Infectious diseases genomic surveillance capacity in the Caribbean: A retrospective analysis of SARS-CoV-2.

Background: The ongoing coronavirus diseases 2019 (COVID-19) pandemic with its numerous variants of concern has shown the need to have a robust and complete global infectious diseases genomic surveillance network worldwide. Various clinical and research institutions have stepped up to perform SARS-CoV-2 sequencing thus enhancing the understanding of this virus' global evolution. However, given that genomic sequencing capacities and capabilities are not available in every region or country, significant gaps exist, which lead to geographic blind spots. One such region is the Caribbean. This paper measures the Caribbean region's SARS-CoV-2 genomic sequencing capacity and highlights the need to improve further regional genomics surveillance capacities and capabilities, which are essential for efficient health interventions for infectious diseases. Methods: A map showing SARS-CoV-2 sequences available for each Caribbean Island was constructed using SARS-CoV-2 genomic, epidemiological and populational data obtained from GISAID, the World Health Organization, the United Nations, and the World Bank. The number of reported SARS-CoV-2 cases and the proportion of cases sequenced in each Caribbean Island was then analysed by the Gross Domestic Product per capita and political status. Findings: As of August 6, 2022, the number of SARS-CoV-2 sequences from the Caribbean are underrepresented with only 40,190 (1.07%) of the over 3.76 million documented cases sequenced, which is further exacerbated by a disparity based not only on the country's income but also on its political status (sovereign country versus dependent or integrated) and accessibility to sequencing technologies. There are a limited number of sequencing centres based in the Caribbean islands with the majority located on the American and European continents. Using mobile sequencing technologies while concomitantly investing in data analysis training could lead to greater and more sustainable coverage. Interpretation: Considering the Caribbean region's dispersed heterogeneous populations, varying political regimes, and resource-constrained healthcare systems, further development of local next-generation sequencing capacity and capabilities in the Caribbean region is needed to achieve global public health goals. Funding: No funding source was required for this study.

Emergence of a mutation in the nucleocapsid gene of SARS-CoV-2 interferes with PCR detection in Canada.

The emergence of Severe Acute Respiratory Syndrome Coronavirus (SARS-CoV-2) was met with rapid development of robust molecular-based detection assays. Many SARS-CoV-2 molecular tests target multiple genetic regions of the virus to maximize detection and protect against diagnostic escape. Despite the relatively moderate mutational rate of SARS-CoV-2, numerous mutations with known negative impact on diagnostic assays have been identified. In early 2021, we identified four samples positive for SARS-CoV-2 with a nucleocapsid (N) gene drop out on Cepheid Xpert® Xpress SARS-CoV-2 assay. Sequencing revealed a single common mutation in the N gene C29200T. Spatiotemporal analysis showed that the mutation was found in at least six different Canadian provinces from May 2020 until May 2021. Phylogenetic analysis showed that this mutation arose multiple times in Canadian samples and is present in six different variants of interest and of concern. The Cepheid testing platform is commonly used in Canada including in remote regions. As such, the existence of N gene mutation dropouts required further investigation. While commercial SARS-CoV-2 molecular detection assays have contributed immensely to the response effort, many vendors are reluctant to make primer/probe sequences publicly available. Proprietary primer/probe sequences create diagnostic 'blind spots' for global SARS-CoV-2 sequence monitoring and limits the ability to detect and track the presence and prevalence of diagnostic escape mutations. We hope that our industry partners will seriously consider making primer/probe sequences available, so that diagnostic escape mutants can be identified promptly and responded to appropriately to maintain diagnostic accuracy.

The differential impact of pediatric COVID-19 between high-income countries and low- and middle-income countries: A systematic review of fatality and ICU admission in children worldwide.

BACKGROUND: The overall global impact of COVID-19 in children and regional variability in pediatric outcomes are presently unknown. METHODS: To evaluate the magnitude of global COVID-19 death and intensive care unit (ICU) admission in children aged 0-19 years, a systematic review was conducted for articles and national reports as of December 7, 2020. This systematic review is registered with PROSPERO (registration number: CRD42020179696). RESULTS: We reviewed 16,027 articles as well as 225 national reports from 216 countries. Among the 3,788 global pediatric COVID-19 deaths, 3,394 (91.5%) deaths were reported from low- and middle-income countries (LMIC), while 83.5% of pediatric population from all included countries were from LMIC. The pediatric deaths/1,000,000 children and case fatality rate (CFR) were significantly higher in LMIC than in high-income countries (HIC) (2.77 in LMIC vs 1.32 in HIC; p < 0.001 and 0.24% in LMIC vs 0.01% in HIC; p < 0.001, respectively). The ICU admission/1,000,000 children was 18.80 and 1.48 in HIC and LMIC, respectively (p < 0.001). The highest deaths/1,000,000 children and CFR were in infants < 1 year old (10.03 and 0.58% in the world, 5.39 and 0.07% in HIC and 10.98 and 1.30% in LMIC, respectively). CONCLUSIONS: The study highlights that there may be a larger impact of pediatric COVID-19 fatality in LMICs compared to HICs.

Evolutionary and structural analyses of SARS-CoV-2 D614G spike protein mutation now documented worldwide.

The COVID-19 pandemic, caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), was declared on March 11, 2020 by the World Health Organization. As of the 31st of May, 2020, there have been more than 6 million COVID-19 cases diagnosed worldwide and over 370,000 deaths, according to Johns Hopkins. Thousands of SARS-CoV-2 strains have been sequenced to date, providing a valuable opportunity to investigate the evolution of the virus on a global scale. We performed a phylogenetic analysis of over 1,225 SARS-CoV-2 genomes spanning from late December 2019 to mid-March 2020. We identified a missense mutation, D614G, in the spike protein of SARS-CoV-2, which has emerged as a predominant clade in Europe (954 of 1,449 (66%) sequences) and is spreading worldwide (1,237 of 2,795 (44%) sequences). Molecular dating analysis estimated the emergence of this clade around mid-to-late January (10-25 January) 2020. We also applied structural bioinformatics to assess the potential impact of D614G on the virulence and epidemiology of SARS-CoV-2. In silico analyses on the spike protein structure suggests that the mutation is most likely neutral to protein function as it relates to its interaction with the human ACE2 receptor. The lack of clinical metadata available prevented our investigation of association between viral clade and disease severity phenotype. Future work that can leverage clinical outcome data with both viral and human genomic diversity is needed to monitor the pandemic.

Rotavirus genotypes circulating in Ontario, Canada, before and after implementation of the rotavirus immunization program.

BACKGROUND AND OBJECTIVES: Ontario introduced a universal publicly-funded group A rotavirus (RVA) immunization program in August 2011, using monovalent vaccine. RVA immunization programs have decreased the incidence of RVA acute gastroenteritis in many countries but it is unclear if it will contribute to the emergence of certain genotypes. We monitored RVA trends and genotypes in Ontario before and after implementation of the publicly-funded immunization program. METHODS: RVA detection was conducted at Public Health Ontario Laboratories from January 2009 to December 2011 (pre-program period) and January 2012 to October 2015 (publicly-funded RVA immunization program period) and number of RVA-positive specimens and percent positivity were analysed. A convenience sample of RVA-positive stool specimens, from September 2010 to December 2011 (pre-program period) and January 2012 to June 2013 (program period), were genotyped using heminested PCR. A literature review on the burden of illness from emergent genotype was performed. RESULTS: Stool specimens showed a significant decrease in RVA percent positivity from the 36 month pre-program period (14.4%; 1537/10700) to the 46 month program period (6.1%; 548/9019). An increase in the proportion of RVA G10 among genotyped specimens, associated with five different P genotypes, from the pre-program (6.3%; 13/205) to the program (31.5%; 40/127) period was observed. Our literature review identified approximately 200 G10-positive human stool specimens from 16 different countries. CONCLUSIONS: This study documented a decrease in the number of RVA-positive specimens and percent positivity after implementation of the immunization program. An unexpected increase in the proportion of RVA G10 was detected following program introduction. Ongoing RVA surveillance is important in evaluating both the long-term impact of immunization and emergence of RVA genotypes.

Whole-genome Sequencing for Surveillance of Invasive Pneumococcal Diseases in Ontario, Canada: Rapid Prediction of Genotype, Antibiotic Resistance and Characterization of Emerging Serotype 22F.

Background: Molecular typing is essential for inferring genetic relatedness between bacterial pathogens. In this study, we applied whole genome sequencing (WGS) for rapid prediction of sequence type and antibiotic resistance for invasive pneumococcal isolates. Methods: 240 isolates from adults (≥50 years old) in Ontario, Canada during 2009 to 2013 were subjected to WGS. Sequence type, antibiotic susceptibility and resistance were predicted directly from short reads. Emerging non-vaccine serotype 22F was further characterized by WGS. Results: Sequence type was successfully determined for 98.3% of isolates. The overall sensitivity and specificity for antibiotic resistance prediction were 95 and 100% respectively, compared to standard susceptibility testing methods. WGS-based phylogeny divided emerging 22F (ST433) strains into two distinct clades: clade A harboring a 23 kb-prophage and anti-phage PhD/Doc system and clade B with virulence-related proteases. Five isolates in clade A developed macrolide resistance via 5.1 kb mega element recombination (encoding mefE and msrD), while one isolate in clade B displayed quinolone resistance via a gyrA mutation. Conclusions: WGS is valuable for routine surveillance of pneumococcal clinical isolates and facilitates prediction of genotype and antibiotic resistance. The emergence of 22F in Ontario in the post-vaccine era and evidence of evolution and divergence of the 22F population warrants heightened pneumococcal molecular surveillance.