Seasonal respiratory virus circulation was diminished during the COVID-19 pandemic.

BACKGROUND: Measures introduced during the COVID-19 pandemic intended to address the spread of SARS-CoV-2 may also influence the incidence of other common seasonal respiratory viruses (SRV). This evaluation reports laboratory-confirmed cases of common SRV in a well-defined region of central Canada to address this issue. METHODS: Surveillance data for common non-SARS-CoV-2 SRV in Ottawa, Canada, was provided by the Eastern Ontario Regional Laboratory Association (EORLA) reference virology lab. Weekly reports of the number of positive tests and the proportion that yielded positive results were analyzed from August 26, 2018, to January 2, 2022. RESULTS: A drastic reduction in influenza and other common SRV was observed during the 2020-2021 influenza season in the Ottawa region. Influenza was virtually undetected post-SARS-CoV-2 emergence. Rhinoviruses and enteroviruses were the only viruses that remained relatively unaffected during this period. CONCLUSIONS: We speculated that the introduction of nonpharmaceutical measures including masking to prevent SARS-CoV-2 transmission contributed to the near absence of SRV in the Ottawa region. These measures should remain a key component in addressing spikes in SRV activity and future pandemics.

RIBAVIRIN DOES NOT ENHANCE HEPATITIS B VIRUS NUCLEOTIDE ANTIVIRAL ACTIVITY: A PILOT STUDY

Purpose: There is a need for effective and affordable treatments that achieve hepatitis B virus (HBV) functional cure and prevent long-term complications. The use of immune-modulators combined with HBV antivirals is a promising therapeutic strategy to achieve these goals. Based on ribavirin (RBV) monotherapy data, we hypothesized that RBV could improve virological responses when used in combination with tenofovir. Methods: In this randomized, open label, controlled pilot trial, we evaluated RBV (n=4) dosed for the initial 24 weeks of treatment versus no RBV (n=4) in tenofovir recipients dosed over 48 weeks. Results: Although well tolerated and safe in combination with tenofovir, RBV demonstrated no beneficial effects on virologic, biochemical or immunological markers of chronic HBV infection over 48 weeks of serial evaluation. Conclusions: Our data does not suggest a HBV-specific immunomodulatory effect or an impact of RBV on HBV virological and antigen suppression.

Temporal Dynamics and Evolution of SARS-CoV-2 Demonstrate the Necessity of Ongoing Viral Genome Sequencing in Ontario, Canada.

Genome-wide variation in SARS-CoV-2 reveals evolution and transmission dynamics which are critical considerations for disease control and prevention decisions. Here, we review estimates of the genome-wide viral mutation rates, summarize current COVID-19 case load in the province of Ontario, Canada (5 January 2021), and analyze published SARS-CoV-2 genomes from Ontario (collected prior to 24 November 2020) to test for more infectious genetic variants or lineages. The reported mutation rate (∼10-6 nucleotide [nt]-1 cycle-1) for SARS-CoV-2 is typical for coronaviruses. Analysis of published SARS-CoV-2 genomes revealed that the G614 spike protein mutation has dominated infections in Ontario and that SARS-CoV-2 lineages present in Ontario have not differed significantly in their rate of spread. These results suggest that the SARS-CoV-2 population circulating in Ontario has not changed significantly to date. However, ongoing genome monitoring is essential for identification of new variants and lineages that may contribute to increased viral transmission.