Rapid disappearance of influenza following the implementation of COVID-19 mitigation measures in Hamilton, Ontario

Abstract

BackgroundPublic health measures, such as social distancing and closure of schools and non-essential services were rapidly implemented in Canada to interrupt the spread of the novel coronavirus disease 2019 (COVID-19).ObjectiveWe sought to investigate the impact of mitigation measures during the spring wave of COVID-19 on the incidence of other laboratory-confirmed respiratory viruses in Hamilton, Ontario.MethodsAll nasopharyngeal swab specimens (n = 57,503) submitted for routine respiratory virus testing at a regional laboratory serving all acute-care hospitals in Hamilton, Ontario between January 2010 and June 2020 were reviewed. Testing for influenza A/B, respiratory syncytial virus, human metapneumovirus, parainfluenza I–III, adenovirus and rhinovirus/enterovirus was done routinely using a laboratory-developed polymerase chain reaction multiplex respiratory viral panel. A Bayesian linear regression model was used to determine the trend of positivity rates of all influenza samples for the first 26 weeks of each year from 2010 to 2019. The mean positivity rate of Bayesian inference was compared with the weekly reported positivity rate of influenza samples in 2020.ResultsThe positivity rate of influenza in 2020 diminished sharply following the population-wide implementation of COVID-19 interventions. Weeks 12-26 reported 0% positivity for influenza, with the exception of 0.1% reported in week 13.ConclusionsPublic health measures implemented during the COVID-19 pandemic have had a clear impact on suppressing the incidence of other respiratory viruses and should be considered to mitigate severe seasonal influenza and other respiratory virus pandemics.

Viral fibrotic scoring and drug screen based on MAPK activity uncovers EGFR as a key regulator of COVID-19 fibrosis

“…Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the cause of the ongoing coronavirus disease (COVID-19) pandemic. Opposed to the majority of coronaviruses, SARS-CoV-2 replicates in the lower respiratory tract resulting in the development of pneumonia, which progresses into acute respiratory distress syndrome (ARDS) with fatal destruction of the human organism in severe cases 1 , 2 . The general step in ARDS development is the elevation of plasma pro-inflammatory cytokines and rapid lung infiltration with immune cells 3 .…”

“…In the advanced stages of COVID-19 pulmonary fibrosis and cytokine release syndrome (CRS) is often present 4 . Vast release of proinflammatory cytokines along with sepsis and massive multiorgan damage is the cause of at least 30% of fatal COVID-19 cases 1 . Molecular pathways that are responsible for the development of SARS-CoV-2 induced fibrosis, ARDS and CRS, are not yet understood.…”

A molecular test based on RT-LAMP for rapid, sensitive and inexpensive colorimetric detection of SARS-CoV-2 in clinical samples

“…To detect SARS-CoV-2 using RT-LAMP, we took advantage of the primer set previously validated in vitro by Zhang et al . 24 and tested, on clinical specimens from large cohorts of COVID-19 patients, by several other authors 16 – 19 . The primer set (N-A) targeted the N gene, which encodes the nucleocapsid protein and has the most abundant expression of subgenomic mRNA during infection 32 – 35 .…”

“…RT-LAMP reaction was performed in a total volume of 20 μL containing the following components: 8 U Bst 2.0 (NEB), 7.5 U RTx (NEB) and 1 × colorimetric buffer mix [1.6 μM FIP/BIP primers, 0.4 μM LF/LB primers, 0.2 μM F3/B3 primers Gene N-A 24 , 10 mM (NH 4 ) 2 SO 4 (Merck), 50 mM KCl (BDH), 8 mM MgSO 4 (BDH), 0.1% Tween 20, 0.2 mM Phenol Red (Sigma), 1.4 mM each dNTP (NZYTech)]. For the in-house-made assay, we used the same colorimetric buffer mix, 0.5 μL of MashUP RT (6.8 mg/mL) and 1 μL of Bst LF (7.6 mg/mL) 50 × diluted.…”

“…The simple technical and instrumental requirements of colorimetric RT-LAMP tests make them extremely attractive for point-of-care (POC) use and implementation in low-resource settings. Colorimetric RT-LAMP has been successfully used for detection of SARS-CoV-2 in NP fluids from COVID-19 patients 15 – 24 .…”