Abstract
AbstractEcuador was an early COVID-19 hotspot with substantial COVID-19-mortality. In developed countries, low socioeconomic status is associated with COVID-19 infection and low compliance with non-pharmaceutical interventions (NPIs). However, if NPI were successful in resource-limited settings with high human mobility and informal labour is still unclear. We performed a retrospective observational molecular and serological study of Ecuador’s reference laboratory. We tested 1,950 respiratory samples from COVID-19 surveillance for SARS-CoV-2 and 12 respiratory viruses using RT-PCR, characterized 642 SARS-CoV-2 genomes, and examined SARS-CoV-2 seroprevalence in 1,967 samples from patients with fever in Ecuador’s reference laboratory during 2020-2021. Molecular and serological data were compared to NPI stringency in Bayesian, maximum-likelihood and modelling frameworks.SARS-CoV-2 (Pearson correlation test; r=-0.74; p=0.01) and other respiratory viruses (r=-0.68; p=0.02) detection correlated negatively with NPI stringency. SARS-CoV-2 seroprevalence increased from <1% during February-March 2020 to 50% within 6 weeks and plateaued after NPI implementation. Decrease of effective reproduction number <1 and antibody reactivity over time suggested intense SARS-CoV-2 transmission during pandemic onset, subsequently limited by NPIs. Phylogeographic analyses revealed that travel restrictions were implemented late not preventing 100 near-parallel SARS-CoV-2 introductions, and implementation of NPIs modified SARS-CoV-2 geographic spread by restricting recreational activity. NPIs stringency correlated negatively with the number of circulating SARS-CoV-2 lineages (r=-0.69; p=0.02). Virological evidence supports NPIs restricting human movement as an effective public health tool to control the spread of respiratory pathogens in resource-limited settings, providing a template for emerging SARS-CoV-2 variants and future epidemics.
Publisher
Cold Spring Harbor Laboratory