Prep workflow (Illumina, CA, USA). Compared to the original protocol, the application of this new method using hundreds of clinical specimens demonstrated equivalent results to the full-length DNA Prep workflow at 45% of the cost, 15% of consumables required (such as pipet tips), 25% of manual hands-on time, and 15% of on-instrument time if performing on a liquid handler, with no compromise in sequence quality. Results demonstrate that this new method is a rapid, simple, cost-effective, and high-quality SARS-CoV-2 WGS protocol. IMPORTANCE: Sequencing has played an invaluable role in the response to the COVID-19 pandemic. Ongoing work in this area, however, demands optimization of laboratory workflow to increase sequencing capacity, improve turnaround time, and reduce cost without compromising sequence quality. This report describes an optimized DNA library preparation method for improved whole-genome sequencing of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pathogen. The workflow advantages summarized here include significant time, cost, and consumable savings, which suggest that this new method is an efficient, scalable, and pragmatic alternative for SARS-CoV-2 whole-genome sequencing.

The Resurgence of Lymphogranuloma Venereum: Changing Presentation of Lymphogranuloma Venereum in the Era of HIV Preexposure Prophylaxis, 2004 to 2022.

BACKGROUND: Before the early 2000s, the sexually transmitted infection lymphogranuloma venereum (LGV) was rare in high-income countries. Initially, most cases in these countries were among symptomatic men who have sex with men (MSM) living with HIV. In the context of widespread HIV preexposure prophylaxis (PrEP), LGV's epidemiology may be changing. We aimed to characterize the epidemiology and clinical presentation of LGV in the PrEP era. METHODS: A retrospective chart review was performed on all LGV cases occurring between November 2004 to October 2022 in British Columbia (BC), Canada. Cases were stratified by having occurred before (2004-2017) or after widespread PrEP availability in BC (2018-2022). Annual rates and test positivity percentages were calculated. Bivariate logistic regression was performed to identify drivers of asymptomatic infection in the PrEP era. RESULTS: Among 545 cases identified, 205 (37.6%) occurred pre-PrEP and 340 (62.4%) occurred during the PrEP era. Most cases were among MSM (97.2%). The estimated rate of LGV has doubled from 2018 to 2022, reaching 1535.2 cases per 100,000 PrEP users. Most PrEP-era cases were among HIV-negative individuals (65.3%), particularly those on PrEP (72.6%). Cases in the PrEP era were often asymptomatic compared with pre-PrEP (38.6% vs. 19.3%; P < 0.001). Users of PrEP were more likely to experience asymptomatic infection compared with HIV-negative PrEP nonusers (odds ratio, 2.07; 95% confidence interval, 1.07-3.99). CONCLUSIONS: In the context of increased asymptomatic testing, LGV may be increasing in BC. Most infections now occur among HIV-negative MSM. A high proportion of infections are asymptomatic.

Prospective, clinical comparison of self-collected throat-bilateral nares swabs and saline gargle compared to health care provider collected nasopharyngeal swabs among symptomatic outpatients with potential SARS-CoV-2 infection.

Background: In British Columbia (BC), self-collected saline gargle (SG) is the only alternative to health care provider (HCP)-collected nasopharyngeal (NP) swabs to detect SARS-CoV-2 in an outpatient setting by polymerase chain reaction (PCR). However, some individuals cannot perform a SG. Our study aimed to assess combined throat-bilateral nares (TN) swabbing as a swab-based alternative. Methods: Symptomatic individuals greater than 12 years of age seeking a COVID-19 PCR test at one of two COVID-19 collection centres in Metro Vancouver were asked to participate in this study. Participants provided a HCP-collected NP sample and a self-collected SG and TN sample for PCR testing, which were either HCP observed or unobserved. Results: Three-hundred and eleven individuals underwent all three collections. Compared against HCP-NP, SG was 99% sensitive and 98% specific (kappa 0.97) and TN was 99% sensitive and 99% specific (kappa 0.98). Using the final clinical test interpretation as the reference standard, NP was 98% sensitive and 100% specific (kappa 0.98), and both SG and TN were 99% sensitive and 100% specific (both kappa 0.99). Mean cycle threshold values for each viral target were higher in SG specimens compared to the other sample types; however, this did not significantly impact the clinical performance, because the positivity rates were similar. The clinical performance of all specimen types was comparable within the first 7 days of symptom onset, regardless of the observation method. SG self-collections were rated the most acceptable, followed by TN. Conclusions: TN provides another less invasive self-collection modality for symptomatic outpatient SARS-CoV-2 PCR testing.

Historique: En Colombie-Britannique (C.-B.), l'autoprélèvement de gargarisme d'eau saline (GS) est la seule alternative aux écouvillons nasopharyngés (NP) prélevés par un professionnel de la santé (PdS) pour déceler le SRAS-CoV-2 par test PCR en milieu ambulatoire. Cependant, certaines personnes ne peuvent pas effectuer de GS. La présente étude visait évaluer l'écouvillonnage de la gorge et des deux narines (GN) pour remplacer le GS. Méthodologie: Les personnes symptomatiques de plus de 12 ans qui demandaient un test PCR de la COVID-19 à l'un des deux centres de dépistage de la COVID-19 du Grand Vancouver ont été invitées à participer à la présente étude. Les participants ont fourni un prélèvement NP recueilli par un PdS ainsi qu'un autoprélèvement de GS et GN en vue d'un test PCR, observés ou non par un PdS. Résultats: Au total, 311 personnes ont participé aux trois prélèvements. Par rapport au prélèvement NP-PdS, le GS avait une sensibilité de 99 % et une spécificité de 98 % (kappa 0,97) et le prélèvement GN, une sensibilité de 99 % et une spécificité de 99 % (kappa 0, 98). À l'aide de l'interprétation définitive du test clinique comme norme de référence, le prélèvement NP avait une sensibilité de 98 % et une spécificité de 100 % (kappa 0,98) et tant le GS que le prélèvement GN avaient une sensibilité de 99 % et une spécificité de 100 % (deux kappa 0,99). Les valeurs seuils du cycle moyen de chaque cible virale étaient plus élevées dans les échantillons de GS quand dans les autres types d'échantillons, mais n'avaient pas d'effet significatif sur le rendement clinique, puisque les taux de positivité étaient semblables. Le rendement clinique de tous les types d'échantillons était comparable dans les sept premiers jours suivant l'apparition de la maladie, quel que soit le mode d'observation. L'autoprélèvement de GS a été classé comme le plus acceptable, suivi du prélèvement GN. Conclusions: Le prélèvement GN est un autre mode d'autoprélèvement moins invasif chez les patients ambulatoires symptomatiques qui effectuent un test PCR du SRAS-CoV-2.

Detection of multiple human enteropathogens in Norway rats (Rattus norvegicus) from an under-resourced neighborhood of Vancouver, British Columbia.

Urban Norway rats (Rattus norvegicus) can carry various human pathogens, and may be involved in pathogen propagation and transmission to humans. From January 31-August 14, 2021, a community outbreak of Shigella flexneri serotype 2a occurred among unhoused or poorly housed people in the Downtown Eastside neighborhood of Vancouver, British Columbia, Canada. The source could not be identified; however, patients reported contact with rats, and previous studies indicated transmission of rat-associated zoonotic pathogens among the unhoused or poorly housed residents of this neighborhood. The study objective was to determine if rats trapped in the outbreak area were carriers of Shigella spp. and other zoonotic enteric pathogens. From March 23-April 9, 2021, 22 rats were lethally trapped within the outbreak area. Colonic content was analyzed using the BioFire FilmArray Gastrointestinal (multiplex PCR) panel for human enteropathogens, which detected: Campylobacter spp. (9/22), Clostridioides difficile (3/22), Yersinia enterocolitica (5/22), Cryptosporidium spp. (8/22), Giardia duodenalis (5/22), Rotavirus A (1/22), enteroaggressive Escherichia coli (2/22), enteropathogenic E. coli (10/22), and Shigella spp. or enteroinvasive E. coli (EIEC) (3/22). An ipaH PCR assay was used for targeted detection of Shigella spp./EIEC, with five rats positive. Two samples contained insertion sites unique to S. flexneri isolated from the human outbreak. This study highlights the potential for rats to carry a broad range of human pathogens, and their possible role in pathogen maintenance and/or transmission.

The utility of SARS-CoV-2 genomic data for informative clustering under different epidemiological scenarios and sampling.

OBJECTIVES: Clustering pathogen sequence data is a common practice in epidemiology to gain insights into the genetic diversity and evolutionary relationships among pathogens. We can find groups of cases with a shared transmission history and common origin, as well as identifying transmission hotspots. Motivated by the experience of clustering SARS-CoV-2 cases using whole genome sequence data during the COVID-19 pandemic to aid with public health investigation, we investigated how differences in epidemiology and sampling can influence the composition of clusters that are identified. METHODS: We performed genomic clustering on simulated SARS-CoV-2 outbreaks produced with different transmission rates and levels of genomic diversity, along with varying the proportion of cases sampled. RESULTS: In single outbreaks with a low transmission rate, decreasing the sampling fraction resulted in multiple, separate clusters being identified where intermediate cases in transmission chains are missed. Outbreaks simulated with a high transmission rate were more robust to changes in the sampling fraction and largely resulted in a single cluster that included all sampled outbreak cases. When considering multiple outbreaks in a sampled jurisdiction seeded by different introductions, low genomic diversity between introduced cases caused outbreaks to be merged into large clusters. If the transmission and sampling fraction, and diversity between introductions was low, a combination of the spurious break-up of outbreaks and the linking of closely related cases in different outbreaks resulted in clusters that may appear informative, but these did not reflect the true underlying population structure. Conversely, genomic clusters matched the true population structure when there was relatively high diversity between introductions and a high transmission rate. CONCLUSION: Differences in epidemiology and sampling can impact our ability to identify genomic clusters that describe the underlying population structure. These findings can help to guide recommendations for the use of pathogen clustering in public health investigations.

Emergence of SARS-CoV-2 Delta Variant and Effect of Nonpharmaceutical Interventions, British Columbia, Canada.

In British Columbia, Canada, initial growth of the SARS-CoV-2 Delta variant was slower than that reported in other jurisdictions. Delta became the dominant variant (>50% prevalence) within ≈7-13 weeks of first detection in regions within the United Kingdom and United States. In British Columbia, it remained at <10% of weekly incident COVID-19 cases for 13 weeks after first detection on March 21, 2021, eventually reaching dominance after 17 weeks. We describe the growth of Delta variant cases in British Columbia during March 1-June 30, 2021, and apply retrospective counterfactual modeling to examine factors for the initially low COVID-19 case rate after Delta introduction, such as vaccination coverage and nonpharmaceutical interventions. Growth of COVID-19 cases in the first 3 months after Delta emergence was likely limited in British Columbia because additional nonpharmaceutical interventions were implemented to reduce levels of contact at the end of March 2021, soon after variant emergence.

Evaluation of the Aptima BV and CV/TV assays compared to conventional laboratory based testing methods for the diagnosis of vaginitis.

PURPOSE: Vaginitis is caused by bacterial vaginosis (BV), Candida vaginitis (CV) and Trichomonas vaginalis (TV). This retrospective study evaluates the performance of the Aptima CV/TV, and BV assays on the automated Panther system. METHODS: Two hundred forty-two multitest swabs were tested on the CV/TV assay and 422 on the BV assay. Positive and negative percent agreement (PPA, NPA) of the Candida glabrata (CG), Candida species group (CSG), TV and BV targets were calculated using a modified gold standard, with review of Gram smear and the usage of the Allplex Vaginitis Screening Assay to resolve discrepancies. RESULTS: The PPA and NPA were respectively 98.4% and 95.9% for BV, 100% and 95.4% for CSG, 100% and 99% for CG, and 100% and 100% for TV, and when compared to consensus results. CONCLUSION: The CV/TV and BV assays surpassed the acceptance criteria threshold of 95%, and proved to be an excellent alternative to conventional testing.

Extraction-free clinical detection of SARS-CoV-2 virus from saline gargle samples using Hamilton STARlet liquid handler.

As part of the COVID-19 pandemic, clinical laboratories have been faced with massive increases in testing, resulting in sample collection systems, reagent, and staff shortages. We utilized self-collected saline gargle samples to optimize high throughput SARS-CoV-2 multiplex polymerase chain reaction (PCR) testing in order to minimize cost and technologist time. This was achieved through elimination of nucleic acid extraction and automation of sample handling on a widely available robotic liquid handler, Hamilton STARlet. A customized barcode scanning script for reading the sample ID by the Hamilton STARlet's software system was developed to allow primary tube sampling. Use of pre-frozen SARS-CoV-2 assay reaction mixtures reduced assay setup time. In both validation and live testing, the assay produced no false positive or false negative results. Of the 1060 samples tested during validation, 3.6% (39/1060) of samples required retesting as they were either single gene positive, had internal control failure or liquid aspiration error. Although the overall turnaround time was only slightly faster in the automated workflow (185 min vs 200 min), there was a 76% reduction in hands-on time, potentially reducing staff fatigue and burnout. This described process from sample self-collection to automated direct PCR testing significantly reduces the total burden on healthcare systems in terms of human resources and reagent requirements.

Abbott ID NOW™ COVID-19 assay: do not discard the swab.

We compared the performance of ID NOW™ COVID-19 assay nasal swabs with RT-PCR of nasopharyngeal swabs for SARS-CoV-2 in an outbreak setting, determining whether addition of RT-PCR of residual nasal swabs (rNS) (post ID NOW™ elution) would increase overall analytic sensitivity. Devices were placed at 2 long term and 1 acute care sites and 51 participants were recruited. Prospective paired nasopharyngeal and nasal samples were collected for RT-PCR and ID NOW™.  ID NOW™ had a positive and negative categorical agreement of 86% and 93% compared to RT-PCR of nasopharyngeal swabs. Sensitivity and specificity of the ID NOW™ was 86% and 100%, positive and negative predictive value was 100% and 95% (COVID-19 positivity rate: 8%). Addition of rNS RT-PCR increased the positive and negative categorical agreement to 93% and 97%. Based on these results, we propose an alternative workflow which includes complementary testing of rNS on a secondary assay.

Clinical Severity of Severe Acute Respiratory Syndrome Coronavirus 2 Omicron Variant Relative to Delta in British Columbia, Canada: A Retrospective Analysis of Whole-Genome Sequenced Cases.

BACKGROUND: In late 2021, the Omicron severe acute respiratory syndrome coronavirus 2 variant emerged and rapidly replaced Delta as the dominant variant. The increased transmissibility of Omicron led to surges in case rates and hospitalizations; however, the true severity of the variant remained unclear. We aimed to provide robust estimates of Omicron severity relative to Delta. METHODS: This retrospective cohort study was conducted with data from the British Columbia COVID-19 Cohort, a large provincial surveillance platform with linkage to administrative datasets. To capture the time of cocirculation with Omicron and Delta, December 2021 was chosen as the study period. Whole-genome sequencing was used to determine Omicron and Delta variants. To assess the severity (hospitalization, intensive care unit [ICU] admission, length of stay), we conducted adjusted Cox proportional hazard models, weighted by inverse probability of treatment weights (IPTW). RESULTS: The cohort was composed of 13 128 individuals (7729 Omicron and 5399 Delta). There were 419 coronavirus disease 2019 hospitalizations, with 118 (22%) among people diagnosed with Omicron (crude rate = 1.5% Omicron, 5.6% Delta). In multivariable IPTW analysis, Omicron was associated with a 50% lower risk of hospitalization compared with Delta (adjusted hazard ratio [aHR] = 0.50, 95% confidence interval [CI] = 0.43 to 0.59), a 73% lower risk of ICU admission (aHR = 0.27, 95% CI = 0.19 to 0.38), and a 5-day shorter hospital stay (aß = -5.03, 95% CI = -8.01 to -2.05). CONCLUSIONS: Our analysis supports findings from other studies that have demonstrated lower risk of severe outcomes in Omicron-infected individuals relative to Delta.

Clinical severity of Omicron subvariants BA.1, BA.2, and BA.5 in a population-based cohort study in British Columbia, Canada.

The SARS-CoV-2 variant Omicron emerged in late 2021. In British Columbia (BC), Canada, and globally, three genetically distinct subvariants of Omicron, BA.1, BA.2, and BA.5, emerged and became dominant successively within an 8-month period. SARS-CoV-2 subvariants continue to circulate in the population, acquiring new mutations that have the potential to alter infectivity, immunity, and disease severity. Here, we report a propensity-matched severity analysis from residents of BC over the course of the Omicron wave, including 39,237 individuals infected with BA.1, BA.2, or BA.5 based on paired high-quality sequence data and linked to comprehensive clinical outcomes data between December 23, 2021 and August 31, 2022. Relative to BA.1, BA.2 cases were associated with a 15% and 28% lower risk of hospitalization and intensive care unit (ICU) admission (aHRhospital = 1.17; 95% confidence interval [CI] = 1.096-1.252; aHRICU = 1.368; 95% CI = 1.152-1.624), whereas BA.5 infections were associated with an 18% higher risk of hospitalization (aHRhospital = 1.18; 95% CI = 1.133-1.224) after accounting for age, sex, comorbidities, vaccination status, geography, and social determinants of health. Phylogenetic analysis revealed no specific subclades associated with more severe clinical outcomes for any Omicron subvariant. In summary, BA.1, BA.2, and BA.5 subvariants were associated with differences in clinical severity, emphasizing how variant-specific monitoring programs remain critical components of patient and population-level public health responses as the pandemic continues.

Antimicrobial susceptibilities of Neisseria gonorrhoeae in Canada, 2021.

Background: In Canada, gonorrhea is the second most prevalent bacterial sexually transmitted infection. The Gonococcal Antimicrobial Surveillance Programme (GASP - Canada), a passive surveillance system monitoring antimicrobial resistance in Neisseria gonorrhoeae in Canada since 1985, is the source for this summary of demographics, antimicrobial resistance and N. gonorrhoeae multi-antigen sequence typing (NG-MAST) of gonococcal isolates collected in Canada in 2021. Methods: Provincial and territorial public health laboratories submitted N. gonorrhoeae cultures and data to the National Microbiology Laboratory in Winnipeg as part of the surveillance system. The antimicrobial resistance and molecular type of each isolate received were determined. Results: In total, 3,439 N. gonorrhoeae cultures were received from laboratories across Canada in 2021, a 9.9% increase since 2020 (n=3,130). Decreased susceptibility to cefixime increased significantly (p<0.001) in 2021 (1.5%) compared to 2017 (0.6%). No significant change in decreased susceptibility to ceftriaxone was detected between 2017 and 2021 (0.6%) (p>0.001); however, one ceftriaxone-resistant isolate was identified. Azithromycin resistance decreased significantly (p<0.001) in 2021 (7.6%) compared to 2017 (11.7%); however, there was a significant increase (p<0.001) in the proportion of cultures with an azithromycin minimum inhibitory concentration of at least 1 mg/L (2017=22.2% to 2021=28.1%). In 2021, NG-MAST-19875 (15.3%) was the most prevalent sequence type in Canada; 20.3% of isolates with this sequence type were resistant to azithromycin. Conclusion: The spread of antimicrobial-resistant gonorrhea is a significant public health concern. The continued regional and national surveillance of antimicrobial resistance in N. gonorrhoeae is essential in ensuring effective treatment therapies are recommended.

Associating Biological Activity and Predicted Structure of Antimicrobial Peptides from Amphibians and Insects.

Antimicrobial peptides (AMPs) are a diverse class of short, often cationic biological molecules that present promising opportunities in the development of new therapeutics to combat antimicrobial resistance. Newly developed in silico methods offer the ability to rapidly discover numerous novel AMPs with a variety of physiochemical properties. Herein, using the rAMPage AMP discovery pipeline, we bioinformatically identified 51 AMP candidates from amphibia and insect RNA-seq data and present their in-depth characterization. The studied AMPs demonstrate activity against a panel of bacterial pathogens and have undetected or low toxicity to red blood cells and human cultured cells. Amino acid sequence analysis revealed that 30 of these bioactive peptides belong to either the Brevinin-1, Brevinin-2, Nigrocin-2, or Apidaecin AMP families. Prediction of three-dimensional structures using ColabFold indicated an association between peptides predicted to adopt a helical structure and broad-spectrum antibacterial activity against the Gram-negative and Gram-positive species tested in our panel. These findings highlight the utility of associating the diverse sequences of novel AMPs with their estimated peptide structures in categorizing AMPs and predicting their antimicrobial activity.

Cov2clusters: genomic clustering of SARS-CoV-2 sequences.

BACKGROUND: The COVID-19 pandemic remains a global public health concern. Advances in sequencing technologies has allowed for high numbers of SARS-CoV-2 whole genome sequence (WGS) data and rapid sharing of sequences through global repositories to enable almost real-time genomic analysis of the pathogen. WGS data has been used previously to group genetically similar viral pathogens to reveal evidence of transmission, including methods that identify distinct clusters on a phylogenetic tree. Identifying clusters of linked cases can aid in the regional surveillance and management of the disease. In this study, we present a novel method for producing stable genomic clusters of SARS-CoV-2 cases, cov2clusters, and compare the accuracy and stability of our approach to previous methods used for phylogenetic clustering using real-world SARS-CoV-2 sequence data obtained from British Columbia, Canada. RESULTS: We found that cov2clusters produced more stable clusters than previously used phylogenetic clustering methods when adding sequence data through time, mimicking an increase in sequence data through the pandemic. Our method also showed high accuracy when predicting epidemiologically informed clusters from sequence data. CONCLUSIONS: Our new approach allows for the identification of stable clusters of SARS-CoV-2 from WGS data. Producing high-resolution SARS-CoV-2 clusters from sequence data alone can a challenge and, where possible, both genomic and epidemiological data should be used in combination.

Mining Amphibian and Insect Transcriptomes for Antimicrobial Peptide Sequences with rAMPage.

Antibiotic resistance is a global health crisis increasing in prevalence every day. To combat this crisis, alternative antimicrobial therapeutics are urgently needed. Antimicrobial peptides (AMPs), a family of short defense proteins, are produced naturally by all organisms and hold great potential as effective alternatives to small molecule antibiotics. Here, we present rAMPage, a scalable bioinformatics discovery platform for identifying AMP sequences from RNA sequencing (RNA-seq) datasets. In our study, we demonstrate the utility and scalability of rAMPage, running it on 84 publicly available RNA-seq datasets from 75 amphibian and insect species-species known to have rich AMP repertoires. Across these datasets, we identified 1137 putative AMPs, 1024 of which were deemed novel by a homology search in cataloged AMPs in public databases. We selected 21 peptide sequences from this set for antimicrobial susceptibility testing against Escherichia coli and Staphylococcus aureus and observed that seven of them have high antimicrobial activity. Our study illustrates how in silico methods such as rAMPage can enable the fast and efficient discovery of novel antimicrobial peptides as an effective first step in the strenuous process of antimicrobial drug development.

Estimating population-based incidence of community-acquired pneumonia and acute otitis media in children and adults in Ontario and British Columbia using health administrative data, 2005-2018: a Canadian Immunisation Research Network (CIRN) study.

BACKGROUND: There is a paucity of data on the burden of the full spectrum of community-acquired pneumonia (CAP) and acute otitis media (AOM) from outpatient and inpatient settings across the age spectrum. METHODS: We conducted a population-based retrospective study in Ontario and British Columbia (BC), Canada, to estimate the incidence rate of CAP and AOM in children and adults over a 14-year period using health administrative databases. CAP and AOM cases were identified from outpatient physician consultation and hospitalisation data in both provinces, and from emergency department visit data in Ontario. RESULTS: During 2005-2018, Ontario had 3 607 124 CAP, 172 290 bacterial CAP, 7814 pneumococcal pneumonia, and 8 026 971 AOM cases. The incidence rate of CAP declined from 3077/100 000 in 2005 to 2604/100 000 in 2010 before increasing to 2843/100 000 in 2018; bacterial CAP incidence rate also declined from 178/100 000 in 2005 to 112/100 000 in 2010 before increasing to 149/100 000 in 2018. The incidence rate of AOM decreased from 4192/100 000 in 2005 to 3178/100 000 in 2018. BC had 970 455 CAP, 317 913 bacterial CAP, 35 287 pneumococcal pneumonia and 2 022 871 AOM cases. The incidence rate of CAP in BC decreased from 2214/100 000 in 2005 to 1964/100 000 in 2010 before increasing to 2176/100 000 in 2018; bacterial CAP incidence rate increased from 442/100 000 in 2005 to 981/100 000 in 2018. The incidence rate of AOM decreased from 3684/100 000 in 2005 to 2398/100 000 in 2018. The incidence rate of bacterial CAP increased with age in older adults (≥65 years) with the highest burden in the oldest cohort aged ≥85 years both before and after 13-valent pneumococcal conjugate vaccine (PCV13) programme in both provinces. Hospitalised pneumococcal pneumonia decreased slightly but non-hospitalised pneumococcal pneumonia increased in BC during PCV13 period. No consistent direct benefit of PCV13 on CAP was observed in the paediatric population. CONCLUSIONS: There is a substantial burden of CAP and AOM in Ontario and BC. Indirect benefits from childhood PCV vaccination and polysaccharide vaccination of older adults have not substantially decreased the burden of pneumococcal pneumonia in older adults.